Patients undergoing treatment to clear blocked arteries in the heart who have a moderate-to-high risk of a recurrence of the blockage appear to have a better outcome if they undergo heart bypass surgery rather than a less invasive procedure, according to new study findings.

Specifically, researchers found that after 1 year, patients with a moderate-to-high risk of blockage recurrence (restenosis), those who were treated with coronary artery bypass grafting (CABG) had better outcomes that those who underwent percutaneous coronary intervention (PCI).

CABG is an “open” surgical procedure that involves transplanting a blood vessel from elsewhere in the body onto the heart to reroute blood around blocked arteries. PCI typically involves angioplasty, in which a balloon-tipped catheter is snaked into a clogged heart artery to push aside blockages.

“These are the first data to demonstrate that a relatively simple risk stratification tool can identify patients who may preferentially benefit from CABG surgery compared with PCI,” Dr. John A. Spertus and colleagues report in Circulation: Journal of the American Heart Association.

Spertus’ group followed patients undergoing treatment to open blocked arteries in the heart at the Mid America Heart Institute in Kansas City, Missouri, between 1999 and 2000. Prior to the procedures, the patients were stratified according to their risk of restenosis.

The risk of restenosis was calculated using several factors such as diabetes, age, gender, and history of prior heart attack or other heart disease.

Health status outcomes, measured by angina frequency and quality of life, were determined in 1027 patients who underwent PCI and 432 who had CABG. The evaluation excluded patients who had a heart attack during the follow-up period, because PCI is known to be the preferred treatment for these patients.

Among the 37 percent of patients at low risk of restenosis, there were no significant differences between the PCI and CABG groups in the 1-year angina frequency or quality of life scores.

However, among the 47 percent in the intermediate risk group, significantly greater angina relief was achieved for those who underwent CABG surgery rather than PCI, and quality of life scores were significantly higher.

The magnitude of these differences was substantially larger among the 16 percent of patients in the high-risk group, the authors note.

Similar findings were observed when the authors restricted the analysis to the 676 in the PCI group and 410 in the CABG group who had blockages of more than one artery.

“This study suggests that patients with moderate-to-high risk of restenosis have better health status outcomes with CABG surgery and that it may be reasonable to preferentially consider surgical revascularization for these patients,” Spertus and his team state.

As physicians try to develop strategies for using expensive new technologies, such as drug-coated stents, a risk stratification approaches such as this one may be helpful determining the best use of these treatments, the group concludes.

SOURCE: Circulation, February 7, 2005.