during device programming. (See "Amiodarone: Adverse effects, potential toxicities, and approach to monitoring" and "Amiodarone: Clinical uses", section on 'Drug interactions' and "Pharmacologic therapy in survivors of sudden cardiac arrest", section on 'Choice of pharmacologic therapy'.) While antiarrhythmic drugs are sometimes required to reduce the frequency of shocks and improve a person's quality of life, a systematic review of 17 studies involving nearly 6000 ICD recipients showed that shock prevention using antiarrhythmic therapy resulted in no improvement in mortality [34]. (See "Pharmacologic therapy in survivors of sudden cardiac arrest", section on 'Antiarrhythmic drugs'.) Other medical therapies Beta blockers The majority of patients who receive an ICD will be treated with a beta blocker as part of the therapy for their underlying heart disease. Beta blockers confer an https://www.uptodate.com/contents/secondary-prevention-of-sudden-cardiac-death-in-heart-failure-and-cardiomyopathy/print 11/24 7/6/23, 3:10 PM Secondary prevention of sudden cardiac death in heart failure and cardiomyopathy - UpToDate additional survival benefit in patients with an MI, HF, congenital long QT syndrome, or catecholaminergic polymorphic VT. Additional benefits of beta-blockers in ICD patients may include reduction in inappropriate ICD shocks from sinus tachycardia and atrial fibrillation with a rapid ventricular response. Careful attention to ICD programming, including programming a long detection delay, may also reduce unnecessary ICD therapy [35,36]. (See "Beta blockers in the management of chronic coronary syndrome".) Among survivors of SCA who were eligible but not randomized in the AVID trial, beta-blocker use was associated with improved survival in patients who were not treated with specific antiarrhythmic therapy (adjusted RR 0.47, 95% CI 0.25-0.88) [37]. Lipid-lowering therapy Most patients with CHD who have an ICD are treated with lipid- lowering therapy. However, data on the effect of lipid-lowering therapy on ventricular arrhythmia are mixed. [38,39]. Among 362 patients with CHD who received an ICD in the AVID trial, there was a significant reduction in the risk of recurrence of VT or VF in the 83 patients receiving lipid-lowering therapy (adjusted HR 0.40, 95% CI 0.15 to 0.58). Reduction in VT/VF was also seen among statin-treated patients in one primary prevention ICD trial [40]. However, there are still no randomized controlled trials to suggest that lipid-lowering therapy confers an independent antiarrhythmic effect in patients with VT/VF. (See "Management of low density lipoprotein cholesterol (LDL-C) in the secondary prevention of cardiovascular disease".) There are mixed data on whether the administration of fish oil reduces the risk of recurrent ventricular tachyarrhythmias. A meta-analysis of three fish oil trials showed no overall effect of fish oil treatment on the risk of ICD discharge [41]. Ranolazine Initially developed as an antianginal therapy, some studies have suggested that ranolazine has antiarrhythmic properties, including one trial in which ranolazine reduced the frequency of both supraventricular and ventricular arrhythmias within seven days of an acute coronary syndrome. This prompted investigators to study the effectiveness of ranolazine in reducing ventricular arrhythmias in patients with an ICD in the RAID trial, which randomized 1012 high-risk patients with ischemic or nonischemic cardiomyopathy and an ICD to receive either ranolazine (1000 mg twice daily) or placebo in addition to usual care [42,43]. During a mean follow-up of 28 months, there was a non-significant reduction in the primary end point of death or appropriate ICD shock among patients in the ranolazine group compared with placebo (HR 0.84; 95% CI 0.67-1.05), with a pre-specified secondary analysis identifying a significant reduction in recurrent ICD therapies (ATP and shocks) in the ranolazine group (HR 0.70; 95% CI 0.51-0.96). Compliance in the study was poor, however, with 50 percent of patients receiving ranolazine and 40 percent of patients receiving placebo discontinuing the medication. Until further data become available, suggesting a benefit, ranolazine should not be used routinely to https://www.uptodate.com/contents/secondary-prevention-of-sudden-cardiac-death-in-heart-failure-and-cardiomyopathy/print 12/24 7/6/23, 3:10 PM Secondary prevention of sudden cardiac death in heart failure and cardiomyopathy - UpToDate prevent VT/VF in patients with an ICD, but there may be select patients (eg, those with frequent ICD therapies in spite of maximal medical therapy) in whom its use is reasonable. Catheter ablation Similar to antiarrhythmic drugs, catheter ablation may be used as adjunctive therapy to improve quality of life in patients with frequent ventricular tachyarrhythmias leading to ICD shocks, or in those patients who are not candidates for or refuse ICD placement. Catheter ablation alone without an ICD is rarely appropriate for patients who survive cardiac arrest due to VT/VF or who have VT associated with structural heart disease. Radiofrequency ablation (RFA) is often an effective treatment for VT, particularly monomorphic VT due to reentry. In patients with a prior MI, the border zone of the infarct is frequently the site of the reentrant circuit, and these sites are often amenable to endocardial catheter ablation [44]. In contrast, patients with nonischemic cardiomyopathy may have multiple endocardial reentrant circuits, epicardial or mid-myocardial circuits, or other mechanisms of VT (eg, triggered arrhythmias or polymorphic VT) [45]. Due to the presence of more complex arrhythmic substrate, endocardial RFA is less effective in patients with nonischemic cardiomyopathy, and an epicardial approach may be required [46]. Catheter ablation may also be effective in selected patients with polymorphic VT or VF associated with triggering PVCs arising in the right ventricular outflow tract or His-Purkinje system [47]. (See "Overview of catheter ablation of cardiac arrhythmias".) Catheter ablation of VT is considered in three settings: As an adjunct to an ICD in patients who have frequent ventricular arrhythmias and ICD therapies. (See "Electrical storm and incessant ventricular tachycardia", section on 'Catheter ablation'.) As an alternative to an ICD in patients who do not want or are not candidates for an ICD. As prophylactic adjunctive therapy in patients who initially presented with sustained VT and received ICD therapy. A meta-analysis of five trials showed that this approach reduces the risk of VT recurrence by 35 percent with no effect on mortality [48]. Arrhythmia surgery Ischemic cardiomyopathy Reentrant VT circuits associated with a chronic myocardial infarct scar can be surgically resected. Arrhythmia surgery was used more commonly prior to the advent of RFA, particularly in patients with an LV aneurysm and sustained monomorphic VT. The successes of ICD implantation and RFA have made surgery for ventricular arrhythmias appropriate only in rare circumstances. (See "Sustained monomorphic ventricular tachycardia in patients with structural heart disease: Treatment and prognosis", section on 'Surgical therapy'.) https://www.uptodate.com/contents/secondary-prevention-of-sudden-cardiac-death-in-heart-failure-and-cardiomyopathy/print 13/24 7/6/23, 3:10 PM Secondary prevention of sudden cardiac death in heart failure and cardiomyopathy - UpToDate Nonischemic cardiomyopathy Surgical treatment of VT/VF in patients with nonischemic cardiomyopathy has not been well studied, but likely has a lower success rate than in ischemic cardiomyopathy, given that the underlying myocardial disease tends to be diffuse without a discrete scar or aneurysm present. In selected patients, however, there remains a role for surgical treatment. In a study of eight patients in whom percutaneous ablation was not an option, successful reduction in VT was reported in six of eight nonischemic cardiomyopathy patients (75 percent) treated with surgical cryoablation [49]. Cardiac transplantation Cardiac transplantation is occasionally required for patients with incessant life-threatening ventricular arrhythmias, which cannot be controlled by medication or catheter ablation. ICD therapy is generally contraindicated in patients with uncontrollable incessant VT/VF, and such patients should proceed to mechanical support and transplantation if they are candidates. (See "Heart transplantation in adults: Indications and contraindications", section on 'Indications for transplantation'.) Another scenario involves patients who are listed for cardiac transplantation who experience cardiac arrest or symptomatic VT while on the waiting list. In such patients, there is an important role for the ICD as a bridge to transplantation [50-54]. In one study, 16 patients with a mean LVEF of 15 percent who were listed for heart transplantation underwent ICD implantation for ventricular arrhythmias refractory to medical therapy [50]. The ICD delivered appropriate shocks for tachyarrhythmias associated with near syncope in all but one of the patients. Twelve patients underwent transplantation after a mean of 156 days. In another study of 60 patients listed for heart transplantation who survived resuscitation from sustained VT/VF, ICD implantation was associated with significantly improved survival. Only 1 of 30 ICD patients (19 transplanted) versus 7 of 30 non-ICD patients (14 transplanted) died on the waiting list [55]. SOCIETY GUIDELINE LINKS Links to society and government-sponsored guidelines from selected countries and regions around the world are provided separately. (See "Society guideline links: Heart failure in adults" and "Society guideline links: Ventricular arrhythmias" and "Society guideline links: Cardiac implantable electronic devices".) INFORMATION FOR PATIENTS https://www.uptodate.com/contents/secondary-prevention-of-sudden-cardiac-death-in-heart-failure-and-cardiomyopathy/print 14/24 7/6/23, 3:10 PM Secondary prevention of sudden cardiac death in heart failure and cardiomyopathy - UpToDate UpToDate offers two types of patient education materials, "The Basics" and "Beyond the Basics." th th The Basics patient education pieces are written in plain language, at the 5 to 6 grade reading level, and they answer the four or five key questions a patient might have about a given condition. These articles are best for patients who want a general overview and who prefer short, easy-to-read materials. Beyond the Basics patient education pieces are longer, more th th sophisticated, and more detailed. These articles are written at the 10 to 12 grade reading level and are best for patients who want in-depth information and are comfortable with some medical jargon. Here are the patient education articles that are relevant to this topic. We encourage you to print or e-mail these topics to your patients. (You can also locate patient education articles on a variety of subjects by searching on "patient info" and the keyword(s) of interest.) Beyond the Basics topic (see "Patient education: Heart failure (Beyond the Basics)") SUMMARY AND RECOMMENDATIONS Reversible causes In some survivors of sudden cardiac arrest (SCA) or sustained ventricular tachycardia (VT), a transient or reversible cause (eg, acute myocardial ischemia [MI], electrolyte disturbances, medication-related proarrhythmia, etc) can be identified as being responsible for the SCA. Initial treatment should be directed at the underlying disorder. However, prior to concluding that SCA was due to a reversible cause, a thorough evaluation should be performed, typically involving a heart rhythm specialist. (See 'Reversible causes of SCA or sustained VT' above.) Secondary prevention Patients with HF and cardiomyopathy who survive an episode of SCA or have hemodynamically unstable VT or stable VT are typically treated with implantable cardioverter-defibrillator (ICD) therapy for secondary prevention if meaningful survival greater than one year is expected. (See 'Secondary prevention of SCD' above.) For survivors of SCA or sustained VT without a clearly reversible cause, we recommend ICD implantation rather than antiarrhythmic drug therapy (Grade 1A). (See 'Evidence for use of ICD therapy' above.) For survivors of SCA or sustained VT who are identified as having a definite transient or reversible cause (eg, acute MI, acute infarction, severe electrolyte disturbances, medication-related proarrhythmia, etc), in particular those whose cardiac rhythm is polymorphic VT or ventricular fibrillation (VF), we do not recommend ICD implantation if the etiology is clearly understood, the underlying cause is fully treated, and the https://www.uptodate.com/contents/secondary-prevention-of-sudden-cardiac-death-in-heart-failure-and-cardiomyopathy/print 15/24 7/6/23, 3:10 PM Secondary prevention of sudden cardiac death in heart failure and cardiomyopathy - UpToDate condition is unlikely to recur (Grade 1B). (See 'Reversible causes of SCA or sustained VT' above and 'Patients with transient or reversible disorders' above.) For patients with HF or cardiomyopathy who have had syncope and either induced or spontaneous VT, we recommend treatment with an ICD for secondary prevention of SCD (Grade 1A). (See 'Patients with syncope' above.) For patients with nonischemic cardiomyopathy, significant LV dysfunction, and unexplained syncope, we suggest ICD implantation (Grade 2B). Most patients with an ischemic cardiomyopathy and left ventricular ejection fraction 35 percent already qualify for an ICD based upon the results of the MADIT-II and SCD-HeFT trials. (See 'Patients with syncope' above and 'Our approach' above and "Primary prevention of sudden cardiac death in patients with cardiomyopathy and heart failure with reduced LVEF".) Antiarrhythmic drugs These may be used to improve quality of life in patients with frequent ventricular tachyarrhythmias leading to ICD shocks, or in those patients who are not candidates for or who decline ICD implantation. In patients who require an antiarrhythmic drug, we typically prefer amiodarone in patients with HF and LV dysfunction due to its superior efficacy and demonstration of short-term safety in such patients. Sotalol and mexiletine may be useful alternative drugs for selected patients. (See 'Antiarrhythmic drugs' above.) Catheter ablation Similar to antiarrhythmic drugs, catheter ablation may be used as adjunctive therapy to improve quality of life in patients with frequent ventricular tachyarrhythmias leading to ICD shocks, or in those patients who are not candidates for or refuse ICD placement. Catheter ablation alone without an ICD is rarely appropriate for patients who survive cardiac arrest due to VT/VF or who have VT associated with structural heart disease. (See 'Catheter ablation' above.) The majority of patients who receive an ICD will be treated with a beta blocker as part of the therapy for their underlying heart disease. (See 'Beta blockers' above.) ACKNOWLEDGMENT The authors and UpToDate thank Dr. Phillip Podrid, Dr. Jie Cheng, Dr. Scott Manaker, and Dr. Leonard Ganz, who contributed to earlier versions of this topic review. Use of UpToDate is subject to the Terms of Use. https://www.uptodate.com/contents/secondary-prevention-of-sudden-cardiac-death-in-heart-failure-and-cardiomyopathy/print 16/24 7/6/23, 3:10 PM Secondary prevention of sudden cardiac death in heart failure and cardiomyopathy - UpToDate REFERENCES 1. Narang R, Cleland JG, Erhardt L, et al. Mode of death in chronic heart failure. A request and proposition for more accurate classification. Eur Heart J 1996; 17:1390. 2. Cleland JG, Erhardt L, Murray G, et al. Effect of ramipril on morbidity and mode of death among survivors of acute myocardial infarction with clinical evidence of heart failure. A report from the AIRE Study Investigators. Eur Heart J 1997; 18:41. 3. Greenberg H, Case RB, Moss AJ, et al. Analysis of mortality events in the Multicenter Automatic Defibrillator Implantation Trial (MADIT-II). J Am Coll Cardiol 2004; 43:1459. 4. Effect of metoprolol CR/XL in chronic heart failure: Metoprolol CR/XL Randomised Intervention Trial in Congestive Heart Failure (MERIT-HF). Lancet 1999; 353:2001. 5. Sabbag A, Suleiman M, Laish-Farkash A, et al. Contemporary rates of appropriate shock therapy in patients who receive implantable device therapy in a real-world setting: From the Israeli ICD Registry. Heart Rhythm 2015; 12:2426. 6. Causes of death in the Antiarrhythmics Versus Implantable Defibrillators (AVID) Trial. J Am Coll Cardiol 1999; 34:1552. 7. Grubman EM, Pavri BB, Shipman T, et al. Cardiac death and stored electrograms in patients with third-generation implantable cardioverter-defibrillators. J Am Coll Cardiol 1998; 32:1056. 8. Mitchell LB, Pineda EA, Titus JL, et al. Sudden death in patients with implantable cardioverter defibrillators: the importance of post-shock electromechanical dissociation. J Am Coll Cardiol 2002; 39:1323. 9. Pires LA, Lehmann MH, Steinman RT, et al. Sudden death in implantable cardioverter- defibrillator recipients: clinical context, arrhythmic events and device responses. J Am Coll Cardiol 1999; 33:24. 10. Al-Khatib SM, Stevenson WG, Ackerman MJ, et al. 2017 AHA/ACC/HRS Guideline for Management of Patients With Ventricular Arrhythmias and the Prevention of Sudden Cardiac Death: A Report of the American College of Cardiology/American Heart Association Task Force on Clinical Practice Guidelines and the Heart Rhythm Society. J Am Coll Cardiol 2018; 72:e91. 11. Antiarrhythmics versus Implantable Defibrillators (AVID) Investigators. A comparison of antiarrhythmic-drug therapy with implantable defibrillators in patients resuscitated from near-fatal ventricular arrhythmias. N Engl J Med 1997; 337:1576. 12. Domanski MJ, Sakseena S, Epstein AE, et al. Relative effectiveness of the implantable cardioverter-defibrillator and antiarrhythmic drugs in patients with varying degrees of left ventricular dysfunction who have survived malignant ventricular arrhythmias. AVID https://www.uptodate.com/contents/secondary-prevention-of-sudden-cardiac-death-in-heart-failure-and-cardiomyopathy/print 17/24 7/6/23, 3:10 PM Secondary prevention of sudden cardiac death in heart failure and cardiomyopathy - UpToDate Investigators. Antiarrhythmics Versus Implantable Defibrillators. J Am Coll Cardiol 1999; 34:1090. 13. Kuck KH, Cappato R, Siebels J, R ppel R. Randomized comparison of antiarrhythmic drug therapy with implantable defibrillators in patients resuscitated from cardiac arrest : the Cardiac Arrest Study Hamburg (CASH). Circulation 2000; 102:748. 14. Connolly SJ, Gent M, Roberts RS, et al. Canadian implantable defibrillator study (CIDS) : a randomized trial of the implantable cardioverter defibrillator against amiodarone. Circulation 2000; 101:1297. 15. Lee DS, Green LD, Liu PP, et al. Effectiveness of implantable defibrillators for preventing arrhythmic events and death: a meta-analysis. J Am Coll Cardiol 2003; 41:1573. 16. Connolly SJ, Hallstrom AP, Cappato R, et al. Meta-analysis of the implantable cardioverter defibrillator secondary prevention trials. AVID, CASH and CIDS studies. Antiarrhythmics vs Implantable Defibrillator study. Cardiac Arrest Study Hamburg . Canadian Implantable Defibrillator Study. Eur Heart J 2000; 21:2071. 17. Betts TR, Sadarmin PP, Tomlinson DR, et al. Absolute risk reduction in total mortality with implantable cardioverter defibrillators: analysis of primary and secondary prevention trial data to aid risk/benefit analysis. Europace 2013; 15:813. 18. Chan PS, Hayward RA. Mortality reduction by implantable cardioverter-defibrillators in high- risk patients with heart failure, ischemic heart disease, and new-onset ventricular arrhythmia: an effectiveness study. J Am Coll Cardiol 2005; 45:1474. 19. Schaer B, K hne M, Reichlin T, et al. Incidence of and predictors for appropriate implantable cardioverter-defibrillator therapy in patients with a secondary preventive implantable cardioverter-defibrillator indication. Europace 2016; 18:227. 20. Katz DF, Peterson P, Borne RT, et al. Survival After Secondary Prevention Implantable Cardioverter-Defibrillator Placement: An Analysis From the NCDR ICD Registry. JACC Clin Electrophysiol 2017; 3:20. 21. Healey JS, Hallstrom AP, Kuck KH, et al. Role of the implantable defibrillator among elderly patients with a history of life-threatening ventricular arrhythmias. Eur Heart J 2007; 28:1746. 22. Panotopoulos PT, Axtell K, Anderson AJ, et al. Efficacy of the implantable cardioverter- defibrillator in the elderly. J Am Coll Cardiol 1997; 29:556. 23. Narasimhan C, Dhala A, Axtell K, et al. Comparison of outcome of implantable cardioverter defibrillator implantation in patients with severe versus moderately severe left ventricular dysfunction secondary to atherosclerotic coronary artery disease. Am J Cardiol 1997; 80:1305. https://www.uptodate.com/contents/secondary-prevention-of-sudden-cardiac-death-in-heart-failure-and-cardiomyopathy/print 18/24 7/6/23, 3:10 PM Secondary prevention of sudden cardiac death in heart failure and cardiomyopathy - UpToDate 24. Huang DT, Sesselberg HW, McNitt S, et al. Improved survival associated with prophylactic implantable defibrillators in elderly patients with prior myocardial infarction and depressed ventricular function: a MADIT-II substudy. J Cardiovasc Electrophysiol 2007; 18:833. 25. Duray G, Richter S, Manegold J, et al. Efficacy and safety of ICD therapy in a population of elderly patients treated with optimal background medication. J Interv Card Electrophysiol 2005; 14:169. 26. Betz JK, Katz DF, Peterson PN, et al. Outcomes Among Older Patients Receiving Implantable Cardioverter-Defibrillators for Secondary Prevention: From the NCDR ICD Registry. J Am Coll Cardiol 2017; 69:265. 27. Kusumoto FM, Schoenfeld MH, Barrett C, et al. 2018 ACC/AHA/HRS Guideline on the Evaluation and Management of Patients With Bradycardia and Cardiac Conduction Delay: A Report of the American College of Cardiology/American Heart Association Task Force on Clinical Practice Guidelines and the Heart Rhythm Society. J Am Coll Cardiol 2019; 74:e51. 28. Moss AJ, Zareba W, Hall WJ, et al. Prophylactic implantation of a defibrillator in patients with myocardial infarction and reduced ejection fraction. N Engl J Med 2002; 346:877. 29. Bardy GH, Lee KL, Mark DB, et al. Amiodarone or an implantable cardioverter-defibrillator for congestive heart failure. N Engl J Med 2005; 352:225. 30. Wyse DG, Friedman PL, Brodsky MA, et al. Life-threatening ventricular arrhythmias due to transient or correctable causes: high risk for death in follow-up. J Am Coll Cardiol 2001; 38:1718. 31. Viskin S, Halkin A, Olgin JE. Treatable causes of sudden death: not really "treatable" or not really the cause? J Am Coll Cardiol 2001; 38:1725. 32. Ladejobi A, Pasupula DK, Adhikari S, et al. Implantable Defibrillator Therapy in Cardiac Arrest Survivors With a Reversible Cause. Circ Arrhythm Electrophysiol 2018; 11:e005940. 33. Steinberg JS, Martins J, Sadanandan S, et al. Antiarrhythmic drug use in the implantable defibrillator arm of the Antiarrhythmics Versus Implantable Defibrillators (AVID) Study. Am Heart J 2001; 142:520. 34. Ha AH, Ham I, Nair GM, et al. Implantable cardioverter-defibrillator shock prevention does not reduce mortality: a systemic review. Heart Rhythm 2012; 9:2068. 35. Gasparini M, Proclemer A, Klersy C, et al. Effect of long-detection interval vs standard- detection interval for implantable cardioverter-defibrillators on antitachycardia pacing and shock delivery: the ADVANCE III randomized clinical trial. JAMA 2013; 309:1903. https://www.uptodate.com/contents/secondary-prevention-of-sudden-cardiac-death-in-heart-failure-and-cardiomyopathy/print 19/24 7/6/23, 3:10 PM Secondary prevention of sudden cardiac death in heart failure and cardiomyopathy - UpToDate 36. Wilkoff BL, Fauchier L, Stiles MK, et al. 2015 HRS/EHRA/APHRS/SOLAECE expert consensus statement on optimal implantable cardioverter-defibrillator programming and testing. Heart Rhythm 2016; 13:e50. 37. Exner DV, Reiffel JA, Epstein AE, et al. Beta-blocker use and survival in patients with ventricular fibrillation or symptomatic ventricular tachycardia: the Antiarrhythmics Versus Implantable Defibrillators (AVID) trial. J Am Coll Cardiol 1999; 34:325. 38. Mitchell LB, Powell JL, Gillis AM, et al. Are lipid-lowering drugs also antiarrhythmic drugs? An analysis of the Antiarrhythmics versus Implantable Defibrillators (AVID) trial. J Am Coll Cardiol 2003; 42:81. 39. De Sutter J, Tavernier R, De Buyzere M, et al. Lipid lowering drugs and recurrences of life- threatening ventricular arrhythmias in high-risk patients. J Am Coll Cardiol 2000; 36:766. 40. Vyas AK, Guo H, Moss AJ, et al. Reduction in ventricular tachyarrhythmias with statins in the Multicenter Automatic Defibrillator Implantation Trial (MADIT)-II. J Am Coll Cardiol 2006; 47:769. 41. Jenkins DJ, Josse AR, Beyene J, et al. Fish-oil supplementation in patients with implantable cardioverter defibrillators: a meta-analysis. CMAJ 2008; 178:157. 42. Scirica BM, Morrow DA, Hod H, et al. Effect of ranolazine, an antianginal agent with novel electrophysiological properties, on the incidence of arrhythmias in patients with non ST- segment elevation acute coronary syndrome: results from the Metabolic Efficiency With Ranolazine for Less Ischemia in Non ST-Elevation Acute Coronary Syndrome Thrombolysis in Myocardial Infarction 36 (MERLIN-TIMI 36) randomized controlled trial. Circulation 2007; 116:1647. 43. Zareba W, Daubert JP, Beck CA, et al. Ranolazine in High-Risk Patients With Implanted Cardioverter-Defibrillators: The RAID Trial. J Am Coll Cardiol 2018; 72:636. 44. Wissner E, Stevenson WG, Kuck KH. Catheter ablation of ventricular tachycardia in ischaemic and non-ischaemic cardiomyopathy: where are we today? A clinical review. Eur Heart J 2012; 33:1440. 45. Soejima K, Stevenson WG, Sapp JL, et al. Endocardial and epicardial radiofrequency ablation of ventricular tachycardia associated with dilated cardiomyopathy: the importance of low- voltage scars. J Am Coll Cardiol 2004; 43:1834. 46. Yamada T, Kay GN. Optimal ablation strategies for different types of ventricular tachycardias. Nat Rev Cardiol 2012; 9:512. 47. Knecht S, Sacher F, Wright M, et al. Long-term follow-up of idiopathic ventricular fibrillation ablation: a multicenter study. J Am Coll Cardiol 2009; 54:522. https://www.uptodate.com/contents/secondary-prevention-of-sudden-cardiac-death-in-heart-failure-and-cardiomyopathy/print 20/24 7/6/23, 3:10 PM Secondary prevention of sudden cardiac death in heart failure and cardiomyopathy - UpToDate 48. Mallidi J, Nadkarni GN, Berger RD, et al. Meta-analysis of catheter ablation as an adjunct to medical therapy for treatment of ventricular tachycardia in patients with structural heart disease. Heart Rhythm 2011; 8:503. 49. Anter E, Hutchinson MD, Deo R, et al. Surgical ablation of refractory ventricular tachycardia in patients with nonischemic cardiomyopathy. Circ Arrhythm Electrophysiol 2011; 4:494. 50. Jeevanandam V, Bielefeld MR, Auteri JS, et al. The implantable defibrillator: an electronic bridge to cardiac transplantation. Circulation 1992; 86:II276. 51. Grimm M, Wieselthaler G, Avanessian R, et al. The impact of implantable cardioverter- defibrillators on mortality among patients on the waiting list for heart transplantation. J Thorac Cardiovasc Surg 1995; 110:532. 52. Bolling SF, Deeb GM, Morady F, et al. Automatic internal cardioverter defibrillator: a bridge to heart transplantation. J Heart Lung Transplant 1991; 10:562. 53. Lorga-Filho A, Geelen P, Vanderheyden M, et al. Early benefit of implantable cardioverter defibrillator therapy in patients waiting for cardiac transplantation. Pacing Clin Electrophysiol 1998; 21:1747. 54. Saba S, Atiga WL, Barrington W, et al. Selected patients listed for cardiac transplantation may benefit from defibrillator implantation regardless of an established indication. J Heart Lung Transplant 2003; 22:411. 55. Grimm M, Grimm G, Zuckermann A, et al. ICD therapy in survivors of sudden cardiac death awaiting heart transplantation. Ann Thorac Surg 1995; 59:916. Topic 946 Version 38.0 https://www.uptodate.com/contents/secondary-prevention-of-sudden-cardiac-death-in-heart-failure-and-cardiomyopathy/print 21/24 7/6/23, 3:10 PM Secondary prevention of sudden cardiac death in heart failure and cardiomyopathy - UpToDate GRAPHICS [1] Summary of secondary prevention ICD trials NCDR [2] [3] [4] Study AVID CASH CIDS [5] Cohort Years 1993 to 1997 1987 to 1998 1990 to 1997 2006 to 2009 Patients 1016 191 659 46,685 Mean age (years) 65 11 58 11 63 9 66 14 Male (%) 78 79 85 73 Follow-up (months) 18 12 57 34 36 None CAD (%) 81 73 83 64 Nonischemic (%) 15 12 10 23 LVEF 32 13 46 19 34 14 36 15 Presenting arrhythmia (%) VF 45 100 45 51 VT with LOC 21 0 16 NR VT without LOC 34 0 24 27 Syncope 0 0 15 22 BB (%) 42 0 33 84 ACE-I/ARB (%) 69 45 NR 72 One-year mortality (%): Control/ICD 17.7/10.7 15.2/8.1 11.2/9.5 NA/10.4 Two-year mortality (%): 25.3/18.4 27.2/17.2 21.0/14.8 NA/16.4 Control/ICD ICD: implantable cardioverter-defibrillator; CAD: coronary artery disease; LVEF: left ventricular ejection fraction; VF: ventricular fibrillation; VT: ventricular tachycardia; LOC: loss of consciousness; BB: beta blocker; ACE-I: angiotensin converting enzyme inhibitor; ARB: angiotensin receptor blocker; NR: not recorded; NA: not applicable. References: 1. Borne R, Katz D, Betz J, et al. Implantable Cardioverter-De brillators for Secondary Prevention of Sudden Cardiac Death: A Review. J Am Heart Assoc 2017; 6:e005515. https://www.uptodate.com/contents/secondary-prevention-of-sudden-cardiac-death-in-heart-failure-and-cardiomyopathy/print 22/24 7/6/23, 3:10 PM Secondary prevention of sudden cardiac death in heart failure and cardiomyopathy - UpToDate 2. Antiarrhythmics versus Implantable De brillators (AVID) Investigators. A comparison of antiarrhythmic-drug therapy with implantable de brillators in patients resuscitated from near-fatal ventricular arrhythmias. N Engl J Med 1997; 337:1576. 3. Kuck KH, Cappato R, Siebels J, R ppel R. Randomized comparison of antiarrhythmic drug therapy with implantable de brillators in patients resuscitated from cardiac arrest: the Cardiac Arrest Study Hamburg (CASH). Circulation 2000; 102:748. 4. Connolly SJ, Gent M, Roberts RS, et al. Canadian implantable de brillator study (CIDS): a randomized trial of the implantable cardioverter de brillator against amiodarone. Circulation 2000; 101:1297. 5. Katz DF, Peterson P, Borne RT, et al. Survival after secondary prevention ICD placement: an analysis from the NCDR ICD Registry. JACC Clin Electrophysiol 2017; 3:20. Graphic 116653 Version 1.0 https://www.uptodate.com/contents/secondary-prevention-of-sudden-cardiac-death-in-heart-failure-and-cardiomyopathy/print 23/24 7/6/23, 3:10 PM Secondary prevention of sudden cardiac death in heart failure and cardiomyopathy - UpToDate Contributor Disclosures Joseph E Marine, MD, FACC, FHRS No relevant financial relationship(s) with ineligible companies to disclose. Andrea M Russo, MD, FACC, FHRS Grant/Research/Clinical Trial Support: BMS/Pfizer [Anticoagulant]; Boston Scientific [Arrhythmia]; Kestra [Arrhythmia]; Medilynx [Arrhythmia]; Medtronic [Arrhythmia]. Consultant/Advisory Boards: Abbott [Arrhythmia]; Atricure [Arrhythmia]; Biosense Webster [Arrhythmia]; Boston Scientific [Arrhythmias]; Medtronic [Arrhythmias]; PaceMate [Arrhythmia]. Speaker's Bureau: Biotronik [Arrhythmia]; Medtronic [Arrhythmia]. Other Financial Interest: ABIM [Cardiovascular board]. All of the relevant financial relationships listed have been mitigated. Bradley P Knight, MD, FACC Grant/Research/Clinical Trial Support: Abbott [Electrophysiology]; Atricure [Electrophysiology]; Biosense Webster [Electrophysiology]; Biotronik [Electrophysiology]; Boston Scientific [Electrophysiology]; BSCI [Electrophysiology]; MDT [Electrophysiology]; Philips [Electrophysiology]. Consultant/Advisory Boards: Abbott [Electrophysiology]; Atricure [Electrophysiology]; Biosense Webster [Electrophysiology]; Biotronik [Electrophysiology]; Boston Scientific [Electrophysiology]; BSCI [Electrophysiology]; CVRx [Heart failure]; MDT [Electrophysiology]; Philips [Electrophysiology]; Sanofi [Arrhythmias]. Speaker's Bureau: Abbott [Electrophysiology]; Biosense Webster [Electrophysiology]; Biotronik [Electrophysiology]; Boston Scientific [Transeptal catheterization]; BSCI [Electrophysiology]; MDT [Electrophysiology]. All of the relevant financial relationships listed have been mitigated. Samuel L vy, MD No relevant financial relationship(s) with ineligible companies to disclose. Nisha Parikh, MD, MPH No relevant financial relationship(s) with ineligible companies to disclose. Contributor disclosures are reviewed for conflicts of interest by the editorial group. When found, these are addressed by vetting through a multi-level review process, and through requirements for references to be provided to support the content. Appropriately referenced content is required of all authors and must conform to UpToDate standards of evidence. Conflict of interest policy https://www.uptodate.com/contents/secondary-prevention-of-sudden-cardiac-death-in-heart-failure-and-cardiomyopathy/print 24/24