Chronic total occlusion of an infarct-related artery: a new predictor of ventricular arrhythmias in primary prevention implantable cardioverter defibrillator patients.

Aims: The aim of this article is to evaluate the impact of a coronary chronic total occlusion in an infarct-related artery (IRA-CTO) on the occurrence of ventricular arrhythmias (VAs) in patients implanted with an implantable cardioverter defibrillator (ICD) for primary prevention. Methods and
Results: The study includes a prospective cohort of 108 consecutive patients with ischaemic cardiomyopathy, in whom an ICD was implanted for primary prevention and a coronary angiography performed before ICD implantation. About 49 patients (45%) had a CTO and 34 (31%) had an IRA-CTO. Patients with IRA-CTO did not differ from the rest of the population in terms of basal characteristics and severity of cardiac disease. Median follow-up was 33 months (interquartile range 46). Infarct-related artery-CTO was associated with higher rates of any VA (53 vs. 26%, P = 0.006) and fast ventricular tachycardia (fast VT, cycle length <300 ms) or ventricular fibrillation (VF) (47 vs. 19%, P = 0.002). At multivariate Cox regression, IRA-CTO was the only independent predictor of any VA [hazard ratio (HR) 3.64, P = 0.002] and fast VT/VF (HR 3.36, P = 0.008). On the contrary, CTO not associated with a prior infarction in their territory did not increase the risk of VA. Infract-related artery-CTO was also an independent predictor of cardiac mortality or heart transplantation (HR 3.46, P = 0.022).
Conclusion: In ischaemic patients implanted with an ICD for primary prevention, a CTO associated with a previous infarction in its territory is an independent predictor of VA and, especially, of fast VT/VF, identifying a subgroup of patients with a very high rate of arrhythmic events at follow-up.