DECISION-CTO Demonstrates No Significant Difference in Death, MI, Stroke, or Any Revascularization with CTO PCI vs. No CTO PCI

The results of the DECISION-CTO trial conducted by Lee et al. showcased that CTO-PCI was feasible with high success rates. In addition to this, there was no difference in the incidence of major adverse cardiovascular events with CTO PCI vs. no CTO-PCI, however, the study was limited by low power for clinical endpoints and high crossover rates between groups. The results were published online in Circulation.

Procedural results for percutaneous coronary intervention (PCI) in coronary vessels with chronic total occlusion (CTO) have improved in recent years, and PCI strategies had shifted towards more complete revascularization with the more liberal use of CTO-PCI. However, evidence evaluating CTO-PCI have been limited to observational studies and small clinical trials. In this open-label, multicenter, randomized, non-inferiority 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. Due to slow recruitment, the trial was stopped before completion of the 1,284 planned enrolments. Time-to-event outcomes were determined from the date of randomization to the final follow-up date. Cumulative event rates and survival curves were generated using the Kaplan-Meier method. The noninferiority hypothesis was assessed with the use of a z-test. Cox proportional hazards regression analyses were conducted to estimate the risk associated with CTO-PCI strategy relative to that of no CTO-PCI strategy. Secondary analysis for the primary outcome was conducted in several clinically relevant subgroups with tests for interactions. Differences in QOL measures between CTO-PCI and no CTO-PCI strategy at each time point was estimated using random-effect growth curve models which accounted for missing data under the missing-at-random assumption. Covariates for the models included treatment group, follow-up time, interactions between treatment and time, and baseline clinical factors (age, sex, hypertension, diabetes, previous stroke, heart failure, renal dysfunction, clinical presentation, the location of CTO, SYNTAX score category). In addition, quadratic and cubic terms of time along with their interactions with treatment group were included in the models to account for non-linear trends. Statistical hypothesis tests with P less than 0.05 were considered significant.

According to the publication, between March 2010 and September 2016, a total of 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.

Chronic total occlusion (CTO)-percutaneous coronary intervention (PCI) did not reduce the 4-year risk of major adverse cardiovascular events in patients with PCI eligible, de novo coronary CTOs. Nearly 20% of patients in the no-CTO PCI group crossed over to CTO PCI within 3 days after randomization, and that the study was stopped early due to slow enrolment. Both study groups (CTO PCI and no CTO PCI) were associated with substantial QOL improvements that were sustained through 36 months, with no differences between groups in the primary QOL analyses. As a result of this study, CTO demonstrated the feasibility of CTO-PCI strategy with low procedural complication rates. This study had several limitations. First, the early termination of the trial reduced its statistical power, which warranted cautious interpretation of the study results. Under the same assumptions as for the original sample size calculation, the study would retain 64% power for the original primary analysis with the given sample size. Second, the high number of crossovers in the no CTO-PCI group limited conclusions drawn from the intention-to-treat analysis and may have led to an underestimation of the true effect of CTO-PCI strategy. Third, the response rate of the QOL questionnaire was low, thus the results may have been potentially biased. Also, the lack of sham control may have introduced a chance of a placebo effect in the treatment group. Fourth, a viability test was not mandatory for patient enrolment in the trial. Concerns existed since reopening a CTO vessel supplying non-viable territories would be unlikely to improve prognosis. In conclusion, the trial demonstrated no significant difference in the primary endpoint of death, MI, stroke, or any revascularization with CTO PCI vs. no CTO PCI over the course of 4 years. Both the CTO PCI and no CTO-PCI groups showed substantial QOL improvements that were sustained through 36 months. The investigators believed that future large scale studies were needed to study the role of CTO-PCI, with careful attention to prevent crossover between groups.