LOS ANGELES, CA—For patients with diabetes and advanced coronary artery disease (CAD), coronary artery bypass graft (CABG) surgery is superior to percutaneous coronary intervention (PCI) over the long-term. The results, presented Sunday, November 4, 2012, at the American Heart Association Scientific Sessions, show that CABG substantially reduces the risk of death and myocardial infarction, though it increases the risk of stroke.

The findings were published simultaneously online in the New England Journal of Medicine.

For the FREEDOM (Future Revascularization Evaluation in Patients with Diabetes Mellitus: Optimal Management of Multivessel Disease) trial, Valentin Fuster, MD, PhD, of Mount Sinai School of Medicine (New York, NY), and colleagues randomized 1,900 patients with diabetes and multivessel CAD to undergo either PCI with DES (n = 953) or CABG (n = 947) at 140 international centers. Intravenous abciximab was given to PCI patients during the procedure and clopidogrel and aspirin were prescribed for at least 12 months.

CABG Safer than PCI

At 5 years, the primary composite endpoint of death, stroke, and MI occurred more often in patients treated with PCI. However, while the individual endpoints of all-cause mortality and MI were lower in the CABG cohort, the stroke rate was higher (table 1).

Table 1. Five-Year Clinical Outcomes

Rates of cardiac death and major adverse cardiovascular and cerebrovascular events (MACCE) did not differ between the study arms at 30 days, but by 1 year MACCE was higher in the PCI group compared with CABG (16.8% vs. 11.8%; P = 0.004). This difference was largely attributable to the preponderance of repeat revascularization events at 1 year in the PCI group compared with the CABG group (12.6% vs. 4.8%; HR 2.74; 95% CI 1.91-3.89; P < 0.001).

CABG proved more beneficial than PCI in all prespecified subgroups, and at 5 years the absolute difference in the rate of the primary outcome between the treatment strategies was similar regardless of Syntax score.

A major bleeding event occurred within 30 days after the index procedure in 23 patients treated with PCI and 34 treated with CABG (P = 0.13). Also, acute renal failure requiring hemodialysis within 30 days after index revascularization was observed in 1 patient treated in the PCI group and 8 patients in the CABG group (P = 0.02).

A Controversy ‘Settled’

“CABG is the preferred method of revascularization for patients with diabetes and multi-vessel disease,” Dr. Fuster said.

In an accompanying editorial, Mark A. Hlatky, MD, of Stanford University School of Medicine (Stanford, CA), agreed, saying the trial “provides compelling evidence of the comparative effectiveness of CABG versus PCI” in this patient group.

Because of the ongoing debate regarding which treatment option to use, he highlighted the importance of such a large, randomized trial in diabetic patients with multivessel disease. “The controversy should finally be settled,” Dr. Hlatky said.

Still, he emphasized the need for optimally educating this patient group about treatment options. “The results of the FREEDOM trial suggest that patients with diabetes ought to be informed about the potential survival benefit from CABG for the treatment of multivessel disease,” Dr. Hlatky concluded. “These discussions should begin before coronary angiography in order to provide enough time for the patient to digest the information, discuss it with family members and members of the heart team, and come to an informed decision.”

Practice Changing Results

Commenting on the trial, Alice K. Jacobs, MD, of Boston University Medical Center (Boston, MA), said the results “add to the consistent evidence base supporting CABG as the preferred strategy for patients with diabetes and multivessel CAD. However, it will be important to determine whether the relationship between the primary endpoint curves is maintained with longer follow-up as the saphenous vein bypass grafts begin to fail.”

The results have the “potential to change clinical practice,” she continued, but it remains unclear if the continued evolution of DES will “diminish the advantage of CABG.” This appears “less likely,” she added, “if CABG protects the myocardium against new disease.”

FREEDOM’s findings are in line with current guideline recommendations, Dr. Jacobs concluded. However, whether or not the new data “will inform a class 1 guideline recommendation perhaps in patients with triple-vessel disease and complex disease will no doubt be the subject of ongoing debate.”

Study Details

Patients were enrolled from April 2005 to April 2010 and had a mean age of 63. Overall, 29% of patients were women and 83% had 3-vessel disease.

Note: Co-author George D. Dangas, MD, PhD, is a faculty member of the Cardiovascular Research Foundation, which owns and operates TCTMD.

Sources:
1. Farkouh ME, Domanski M, Sleeper LA, et al. Strategies for multivessel revascularization in patients with diabetes. N Engl J Med. Epub ahead of print.

2. Hlatky MA. Compelling evidence for coronary-bypass surgery in patients with diabetes. N Engl J Med. Epub ahead of print.

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