The rates of death and stroke were similar; however, MI (3.6% for CABG, 7.1% for DES) and repeat revascularization (10.7% for CABG, 19.7% for DES) were more likely to occur with DES implantation.46 In SYNTAX, the extent of CAD was assessed using the SYNTAX score, which is based on the location, severity, and extent of coronary stenoses, with a low score indicating less complicated anatomic CAD. In post hoc analyses, a low score was defined as 22; intermediate, 23 to 32; and high, 33. The occurrence of MACE correlated with the SYNTAX score for DES patients but not for those undergoing CABG. At 12-month follow-up, the primary endpoint was similar for CABG and DES in those with a low SYNTAX score. In contrast, MACE occurred more often after DES implantation than after CABG in those with an intermediate or high SYN- TAX score.14 At 3 years of follow-up, the mortality rate was greater in subjects with 3-vessel CAD treated with PCI than in those treated with CABG (6.2% versus 2.9%). The differences in MACE between those treated with PCI or CABG increased with an increasing SYNTAX score (Figure 1).46 Although the utility of using a SYNTAX score in everyday clinical practice remains uncertain, it seems reasonable to conclude from SYNTAX and other data that outcomes of patients undergoing PCI or CABG in those with relatively uncomplicated and lesser degrees of CAD are comparable, whereas in those with complex and diffuse CAD, CABG appears to be preferable.46 See Online Data Supplements 5 and 6 for additional data comparing CABG with DES. 2.7. Left Main CAD 2.7.1. CABG or PCI Versus Medical Therapy for Left Main CAD CABG confers a survival benefit over medical therapy in patients with left main CAD. Subgroup analyses from RCTs performed 3 decades ago included 91 patients with left main CAD in the Veterans Administration Cooperative Study.28 A meta-analysis of these trials demonstrated a 66% reduction in relative risk in mortality with CABG, with the benefit extending to 10 years.30 The CASS Registry24 contained data Figure 1. Cumulative incidence of MACE in patients with 3-vessel CAD based on SYNTAX score at 3-year follow-up in the SYNTAX trial treated with either CABG or PCI. CABG indicates coronary artery bypass graft; CAD, coronary artery disease; MACE, major adverse cardiovascular event; PCI, percutaneous coronary intervention; and SYNTAX, Synergy between Percutaneous Coronary Inter- vention with TAXUS and Cardiac Surgery. Adapted with permission from Kappetein.46 Levine et al 2011 ACCF/AHA/SCAI PCI Guideline e585 from 1484 patients with 50% diameter stenosis left main CAD initially treated surgically or nonsurgically. Median survival duration was 13.3 years in the surgical group; and 6.6 years in the medical group. The survival benefit of CABG over medical therapy appeared to extend to 53 asymptomatic patients with left main CAD in the CASS Registry.29 Other therapies that subsequently have been shown to be associated with improved long-term outcome, such as the use of aspirin, statins, and internal mammary artery grafting, were not widely used in that era. RCTs and subgroup analyses that compare PCI with medical therapy in patients with unprotected left main CAD do not exist. 2.7.2. Studies Comparing PCI Versus CABG for Left Main CAD Of all subjects undergoing coronary angiography, approxi- mately 4% are found to have left main CAD,175 80% of whom have significant ( 70% diameter) stenoses in other epicardial coronary arteries. Published cohort studies have found that major clinical outcomes are similar with PCI or CABG 1 year after revascularization and that mortality rates are similar at 1, 2, and 5 years of follow-up; however, the risk of needing target-vessel revascularization is significantly higher with stenting than with CABG. In the SYNTAX trial, 45% of screened patients with unprotected left main CAD had complex disease that pre- vented randomization; 89% of these underwent CABG.13,14 In addition, 705 of the 1800 patients who were randomized had revascularization for unprotected left main CAD. The major- ity of patients with left main CAD and a low SYNTAX score had isolated left main CAD or left main CAD plus 1-vessel CAD; the majority of those with an intermediate score had left main CAD plus 2-vessel CAD; and most of those with a high SYNTAX score had left main CAD plus 3-vessel CAD. At 1 year, rates of all-cause death and MACE were similar for the 2 groups.13 Repeat revascularization rates were higher in the PCI group than the CABG group (11.8% versus 6.5%), but stroke occurred more often in the CABG group (2.7% versus 0.3%). At 3 years of follow-up, the incidence of death in those undergoing left main CAD revascularization with low or intermediate SYNTAX scores ( 32) was 3.7% after PCI and 9.1% after CABG (P 0.03), whereas in those with a high SYNTAX score ( 33), the incidence of death after 3 years was 13.4% after PCI and 7.6% after CABG (P 0.10).46 Because the primary endpoint of SYNTAX was not met (ie, noninferiority comparison of CABG and PCI), these sub- group analyses need to be considered in that context. In the LE MANS (Study of Unprotected Left Main Stenting Versus Bypass Surgery) trial,23 105 patients with left main CAD were randomized to receive PCI or CABG. Although a low proportion of patients treated with PCI received DES (35%) and a low proportion of patients treated with CABG received internal mammary grafts (72%), the outcomes at 30 days and 1 year were similar between the groups. In the PRECOMBAT (Premier of Randomized Com- parison of Bypass Surgery versus Angioplasty Using Sirolimus-Eluting Stent in Patients with Left Main Coronary Artery Disease) trial of 600 patients with left main disease, the composite endpoint of death, MI, or stroke at 2 years occurred in 4.4% of patients treated with PCI patients and 4.7% of patients treated with CABG, but ischemia-driven target-vessel revascularization was more often required in the patients treated with PCI (9.0% versus 4.2%).52 The results from these 3 RCTs suggest (but do not definitively prove) that major clinical outcomes in selected patients with left main CAD are similar with CABG and PCI at 1- to 2-year follow-up, but repeat revascularization rates are higher after PCI than after CABG. RCTs with extended follow-up of 5 years are required to provide definitive conclusions about the optimal treatment of left main CAD. In a meta-analysis of 8 cohort studies and 2 RCTs,41 death, MI, and stroke occurred with similar frequency in the PCI- and CABG-treated patients at 1, 2, and 3 years of follow-up. Target-vessel revascularization was performed more often in the PCI group at 1 year (OR: 4.36), 2 years (OR: 4.20), and 3 years (OR: 3.30). See Online Data Supplements 7 to 12 for additional data comparing PCI with CABG for left main CAD. 2.7.3. Revascularization Considerations for Left Main CAD Although CABG has been considered the gold standard for unprotected left main CAD revascularization, more recently PCI has emerged as a possible alternative mode of revascu- larization in carefully selected patients. Lesion location is an important determinant when considering PCI for unprotected left main CAD. Stenting of the left main ostium or trunk is more straightforward than treating distal bifurcation or trifur- cation stenoses, which generally requires a greater degree of operator experience and expertise.176 In addition, PCI of bifurcation disease is associated with higher restenosis rates than when disease is confined to the ostium or trunk.39,177 Although lesion location influences technical success and long-term outcomes after PCI, location exerts a negligible influence on the success of CABG. In subgroup analyses, patients with left main CAD and a SYNTAX score 33 with more complex or extensive CAD had a higher mortality rate with PCI than with CABG.46 Physicians can estimate opera- tive risk for all CABG candidates using a standard instru- ment, such as the risk calculator from the STS database. The above considerations are important factors when choosing among revascularization strategies for unprotected left main CAD and have been factored into revascularization recom- mendations. Use of a Heart Team approach has been recom- mended in cases in which the choice of revascularization is not straightforward. As discussed in Section 2.9.7, the ability of the patient to tolerate and comply with dual antiplatelet therapy (DAPT) is also an important consideration in revas- cularization decisions. The 2005 PCI guideline8 recommended routine angio- graphic follow-up 2 to 6 months after stenting for unprotected left main CAD. However, because angiography has limited ability to predict stent thrombosis and the results of SYNTAX suggest good intermediate-term results for PCI in subjects with left main CAD, this recommendation was removed in the 2009 STEMI/PCI focused update.10 Experts have recommended immediate PCI for unprotected left main CAD in the setting of STEMI.51 The impetus for such a strategy is greatest when left main CAD is the site of the culprit lesion, antegrade coronary flow is diminished (eg, TIMI flow grade 0, 1, or 2), the patient is hemodynamically unstable, and it is believed that PCI can be performed more quickly than CABG. When possible, the interventional car- diologist and cardiac surgeon should decide together on the optimal form of revascularization for these subjects, although it is recognized that these patients are usually critically ill and therefore not amenable to a prolonged deliberation or discus- sion of treatment options. 2.8. Proximal LAD Artery Disease A cohort study53 and a meta-analysis30 from the 1990s suggested that CABG confers a survival advantage over contemporaneous medical therapy for patients with disease in the proximal segment of the LAD artery. Cohort studies and RCTs30,133,146,148,161,178 181 as well as collaborative- and meta- analyses164,182 184 showed that PCI and CABG result in similar survival rates in these patients. See Online Data Supplement 13 for additional data regarding proximal LAD artery revascularization. 2.9. Clinical Factors That May Influence the Choice of Revascularization 2.9.1. Diabetes Mellitus An analysis performed in 2009 of data on 7812 patients (1233 with diabetes) in 10 RCTs demonstrated a worse long-term survival rate in patients with diabetes mellitus after balloon angioplasty or BMS implantation than after CABG.164 The BARI 2D trial116 randomly assigned 2368 patients with type 2 diabetes and CAD to undergo intensive medical therapy or prompt revascularization with PCI or CABG, according to whichever was thought to be more appropriate. By study design, those with less extensive CAD more often received PCI, whereas those with more extensive CAD were more likely to be treated with CABG. The study was not designed to compare PCI with CABG. At 5-year follow-up, no differ- ence in rates of survival or MACE between the medical therapy group and those treated with revascularization was noted. In the PCI stratum, no significant difference in MACE between medical therapy and revascularization was demon- strated (DES in 35%; BMS in 56%); in the CABG stratum, MACE occurred less often in the revascularization group. One-year follow-up data from the SYNTAX study demon- strated a higher rate of repeat revascularization in patients with diabetes mellitus treated with PCI than with CABG, driven by a tendency for higher repeat revascularization rates in those with higher SYNTAX scores undergoing PCI.76 In summary, in subjects requiring revascularization for multi- vessel CAD, current evidence supports diabetes mellitus as an important factor when deciding on a revascularization strat- egy, particularly when complex or extensive CAD is present (Figure 2). See Online Data Supplements 14 and 15 for additional data regarding diabetes mellitus. 2.9.2. Chronic Kidney Disease Cardiovascular morbidity and mortality rates are markedly increased in patients with chronic kidney disease (CKD) when compared with age-matched controls without CKD. The mortality rate for patients on hemodialysis is 20% per year, and approximately 50% of deaths among these patients are due to a cardiovascular cause.187,188 To date, randomized comparisons of coronary revascular- ization (with CABG or PCI) and medical therapy in patients with CKD have not been reported. Some, but not all, observational studies or subgroup analyses have demon- strated an improved survival rate with revascularization compared with medical therapy in patients with CKD and multivessel CAD,189 191 despite the fact that the incidence of periprocedural complications (eg, death, MI, stroke, infec- tion, renal failure) is increased in patients with CKD com- pared with those without renal dysfunction. Some studies have shown that CABG is associated with a greater survival benefit than PCI among patients with severe renal 2.9.3. Completeness of Revascularization Most patients undergoing CABG receive complete or nearly complete revascularization, which seems to influence long- term prognosis positively.197 In contrast, complete revascu- larization is accomplished less often in subjects receiving PCI (eg, in 70% of patients), but the extent to which the absence of complete initial revascularization influences outcome is less clear. Rates of late survival and survival free of MI appears to be similar in patients with and without complete revascularization after PCI. Nevertheless, the need for subse- quent CABG is usually higher in those whose initial revas- cularization procedure was incomplete (compared with those with complete revascularization) after PCI.198 200 Figure 2. 1-year mortality after revascularization for multivessel disease and diabetes mellitus. An OR of 1 suggests an advantage of CABG over PCI. ARTS I indicates Arterial Revascularization Therapy Study I185; BARI I, Bypass Angioplasty Revascularization Investiga- tion I74; CABG, coronary artery bypass graft; CAD, coronary artery disease; CARDia, Coronary Artery Revascularization in Diabetes186; CI, confidence interval; MASS II, Medicine, Angioplasty, or Surgery Study II78; OR, odds ratio; PCI, percutaneous coronary intervention; SYNTAX, Synergy between Percutaneous Coronary Intervention with TAXUS and Cardiac Surgery; and W, weighted.76 Levine et al 2011 ACCF/AHA/SCAI PCI Guideline e587 2.9.4. LV Systolic Dysfunction Several older studies and a meta-analysis of the data from these studies reported that patients with LV systolic dys- function (predominantly mild to moderate in severity) had better survival with CABG than with medical therapy alone.30,64 68 For patients with more severe LV systolic dysfunction, however, the evidence that CABG results in better survival compared with medical therapy is lacking. In the STICH (Surgical Treatment for Ischemic Heart Failure) trial of subjects with LVEF 35% with or without viability testing, CABG and GDMT resulted in similar rates of survival (death from any cause, the study s primary outcome) after 5 years of follow-up. For a number of secondary outcomes at this time point, including 1) death from any cause or hospitalization for heart failure, 2) death from any cause or hospitalization for cardiovascular causes, 3) death from any cause or hospitalization for any cause, or 4) death from any cause or revascularization with PCI or CABG, CABG was superior to GDMT. Although the primary out- come (death from any cause) was similar in the 2 treatment groups after an average of 5 years of follow-up, the data suggest the possibility that outcomes would differ if the follow-up were longer in duration; as a result, the study is being continued to provide follow-up for up to 10 years.83,84 Only very limited data comparing PCI with medical therapy in patients with LV systolic dysfunction are avail- able.68 In several ways, these data are suboptimal, in that many studies compared CABG with balloon angioplasty, many were retrospective, and many were based on cohort or registry data. Some of the studies demonstrated a similar survival rate in patients having CABG and PCI,71,164,201 203 whereas others showed that those undergoing CABG had better outcomes.32 The data that exist at present on revascu- larization in patients with CAD and LV systolic dysfunction are more robust for CABG than for PCI, although data from contemporary RCTs in this patient population are lacking. Therefore, the choice of revascularization in patients with CAD and LV systolic dysfunction is best based on clinical variables (eg, coronary anatomy, presence of diabetes melli- tus, presence of CKD), magnitude of LV systolic dysfunction, patient preferences, clinical judgment, and consultation be- tween the interventional cardiologist and the cardiac surgeon. 2.9.5. Previous CABG In patients with recurrent angina after CABG, repeat revas- cularization is most likely to improve survival in subjects at highest risk, such as those with obstruction of the proximal LAD artery and extensive anterior ischemia.85 93 Patients with ischemia in other locations and those with a patent LIMA to the LAD artery are unlikely to experience a survival benefit from repeat revascularization.92 Cohort studies comparing PCI and CABG among post- CABG patients report similar rates of mid- and long-term survival after the 2 procedures.85,88 91,93,204 In the patient with previous CABG who is referred for revascularization for medically refractory ischemia, factors that may support the choice of repeat CABG include vessels unsuitable for PCI, number of diseased bypass grafts, availability of the internal mammary artery for grafting chronically occluded coronary arteries, and good distal targets for bypass graft placement. Factors favoring PCI over CABG include limited areas of ischemia causing symptoms, suitable PCI targets, a patent graft to the LAD artery, poor CABG targets, and comorbid conditions. 2.9.6. Unstable Angina/Non ST-Elevation Myocardial Infarction The main difference between management of the patient with SIHD and the patient with UA/NSTEMI is that the impetus for revascularization is stronger in the setting of UA/ NSTEMI, because myocardial ischemia occurring as part of an ACS is potentially life threatening, and associated anginal symptoms are more likely to be reduced with a revascular- ization procedure than with GDMT.205 207 Thus, the indica- tions for revascularization are strengthened by the acuity of presentation, the extent of ischemia, and the ability to achieve full revascularization. The choice of revascularization method is generally dictated by the same considerations used to decide on PCI or CABG for patients with SIHD. 2.9.7. DAPT Compliance and Stent Thrombosis: Recommendation Class III: HARM 1. PCI with coronary stenting (BMS or DES) should not be performed if the patient is not likely to be able to tolerate and comply with DAPT for the appropri- ate duration of treatment based on the type of stent implanted.208 211 (Level of Evidence: B) The risk of stent thrombosis is increased dramatically in patients who prematurely discontinue DAPT, and stent thrombosis is associated with a mortality rate of 20% to 45%.208 Because the risk of stent thrombosis with BMS is greatest in the first 14 to 30 days, this is the generally recommended minimum duration of DAPT therapy for these individuals. Consensus in clinical practice is to treat DES patients for at least 12 months with DAPT to avoid late (after 30 days) stent thrombosis.208,212 Therefore, the ability of the patient to tolerate and comply with at least 30 days of DAPT with BMS treatment and at least 12 months of DAPT with DES treatment is an important consideration in deciding whether to use PCI to treat patients with CAD. 2.10. TMR as an Adjunct to CABG TMR has been used on occasion in patients with severe angina refractory to GDMT in whom complete revascular- ization cannot be achieved with PCI and/or CABG. Although the mechanism by which TMR might be efficacious in these patients is unknown,213,214 several RCTs of TMR as sole therapy demonstrated a reduction in anginal symptoms com- pared with intensive medical therapy alone.109 111,215 217 A single randomized multicenter comparison of TMR (with a holmium:YAG laser) plus CABG and CABG alone in pa- tients in whom some myocardial segments were perfused by arteries considered not amenable to grafting112 showed a significant reduction in perioperative mortality rate (1.5% versus 7.6%, respectively), and the survival benefit of the TMR CABG combination was present after 1 year of follow- up.112 At the same time, a large retrospective analysis of data from the STS National Cardiac Database as well as a study of 169 patients from the Washington Hospital Center who underwent combined TMR CABG, showed no difference in adjusted mortality rate compared with CABG alone.113,218 In short, a TMR CABG combination does not appear to im- prove survival compared with CABG alone. In selected patients, however, such a combination may be superior to CABG alone in relieving angina. 2.11. Hybrid Coronary Revascularization: Recommendations Class IIa 1. Hybrid coronary revascularization (defined as the planned combination of LIMA-to-LAD artery graft- ing and PCI of >1 non-LAD coronary arteries) is reasonable in patients with 1 or more of the follow- ing219 225 (Level of Evidence: B): a. Limitations to traditional CABG, such as heavily calcified proximal aorta or poor target vessels for CABG (but amenable to PCI); b. Lack of suitable graft conduits; c. Unfavorable LAD artery for PCI (ie, excessive vessel tortuosity or CTO). Class IIb 1. Hybrid coronary revascularization (defined as the planned combination of LIMA-to-LAD artery graft- ing and PCI of >1 non-LAD coronary arteries) may be reasonable as an alternative to multivessel PCI or CABG in an attempt to improve the overall risk- benefit ratio of the procedures. (Level of Evidence: C) Hybrid coronary revascularization, defined as the planned combination of LIMA-to-LAD artery grafting and PCI of 1 non-LAD coronary arteries,226 is intended to combine the advantages of CABG (ie, durability of the LIMA graft) and PCI.227 Patients with multivessel CAD (eg, LAD and 1 non-LAD stenoses) and an indication for revascularization are potentially eligible for this approach. Hybrid revascular- ization is ideal in patients in whom technical or anatomic limitations to CABG or PCI alone may be present and for whom minimizing the invasiveness (and therefore the risk of morbidity and mortality) of surgical intervention is pre- ferred221 (eg, patients with severe preexisting comorbidities, recent MI, a lack of suitable graft conduits, a heavily calcified ascending aorta, or a non-LAD coronary artery unsuitable for bypass but amenable to PCI, and situations in which PCI of the LAD artery is not feasible because of excessive tortuosity or CTO). Hybrid coronary revascularization may be performed in a hybrid suite in one operative setting or as a staged procedure (ie, PCI and CABG performed in 2 different operative suites, separated by hours to 2 days, but typically during the same hospital stay). Because most hospitals lack a hybrid operating room, staged procedures are usually performed. With the staged procedure, CABG before PCI is preferred, because this approach allows the interventional cardiologist to 1) verify the patency of the LIMA-to-LAD artery graft before attempting PCI of other vessels and 2) minimize the risk of perioperative bleeding that would occur if CABG were performed after PCI (ie, while the patient is receiving DAPT). Because minimally invasive CABG may be associated with lower graft patency rates compared with CABG performed through a midline sternotomy, it seems prudent to angio- graphically image all grafts performed through a minimally invasive approach to confirm graft patency.221 To date, no RCTs involving hybrid coronary revascular- ization have been published. Over the past 10 years, several small, retrospective series of hybrid revascularization using minimally invasive CABG and PCI have reported low mor- tality rates (0 to 2%) and event-free survival rates of 83% to 92% at 6 to 12 months of follow-up. The few series that have compared the outcomes of hybrid coronary revascularization with standard CABG report similar outcomes at 30 days and 3. PCI Outcomes 3.1. Definitions of PCI Success The success of a PCI procedure is best defined by 3 interrelated components: angiographic findings, procedural events, and clinical outcomes. 3.1.1. Angiographic Success A successful PCI produces sufficient enlargement of the lumen at the target site to improve coronary artery blood flow. A successful balloon angioplasty is defined as the reduction of a minimum stenosis diameter to 50% with a final TIMI flow grade 3 (visually assessed by angiography) without side branch loss, flow-limiting dissection, or angio- graphic thrombus.7 For coronary stents, a minimum stenosis diameter of 20% (as visually assessed by angiography) has previously been the clinical benchmark of an optimal angio- graphic result. Given improvements in technology and tech- niques, as well as recognition of the importance of an adequately deployed stent to decrease the risks of stent restenosis and thrombosis,12,228,229 the writing committee concluded that a minimum diameter stenosis of 10% (with an optimal goal of as close to 0% as possible) should be the new benchmark for lesions treated with coronary stenting. As with balloon angioplasty, there should be final TIMI flow grade 3, without occlusion of a significant side branch, flow-limiting dissection, distal embolization, or angiographic thrombus. Problems with determining angiographic success include disparities between the visual assessment and computer-aided quantitative stenosis measurement and self- reporting of success in clinical reports or databases. 3.1.2. Procedural Success A successful PCI should achieve angiographic success with- out associated in-hospital major clinical complications (eg, death, MI, stroke, emergency CABG).7,8 Issues regarding the diagnosis and prognostic implications of procedure-related MI are discussed in Sections 3.3 and 5.10. 3.1.3. Clinical Success In the short term, a clinically successful PCI requires both anatomic and procedural success along with relief of signs and/or symptoms of myocardial ischemia. Long-term clinical success requires that the short-term clinical success remain Levine et al 2011 ACCF/AHA/SCAI PCI Guideline e589 durable and that relief of signs and symptoms of myocardial ischemia persist 9 months after the procedure. Restenosis is the principal cause of lack of long-term clinical success after a short-term clinical success has been achieved. Restenosis is not a complication; it is the expected biological response to vascular injury. The frequency of clinically important reste- nosis may be judged by the frequency with which subsequent revascularization procedures are performed on target arteries after the index procedure. 3.2. Predictors of Clinical Outcome After PCI Factors associated with increased PCI complication rates include advanced age, diabetes, CKD, ACS, congestive heart failure, and multivessel CAD.8,230 232 Several models have been developed and refined over the past 2 decades to predict mortality with PCI.230,233 236 At present, perhaps the best accepted system is from the ACC National Cardiovascular Data Registry (NCDR) CathPCI Risk Score system, which uses clinical variables and PCI setting to predict inpatient mortality (Appendix 4A).236 In general, these models perform very well (C statistic: approximately 0.90), although predic- tive capability decreases in high-risk patients. Models have also been developed to predict procedural success. Presently, the modified ACC/AHA score230 and the SCAI score (Appendix 4B)237 are both in use, with the latter slightly outperforming the former. Discrimination as mea- sured by the C statistic is generally good to very good (0.70 to 0.82), depending on the outcome variable and patient population. The angiographic SYNTAX score238 has been developed to predict long-term risk of MACE after multivessel interven- tion. The SYNTAX score and its potential utility in helping guide revascularization strategies are discussed in Section 2. Composite models including angiographic and clinical vari- ables have been developed but generally require validation in larger cohorts of patients. 3.3. PCI Complications In an analysis of the NCDR CathPCI database of patients undergoing PCI between 2004 and 2007, the overall inhos- pital mortality rate was 1.27%, ranging from 0.65% in elective PCI to 4.81% in STEMI.236 Factors associated with an increased risk of PCI-related death include advanced age, comorbidities (eg, diabetes, CKD, congestive heart failure), multivessel CAD, high-risk lesions, and the setting of PCI (eg, STEMI, urgent or emergency procedure, cardiogenic Causes of procedural and periprocedural MI include acute artery closure, embolization and no-reflow, side branch oc- clusion, and acute stent thrombosis. The incidence of procedure-related MI depends to a great degree on the definition of MI used, the patient population studied, and whether or not cardiac biomarkers are routinely assessed after PCI. The definition and clinical significance of PCI-related MI have been controversial. Criteria for defining a PCI- related MI have evolved over time.8,239,240 The 2007 universal definition of MI240 states that after PCI, elevations of cardiac biomarkers above the 99th percentile upper reference limit indicate periprocedural myocardial necrosis. Increases of biomarkers 3 times the 99th percentile upper reference limit were designated as defining PCI-related MI.240 According to this definition, 15% of patients undergoing PCI would be defined as having periprocedural MI.241,242 Issues in procedure-related MI are discussed in Section 5.10. The need for emergency CABG has dramatically decreased with advances in PCI technology, particularly coronary stents.243,244 Recently the NCDR reported the rate of emer- gency CABG at 0.4%.244 Procedure-related indications for CABG in 1 large series included coronary dissection (27%), acute artery closure (16%), perforation (8%), and failure to cross the lesion (8%).245 The strongest predictors of the need for emergency CABG in several analyses are cardiogenic shock (OR: 11.4), acute MI or emergency PCI (OR: 3.2 to 3.8), multivessel disease (OR: 2.3 to 2.4), and type C lesion (OR: 2.6).243,245 In-hospital mortality for emergency CABG ranges from 7.8% to 14%.243,245,246 In a contemporary analysis from the NCDR, the incidence of PCI-related stroke was 0.22%.247 In-hospital mortality in patients with PCI-related stroke is 25% to 30%.247,248 Factors associated with an increased risk of stroke include fibrinolytic therapy administered before PCI (OR: 4.7), known cerebro- vascular disease (OR: 2.20), STEMI as the indication for PCI (OR: 3.2), use of an intra-aortic balloon pump (IABP) (OR: 2.6), older age (OR: 1.17 per 5-year increase), and female sex.247 249 Initial imaging after a stroke in 1 small series revealed hemorrhagic etiology in 18%, ischemic etiology in 58%, and no clear etiology in 24%.248 One potential algo- rithm for the treatment of catheterization-related stroke has been recently proposed.250 This document includes no spe- cific recommendations for the management of PCI-related stroke but refers the reader to the AHA/American Stroke Association guidelines for the management of adults with Vascular complications from PCI are primarily related to vascular access. Important femoral vascular complications include access site hematoma, retroperitoneal hematoma, pseudoaneurysm, arteriovenous fistula, and arterial dissection and/or occlusion.252 The incidence of these vascular compli- cations in various reports generally ranges from 2% to 6% and has decreased with time.249,253 257 Factors associated with an increased risk of vascular complication include age 70 years, body surface area 1.6 m2 , emergency procedures, peripheral artery disease, periprocedural use of glycoprotein (GP) IIb/IIIa inhibitors, and female sex (if not corrected for body surface area).249,253,254,257,258 Ultrasound guidance has been used for femoral artery access to potentially decrease complications.259 As discussed in Section 5.11, vascular closure devices have not been clearly demonstrated to decrease vascular complication rates. Radial site access decreases the rate of access-related bleeding and complica- tions compared with femoral access.255,260 Loss of the radial pulse has been reported in 5% of radial procedures.261 Infrequent to rare complications occurring with the radial artery approach include compartment syndrome, pseudoan- eurysm ( 0.01%), and sterile abscess (occurring with previous-generation hydrophilic sheaths).262 Radial artery spasm may occur and treatment at times may be challenging. Local hematomas may occur from small-branch vessel hy- drophilic wire perforation or inexperience with wristband use. The risk of coronary perforation is approximately 0.2%, most commonly by wire perforation during PCI for CTO or by ablative or oversized devices during PCI of heavily diseased or tortuous coronary arteries.263 The risk of tampon- ade and management of the perforation varies with the type of Periprocedural bleeding is now recognized to be associated with subsequent mortality,265,266 and the avoidance of bleed- ing complications has become an important consideration in performing PCI. The risk of bleeding is associated with patient factors (eg, advanced age, low body mass index, CKD, baseline anemia), as well as the degree of platelet and thrombin inhibition, vascular access site, and sheath size.267 269 Issues of periprocedural bleeding are discussed in Section 4.7. The incidence of contrast-induced acute kidney injury (AKI) or contrast nephropathy in published reports depends on the definition of contrast nephropathy used and the frequency of risk factors for contrast-induced AKI in the patient population studied. Important risk factors for contrast- induced AKI include advanced age, CKD, congestive heart failure, diabetes, and the volume of contrast administered. Contrast-induced AKI and strategies to prevent it are dis- cussed in Section 4.4. 4. Preprocedural Considerations Table 4 contains recommendations for preprocedural consid- erations and interventions in patients undergoing PCI. 4.1. Cardiac Catheterization Laboratory Requirements Defibrillators are considered by The Joint Commission to be life-support equipment requiring routine assessment and completion of appropriate logs. Many hospitals require peri- odic inspection of consoles for ancillary devices used in coronary intervention (eg, Doppler wires, pressure-tipped sensor wires, and IVUS catheters). Point-of-care testing devices (eg, activated clotting time and arterial blood gas machines) require routine calibration. Duration of storage of digital cine images is often mandated by law. Operating parameters for x-ray imaging equipment are adjusted at installation and periodically assessed by a qualified physicist in cooperation with the equipment manufacturer. Familiarity with radiation dose reducing features of catheterization lab- oratory equipment and assistance from a qualified physicist are important for radiation dose minimization and image optimization. An interventional cardiologist must be present in the labora- tory for the duration of each procedure and is responsible for Table 4. Summary of Recommendations for Preprocedural Considerations and Interventions in Patients Undergoing PCI Recommendations COR LOE References Contrast-induced AKI Patients should be assessed for risk of contrast-induced AKI before PCI. I C 270,271 Patients undergoing cardiac catheterization with contrast media should receive adequate preparatory hydration. I B 272 275 In patients with CKD (creatinine clearance 60 mL/min), the volume of contrast media should be minimized. I B 276 278 Administration of N-acetyl-L-cysteine is not useful for the prevention of contrast-induced AKI. III: No Benefit A 279 283 Anaphylactoid reactions Patients with prior evidence of an anaphylactoid reaction to contrast media should receive appropriate prophylaxis before repeat contrast administration. I B 252,284 286 In patients with a prior history of allergic reactions to shellfish or seafood, anaphylactoid prophylaxis for contrast reaction is not beneficial. III: No Benefit C 287 289 Statins Administration of a high-dose statin is reasonable before PCI to reduce the risk of periprocedural MI. IIa A: Statin na ve 290 296 B: Chronic statin therapy Bleeding risk All patients should be evaluated for risk of bleeding before PCI. I C N/A CKD In patients undergoing PCI, the glomerular filtration rate should be estimated and the dosage of renally cleared medications should be adjusted. I B 298 300 Aspirin Patients already on daily aspirin therapy should take 81 mg to 325 mg before PCI. I B 301 304 Patients not on aspirin therapy should be given nonenteric aspirin 325 mg before PCI. I B 301,303,304 AKI indicates acute kidney injury; CKD, chronic kidney disease; COR, class of recommendation; LOE, level of evidence; MI, myocardial infarction; N/A, not applicable; and PCI, percutaneous coronary intervention. Levine et al 2011 ACCF/AHA/SCAI PCI Guideline e591 procedure outcome. Nursing and technical personnel are also required to be present in the catheterization laboratory, with specific staffing dependent on state requirements and labora- tory caseload and mix. Catheterization laboratory technical staff may include nurse practitioners, registered nurses, li- censed vocational or practical nurses, physician assistants, nursing assistants, radiology technicians, or catheterization laboratory technicians. All catheterization laboratory staff are usually certified in basic life support, advanced cardiovascu- lar life support, and, where appropriate, pediatric advanced life support. Catheterization laboratory personnel have a nursing degree/certification or invasive cardiovascular cre- dentials such as registered cardiovascular invasive specialist or American Society of Radiation technologists.305 4.1.3. Time-Out Procedures In 2003, The Joint Commission mandated a universal proto- col requiring proper preoperative identification of the patient by the members of the catheterization laboratory team, marking of the operative site, and a final time-out just before the procedure.306 Although initially intended to prevent wrong-site surgery, this has been expanded to include all invasive procedures despite limited scientific evidence of its effectiveness.307 The intent of the time-out is for all members of the team to improve patient care by collectively discussing the case. The content of a time-out includes confirmation of the correct patient, correct side and site, agreement on the procedure to be performed, correct patient position, and availability of needed equipment, supplies, and implants. The timeout may be checklist driven or conversational, depending on laboratory preferences.308 The writing committee strongly endorses the practice of conducting a time-out before all PCI procedures. 4.2. Ethical Aspects The 3 principles of medical ethics are beneficence, autonomy, and justice. Beneficence involves the physician s duty to act in the best interests of the patient and avoid maleficence, or harm (primum non nocere). Autonomy describes the physi- cian s duty to help the patient maintain control over his or her medical treatments. Justice describes the physician s duty to treat the individual patient responsibly with due consideration of other patients and stakeholders in the healthcare system. Ethical considerations specific to PCI have been previously discussed309 and are highlighted below: Place the patient s best interest first and foremost when making clinical decisions (beneficence). Ensure that patients actively participate in decisions affecting their care (autonomy). Consider how decisions regarding one patient may also affect other patients and providers (justice). Plan and perform procedures and provide care with the intention of improving the patient s quality of life and/or decreasing the risk of mortality, independent of reim- bursement considerations and without inappropriate bias or influence from industry, administrators, referring physicians, or other sources. Before performing procedures, obtain informed con sent after giving an explanation regarding the details of the procedure and the risks and benefits of both the proce- dure and alternatives to the procedure. Plan and perform procedures according to standards of care and recommended guidelines, and deviate from them when appropriate or necessary in the care of individual patients. Seek advice, assistance, or consultation from colleagues when such consultation would benefit the patient. 4.2.1. Informed Consent Obtaining informed consent for procedures is a legal and ethical necessity. Ideally, informed consent is obtained long enough before the procedure that the patient can fully consider informed consent issues and discuss them with family or other providers, avoiding any sense of coercion. Ad hoc PCI, or PCI immediately following diagnostic proce- dures, presents special problems. When informed consent for PCI is obtained before diagnostic catheterization is per- formed, it is impossible to predict the levels of risk and benefit from an ad hoc PCI.310,311 If diagnostic catheterization reveals anatomy that poses a particularly high risk or for which the superiority of PCI compared with other strategies is unclear, the precatheterization informed consent discussion may be inadequate. In such cases, deferral of PCI until additional informed consent discussions and/or consultations occur may be appropriate, even though it inconveniences the patient and the healthcare system. It is the responsibility of the interventionalist to act in the patient s best interest in these circumstances. Informed consent before emergency procedures is partic- ularly difficult.312 314 The patient presenting with STEMI is usually in distress and often sedated, making true informed consent impossible. Rapid triage, transport, and treatment of STEMI patients create a pressured atmosphere that by neces- sity limits a prolonged and detailed informed consent process. Nevertheless, the interventionist must attempt to provide information about the risks and benefits of different strategies to the patient and family and balance the benefit of thorough discussion with the benefits of rapid intervention. 4.2.2. Potential Conflicts of Interest Decisions about the performance and timing of PCI may pose additional ethical dilemmas. When considering whether to perform multivessel PCI in 1 stage versus 2 stages, safety and convenience for the patient must guide the decision, regard- less of payment policies that maximize reimbursement when PCI is staged.311 A separate issue is self-referral, through which diagnostic catheterization often leads seamlessly to PCI by the same operator.315 The interventionist has an ethical obligation to the patient to consider all treatment options, consult with additional specialists (eg, cardiac sur- geons) when their input would be helpful to the patient, avoid unnecessary interventional procedures, and allow the patient to consult family members and other physicians.311 4.3. Radiation Safety: Recommendation Class I 1. Cardiac catheterization laboratories should rou- tinely record relevant available patient procedural radiation dose data (eg, total air kerma at the international reference point [Ka,r], air kerma air product [PKA], fluoroscopy time, number of cine images), and should define thresholds with corre- sponding follow-up protocols for patients who re- ceive a high procedural radiation dose. (Level of Evidence: C) The issue of radiation exposure during imaging procedures has received increased attention, and the writing committee believes that radiation safety should be addressed in this guideline. Current standards for cardiac catheterization labo- ratories include the following: Specific procedures and policies are in place to mini mize patient (and operator) risk. A radiation safety officer coordinates all radiation safety issues and works conjointly with the medical or health physicist. Patient radiation exposure is reduced to as low a level as reasonably can be achieved. Patients at increased risk for high procedural radiation exposure are identified. Informed consent includes radiation safety informa tion, particularly for the high-risk patient. A basic primer on the physics of x-ray imaging, essential to the safe practice of radiation dose management, has been published in an ACCF/AHA/Heart Rhythm Society/SCAI clinical competence statement.316 Appendix 4C summarizes strategies to minimize patient and operator radiation expo- sure. Adverse radiation effects are now well recognized as infrequent but potentially serious complications of prolonged interventional procedures.317 Fluoroscopic time does not in- clude cine acquisition imaging and is therefore not an accurate measure of patient radiation dose. Total air kerma at the interventional reference point (Ka,r, in Gy) and air kerma area product (PKA, in Gycm2 ) are required to be reported on interventional x-ray systems since 2006. These are useful in the assessment of potential tissue adverse effects or long-term radiation sequelae, respectively, and it is reasonable to include them in the catheterization record at the conclusion of each procedure. Appendix 4D summarizes considerations for patient follow-up based on radiation dose during the 4.4. Contrast-Induced AKI: Recommendations Class I 1. Patients should be assessed for risk of contrast- induced AKI before PCI.270,271 (Level of Evidence: C) 2. Patients undergoing cardiac catheterization with contrast media should receive adequate preparatory hydration.272 275 (Level of Evidence: B) 3. In patients with CKD (creatinine clearance <60 mL/min), the volume of contrast media should be minimized.276 278 (Level of Evidence: B) Class III: NO BENEFIT 1. Administration of N-acetyl-L-cysteine is not useful for the prevention of contrast-induced AKI.279 283 (Level of Evidence: A) See Online Data Supplements 16 to 18 for additional data regarding contrast-induced AKI. Contrast-induced AKI or contrast nephropathy is one of the leading causes of hospital-acquired AKI. Major risk factors for contrast-induced AKI include advanced age, CKD, congestive heart failure, diabetes, and the volume of contrast administered. A risk-scoring system is available to predict the risk of contrast nephropathy using these risk factors and additional variables.270 Thus far, the only strategies clearly shown to reduce the risk of contrast-induced AKI are hydra- tion and minimizing the amount of contrast media. Other than saline hydration, measures that were believed to reduce the risk of contrast-induced AKI have been found to be neutral, to have deleterious effects, or to be characterized by heteroge- neous and conflicting data. Studies of hydration to reduce the risk of contrast-induced AKI suggest that isotonic saline is preferable to half isotonic saline, intravenous (IV) hydration is preferable to oral hydra- tion, hydration for hours before and after exposure to contrast media is preferable to a bolus administration of saline immedi- ately before or during contrast media exposure, and administra- tion of isotonic saline alone is preferable to administration of isotonic saline plus mannitol or furosemide.272 275,320 On the basis of these studies, a reasonable hydration regimen would be isotonic crystalloid (1.0 to 1.5 mL/kg per hour) for 3 to 12 hours before the procedure and continuing for 6 to 24 hours after the Prior studies of N-acetyl-L-cysteine and sodium bicarbon- ate have produced conflicting results. Some, often small, earlier studies suggested benefit, but many other more con- temporary studies and meta-analyses found no clear evidence of benefit, and there are potential issues of publication bias and poor methodology issues in several analyses.279 282,322 332 The recently completed largest randomized study on N-acetyl-L-cysteine and contrast nephropathy in patients undergoing angiographic procedures, ACT (Acetylcysteine for Contrast-Induced Nephropathy Trial), demonstrated no benefit in primary or secondary endpoints. An updated meta-analysis using only high-quality trials similarly demon- strated no benefit.283 Taken as a whole, these studies do not support any recommendation for the use of N-acetyl-L- cysteine, they do, however, provide sufficient data to con- clude that N-acetyl-L-cysteine does not prevent contrast- induced AKI in patients undergoing angiographic procedures. The correlation between the volume of contrast media and the risk of contrast-induced AKI has been documented in several studies.276,277 Thus, minimization of contrast media volume is important to prevent contrast-induced AKI in patients undergoing angiography. The volume of contrast already administered during diagnostic catheterization is an important factor when considering possible ad hoc PCI. Comparative studies of different contrast media (eg, low- osmolar versus iso-osmolar, one agent versus another agent) have produced variable and sometimes contradictory re- Levine et al 2011 ACCF/AHA/SCAI PCI Guideline e593 sults.334 339 Thus, current data are insufficient to justify specific recommendations about low- and isoosmolar contrast media. This issue is discussed in detail in the 2011 UA/ NSTEMI focused update.340 For a further discussion of contrast media and PCI, the reader is referred to a position statement by the SCAI.284 4.5. Anaphylactoid Reactions: Recommendations Class I 1. Patients with prior evidence of an anaphylactoid reaction to contrast media should receive appropri- ate steroid and antihistamine prophylaxis before repeat contrast administration.252,284 286 (Level of Evidence: B) Class III: NO BENEFIT 1. In patients with a prior history of allergic reactions to shellfish or seafood, anaphylactoid prophylaxis for contrast reaction is not beneficial.287 289 (Level of Evidence: C) The incidence of anaphylactoid reactions to contrast media is 1%, and the incidence of severe reactions may be as low as 0.04%.284 Limited data suggest that in patients with a history of prior anaphylactoid reaction, the recurrence rate without prophylaxis is in the range of 16% to 44%.341 Adequate pretreatment of patients with prior anaphylactoid reactions reduces the recurrence rate to close to zero.284 286 A regimen of 50 mg of prednisone administered 13 hours, 7 hours, and 1 hour before the procedure (as well as 50 mg of diphenhy- dramine 1 hour before the procedure) has been shown to reduce the risk of recurrent anaphylactoid reaction.286 In practice, a regimen of 60 mg of prednisone the night before and morning of the procedure (as well as 50 mg of diphen- hydramine 1 hour before the procedure) is often used.252 There are minimal data on the pretreatment of patients undergoing emergency PCI.342 One group has suggested IV steroids (eg, 80 mg to 125 mg of methylprednisolone, 100 mg of hydrocortisone sodium succinate), as well as oral or IV diphenhydramine and possible IV cimetidine.284 For a more detailed discussion of issues related to contrast-induced anaphylactoid reactions, the reader is referred to several dedicated discussions on contrast agents.284,341 There are no data to suggest that those patients with seafood or shellfish allergies are at risk for an anaphylactoid reaction from exposure to contrast media. Iodine does not mediate seafood, shellfish, or contrast media reactions. The common misconception that seafood allergies and contrast reactions are cross-reactions to iodine probably arose from a survey published in 1975 in which 15% of patients with a history of contrast reaction reported a personal history of shellfish allergy, but nearly identical proportions of patients reported allergies to other foods, such as milk and egg, in the same survey.287 Pretreatment of patients with steroids based only on a history of seafood or shellfish allergy has a small but non-zero risk of adverse effect (eg, hyperglycemia in a patient with diabetes) without any demonstrated benefit.288,289 4.6. Statin Treatment: Recommendation Class IIa 1. Administration of a high-dose statin is reasonable before PCI to reduce the risk of periprocedural MI. (Level of Evidence: A for statin-na ve patients290 296; (Level of Evidence: B for those on chronic statin See Online Data Supplement 19 for additional data regarding preprocedural statin treatment. Statins have long-term benefits in patients with CAD343,344 and ACS.345,346 The benefits of statins in ACS begin early, before substantial lipid lowering has oc- curred,345,347 suggesting pleiotropic effects of statins. These might include anti-inflammatory effects, improve- ment of endothelial function, decrease of oxidative stress, or inhibition of thrombogenic responses.348 Statins were beneficial when pretreatment was started from 7 days to 4.7. Bleeding Risk: Recommendation Class I 1. All patients should be evaluated for risk of bleeding before PCI. (Level of Evidence: C) Periprocedural bleeding is now recognized as a major risk factor for subsequent mortality.265,266 Bleeding may lead to mortality directly (because of the bleeding event) or through ischemic complications that occur when antiplatelet or anti- coagulant agents are withdrawn in response to the bleeding. Bleeding may also be a marker of comorbidities associated with worse prognosis (eg, occult cancer). The risk of bleeding is associated with a number of patient factors (eg, advanced age, low body mass index, CKD, baseline anemia), as well as the degree of platelet and thrombin inhibition, vascular access site, and sheath size.267 269 The overall approach to PCI should be individualized to minimize both ischemic and bleeding risks. Measures to minimize the risks of bleeding complica- tions are discussed in several sections of this guideline. These include use of anticoagulation regimens associated with a lower risk of bleeding, weight-based dosing of heparin and other agents, use of activated clotting times to guide unfractionated heparin (UFH) dosing, avoidance of excess anticoagulation,349 dosing adjustments in patients with CKD (eg, eptifibatide, tirofiban, bivalirudin),350 use of radial artery access site,255 and avoidance of femoral vein cannulation when possible. Vascular closure devices have not been clearly demonstrated to decrease bleeding complications and are discussed in detail in Section 5.11. 4.8. PCI in Hospitals Without On-Site Surgical Backup: Recommendations Class IIa 1. Primary PCI is reasonable in hospitals without on-site cardiac surgery, provided that appropriate planning for program development has been accom- plished.351,352 (Level of Evidence: B) Class IIb 1. Elective PCI might be considered in hospitals with- out on-site cardiac surgery, provided that appropri- ate planning for program development has been accomplished and rigorous clinical and angiographic criteria are used for proper patient selection.352 354 (Level of Evidence: B) Class III: HARM 1. Primary or elective PCI should not be performed in hospitals without on-site cardiac surgery capabilities without a proven plan for rapid transport to a cardiac surgery operating room in a nearby hospital or without appropriate hemodynamic support capa- bility for transfer. (Level of Evidence: C) See Online Data Supplement 20 for additional data regarding hospitals without on-site surgical backup. Primary and elective PCI can be performed at hospitals without on-site cardiac surgical backup with a high success rate, low in-hospital mortality rate, and low rate for emer- gency CABG.351,353,354 The best outcomes for patients with STEMI are achieved at hospitals with 24/7 access to primary PCI.355 Criteria for the performance of PCI without on-site surgical backup have been proposed in an SCAI expert consensus document.352 Consideration of elective PCI with- out on-site cardiac surgical backup is thought to be appropri- ate only when performed by experienced operators with complication rates and outcomes equivalent or superior to national benchmarks. Accurate assessment of complication rates and patient outcomes via a regional or national data registry, so that outcomes can be compared with established benchmarks, is an important quality control component of any PCI program. Desires for personal or institutional finan- cial gain, prestige, market share, or other similar motives are not appropriate considerations for initiation of PCI programs without on-site cardiac surgery. It is only appropriate to consider initiation of a PCI program without on-site cardiac surgical backup if this program will clearly fill a void in the healthcare needs of the community. Competition with another PCI program in the same geographic area, particularly an established program with surgical backup, may not be in the best interests of the community. Tables 5 and 6 list the SCAI expert consensus document requirements for PCI programs without on-site surgical backup. Table 7 gives the requirements for primary PCI and emergency CABG at hospitals without on-site cardiac sur- gery, and Table 8 lists the requirements for patient and lesion selection and backup strategy for nonemergency PCI.352 5. Procedural Considerations 5.1. Vascular Access: Recommendation Class IIa 1. The use of radial artery access can be useful to decrease access site complications.255,260,356 362 (Level of Evidence: A) See Online Data Supplement 21 for additional data regarding radial access. Femoral artery access remains the most commonly used approach in patients undergoing PCI in the United States. Choosing a femoral artery puncture site is facilitated by fluoroscopic landmark identification or ultrasound guidance. Low punctures have a high incidence of peripheral artery complications, whereas high punctures have an increased risk of retroperitoneal hemorrhage. In patients with a synthetic graft, arterial access is possible after the graft is a few months old and complication rates are not increased.254 Radial site access is used frequently in Europe and Canada but not in the United States.260 A learning curve exists for the radial approach that will affect procedure time and radiation dose, with a trend toward lower procedural success rates for radial versus femoral access.255 However, compared with femoral access, radial access decreases the rate of access- Table 5. SCAI Expert Consensus Document Personnel and Facility Requirements for PCI Programs Without On-Site Surgical Backup Experienced nursing and technical laboratory staff with training in interventional laboratories. Personnel must be comfortable treating acutely ill patients with hemodynamic and electrical instability. On-call schedule with operation of laboratory 24 h/d, 365 d/y.* Experienced coronary care unit nursing staff comfortable with invasive hemodynamic monitoring, operation of temporary pacemaker, and management of IABP. Personnel capable of endotracheal intubation and ventilator management both on-site and during transfer if necessary. Full support from hospital administration in fulfilling the necessary institutional requirements, including appropriate support services (eg, respiratory care, blood bank). Written agreements for emergency transfer of patients to a facility with cardiac surgery. Transport protocols should be developed and tested a minimum of 2 times per year. Well-equipped and maintained cardiac catheterization laboratory with high-resolution digital imaging capability and IABP equipment compatible with transport vehicles. The capability for real-time transfer of images and hemodynamic data (via T-1 transmission line) as well as audio and video images to review terminals for consultation at the facility providing surgical backup support is ideal. Appropriate inventory of interventional equipment, including guide catheters, balloons, and stents in multiple sizes; thrombectomy and distal protection devices; covered stents; temporary pacemakers; and pericardiocentesis trays. Pressure wire device and IVUS equipment are optimal but not mandatory. Rotational or other atherectomy devices should be used cautiously in these facilities because of the greater risk of perforation. Meticulous clinical and angiographic selection criteria for PCI (Tables 6 and 7). Performance of primary PCI as the treatment of first choice for STEMI to ensure streamlined care paths and increased case volumes. Door-to-balloon times should be tracked, and 90 min outlier cases should be carefully reviewed for process improvement opportunities. On-site rigorous data collection, outcomes analysis, benchmarking, quality improvement, and formalized periodic case review. Participation in a national data registry where available, such as the ACC NCDR in the United States. *Required for US facilities but may not be possible for all facilities worldwide. ACC indicates American College of Cardiology; IABP, intra-aortic balloon pump; IVUS, intravascular ultrasound; NCDR, National Cardiovascular Data Registry; PCI, percutaneous coronary intervention; SCAI, Society for Cardiovas- cular Angiography and Interventions; and STEMI, ST-elevation myocardial infarction. Adapted with permission from Dehmer et al.352 Levine et al 2011 ACCF/AHA/SCAI PCI Guideline e595 related bleeding and complications.255,260,363 In a recent large RCT comparing radial and femoral access in patients with ACS undergoing PCI, there was no difference in the primary composite endpoint (death, MI, stroke, major bleeding), although there was a lower rate of vascular complications with the use of radial access.362 Radial artery access is particularly appealing in patients with coagulopathy, elevated international normalized ratio due to warfarin, or morbid obesity. 5.2. PCI in Specific Clinical Situations 5.2.1. UA/NSTEMI: Recommendations Class I 1. An early invasive strategy (ie, diagnostic angiogra- phy with intent to perform revascularization) is indicated in UA/NSTEMI patients who have refrac- tory angina or hemodynamic or electrical instability (without serious comorbidities or contraindications to such procedures).207,364,365 (Level of Evidence: B) 2. An early invasive strategy (ie, diagnostic angiography with intent to perform revascularization) is indicated in initially stabilized UA/NSTEMI patients (without serious comorbidities or contraindications to such pro- cedures) who have an elevated risk for clinical events.207,365 367 (Level of Evidence: A) 3. The selection of PCI or CABG as the means of revascularization in the patient with ACS should generally be based on the same considerations as those without ACS.53,156,207,368 (Level of Evidence: B) Class III: NO BENEFIT 1. An early invasive strategy (ie, diagnostic angiogra- phy with intent to perform revascularization) is not recommended in patients with extensive comorbidi- ties (eg, liver or pulmonary failure, cancer) in whom (Level of Evidence: C) a. The risks of revascularization and comorbid con- ditions are likely to outweigh the benefits of revascularization, b. There is a low likelihood of ACS despite acute chest pain, or c. Consent to revascularization will not be granted regardless of the findings. The goals of coronary angiography and revascularization in UA/NSTEMI patients are to reduce the risk of death and MI and provide symptom relief. To improve prognosis, early risk stratification is essential for selection of medical and/or invasive treatment strategies. Indications for revasculariza- tion depend on the patient s clinical risk characteristics and coronary anatomy and are in general stronger in the presence of high-risk clinical presentation (eg, dynamic electrocardio- Table 6. SCAI Expert Consensus Document Requirements for Off-Site Surgical Backup 1. Interventional cardiologists establish a working relationship with cardiac surgeons at the receiving facility. 2. Cardiac surgeon must have privileges at the referring facility to allow review of treatment options as time allows. 3. Cardiac surgeon and receiving hospital agree to provide cardiac surgical backup for urgent cases at all hours and for elective cases at mutually agreed hours. 4. Surgeon and receiving facility ensure that patients will be accepted based on medical condition, capacity of surgeon to provide services at the time of request, and availability of resources. If this cannot be ensured before the start of an elective procedure, the case should not be done at this time. 5. Interventional cardiologists must review with surgeons the immediate needs and status of any patient transferred for urgent surgery. 6. Hospital administrations from both facilities endorse transfer agreement. 7. Transferring and receiving facilities establish a rigorous protocol for rapid transfer of patients, including the proper personnel with appropriate experience. 8. A transport provider is available to begin transport within 20 min of the request and provide vehicle/helicopter with necessary life-sustaining equipment, including IABP and monitoring capability. 9. Transferring physician obtains consent for surgery from patient or appropriate surrogate. 10. Initial informed consent for PCI discloses that the procedure is being done without on-site surgical backup and acknowledges the possibility of risks related to transfer. The consent process should include the risk of urgent surgery (approximately 0.3%) and state that a written plan for transfer exists. 11. As part of the local continuous quality improvement program, a regular review of all patients transferred for emergency surgery with the outcome of surgery and identification of any improvement opportunities. IABP indicates intra-aortic balloon pump; PCI, percutaneous coronary interven- tion; and SCAI, Society for Cardiovascular Angiography and Interventions. Adapted with permission from Dehmer et al.352 Table 7. 