Practice Changer: CABG Bests Multivessel Stenting in Diabetes

LOS ANGELES – Patients with diabetes who had revascularization for multivessel coronary artery disease fared significantly better with coronary artery bypass grafting than with percutaneous coronary intervention using drug-eluting stents in the landmark FREEDOM trial.

FREEDOM (Future Revascularization Evaluation in Patients With Diabetes Mellitus: Optimal Management of Multivessel Disease) was an international randomized trial involving 1,900 subjects who were considered candidates for both CABG and PCI. The primary outcome – a composite of 5-year all-cause mortality and nonfatal MI or stroke – occurred in 26.6% of the PCI group, compared with 18.7% of the CABG group. That’s a 7.9% absolute reduction and 30% lower relative risk. The CABG advantage held up regardless of SYNTAX score, a measure of disease extent.

^{Bruce Jancin/IMNG Medical Media}

Dr. Valentin Fuster

"The results are clear. I think this is going to change practice," FREEDOM chair Dr. Valentin Fuster predicted in presenting the study’s main findings at the conference.

Participants in the CABG group had a 5-year mortality of 10.9%, compared with 16.3% in the PCI group. Their nonfatal MI rate was less than half of that in the PCI group: 6.0% vs. 13.9%.

The CABG group’s 5.2% nonfatal stroke rate was significantly higher than the 2.4% rate in the PCI group. However, the excess of strokes in the CABG group was confined to the first 30 days post procedure; after that, stroke rates in the two groups didn’t differ significantly. Only 13% of strokes were hemorrhagic. The majority of strokes occurred more than 1 year post procedure, according to Dr. Fuster, professor of medicine and director of the cardiovascular institute at Mount Sinai Medical Center, New York.

The repeat revascularization rate after 1 year of follow-up was 13% in the PCI group and 5% in CABG-treated patients. At 5 years, repeat revascularization had occurred in 30% of the PCI group, compared with 13% in the CABG group.

Thirteen percent of FREEDOM participants had two-vessel disease, and the rest had triple-vessel disease. Outcomes in both groups were superior with CABG.

The CABG and PCI groups didn’t differ significantly in 30-day rates of major bleeding or acute renal failure.

Dr. David O. Williams

Seventeen years ago, the National Heart, Lung, and Blood Institute issued a clinical alert recommending CABG over PCI for patients with diabetes on the strength of the results of BARI, the Bypass Angioplasty Revascularization Investigation (N. Engl. J. Med. 1996;335:217-25) Yet, PCI has since become increasingly popular in diabetes patients.

Many interventional cardiologists have dismissed the results of BARI and other smaller studies favoring CABG as irrelevant in the contemporary era of much-improved PCI techniques and drug-eluting stents, even though the current joint AHA/American College of Cardiology/Society for Coronary Angiography and Interventions guidelines state as a class IIa recommendation that "it is reasonable" to choose CABG with left internal mammary artery grafting over PCI in diabetic patients with multivessel disease.

FREEDOM discussant and interventional cardiologist Dr. David O. Williams said that this new study should put an end to the controversy. He predicted the guidelines will be revised to raise CABG from a class IIa recommendation to class I.

"The study is very convincing, and I think the guidelines will eventually come down very strongly on this. And so will payers, by the way – and that’s another group that can exert influence," observed Dr. Williams of Brigham and Women’s Hospital, Boston.

Another discussant, Dr. Alice K. Jacobs, also an interventional cardiologist, said she was impressed by the FREEDOM finding that CABG was superior in all patient subgroups, even in patients with normal left ventricular function.

Dr. Alice K. Jacobs

"Certainly it has been the case that if you had reduced left ventricular function, the needle would swing toward CABG, but now even with normal left ventricular function, patients fare better. That needs to be recognized," said Dr. Jacobs, professor of medicine at Boston University.

"With a diabetic patient who is a candidate for either procedure, one would have to think long and hard about performing PCI at this point," she added.

Interventional cardiologist Dr. Gilles Montalescot of Pitie-Salpétrière University Hospital, Paris, found the demonstrated mortality benefit for CABG in FREEDOM compelling.

"This signal cannot be ignored. There has been some reluctance on the part of interventional cardiologists to send patients who have diabetes to the [operating room] for CABG. We should use these FREEDOM data to convince our colleagues that the way to go is to send our patients for surgery, whatever their SYNTAX score. But I think often the patients, too, have been reluctant to go to the OR," he said.