New data from a long-term study comparing newer beating-heart (off-pump) bypass with traditional on-pump bypass surgery show the two procedures are equally safe and effective, according to an article in the November 23rd issue of Circulation.

“Our data show that operating on a beating heart is as safe and effective as the traditional method of placing patients on a heart-lung machine during surgery,” said lead study author Petr Widimsky, MD, DrSc.

The current study, known as PRAGUE-4, does not prove that one method is better than the other - just that the surgeon and his or her patient now have two equally effective options, Widimsky said. “The decision of which option to choose should be made on an individual basis and depends on a number of factors, such as age, how sick the patient is, and co-existing illnesses.”

He added, “Until now, we did not have a long-term study directly comparing the newer off-pump method with classic on-pump surgery, so we did not really know which was best.”

Many of the complications after bypass surgery occur when the bypass graft develops restenosis, Widimsky said. The goal of the current study was to investigate how bypass grafts done on the beating heart keep their function after one year. In the study, 400 patients with restenosis were randomly assigned to on-pump or off-pump surgery.

One year later, doctors examined all the patients’ grafts using coronary angiography. The two methods were equally effective, with restenosis in only 9 percent of patients in both groups. Restenosis of leg bypass grafts did not vary significantly between the groups - 41 percent in the on-pump group versus 51 percent in the off-pump group.

“The higher rates [of leg graft restenosis] most likely reflect the fact that the patients in the study had extensive, advanced disease, as is the case in the current era of prevailing coronary stenting, when only patients with very advanced disease are referred to bypass graft surgery,” Widimsky added.

A previous analysis of PRAGUE-4 data showed that 30 days after the procedure, death, myocardial infarction, stroke, and severe kidney disease rates were also basically equivalent between the two groups: 2.9 percent in the on-pump group versus 3.8 percent in the off-pump group, Widimsky said.

“We believe this study will have two big implications,” he concluded. “First, off-pump bypass surgery is used in about one-quarter of patients nationwide, but that number will increase steadily. Secondly, the problem of venous bypass graft restenosis is currently more frequent than in older studies due to the changed spectrum of cardiac surgery patients - who are older with more extensive coronary artery narrowing and calcification.”