BARI 2D Study Favors Medication over Bypass Surgery for Diabetes Patients

A summary of the economic analysis of the BARI 2D trial was presented by Dr. Mark Hlatky (Stanford University, CA) at the American Heart Association (AHA)2009 Scientific Sessions on November 17 and simultaneously published online in Circulation. As previously reported, the 2,368 patient BARI 2D study showed that PCI, bypass surgery, and optimal medical therapy led to similar survival rates in patients with Type 2 diabetes and stable ischemic heart disease, but CABG reduced the risk of cardiovascular events, primarily nonfatal MI, more than intensive medical management, while the risks were similar in patients treated with PCI or medical management.

In BARI 2D, patients with Type 2 diabetes and stable ischemic heart disease were randomly assigned to early revascularization plus intensive medical therapy or intensive medical therapy alone. For patients randomized to revascularization, the treating physician decided whether PCI or CABG was more appropriate. The drug treatments were also randomly assigned: either insulin-provision therapy -- an insulin secretagogue or insulin -- or insulin-sensitization therapy.

After two years, patients treated with insulin-sensitivity drugs had higher costs than those treated with insulin-provision therapy ($43,295 vs. $42,246), mainly because the insulin-sensitivity drug thiazolidinedione (TZD) is so expensive.

A five-year analysis shows that cost differences were driven mainly by the up-front costs of the PCI or CABG. The cost for patients assigned to prompt PCI was $46,890 compared with $33,354 for medical therapy alone. Patients treated with surgery had a two-year cost of $55,966 compared with $34,096 for comparable patients treated with medical management. The cost comparisons remained unchanged over the four years of follow-up.

Therefore, Hlatky et al conclude that the best strategy in Type 2 diabetics with stable coronary disease that is identified as suitable for PCI is to start with medical therapy and resort to revascularization only if the patient's quality of life is not satisfactory.

Hlatky stated that, "Prompt CABG may be the cost-effective way to go in patients with more severe disease who are willing to accept the periprocedural risks." He and his colleagues conducted a "bootstrapping analysis" whereby they statistically simulated 1,000 decisions of CABG vs. medical therapy based on the study results and cost data and found that CABG was favored in 56% of the simulations. "So it must be considered just suggestive rather than conclusive."

Dr. Bernard Chaitman (St. Louis University, MO) presented stats that showed the cost-effectiveness analysis appears to complement an analysis of BARI 2D cardiac death and MI data, presented at the same AHA session and also published online in Circulation. This analysis showed that in the BARI 2D population, the type of patients who were assigned to PCI are best served by intensive medical therapy.

In patients who were enrolled in the CABG stratum of BARI 2D -- with more extensive coronary disease -- prompt CABG, in the absence of contraindications, intensive medical therapy, and insulin sensitization, appears to be the best way to reduce the risk of MI, Chaitman reported.

Overall, five-year cardiac death rates were similar in the patients getting medical therapy or revascularization (5.7% vs. 5.9%). Among the 763 patients with more extensive disease deemed suitable for bypass surgery, MI and death (10%) or MI (21.1%) were much less common after prompt surgery than medical therapy alone (17.6% and 29.2%, respectively). However, all of this benefit was seen in the patients taking insulin-sensitizing drugs, he reported.

Dr. Maria Brooks (University of Pittsburgh, PA) presented a quality-of-life analysis of BARI 2D, which assessed patients' energy, distress about their health, and their own rating of their health.

The study found that patients in all of the treatment groups reported improvements in their health-related quality of life a year after beginning treatment. Patients who underwent CABG or PCI reported bigger improvements in activity, energy, and self-reported quality of life.

Dr. Robert Chilton stated that, "As both a diabetologist and cardiologist, data from the BARI 2D substudies confirm what I see in my everyday practice: diabetes patients with extensive coronary disease who significantly benefit from revascularization in that they have fewer heart attacks and improved quality of life."

Hlatky M, Boothroyd D, Melsop K, et al. Economic outcomes of treatment strategies for Type 2 diabetes mellitus and coronary artery disease in the bypass angioplasty revascularization investigation 2 diabetes trial. Circulation 2009; DOI:10.1161/CIRCULATIONAHA.109.912709.

Chaitman B, Hardison R, Adler D, et al. The bypass angioplasty revascularization investigation 2 diabetes randomized trial of different treatment strategies in Type 2 diabetes mellitus with stable ischemic heart disease. Circulation 2009; DOI:10.1161/circulationaha.109.913111.