ABSTRACT

BACKGROUND - Procedural results for percutaneous coronary intervention (PCI) in coronary vessels with chronic total occlusion (CTO) have improved in recent years, and PCI strategies have moved toward more complete revascularization with more liberal use of CTO-PCI. However, evidence evaluating CTO-PCI is limited to observational studies and small clinical trials.

METHODS - In this open-label, multicenter, randomized, noninferiority trial, PCI-eligible patients were assigned to receive either one of two strategies; PCI or no PCI for the qualifying de novo CTO lesion with the option for PCI of obstructive non-CTO lesions at the discretion of the operator. The primary endpoint was a composite of death, myocardial infarction, stroke, or any revascularization. Health-related quality of life was assessed at baseline and at 1, 6, 12, 24, and 36 months. Because of slow recruitment, the trial was stopped before completion of the 1,284 planned enrollments.

RESULTS - Between March 2010 and September 2016, 834 patients were randomly assigned to the CTO-PCI (n=417) or no CTO-PCI (n=398) strategy. Among the patients assigned to the no CTO-PCI strategy, 78 (19.6%) crossed over to receive staged CTO-PCI within 3 days of randomization. The overall CTO-PCI success rate was 90.6%. Serious nonfatal complications associated with CTO-PCI occurred in three patients (one stroke, one cardiac tamponade, and one patient with recurrent episodes of ventricular tachyarrhythmia induced by intracoronary thrombus). Approximately half of the patients in each group underwent PCI for an average of 1.3 non-CTO lesions, resulting in a comparable residual SYNTAX score (3.7±5.4 vs. 4.0±5.9, P=0.42) confined to non-CTO vessels. During a median follow-up of 4.0 years (interquartile range, 2.4-5.1 years), there was no significant difference between the CTO-PCI and the no CTO-PCI strategy in the incidence of the primary endpoint (22.3% vs. 22.4%, hazard ratio, 1.03; 95% CI, 0.77-1.37; P=0.86). Both CTO-PCI and no CTO-PCI strategy were associated with significant improvements, but without between-group differences, in disease-specific health status that was sustained through 36 months.

CONCLUSIONS - CTO-PCI was feasible with high success rates. There was no difference in the incidence of major adverse cardiovascular events with CTO PCI vs. no CTO-PCI, but the study was limited by low power for clinical endpoints and high crossover rates between groups.

CLINICAL TRIAL REGISTRATION - URL: https://clinicaltrials.gov Unique Identifier: NCT01075051.