Reversible Cause of Cardiac Arrest and Secondary Prevention Implantable Cardioverter Defibrillators in Patients With Coronary Artery Disease: Value of Complete Revascularization and LGE-CMR

Background In survivors of sudden cardiac arrest with obstructive coronary artery disease, it remains challenging to distinguish ischemia as a reversible cause from irreversible scar-related ventricular arrhythmias. We aimed to evaluate the value of implantable cardioverter-defibrillator (ICD) implantation in sudden cardiac arrest survivors with presumably reversible ischemia and complete revascularization. Methods and Results This multicenter retrospective cohort study included 276 patients (80% men, age 67 +/- 10 years) receiving ICD implantation for secondary prevention. Angiography was performed before ICD implantation. A subgroup of 166 (60%) patients underwent cardiac magnetic resonance imaging with late gadolinium enhancement before implantation. Patients were divided in 2 groups, (1) ICD-per-guideline, including 228 patients with incomplete revascularization or left ventricular ejection fraction 35%. The primary outcome was time to appropriate device therapy (ADT). During 4.0 years (interquartile range, 3.5-4.6) of follow-up, ADT developed in 15% of the ICD-off-label group versus 43% of the ICD-per-guideline group. Time to ADT was comparable in the ICD-off-label and ICD-per-guideline groups (hazard ratio (HR), 0.46; P=0.08). No difference in mortality was observed (HR, 0.95; P=0.93). Independent predictors of ADT included age (HR, 1.03; P=0.01), left ventricular end-diastolic volume HR, (1.05 per 10 mL increase; P