In sharp contrast to earlier studies, patients with severe triple-vessel heart disease fared equally well whether they underwent open-heart bypass surgery (CABG) or a less invasive procedure called PCI (percutaneous coronary intervention) at five years of follow-up, according to research presented at the American College of Cardiology’s Annual Scientific Session (ACC.25).

Patients enrolled in the study, known as FAME-3, had triple-vessel heart disease, a severe form of heart disease in which three of the major arteries that supply blood to the heart become inflamed or partially blocked by cholesterol deposits, causing chest pain and shortness of breath and often leading to a heart attack. An estimated 68 million people in the United States will develop triple-vessel heart disease during their lifetime, the majority of whom are men.

“This is the only study to compare CABG and PCI as they are currently used in cardiology––incorporating recent advances in surgical and minimally invasive techniques as well as in medical therapy––in patients with triple-vessel disease,” said William F. Fearon, MD, chief of interventional cardiology at Stanford University School of Medicine in Stanford, California, and the study’s principal investigator. “At five years after random assignment to either PCI or CABG, we found no significant differences between the two groups in the primary endpoint—a composite of death, stroke or heart attack.”

Studies published in or before 2015 found that patients with triple-vessel disease were less likely to die or have a heart attack or stroke after undergoing CABG, in which blood vessels from elsewhere in the body are used to bypass the blocked coronary arteries, compared with PCI, a less-invasive procedure that involves placing tiny metal tubes called stents into the partially blocked arteries to prop them open.

CABG is open-heart surgery in which, in most cases, the heart is stopped, and a heart-lung machine takes over pumping blood to the body. It can involve a hospital stay of several days followed by weeks or months of recovery. PCI, by contrast, is not a major surgery and can in some cases be performed as an outpatient procedure. Patients often can resume normal activities a week after PCI.

“The way these procedures are performed has evolved significantly in the past decade,” Fearon said. “Our aim in doing this study was to determine whether, given all of the advances that have occurred, PCI would perform more similarly to CABG in patients with triple-vessel disease.”

Fearon said techniques for performing CABG have improved, as has patient management before, during and after surgery. In PCI, next-generation drug-eluting stents––stents coated in medication––have been shown to result in fewer repeat procedures and fewer complications such as the development of blood clots in the stent.

Additionally, new techniques to improve lesion selection, such as fractional flow reserve (FFR) guidance, which measures pressure gradients in partially blocked vessels, as well as medical therapy, have improved PCI outcomes, he said.

The FAME-3 trial enrolled 1,500 patients in North America, Europe, Asia and Australia. The patients’ average age was 65, 82% were men—reflecting the disease’s predominance in men, Fearon said—and 93% were White. To be eligible for the study, patients had to have blockages of at least 50% in three of the major arteries supplying blood to the heart, but no blockages in the left main coronary artery.

Nearly 4 in 10 of the enrolled patients had been hospitalized with a heart attack (although patients with the most severe type of heart attack were excluded) or unstable angina (chest pain due to an unstable coronary artery blockage that can lead to a heart attack). Nearly 1 in 5 had heart failure with reduced ejection fraction, a condition in which less than half of the blood in the heart’s main pumping chamber is pumped out with each heartbeat; 29% had Type 1 or Type 2 diabetes.

Patients were randomly assigned to one of two treatment groups. Those assigned to CABG underwent bypass surgery. Those assigned to the second group first had FFR measured; only narrowed arteries with an FFR score of 0.8 or less underwent PCI to place a drug-eluting stent. After the procedure, these patients also took two medications for at least six months to reduce the risk of a heart attack, stroke or blood clot. Blockages with FFR scores above 0.8 did not undergo PCI but were treated with medicine. All patients enrolled in the study received guideline-recommended medical treatment for their heart disease, including aspirin, statins and other medicines as needed.

All patients were followed in the hospital and at 30 days, six months, and one, two, three and five years after treatment. For the one-year follow-up, the study’s primary endpoint was a composite of death from any cause, stroke, heart attack or need for a repeat procedure. For the three- and five-year follow-ups, the primary endpoint was a composite of death from any cause, stroke or heart attack. The trial was designed to determine, at one year of follow-up and with over 90% probability, the non-inferiority of PCI, compared with CABG, on meeting the study’s primary endpoint.

At the one-year analysis, PCI did not meet the preset criterion for non-inferiority compared with CABG. At three years, no significant differences were observed between the two groups for the composite endpoint of death from any cause, stroke or heart attack.

Almost 95% of patients completed five years of follow-up. At the five-year analysis, more than 90% of patients in both treatment groups were taking an antiplatelet medication to prevent blood clots. A similar percentage were taking a statin to reduce blood levels of “bad” cholesterol. In addition, more than 70% were taking a beta blocker to control irregular heart rhythms and blood pressure and a similar percentage were taking a medication to reduce strain on the heart by lowering blood pressure and prevent or manage heart failure or kidney disease.

No significant difference was seen between patients assigned to PCI or CABG on the composite endpoint. When each component of the composite endpoint was analyzed separately, death rates were identical in the two groups (7.2%) and rates of stroke (PCI, 1.9%; CABG, 3%) were not significantly different. However, more heart attacks occurred in patients assigned to PCI (8.2%) compared with CABG (5.3%). Patients treated with PCI also needed more repeat procedures than those treated with CABG (15.6% vs. 7.8% ).

“In previous studies, the difference in outcomes for patients with three-vessel disease favoring those treated with CABG continued to widen over time,” Fearon said. “But in FAME-3 we did not see that. At five years, there were no statistically significant differences between the two groups in the composite endpoint of death, stroke or heart attack and the absolute difference was similar to what we saw at three years.”

These findings support better-informed shared decision-making between patients and their clinicians, Fearon said.

A possible limitation of the study is that only 12% of patients treated with PCI received intravascular ultrasound, an imaging technique that uses sound waves to view plaque buildup inside arteries, Fearon said.

Fearon and his colleagues are currently working on a cost-effectiveness analysis of the FAME-3 five-year data. In addition, he said, “We hope these findings will spur continued research on subgroups such as women and non-White patients, who were not highly represented in FAME-3.”

The study was funded by research grants to Stanford University from Medtronic, Inc., which makes the drug-eluting stent used in the study, and Abbott Vascular, Inc., which makes the FFR measurement device used.

This study was simultaneously published online in The Lancet at the time of presentation.

ACC.25 will take place March 29-31, 2025, in Chicago, bringing together cardiologists and cardiovascular specialists from around the world to share the newest discoveries in treatment and prevention. Follow @ACCinTouch, @ACCMediaCenter and #ACC25 for the latest news from the meeting.

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