Arrhythmia Risk Stratification with Regard to Prophylactic Implantable Defibrillator Therapy in Patients with Dilated Cardiomyopathy

Abstract

To date, generally accepted indications for prophylactic defibrillator implantation in patients with dilated cardiomyopathy do not exist. Recently, the Marburg Cardiomyopathy Study (MACAS) revealed left ventricular ejection fraction to be the only significant arrhythmia risk predictor in a relatively large patient population with dilated cardiomyopathy. Meanwhile, the preliminary results of two prospective randomized trials evaluating prophylactic defibrillator therapy in dilated cardiomyopathy have been reported. The Defibrillators in Nonischemic Cardiomyopathy Treatment Evaluation study (DEFINITE) randomized 458 patients with a history of symptomatic heart failure, a left ventricular ejection fraction < or = 35% and arrhythmias on Holter to an ICD versus no ICD. As a result, ICD therapy was associated with a significant reduction of arrhythmic deaths, which failed to result in a significant decrease in total mortality due to an insufficient number of patients in DEFINITE. The Sudden Cardiac Death in Heart Failure Trial (SCD-HeFT) was a three-arm study comparing placebo to amiodarone to prophylactic ICD therapy in a total of 2,521 patients with ischemic cardiomyopathy (51%) or nonischemic dilated cardiomyopathy (49%). All patients in SCD-HeFT had a left ventricular ejection fraction inverted exclamation mark U 35% despite optimized medical heart failure therapy. SCD-HeFT showed a significant reduction of total mortality in the ICD group, whereas amiodarone did not improve survival.

ACC/AHA/ESC 2006 Guidelines for Management of Patients With Ventricular Arrhythmias and the Prevention of Sudden Cardiac Death

“…After 2 y, mortality was 13.8% in the standard therapy group versus 8.1% among those receiving an ICD, amounting to a 5.7% absolute reduction and a 35% relative risk reduction with ICD implantation. This failed to reach statistical significance (p ϭ 0.06), but the findings are comparable to those of other similar trials (647,648). The SCD-HeFT compared amiodarone, ICD, and best medical therapy in 2521 patients with CHD or nonischemic cardiomyopathy who were in NYHA functional class II or III HF with EF less than 35%.…”

A new methodological approach to assess cardiac work by pressure–volume and stress–length relations in patients with aortic valve stenosis and dilated cardiomyopathy

“…To date, the depression of LVEF is the predominant indicator to asses an increased risk of cardiac mortality in patients with heart failure of various etiology. Therefore, a threshold of LVEF less than 30 to 35% is used as a criterion to indicate implantation of cardioverter-defibrillators to prevent sudden cardiac death [7,17]. Although these patients benefit from this therapy, malignant ventricular tachycardia does not occur in the majority.…”

Ventricular tachycardia – an atypical initial presentation of sarcoidosis: a case report

“…Most authorities recommend placement of an electronic pacemaker for complete heart block and an automatic implantable cardioverter-defibrillator for ventricular fibrillation or tachycardia and markedly reduced left ventricular EF [18]. Cardiac transplantation is a useful option in cardiac sarcoidosis refractory to medical management, however, some studies have shown a trend towards increased mortality [19,20].…”