Increased risk of ventricular arrhythmias in survivors of out-of-hospital cardiac arrest with chronic total coronary occlusion.

BACKGROUND: Chronic total occlusion (CTO) is common in out-of-hospital cardiac arrest (OHCA) survivors with coronary artery disease. It is unclear whether CTO contributes to ventricular arrhythmias in this population.
OBJECTIVE: This study sought to evaluate the impact of unrevascularized CTOs on the occurrence of appropriate implantable cardioverter-defibrillator (ICD) therapy and all-cause mortality in OHCA survivors with coronary artery disease.
METHODS: This was a retrospective study that included all consecutive OHCA survivors with coronary artery disease who received an ICD from December 1999 until June 2015. Study end points were appropriate ICD therapy and all-cause mortality.
RESULTS: We identified 217 OHCA survivors (mean age 63 ± 10 years; 187 men (86%)) with coronary artery disease. Unrevascularized CTO was present in 71 of 217 patients (33%) at the time of ICD implantation. During a median follow-up of 61 months (interquartile range, 28-97 months), 57 of 217 patients (26%) experienced an appropriate ICD therapy. Patients with CTO had a higher incidence of appropriate ICD therapy in comparison to patients without CTO (log-rank, P = .002). Multivariate Cox regression analysis identified CTO (hazard ratio 2.07; 95% confidence interval 1.23-3.50; P = .007) as an independent predictor of appropriate ICD therapy. The presence of CTO was not associated with a higher mortality rate (log-rank, P = .18).
CONCLUSIONS: In OHCA survivors with coronary artery disease receiving an ICD for secondary prevention, CTO was an independent predictor for the occurrence of ventricular arrhythmias but not for mortality.