Coronary artery bypass grafting (CABG) is preferred to percutaneous coronary intervention for patients with diabetes and coronary artery disease (CAD). But new research showed CABG outperformed PCI when focusing specifically on individuals with left ventricular dysfunction (LVD), a population that had been excluded in past studies.
The study—led by Jeevan Nagendran, MD, PhD, with the department of surgery at the University of Alberta in Alberta, Canada—was published online Feb. 19 in the Journal of the American College of Cardiology.
“[O]our finding that CABG is associated with better outcomes than PCI in patients with CAD, [diabetes] and LVD addresses a gap in the research,” Nagendran and colleagues wrote. “This study provides the first data to suggest that patients who have CAD, diabetes and LVD benefit from CABG, as it offers a long-term overall survival benefit, reduced risk for MI and repeat revascularization and no increased rate of stroke compared with PCI for this subgroup of patients.”
The team used the APPROACH (Alberta Provincial Project for Outcome Assessment in Coronary Heart Disease) database, which includes information on all patients undergoing coronary angiography in Alberta, Canada. A total of 2,837 patients were included in the study—1,556 who underwent PCI and 1,281 who underwent isolated CABG between Jan. 1, 2004, and March 31, 2016. Outcomes were measured over a 12-year span, with a mean follow-up of 5.5 years.
Researchers found in patients with an ejection fraction of 35 percent to 49 percent, the risk of a major adverse event was lower after CABG (28 percent) than PCI (51 percent).
For those with ejection fraction below 35 percent, the risk for a major event was 61 percent for PCI versus 29 percent for CABG.
Mortality rates for those in the PCI group were also higher than CABG patients. For those with 35 to 49 percent ejection fraction, the five-year mortality rate was 26 percent for PCI and 16 percent for CABG. For those with less than 35 percent ejection fraction, mortality was 35 percent for PCI and 19 percent for CABG.
“Apart from those patients who have prohibitive surgical risk or technical factors limiting surgical revascularization, CABG should be considered first-line therapy for the treatment of multivessel CAD in patients with diabetes and LVD,” wrote Nagendran et al.
In an accompanying editorial, Eric J. Velazquez, MD, with Duke University, and Mark C. Petrie, with the University of Glasgow in Scotland, emphasized the need for such research.
“Remarkably, there have been no randomized controlled trials (RCTs) (or even sufficiently powered subgroup analyses of trials) completed that can direct decisions regarding CABG or PCI among patients with diabetes, CAD and left ventricular systolic dysfunction,” they wrote.
But the pair warned altering standards of practice for these patients may be difficult—though releasing data like that collected in this study is an important first step.
“[T]here is increasing enthusiasm regarding the use of coordinated electronic heath data repositories akin to what Nagendran et al. used to track the complexity of care and critical outcomes across health systems, provinces, states or countries,” Velazquez and Petrie wrote. “Now imagine pragmatic RCT protocols of PCI versus CABG for LVSD embedded within this larger data landscape, and one can envision a day soon when patients and clinicians will be neither surprised nor, worse, disappointed regarding the decisions made in routine care.”