Rate of Recovery of Left Ventricular Ejection Fraction in a Real-World Population of Patients Receiving a Wearable Cardioverter Defibrillator

BACKGROUND: This study aimed to investigate the rate of early improvement in ejection fraction (EF) within 21 - 60 days among patients with cardiomyopathy who were provided with a wearable cardioverter defibrillator (WCD). METHODS: This was a retrospective study of patients who received a WCD at our institution to determine the rate of improvement in left ventricular EF (LVEF) to ≥ 35-40%. Among 990 patients who received a WCD during the study period, 101 had an echocardiogram performed during the subsequent 21 - 60 days. Patients were stratified according to their initial EF, as well as age, gender, number of heart failure medications, and ischemic vs. nonischemic cardiomyopathy. Multivariate logistic regression analysis was performed to assess the influence of these variables on the subsequent improvement in EF. RESULTS: There were 39 patients who had improvement in their EF to ≥ 35-40%. The only significant predictor of EF recovery was the initial EF. There was a direct correlation between initial EF category and the likelihood of improvement in EF. For every unit increase in initial EF category, the odds of improvement increased 1.73 times (95% confidence interval (CI): 1.22 - 2.45). Age (P = 0.20), gender (P = 0.10), ischemic cardiomyopathy (P = 0.40), and number of heart failure medications at the time of WCD placement (P = 0.26) were not significant predictors of improved LVEF. CONCLUSIONS: This study showed a rate of improvement in EF to ≥ 35-40% of 39% within 21 - 60 days of placement of a WCD among patients with both ischemic and nonischemic cardiomyopathy. The only significant clinical predictor of EF improvement was initial EF.