Impact of Chronic Total Coronary Occlusion on Recurrence of Ventricular Arrhythmias in Ischemic Secondary Prevention Implantable Cardioverter-Defibrillator Recipients (VACTO Secondary Study): Insights From Coronary Angiogram and Electrogram Analysis

Abstract

ObjectivesThis study sought to evaluate the incidence and clinical effect of coronary chronic total occlusions (CTOs) in patients with ischemic cardiomyopathy receiving an implantable cardioverter-defibrillator (ICD) for secondary prevention of sudden cardiac death (SCD). BackgroundCTOs are common in patients with ischemic cardiomyopathy, which is the major cause of SCD. However, the impact of CTO in SCD survivors receiving an ICD is unknown. MethodsA total of 425 patients who had survived an episode of ventricular arrhythmias and underwent ICD implantation for secondary prevention in 8 centers were included. Coronary angiogram, CTO angiographic characteristics, and ventricular arrhythmia pattern were centrally analyzed. Primary and secondary endpoints were appropriate ICD therapies and mortality during a median follow-up of 4.1 years, according to the presence of CTO in the baseline angiogram. ResultsAppropriate ICD therapies were higher in patients with CTO (51.7% vs. 36.3%; p = 0.001 at 4 years). Left ventricular ejection fraction (LVEF) (p = 0.015) and CTO (p = 0.001) were independent predictors of appropriate ICD therapy. Ventricular arrhythmia onset was associated to a shorter coupling interval and lower prematurity index in CTO patients. Defibrillator therapies were independently associated with worse LVEF (p = 0.046) and renal dysfunction (p = 0.023) among patients with CTO, and a tendency was observed in patients with better collateral flow (p = 0.093). Patients with poorer renal function (p = 0.029), LVEF (p = 0.041), and CTO (p = 0.033) experienced higher mortality rate. ConclusionsAmong ICD recipients for secondary prevention of SCD, coronary CTO conferred a higher risk of VA recurrence and mortality in long-term follow-up. Angiographic and VA patterns could provide insights into the mechanisms of SCD and may have implications for the use of interventions designed to limit ICD shocks in this high-risk population.