Patients with improved left ventricular ejection fraction without implantable cardioverter defibrillator may continue to be at high mortality risk despite optimal medical management

BACKGROUND: With advances in medical and interventional management, the risk of sudden cardiac death (SCD) has decreased in the high-risk patients identified by left ventricular ejection fraction (LVEF) \u3c35%. However, in the cohort of patients who have improved LVEF and no ICD, whether ICD would have benefitted remains largely unknown. OBJECTIVE: To evaluate benefit of ICD in addition to optimal medical management (OMT) in patients with improved LVEF. METHODS: Aurora Healthcare patient records from 1/2010 to 10/2014 were screened to identify patients with LVEF≤35% and subsequent improvement to EF≥40%, in whom ICD implant was deferred vs. patients who received ICD. Propensity score matching was applied to match the medications and other clinical confounders. The primary outcome was all-cause mortality. RESULTS: One thousand three hundred sixty-four patients were identified with improved LVEF during the study period. We further propensity matched both groups for clinical characteristics and medications at improved LVEF (40-49%) to evaluate additional benefit of ICD in this cohort of patients. A total of 540 patients were included in the mortality analysis. Sixty-eight patients (15%) in non-ICD group died (majority as SCD) as compared to 10 (9%) in the ICD group (majority non-SCD), p=0.0108 . This effect was not statistically significant in patients with completely recovered LVEF \u3e50%. CONCLUSIONS: Our findings suggest that the ICD may continue to provide survival benefit over and above OMT in patients with improved LVEF