Complete revascularization more beneficial than culprit-only PCI after STEMI

Complete revascularization is superior to culprit-lesion-only percutaneous coronary intervention (PCI) in patients with both ST-segment elevation myocardial infarction (STEMI) and multivessel coronary artery disease (CAD), according to results from the COMPLETE trial, published Sept. 1 in the New England Journal of Medicine.

COMPLETE (the Complete Versus Culprit-Only Revascularization Strategies to Treat Multivessel Disease After Early PCI for STEMI trial), which was funded by the Canadian Institutes of Health Research and led by Sharmi R. Mehta, MD, of the Population Health Research Institute, was designed to address an important evidence gap in cardiology. While a handful of mid-sized observational and randomized studies have suggested a clinical benefit with staged non-culprit lesion PCI, research to date has been limited, and major society guidelines maintain a class IIb—weak—recommendation for the treatment of non-culprit lesions.

“Non-culprit lesions, which are usually discovered incidentally at the time of primary PCI, may represent stable coronary artery plaques, for which additional revascularization may not offer additional benefit,” Mehta and colleagues wrote in NEJM. “However, if non-culprit lesions have morphologic features consistent with unstable plaques, which confer an increased risk of future cardiovascular events, there may be a benefit of routine non-culprit-lesion PCI.”

The scope of Mehta et al.’s study was wider than its predecessors, enrolling a total of 4,041 STEMI and multivessel CAD patients. All participants had non-culprit lesions with at least 70% stenosis of the vessel diameter or a fractional flow reserve value of 0.80 or less; they were randomized 1:1 to either complete revascularization with PCI or no further revascularization.

COMPLETE recruits were randomized within 72 hours of their index PCI procedure, and Mehta’s team stratified them according to the intended timing of non-culprit-lesion PCI. The authors considered a pair of coprimary outcomes during follow-up—a composite of CV death or MI; and a composite of CV death, MI or ischemia-driven revascularization.

At three years, 7.8% of patients randomized to complete revascularization and 10.5% of patients randomized to culprit-lesion-only PCI had experienced the first coprimary outcome. The second outcome occurred in 8.9% and 16.7% of participants, respectively. Mehta and colleagues noted the benefit of complete revascularization for both coprimary outcomes, regardless of the intended timing of non-culprit-lesion PCI.

In a related editorial, the University of Copenhagen’s Lars Kober, MD, and Thomas Engstrom, MD, said the team’s findings indicate complete revascularization can be safely postponed until after hospital discharge in some patients. The risk of bleeding, stroke and kidney injury were similar between groups, they said, proving the safety of an additional procedure.

“Comparing the COMPLETE trial with previous trials provides important information,” Kober and Engstrom wrote. “Although the patients in the COMPLETE trial had an age and sex distribution similar to that of the patients in the other trials, they had a lower yearly risk of the primary outcomes but still had more events than did the patients in all the other trials together, a finding that shows the importance of having properly sized trials with long-term follow-up.”

The editorialists said Mehta and colleagues’ study could be a game-changer, noting they hoped the authors would continue to collect longer-term follow-up data for further analysis.

“Regardless, in light of the results of the well-planned and well-executed trial by Mehta et al., the guidelines should recommend a strategy of full revascularization in patients with STEMI and multivessel disease, at least in those who have suitable non-culprit lesions,” they wrote.