***TASK*** the task is to summarize an input biomedical literature in six sentences 
    ***INPUT*** the input is a biomedical literature 
    ***OUTPUT*** the output is the summary of an input biomedical literature in six sentences 
    ***DOCUMENTATION*** 
    ***EXAMPLES*** 
    Input: Background Current guidelines recommend treatment of significant coronary artery disease by concomitant coronary artery bypass grafting ( CABG ) in patients undergoing surgical aortic valve replacement . However there is no consensus as to how best to treat coronary disease in high-risk patients requiring transcatheter aortic valve implantation ( TAVI ) .  Methods / Design The percutaneous coronary intervention prior to transcatheter aortic valve implantation ( ACTIVATION ) trial is a r and omized , controlled open-label trial of 310 patients r and omized to treatment of significant coronary artery disease by percutaneous coronary intervention ( PCI - test arm ) or no PCI ( control arm ) . Significant coronary disease is defined as ≥1 lesion of ≥70 % severity in a major epicardial vessel or 50 % in a vein graft or protected left main stem lesion . The trial tests the hypothesis that the strategy of performing pre-TAVI PCI is non-inferior to not treating such coronary stenoses with PCI prior to TAVI , with a composite primary outcome of 12-month mortality and rehospitalization . Secondary outcomes include efficacy end-points such as 30-day mortality , safety endpoints including bleeding , burden of symptoms , and quality of life ( assessed using the Seattle Angina Question naire and the Kansas City Cardiomyopathy Question naire).In conclusion , we hope that using a definition of coronary artery disease severity closer to that used in everyday practice by interventional cardiologists - rather than the 50 % severity used in surgical guidelines - will provide robust evidence to direct guidelines regarding TAVI therapy and improve its safety and efficacy profile of this developing technique . Trial registration IS RCT N75836930 , http://www.controlled-trials.com/IS RCT N75836930 ( registered 19 November 2011 ) Background — The residual Synergy Between Percutaneous Coronary Intervention With Taxus and Cardiac Surgery ( SYNTAX ) Score is an objective measure of the degree and complexity of residual stenosis after percutaneous coronary intervention ( PCI ) .  Methods and Results — In the r and omized PCI cohort of the SYNTAX Trial ( n=903 ) , the baseline and residual SYNTAX Scores were calculated . Subjects with a residual SYNTAX Score of 0 were defined as having undergone complete revascularization ( CR ) , and a residual SYNTAX Score > 0 as incomplete revascularization ( ICR ) . Five-year clinical outcomes were stratified by CR and ICR ( tertiles of the residual SYNTAX Score : > 0–4 , > 4–8 , and > 8) . In the  PCI cohort , the mean baseline and residual SYNTAX Scores were 28.4±11.5 and 4.5±6.9 , respectively . The mean & Dgr ; SYNTAX Score ( representative of the burden of disease removed by PCI ) was 23.8±10.9 . The residual SYNTAX Score was distributed as follows : CR , 0 ( n=386 , 42.7 % ) ; ICR , > 0 to 4 ( n=184 , 20.4 % ) , > 4 to 8 ( n=167 , 18.5 % ) , > 8 ( n=153 , 16.9 % ) . A progressively higher residual SYNTAX Score was shown to be a surrogate marker of increasing clinical comorbidity and anatomic complexity . Subjects with CR or residual SYNTAX Scores ⩽8 had comparable 5-year mortality ( CR , 8.5 % ; residual SYNTAX Score > 0–4 , 8.7 % ; > 4–8 , 11.4 % ; P=0.60 ) . A residual SYNTAX Score > 8 was associated with 35.3 % all-cause mortality at 5-years ( P<0.001 ) . Stratified analyses in the predefined medical treated diabetic and left main subgroups yielded similar results . Conclusions — The residual SYNTAX Score was shown to be a powerful indicator of 5-year mortality in the SYNTAX Trial . The residual SYNTAX Score may aid in determining a reasonable level of revascularization . Clinical Trial Registration — URL : http://www . clinical trials.gov . Unique identifier : NCT00114972 OBJECTIVES The purpose of this study was to quantify the extent and complexity of residual coronary stenoses following  percutaneous coronary intervention ( PCI )  and to evaluate its impact on adverse ischemic outcomes . BACKGROUND Incomplete revascularization ( IR ) after PCI is common , and most studies have suggested that IR is associated with a worse prognosis compared with complete revascularization ( CR ) . However , formal quantification of the extent and complexity of residual atherosclerosis after PCI has not been performed . METHODS The baseline Synergy Between PCI With Taxus and Cardiac Surgery ( SYNTAX ) score ( bSS ) from 2,686 angiograms from patients with moderate- and high-risk acute coronary syndrome ( ACS ) undergoing PCI enrolled in the prospect i ve ACUITY ( Acute Catheterization and Urgent Intervention Triage Strategy ) trial was determined . The SS after PCI was also assessed , generating the " residual " SS ( rSS ) . Patients with rSS > 0 were defined as having IR and were stratified by rSS tertiles , and their outcomes were compared to the CR group . RESULTS The bSS was 12.8 ± 6.7 , and after PCI the rSS was 5.6 ± 2.2 . Following PCI , 1,084 patients ( 40.4 % ) had rSS = 0 ( CR ) , 523 ( 19.5 % ) had rSS > 0 but ≤2 , 578 ( 21.5 % ) had rSS > 2 but ≤8 , and 501 patients ( 18.7 % ) had rSS > 8 . Age , insulin-treated diabetes , hypertension , smoking , elevated biomarkers or ST-segment deviation , and lower ejection fraction were more frequent in patients with IR compared with CR . The 30-day and 1-year rates of ischemic events were significantly higher in the IR group compared with the CR group , especially those with high rSS . By multivariable analysis , rSS was a strong independent predictor of all ischemic outcomes at 1 year , including all-cause mortality ( hazard ratio : 1.05 , 95 % confidence interval : 1.02 to 1.09 , p = 0.006 ) . CONCLUSIONS The rSS is useful to quantify and risk-stratify the degree and complexity of residual stenosis after PCI . Specifically , rSS > 8.0 after PCI in patients with moderate- and high-risk ACS is associated with a poor 30-day and 1-year prognosis . ( Comparison of Angiomax Versus Heparin in Acute Coronary Syndromes ; NCT00093158 ) OBJECTIVES This study sought to evaluate the impact of frailty in older adults undergoing transcatheter aortic valve replacement ( TAVR ) for symptomatic aortic stenosis . BACKGROUND Frailty status impacts prognosis in older adults with heart disease ; however , the impact of frailty on prognosis after TAVR is unknown . METHODS Gait speed , grip strength , serum albumin , and activities of daily living status were collected at baseline and used to derive a frailty score  among patients who underwent TAVR procedures at a single large-volume institution . The cohort was dichotomized on the basis of median frailty score into frail and not frail groups . The impact of frailty on procedural outcomes ( stroke , bleeding , vascular complications , acute kidney injury , and mortality at 30 days ) and 1-year mortality was evaluated . RESULTS Frailty status was assessed in 159 subjects who underwent TAVR ( age 86 ± 8 years , Society of Thoracic Surgery Risk Score 12 ± 4 ) .  Baseline frailty score was not associated with conventionally ascertained clinical variables or Society of Thoracic Surgery score . Although high frailty score was associated with a longer post-TAVR hospital stay when compared with lower frailty score ( 9 ± 6 days vs. 6 ± 5 days , respectively , p = 0.004 ) , there were no significant crude associations between frailty status and procedural outcomes , suggesting adequacy of the st and ard selection process for identifying patients at risk for periprocedural complications after TAVR . Frailty status was independently associated with increased 1-year mortality ( hazard ratio : 3.5 , 95 % confidence interval : 1.4 to 8.5 , p = 0.007 ) after TAVR . CONCLUSIONS Frailty was not associated with increased periprocedural complications in patients selected as c and i date s to undergo TAVR but was associated with increased 1-year mortality after TAVR . Further studies will evaluate the independent value of this frailty composite in older adults with aortic stenosis AIM The aim of this study was to evaluate whether coronary artery disease ( CAD ) severity exerts a gradient of risk in patients with aortic stenosis ( AS ) undergoing transcatheter aortic valve implantation ( TAVI ) .  METHODS AND RESULTS A total of 445 patients with severe AS undergoing TAVI were included into a prospect i ve registry between 2007 and 2012 . The preoperative SYNTAX score ( SS ) was determined from baseline coronary angiograms . In case of revascularization prior to TAVI , residual SS ( rSS ) was also determined . Clinical outcomes were compared between patients without CAD ( n = 158 ) , patients with low SS ( 0 - 22 , n = 207 ) , and patients with high SS ( SS > 22 , n = 80 ) . The pre-specified primary endpoint was the composite of cardiovascular death , stroke , or myocardial infa rct ion ( MI ) . At 1 year , CAD severity was associated with higher rates of the primary endpoint ( no CAD : 12.5 % , low SS : 16.1 % , high SS : 29.6 % ; P = 0.016 ) . This was driven by differences in cardiovascular mortality ( no CAD : 8.6 % , low SS : 13.6 % , high SS : 20.4 % ; P = 0.029 ) , whereas the risk of stroke ( no CAD : 5.1 % , low SS : 3.3 % , high SS : 6.7 % ; P = 0.79 ) and MI ( no CAD : 1.5 % , low SS : 1.1 % , high SS : 4.0 % ; P = 0.54 ) was similar across the three groups . Patients with high SS received less complete revascularization as indicated by a higher rSS ( 21.2 ± 12.0 vs. 4.0 ± 4.4 , P < 0.001 ) compared with patients with low SS . High rSS tertile ( > 14 ) was associated with higher rates of the primary endpoint at 1 year ( no CAD:12.5 % , low rSS : 16.5 % , high rSS : 26.3 % , P = 0.043 ) . CONCLUSIONS Severity of CAD appears to be associated with impaired clinical outcomes at 1 year after TAVI . Patients with SS > 22 receive less complete revascularization and have a higher risk of cardiovascular death , stroke , or MI than patients without CAD or low SS BACKGROUND Many patients with severe aortic stenosis and coexisting conditions are not c and i date s for surgical replacement of the aortic valve . Recently , transcatheter aortic-valve implantation ( TAVI ) has been suggested as a less invasive treatment for high-risk patients with aortic stenosis . METHODS We r and omly assigned patients with severe aortic stenosis , whom surgeons considered not to be suitable c and i date s for surgery , to st and ard therapy ( including balloon aortic valvuloplasty ) or transfemoral transcatheter implantation of a balloon-exp and able bovine pericardial valve .  The primary end point was the rate of death from any cause . RESULTS A total of 358 patients with aortic stenosis who were not considered to be suitable c and i date s for surgery underwent r and omization at 21 centers ( 17 in the United States ) . At 1 year , the rate of death from any cause ( Kaplan – Meier analysis ) was 30.7 % with TAVI , as compared with 50.7 % with st and ard therapy ( hazard ratio with TAVI , 0.55 ; 95 % confidence interval [ CI ] , 0.40 to 0.74 ; P<0.001 ) . The rate of the composite end point of death from any cause or repeat hospitalization was 42.5 % with TAVI as compared with 71.6 % with st and ard therapy ( hazard ratio , 0.46 ; 95 % CI , 0.35 to 0.59 ; P<0.001 ) . Among survivors at 1 year , the rate of cardiac symptoms ( New York Heart Association class III or IV ) was lower among patients who had undergone TAVI than among those who had received st and ard therapy ( 25.2 % vs. 58.0 % , P 
    Output:
    
Conclusions — Our results suggest that for patients with CAD undergoing transcatheter aortic valve replacement , a residual SYNTAX score – guided revascularization strategy may carry significant benefits in terms of mortality .
Adequate revascularization may offer a unique and valuable opportunity to improve the prognosis of these patients