Heart patients with more than one clogged artery benefit most from bypass surgery when compared to drug-coated stents, according to a recent study.

The new research puts a damper on hopes the less invasive stent procedure would prove to be just as good for people with multiple blockages.

In the study, heart attack and death rates were lower among people who had surgery than those given artery-opening balloon angioplasty and stents -- mesh cylinders dripping drugs to keep vessels from reclogging.

It is latest setback for drug-coated stents, which have revolutionized heart care and have been implanted in about 6 million people worldwide. They are far better at keeping vessels open than older bare metal stents. However, sales have been hurt in the past year by safety concerns and studies questioning the value of angioplasty itself for certain patients.

A second study gave stent makers some good news, finding that using these devices "off label," in non-approved situations, is not as dangerous as many had feared.

Both studies were published in Thursday's New England Journal of Medicine. Neither is definitive enough to resolve these issues, but they help guide doctors and patients confused about which treatment is best for whom.

The bypass study is "a sobering reality check" for people hoping that the newer drug-coated stents "would level the playing field" and make these treatments equally effective, Harvard University cardiologist Dr. Joseph Carrozza wrote in an accompanying editorial.

Bypass surgery has become less common as angioplasty has risen dramatically. In 2005, about 469,000 bypasses were performed on 261,000 patients. More than 1.2 million angioplasties were done, though many people had more than one procedure.

(Xinhua News Agency January 25, 2008)