No difference in cardiac, cerebrovascular events with left main PCI vs. CABG at 10 years: PRECOMBAT
Ten-year extended follow-up of the PRECOMBAT trial demonstrates no difference in the incidence of major adverse cardiac or cerebrovascular events regardless of whether patients with unprotected left main CAD were treated with PCI with a first-generation drug-eluting stent or CABG.
However, the rate of ischemia-driven target vessel revascularization at 10 years was higher among patients who underwent PCI.
The results are relevant, as “data are still limited on very long-term — beyond 5 years — outcomes of PCI or CABG in patients with left main coronary artery disease [and] available long-term studies showed conflicting results,” Duk-Woo, Park, MD, with Asan Medical Center and University of Ulsan College of Medicine in Seoul, South Korea, said during a virtual presentation at the American College of Cardiology Scientific Session.
The prospective, open-label, randomized PRECOMBAT trial included 600 patients with newly diagnosed unprotected left main coronary artery stenosis (> 50% diameter stenosis) and a diagnosis of angina or non-STEMI. Patients were randomly assigned to undergo CABG or PCI with a sirolimus-eluting stent (Cypher, Cordis) at 13 hospitals in South Korea from 2004 to 2009.
At 10 years, the primary outcome — incidence of major adverse cardiac or cerebrovascular events (MACCE), defined as a composite of death from any cause, MI, stroke or ischemia-driven TVR — in the intent-to-treat analysis occurred in 29.8% of patients assigned PCI vs. 24.7% assigned CABG (HR = 1.25; 95% CI, 0.93-1.69), according to Park.
Similarly, 10-year data showed no difference in secondary outcomes including the composite outcome of death, MI or stroke (18.2% with PCI vs. 17.5% with CABG; HR = 1; 95% CI, 0.7-1.44) or all-cause mortality (14.5% with PCI vs. 13.8% with CABG; HR = 1.13; 95% CI, 0.75-1.7), Park said.
The 10-year rate of ischemia-driven TVR was two times higher in the PCI group, Park said, at 16.1% vs. 8% in the CABG group (HR = 1.98; 95% CI, 1.21-3.21).
The new 10-year data were published simultaneously in Circulation.
The Circulation publication includes additional information on sensitivity and subgroup analyses, Park said during a discussion of the trial. Per-protocol and as-treated analyses showed PCI was associated with higher incidence of the primary endpoint, mainly driven by repeat revascularization.
Patients enrolled in PRECOMBAT had a mean age at baseline of 62 years, three-quarters were men and one-third had medically treated diabetes. Three-quarters of patients had left main plus multivessel involvement at baseline. Mean SYNTAX score was 24.8. Operators achieved complete revascularization in 70.3% of the CABG group and 68.3% of the PCI group.
The trial was planned to complete follow-up at 5 years in the original protocol, but all of the 13 participating centers agreed to participate in extended follow-up through 10 years, Park said. Median follow-up was 11.3 years.
Park noted several limitations of the trial, including a lack of masking of PCI vs. CABG, no detailed information on concurrent CV medications during the long-term follow-up and use of the first-generation Cypher DES.
Discussing the PRECOMBAT results during a virtual press conference, Frederick G.P. Welt, MD, MS, FACC, associate chief of cardiovascular medicine and director of the catheterization lab at University of Utah Health, said long-term data in this left main CAD population are important.
“We’re seeing data out to 10 years, and that’s of course very important because we are all concerned about this sort of ‘catch-up phenomenon,’ where perhaps CABG will tend to have a benefit that is more manifest at later time points,” Welt said. “... The big question is how does this trial inform a field that has had such controversy and very divergent findings from trial to trial?”
Park, in response, noted that “there is a lot of debate about the match between PCI vs. bypass surgery, especially after release of the 5-year EXCEL trial (results).” He highlighted several key important findings of PRECOMBAT, including no difference between PCI and CABG in hard endpoints like death, MI and stroke, and an overall event rate incidence that is “relatively low compared to other trials, like SYNTAXES and NOBLE.” Park said there are many reasons for the differences observed in these trials, such as different clinical anatomy and more than 90% use of IVUS in PRECOMBAT.
“Owing to the limited number of patients and low event rates, [the PRECOMBAT] trial did not have sufficient statistical power to detect a clinically significant difference in endpoints. ... Our findings should be confirmed or refuted through longer follow-up of trials involving contemporary drug-eluting stents, such as EXCEL and NOBLE,” Park concluded during his virtual presentation. – by Katie Kalvaitis
References:
Park D-W, et al. Late-Breaking Clinical Trials IV. Presented at: American College of Cardiology Scientific Session; March 28-30, 2020 (virtual meeting).
Park D-W, et al. Circulation. 2020;doi:10.1161/CIRCULATIONAHA.120.046039.
Disclosure: Park reports he received grants from Chong Kun Dang Pharm, Daiichi Sankyo and Daewoong Pharm; personal fees from Edwards Lifesciences; grants and personal fees from Abbott Vascular; and personal fees from Medtronic.