INDIANAPOLIS, IN – A new study from the Roudebush VAMC in Indianapolis suggests survival rates are better when diabetes patients with multivessel coronary artery disease receive coronary artery bypass graft (CABG) surgery as opposed to angioplasty, even when the most current drug-eluting stents (DES) are used.1
Results are not conclusive, however, because the study was stopped due to slow recruitment; only 25% of the intended sample size was recruited, leaving it severely underpowered for the primary endpoint.
Stephen G. Ellis, MD, of the Cleveland Clinic, questions in an accompanying editorial why the study could not be completed.2
“Why, particularly when the VA system has contributed many important randomized trials in the field of CAD, could the VA system not complete such an important study?” Ellis asked.
The study, led by Masoor Kamalesh, MD, of the Indianapolis VAMC, was reported in a February issue of the Journal of the American College of Cardiology.
While the results are in line with the Future Revascularization Evaluation in Patients with Diabetes Mellitus: Optimal Management of Multivessel Disease (FREEDOM) trial, presented last year, the new study compared contemporary surgical techniques with later-generation DES.
The Coronary Artery Revascularization in Diabetes (VA CARDS) study was a prospective, multicenter effort conducted at VAMCs between 2006 and 2010. Researchers randomly assigned 198 eligible patients with diabetes with severe coronary artery disease to either CABG (97 patients) or percutaneous coronary intervention (PCI) with DES (101 patients). All commercially available and approved DES were allowed in the study.
Patients were followed for at least two years, with the primary outcome measure being a nonfatal myocardial infarction (MI) or death. Secondary-outcome measures included all-cause mortality, cardiac mortality, nonfatal MI and stroke.
The report notes that all-cause mortality was 5% for CABG and 21% for PCI (hazard ratio, 0.30; 95% CI, 0.11-0.80). The risk for nonfatal MI, meanwhile, was 15% for CABG and 6.2% for PCI (hazard ratio, 3.32; 95% CI, 1.07-10.30).
“This study was severely underpowered for its primary endpoint, and therefore no firm conclusions about the comparative effectiveness of CABG and PCI are possible,” the authors concluded. “There were interesting differences in the components of the primary endpoint. However, the confidence intervals are very large, and the findings must be viewed as hypothesis generating only.”
Combined with previous studies, however, Ellis suggested the findings offer some treatment guidance.
“On the basis of the current body of evidence, CABG should be preferred over PCI in patients with diabetes and multivessel disease with complex anatomy exemplified by SYNTAX scores >22 and perhaps even all patients with diabetes with multivessel disease,” he wrote, suggesting that further data are needed “regarding the important interaction between lesion number and complexity and clinical outcomes” with the two approaches.
1. Kamalesh M, Sharp TG, Tang XC, Shunk K, Ward HB, Walsh J, King S 3rd, Colling C, Moritz T, Stroupe K, Reda D; VA CARDS Investigators. Percutaneous coronary intervention versus coronary bypass surgery in United States veterans with diabetes. J Am Coll Cardiol. 2013 Feb 26;61(8):808-16. doi: 10.1016/j.jacc.2012.11.044. PubMed PMID: 23428214.
2.Ellis SG. Coronary revascularization for patients with diabetes: updated data favor coronary artery bypass grafting. J Am Coll Cardiol. 2013 Feb26;61(8):817-9. doi: 10.1016/j.jacc.2012.12.003. PubMed PMID: 23428215.