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

Abstract

Objective To evaluate predictors of procedural success of percutaneous coronary intervention (PCI) of chronic total coronary occlusions (CTOs) in a non‐infarct‐related artery following ST‐segment elevation myocardial infarction (STEMI), and demonstrate the effect on left ventricular functionality (LVF), infarct size (IS), and pro‐arrhythmic electrocardiogram (ECG) parameters. Background Predictors of unsuccessful revascularization of a CTO are numerous, although following STEMI, these are lacking. Besides, effects of failed CTO PCI (FPCI) on the myocardium are unknown. Methods This is a subanalysis of the EXPLORE trial, in which 302 STEMI patients with a concurrent CTO were randomized to CTO PCI (n = 147) or no‐CTO PCI (NPCI, n = 154). For the purpose of this subanalysis, we divided patients into successful CTO PCI (SPCI, n = 106), FPCI (n = 41), and NPCI (n = 154) groups. Cardiac magnetic resonance imaging and angiographic data were derived from the EXPLORE database, combined with ECG parameters. To gain more insight, all outcomes were compared with patients that did not undergo CTO PCI. Results In multivariate regression, only CTO lesion length >20 mm was an independent predictor of procedural failure (OR 3.31 [1.49–7.39]). No significant differences in median left ventricular ejection fraction, left ventricular end‐diastolic volume, IS, and the pro‐arrhythmic ECG parameters such as QT‐dispersion, QTc‐time, and TpTe‐intervals were seen between the SPCI and FPCI groups at 4 months follow‐up. Conclusion This subanalysis of the EXPLORE trial has demonstrated that a CTO lesion length >20 mm is an independent predictor of CTO PCI failure, whereas procedural failure did not lead to any adverse effects on LVF nor pro‐arrhythmic ECG parameters.

Establishment of a Risk Scoring Model for Perioperative Unex-Plained Shock during Percutaneous Coronary Intervention for the Treatment of Chronic Total Occlusion

“…The unexplained shock incidence rate for the 924 cases in this study (4.8%) was in line with the CTO complication rates reported previously [ 2 ]. This emphasizes the need for CTO operators to take this complication into consideration, given that shock-related data have not been reported for large CTO-related clinical studies such as the OPEN CTO study [ 12 ], EXPLORE study [ 13 ], and the EuroCTO study [ 14 ].…”

Chronic coronary total occlusions: Let's make the long story short

“…Any post hoc analysis of a randomized trial should be viewed as hypothesis‐generating. In this particular substudy, the sample size is relatively small, as the authors acknowledged 5 . The short follow‐up of 4 months does not permit definitive conclusions on any mid‐ or long‐term outcomes.…”

“…In this particular substudy, the sample size is relatively small, as the authors acknowledged. 5 The short follow-up of 4 months does not permit definitive conclusions on any mid-or longterm outcomes. Clinical trials in CTO-PCI are hard to conduct, mainly because of slow enrollment, exclusion of the patients who are triaged to bypass surgery or medical therapy alone, and CTO identification after an acute setting rather than before its occurrence as explained above.…”

“…In this issue of Catheterization and Cardiovascular Interventions journal, Kolk et al perform an interesting post hoc analysis of the EXPLORE trial. 5 The authors evaluated the predictors of unsuccessful CTO-PCI in the patients randomized into the CTO-PCI group of the EXLORE trial. The authors also evaluated the effects of intervention (unsuccessful vs. successful vs. no CTO-PCI) on LVEF, LVEDV, infarct size, and proarrhythmic electrocardiographic (ECG) parameters.…”

“…In this issue of Catheterization and Cardiovascular Interventions journal, Kolk et al perform an interesting post hoc analysis of the EXPLORE trial 5 . The authors evaluated the predictors of unsuccessful CTO‐PCI in the patients randomized into the CTO‐PCI group of the EXLORE trial.…”