Evaluation of the Impact of a Chronic Total Coronary Occlusion on Ventricular Arrhythmias and Long‐Term Mortality in Patients With Ischemic Cardiomyopathy and an Implantable Cardioverter‐Defibrillator (the eCTOpy‐in‐ICD Study)

Abstract

BackgroundPrevious studies report conflicting results about a higher incidence of ventricular arrhythmias in patients with a chronic total coronary occlusion (CTO). We aimed to investigate this association in a large cohort of implantable cardioverter defibrillator patients with long‐term follow‐up.Methods and ResultsAll consecutive patients from 1992 onwards who underwent implantable cardioverter defibrillator implantation for ischemic cardiomyopathy at the Leiden University Medical Center were evaluated. Coronary angiograms were reviewed for the presence of a CTO. The occurrence of ventricular arrhythmias and survival status at follow‐up were compared between patients with and patients without a CTO. A total of 722 patients constitute the study cohort (age 66±11 years; 84% males; 74% primary prevention, median left ventricular ejection fraction 30% [first–third quartile: 25–37], 44% received a cardiac resynchronization therapy defibrillator). At baseline, 240 patients (33%) had a CTO, and the CTOs were present for at least 44 (2–127) months. The median follow‐up duration was 4 (2–6) years. On long‐term follow‐up, CTO patients had a higher crude appropriate device therapy rate (37% versus 27%, P=0.010) and a lower crude survival rate (51% versus 67%, P<0.001) compared with patients without a CTO. Corrected for baseline characteristics including left ventricular ejection fraction, the presence of a CTO was an independent predictor for appropriate device therapy.ConclusionsThe presence of a CTO in implantable cardioverter defibrillator patients was associated with more appropriate device therapy and worse prognosis at long‐term follow‐up. Further investigation is warranted regarding a potential beneficial effect of CTO revascularization on the incidence of ventricular arrhythmias.

Predictors and outcomes of procedural failure of percutaneous coronary intervention of a chronic total occlusion—A subanalysis of the EXPLORE trial

“…Also, the eCTOpy‐in‐ICD study showed that patients with an ICD for ischemic cardiomyopathy (ICM) with a concurrent CTO received more appropriate device therapy and had a higher all‐cause mortality, compared with ICD patients with ICM without a CTO. Accordingly, in this study a suggestion of electrical stabilization after successful revascularization of a CTO was observed 26 . Interestingly, a previous study has demonstrated higher rates of ventricular ectopy during exercise in patient who underwent SPCI compared to FPCI 27 .…”

“…Accordingly, in this study a suggestion of electrical stabilization after successful revascularization of a CTO was observed. 26 Interestingly, a previous study has demonstrated higher rates of ventricular ectopy during exercise in patient who underwent SPCI compared to FPCI. 27 Thus, although previous research indicates an association between arrhythmogenesis and CTOs, the extent to which FPCI affects arrhythmogenesis remains hard to define.…”

Exercise testing after chronic total coronary occlusion revascularization in patients with STEMI and a concurrent CTO: A subanalysis of the EXPLORE‐trial

“…The recovering hibernating cardiomyocytes and ion channels in the revascularized CTO‐area could become overstimulated and therefore be more prone for VE than untreated hibernating myocardium. The eCTOpy‐in‐ICD study, investigating ICD‐therapy in CTO patients, shows that revascularization of the CTO is associated with reduction of appropriate ICD‐therapy rates for VT and VF on the long‐term, suggesting that CTO PCI might eventually, but not early on, lead to stabilization of the electrical vulnerability . Given these apparently disparate findings between the current study and the eCTOpy‐in‐ICD study further research is warranted to investigate whether revascularization of a CTO leads to electrical reactivation of the hibernating CTO area, which could initially induce proarrhythmogenicity but has a stabilizing effect in the long‐run.…”

“…(b). QTc-duration during the exercise test per randomization group CTO is associated with reduction of appropriate ICD-therapy rates for VT and VF on the long-term, suggesting that CTO PCI might eventually, but not early on, lead to stabilization of the electrical vulnerability 22.…”

Vulnerability for ventricular arrhythmias in patients with chronic coronary total occlusion

“…Among patients with CTO, renal dysfunction and LVEF <40% were independent factors associated with appropriate ICD therapy. Van Dongen et al evaluated 722 patients with ischemic cardiomyopathy who received an ICD for primary and secondary prevention [33]. A CTO was an independent predictor of appropriate ICD therapy.…”