1. Home>
2. Specialties>
3. Cardiology>
4. Summary and Comment

Treating Diabetes and Coronary Artery Disease

Prompt revascularization or initial medical therapy? Insulin sensitization or provision? From the BARI 2D trial, no strategy emerged a clear winner.

The international Bypass Angioplasty Revascularization Investigation 2 Diabetes (BARI 2D) trial involved 2368 patients (51% of those screened, 70% men) with type 2 diabetes and coronary artery disease. Participants were randomized to receive either prompt revascularization or medical therapy alone for CAD, and either insulin provision (with insulin or a sulfonylurea) or insulin sensitization (mostly with metformin or rosiglitazone) to a target glycosylated hemoglobin (HbA_1c) level of <7%. All patients had angina and 70% stenosis of a major epicardial artery or 50% stenosis plus a positive stress test result. Before randomization, patients were judged by their physicians to be best suited for either coronary artery bypass grafting or percutaneous coronary intervention. The primary endpoint was all-cause mortality, and the main secondary endpoint was a composite of cardiovascular events (death, MI, and stroke).

At baseline, the average patient age was 64, 82% had symptomatic ischemia, mean LV ejection fraction was 57%, 31% had 3-vessel disease, and mean duration of diabetes was 10.4 years. During an average follow-up of 5.3 years, mortality did not differ significantly among any of the treatment-strategy groups. The 5-year survival rate was 88.3% in the revascularization group, 87.8% in the medical-therapy group, 88.2% in the insulin-sensitization group, and 87.9% in the insulin group. The proportion of patients free of major cardiovascular events was also similar in all of the treatment groups.

Compared with medical therapy, neither revascularization method was associated with a mortality benefit. With regard to cardiovascular events, no difference was seen between the PCI and medical-therapy groups, but a significant difference favoring revascularization was found between the CABG and medical-therapy groups (5-year event-free survival, 77.6% vs. 69.5%; P=0.01).

Comment: These results fail to demonstrate a firm advantage of revascularization over medical therapy in diabetic patients with CAD; the single favorable finding of fewer cardiovascular events in the CABG group is suggestive but not definitive. The findings reinforce those of the COURAGE trial, which supported medical therapy as a reasonable initial approach in these patients (JW Cardiol Mar 26 2007. In addition, the results suggest that insulin-sensitizing drugs confer no advantage in these patients.

— Harlan M. Krumholz, MD, SM

Published in Journal Watch Cardiology June 10, 2009

Citation(s):

Frye RL et al. for the BARI 2D Study Group. A randomized trial of therapies for type 2 diabetes and coronary artery disease. N Engl J Med 2009 Jun 11; 360:2503.

• Original article (Subscription may be required)
• Medline abstract (Free)

Boden WE and Taggart DP. Diabetes with coronary disease — A moving target amid evolving therapies? N Engl J Med 2009 Jun 11; 360:2570.

• Original article (Subscription may be required)
• Medline abstract (Free)