Early Risk of Mortality after Coronary Artery Revascularization in Patients with Left Ventricular Dysfunction and Potential Role of the Wearable Cardioverter Defibrillator

BACKGROUND: Implantable cardioverter defibrillator (ICD) implantation for prevention of sudden cardiac death is typically deferred for 90 days after coronary revascularization, but mortality may be highest early after cardiac procedures in patients with ventricular dysfunction. We determined mortality risk in post-revascularization patients with left ventricular ejection fraction (LVEF) ≤35% and compared survival to those discharged with a wearable cardioverter defibrillator (WCD).

METHODS AND RESULTS: Hospital survivors after surgical (CABG) or percutaneous (PCI) revascularization with LVEF≤35% were included from Cleveland Clinic and national WCD registries. Kaplan-Meier, Cox proportional hazards, propensity score-matched survival and hazard function analyses were performed. Early mortality hazard was higher among 4149 patients discharged without a defibrillator compared to 809 with WCDs (90-day mortality post-CABG 7% vs. 3%, p=0.03; post-PCI 10% vs. 2%, p<0.0001). WCD use was associated with adjusted lower risks of long-term mortality in the total cohort (39%, p<0.0001) and both post-CABG (38%, p=0.048) and post-PCI (57%, p<0.0001) cohorts (mean follow-up 3.2 years). In propensity-matched analyses, WCD use remained associated with lower mortality (58% post-CABG, p=0.002; 67% post-PCI, p<0.0001). Mortality differences were not attributable solely to therapies for ventricular arrhythmia. Only 1.3% of the WCD group had a documented appropriate therapy. CONCLUSIONS: Patients with LVEF≤35% have higher early compared to late mortality after coronary revascularization, particularly after PCI. As early hazard appeared less marked in WCD users, prospective studies in this high risk population are indicated to confirm whether WCD use as a bridge to LVEF improvement or ICD implantation can improve outcomes after coronary revascularization.