Changes to clinical guidelines could be on the way for diabetic patients with multiple clogged coronary arteries, favoring a surgical procedure over a less invasive alternative and raising questions about the potential financial impact on hospitals that specialize in one or the other.
According to results of a large-scale, five-year randomized trial, diabetic patients who underwent coronary artery bypass grafting, also known as bypass surgery, fared considerably better than their counterparts who received percutaneous coronary intervention.
Also known as angioplasty, PCI is a non-surgical procedure used to open narrowed arteries to the heart, often through the use of tiny drug-coated stents made of metal mesh.
Bypass patients had fewer heart attacks and reduced rates of death from any cause compared with patients in the PCI group, according to the findings announced at the American Heart Association's recent Scientific Sessions meeting in Los Angeles. Combined five-year rates of heart attack, stroke and death from any cause were 18.7% in the bypass group but 26.6% among patients who underwent PCI.
Despite a higher initial price tag—more than $8,000 more than PCI—bypass surgery was more cost effective in the long run for patients with diabetes because of those improved patient outcomes and because PCI often requires multiple procedures over time, researchers said.
“Our results demonstrate that bypass surgery is not only beneficial from a clinical standpoint, but also economically attractive from the perspective of the U.S. healthcare system,” Elizabeth Magnuson, an author of the study and director of health economics and technology assessment at St. Luke's Mid-America Heart Institute, Kansas City, Mo., said in an American Heart Association news release.
The study marks the first time researchers have demonstrated a clear mortality benefit for CABG, said Dr. Michael Farkouh, associate professor of medicine at Mount Sinai School of Medicine, New York, and another of the study's authors.
“I believe that due to the strength and the robustness of these findings, there will be changes to the guidelines,” Farkouh said. “That's our hope. There's clearly a group of patients for whom bypass is superior.”
And that group is relatively sizable. Of the 700,000 patients who undergo some form of multivessel coronary revascularization each year, roughly a quarter—or 175,000—are diabetic, according to American Heart Association data cited in the study.
“The study does suggest a conversation with diabetic patients needs to include that research information,” said Dr. Jeff Snell, associate professor of medicine and director of interventional cardiology at Rush University Medical Center, Chicago. “Most patients would prefer angioplasty rather than surgery.”
If clinical guidelines are adjusted to account for the findings, hospitals could see a small drop in the volume of PCI procedures, Snell said, but those that have on-site cardiac surgery could also see a spike in their number of bypass surgeries. “That would actually be financially advantageous to hospitals,” he said.
Still, Snell said a change in the guidelines would probably not result in large numbers of patients undergoing CABG instead of PCI, particularly because diabetic status is already a factor considered in cardiologists' decision-making process.
This study is just the latest of many to compare outcomes associated with CABG with PCI. In April, an observational study in the New England Journal of Medicine that relied on claims data found improved outcomes among older patients with multivessel coronary artery disease who underwent bypass surgery.
And in guidelines released last November, the American Heart Association and the American College of Cardiology Foundation said CABG was superior to both PCI and medical therapy for most patients with three-vessel coronary artery disease.
But Farkouh was quick to point out that these latest findings cannot be generalized to non-diabetic patients. “For these specific patients—diabetics—the two procedures should not be presented as equal,” he said. “You have to provide them with that information ahead of time because most patients, if given the choice of having a stent and going home the next day or having their chest cut open, would choose PCI.”