Does successful chronic total occlusion recanalization fail to improve long-term survival?

Abstract

There has been a significant increase in the number of patients undergoing successful CTO PCI in recent years, even though there might remains considerable controversy regarding the clinical benefit of this procedure. Although no randomized controlled clinical trials comparing CTO-PCI with medical therapy have been published to date, there is a growing body of evidence suggesting clinical benefits (1). These benefits include improvement of anginal symptoms, decreased anti-anginal medication intake, improved exercise capacity, improved left ventricular systolic function, decreased risk of arrhythmia, decreased the number of coronary artery bypass graft (CABG) procedures, and improved tolerance of future coronary occlusion events such as acute coronary syndrome among patients with successful versus failed CTO-PCI. Moreover, CTO is the most common reason for failing to achieve complete revascularization, and incomplete revascularization is associated with poorer clinical outcome compared with complete revascularization.Application of drug-eluting stents (DES) has resulted in significant reduction of target vessel revascularization in non-CTO PCI, and has also led to a surge of interest in CTO-PCI. As a consequence, second-generation DES implantation is the current therapy of choice for percutaneous revascularization of CTO, because it is clear due to supporting clinical evidence in many meta-analyses that implantation of the second-generation DES improves long-term angiographic and clinical outcomes compared with first-generation DES, bare metal stents, and balloon angioplasty without using stents (2).In regards to long-term clinical outcomes, the survival benefit of CTO recanalization is less clearly established, although it has been previously suggested in prior studies (3)(4)(5).A recent study published in this issue of JACC Cardiovasc Interv describes the long-term survival of CTO-PCI. Lee and colleagues evaluated (6) 1,173 consecutive patients with CTO of native coronary vessels requiring PCI of Asan Medical Center in Seoul between March 2003 and May 2014. The procedure was performed successfully, in 1,004 (85.6%) using DES implantation. However, successful recanalization of CTO PCI using DES was not associated with a reduction in long-term mortality over a median follow-up 4.6 years [hazard ratio (HR), 1.04; 95% confidence interval (CI), 0.53-2.04; P=0.94].This report also described that successful CTO PCI was associated with significant fewer subsequent CABG procedures. In contrast, in the group with failed CTO PCI a substantially higher rates of subsequent TVR (HR, 0.15; 95% CI, 0.10-0.25; P<0.001) and CABG procedure (HR, 0.02; 95% CI, 0.006-0.06; P<0.001) was observed.In an evaluation of details of these results, complete revascularization was achieved in 77.2% and 75.9% of patients with failed CTO PCI excluding the CTO lesion and patients with successful CTO PCI within 6 months, respectively (P=0.77). Nevertheless, patients with failed CTO PCI had significantly higher rates of TVR (4.4% vs. Editorial