TUESDAY, May 3 (HealthDay News) -- The number of heart patients getting bypass surgery fell by nearly 40 percent between 2001 and 2008, new U.S. research finds.

The drop likely reflects several factors, including a decline in smoking rates, which has led to less coronary artery disease, said senior study author Dr. Peter Groeneveld, an assistant professor of medicine at the University of Pennsylvania School of Medicine.

Also, better and more aggressive treatment of coronary artery disease risk factors, such as high blood pressure, high cholesterol and diabetes, means fewer patients progress to needing surgery.

Another factor is that many patients with blocked arteries instead undergo percutaneous coronary intervention (PCI), also called balloon angioplasty, in which a doctor threads a catheter into the artery and inflates a balloon at the tip. Usually, a wire mesh structure called a stent is left behind to prevent the artery from narrowing again.

Though PCI is an excellent option for many patients, researchers stressed that bypass surgery -- officially called coronary artery bypass graft, or CABG -- may be the best option for some patients with certain severe blockages, including those with triple blockages or left main coronary artery stenosis, Groeneveld said.

"Patients need to be aware that CABG can be a good treatment option, and it's gotten better," Groeneveld said. "There have been several innovations that have made the recovery time much less than it used to be." In CABG, a new artery or vein is grafted, or connected, to the blocked artery to restore blood flow.

The study is published in the May 4 issue of the Journal of the American Medical Association.

Groeneveld and his colleagues analyzed data on a national sample of patients who underwent procedures to clear blockages at U.S. hospitals between 2001 and 2008. Most of the procedures were scheduled, though some were for emergency situations such as heart attacks.

During that period, there was a 15 percent overall decrease in procedures to clear coronary blockages, the investigators found.

Most of that reduction was because of a decline in annual CABG surgeries, which dropped by 38 percent. PCI, in contrast, held mostly steady with a 4 percent dip.

When the figures were projected to the entire U.S. population, there were an estimated 130,000 fewer CABG surgeries in 2008 compared with 2001, according to the study.

Dr. Debabrata Mukherjee, chief of cardiology at Texas Tech University Health Sciences Center, said even though PCI popularity has risen (the number of hospitals offering PCI increased by 26 percent during the study period, compared to about 12 percent for CABG), technological advances have made fewer PCI surgeries necessary.

In 2003, the U.S. Food and Drug Administration approved drug-eluting stents, which come with an immunosuppressant coating that helps prevent scarring and inflammation around the stent. The improved stents, which were in widespread use by 2005, reduced the need for redoing procedures because of scarring, Mukherjee said.

Prior to the innovation, about one-third of PCI patients needed a re-do within six months, he said. "Now, 5 percent, maybe 10 percent at most, need to come back," he said. "There has been a marked decrease in repeat procedures. So even as cardiologists are taking on more complex, multi-vessel cases, the overall volume of PCI hasn't gone up."

Groeneveld raised another possibility for the decline in CABG: Interventional cardiologists can do PCI, while only cardiac surgeons do bypass surgery.

Since most people see a cardiologist who would refer them to a cardiac surgeon if necessary, it's possible some patients who might be better off getting bypass surgery are being offered PCI instead, Groeneveld said.

"My hunch is cardiologists are referring fewer [patients] onto surgeons and treating more with interventional cardiology," he said. "The worry is there are patients who really who should be getting CABG that aren't getting it."

While bypass procedures used to involve cutting through the chest, technological advances now allow surgeons to do the procedure much less invasively. Innovations include doing the surgery through a small incision and using fiber-optic cameras, or even robotic surgery.

Despite the improvements, it's possible old perceptions die hard. Given the choice between doing PCI on the spot or waiting to see a surgeon and getting bypass surgery that comes with a longer recovery time, many patients may opt for the PCI, Groeneveld said.

"Patients are sometimes put in positions to make decisions while lying on a cath lab table with a cardiologist leaning over them," Groeneveld said, referring to the catheterization lab, where cardiologists perform PCIs.

"Patients should be made aware that there are alternatives to PCI, and those conversations about whether PCI is the right thing should be happening before the patient goes into the cath lab," he added.

More information

The American Heart Association has more on heart attack risk factors.