Implantable cardiac defibrillators and sudden death in recent onset nonischemic cardiomyopathy: Results from IMAC2

Background: Given the potential for recovery in recent onset nonischemic cardiomyopathy (ROCM), the timing and need for implantable cardioverter- defibrillator (ICDs) remains controversial. We examined the utilization of ICDs and the impact on survival for subjects with ROCM. Methods and Results: An National Heart, Lung, and Blood Institute sponsored registry enrolled 373 subjects with ROCM, all with a left ventricular ejection fraction (LVEF) ≤0.40 and ≤6 months of symptoms. The mean age was 45 ± 14 years, 38% were female, 21% black, 75% New York Heart Association II/III, and the mean LVEF was 0.24 ± 0.08. Survival was comparable for subjects with an ICD within 1 month of entry (n = 43, 1/2/3 year % survival = 97/97/92) and those with no ICD at 1 month (n = 330, % survival = 98/97/95, P =.30) and between those with and without an ICD at 6 months (ICD, n = 73, 1/2/3 year % survival = 98/98/95; no ICD, n = 300, % survival = 98/96/95, P =.95). There were only 6 sudden cardiac deaths (SCD) noted (% survival free from SCD = 99/98/97) and these occurred in 1.9% of subjects without ICD and 0.9% of those with a device (P =.50). Conclusions: In a multicenter cohort of ROCM the risk of SCD was low at 1% per year. Early ICD placement did not impact survival and can be deferred while assessing potential for myocardial recovery.