Successful Chronic Total Occlusion Recanalization Not Associated With Lower Risk of Mortality

In an evaluation of long-term clinical outcomes after drug eluting stent (DES)-supported percutaneous coronary intervention (PCI) for coronary total occlusion (CTO), successful recanalization of CTO was not associated with a lower risk of mortality.

Researchers did find, however, that successful CTO-PCI was associated with significantly fewer subsequent coronary artery bypass grafting (CABG) procedures.

Successful reopening of CTO has been reported to alleviate symptoms, improve left ventricular function, and reduce the number of CABG procedures. In addition, restenosis and repeated revascularization procedures have decreased with DESs compared with bare metal stents (BMS).

The study, published in JACC: Cardiovascular Interventions, included 1004 patients from a CTO registry database at the Asan Medical Center in Seoul, South Korea. Patients were prescribed aspirin (loading dose, 200 mg) and clopidogrel (loading dose, 300 or 600 mg) and periprocedural anticoagulation was administered via the standard regimens. Aspirin was continued following the procedure, and patients treated with DESs were prescribed clopidogrel for at least 12 months.

The primary safety end points between successful PCI and failed PCI were all-cause mortality and a composite of all-cause death or Q-wave myocardial infarction (MI). Target vessel revascularization (TVR) and CABG were the primary efficacy end points. In addition, cardiac death, Q-wave MI, stroke, stent thrombosis, any repeat revascularization, and angina severity changes were considered secondary end points.

First-generation DESs were used in 46.1% (n=463) and newer-generation DESs were used in 53.9% (n=541). Of the 1021 CTO lesions in patients with successful PCI, stent implantation was guided by intravascular ultrasound in 87.6%.

No cases of in-hospital death occurred, but 4 patients required emergency CABG. In addition, 2 patients experienced coronary perforation in the successful PCI group and 5 in the failed PCI group (P=.001). The cumulative rate of TVR was not significant between the 2 groups (P=.59), but the CABG rate was significantly higher in patients with failed CTO-PCI (P=.03).

In a multivariable analysis, age, BMI, presence of diabetes, and presence of renal failure were independently associated with an increase in mortality at 4.6 years of follow-up. Age was per 10 year increment (hazard ratio [HR]: 1.96; 95% confidence interval [CI]: 1.47-2.60; P<.001) and BMI was per 2.5 kg/m² (HR: 0.67; 95% CI: 0.54-0.83; P<.001). An increase in CTO vessels per patient was associated with a higher risk of death (HR: 1.85; 95% CI: 0.97-3.53; P=.06). However, failed CTO-PCI did not independently predict mortality, but was an independent determinant for TVR (HR: 6.11; 95% CI: 3.79-9.84; P<.001) and CABG (HR: 55.78; 95% CI: 16.84-184.84; P<.001).

“During the last few decades, there has been much debate on the benefit of reopening a coronary CTO primarily because of the lack of high-level evidence from studies,” the authors wrote. “However, in the present study, the impact of successful CTO recanalization on survival was in contrast to previous studies. We observed that the risk of death and Q-wave MI were comparable during long-term follow-up regardless of the procedure success.”

They concluded, “The true prognostic impact of CTO-PCI should be defined by a randomized comparison between successful CTO-PCI and optimal medical therapy.”

Reference

Lee PH, Lee S-W, Park H-S, et al. Successful recanalization of native coronary chronic total occlusion is not associated with improved long-term survival. JACC Cardiovasc Interv. 2016. doi:10.1016/j.jcin.2015.11.016.