CHICAGO -(Dow Jones)- Using stents to prop open a key artery that fuels the heart's main pumping chamber was associated with a similar positive impact on patient survival as more invasive bypass surgery, which is the typical treatment for such cases, according to a study released Monday.

Patients with stents in the study were more likely to need another procedure down the road, however. Researchers pointed to the need for a more rigorous clinical trial, beyond this observational, three-year study, to explore the stents-verses-bypass question for these patients. The new study is set for presentation Monday during the Society for Cardiovascular Angiography and Interventions annual meeting, which is being held alongside the American College of Cardiology's conference this year.

The new study, called Main-Compare and based on patient data from 12 centers in Korea, is also being published in the New England Journal of Medicine. An editorial in NEJM said the Korean study "supports, but does not eliminate," the need for a randomized trial.

Stents are tiny metal devices commonly used in angioplasty procedures to prop open clogged heart arteries without the need for major surgery. But stents are not viewed as the best option when the blood vessel in question is the left main coronary artery, except when patients had a prior bypass operation to reroute blood elsewhere.

The Korean study included data on 2,240 patients with left main coronary disease, and without the protection of a prior bypass, who were followed for three years. The study's goal was to track rates of death, and also a composite measure of major events. Patients first enrolled in the study only received bare-metal stents, but received coated stents after they reached the market, and coated stents ended up being the more commonly used device in the study. Such devices use medication to battle renarrowing.

The study found that after three years, the rates of death did not differ significantly for patients with stents or bypass surgery. The composite rate measuring major events was also similar between bare-metal stent patients and bypass patients. Coated-stent patients leaned toward a higher rate of major events than bypass patients, but not to a degree that was considered significant.

The study evaluated patients who had surgery or received stents over a more than six-year period.

"Because the recommendation for surgery for left main disease is based mostly on survival benefit, the lack of a statistically significant difference in mortality may support PCI as an alternative option to bypass surgery," Seung- Jung Park, a study researcher and director of interventional cardiology at Asan Medical Center in Seoul, said in an SCAI release. PCI refers to the type of procedure used to implant stents.

Researchers also concluded that the rates of retreatment were higher among patients with stents than with bypass surgery, particularly bare-metal stents, which triggered nearly 11 times the retreatment rate as bypass surgery. Park noted, though, that patients can be treated again with stents without significant increase in death or serious complications.

The Main-Compare study was sponsored by the Korean Society of Interventional Cardiology and the Cardiovascular Research Foundation, Seoul. Researchers involved in the study have received grants, research fees and lecture fees from the major stent makers, which are Boston Scientific Corp. (BSX), Johnston & Johnson (JNJ), Medtronic Inc. (MDT) and Abbott Laboratories Inc. (ABT).

In the NEJM editorial Robert Jones, a professor of Cardiothoracic Surgery at Duke University Medical Center, pointed to several factors that could skew the study's results, including the fact that survival rates among stent patients improved after coated stents were introduced. Jones credited experience gained among operators during stenting procedures, which became more frequent when coated stents were introduced.

The study did highlight ways in which a randomized trial comparing stents and bypass for this type of disease could be designed, Jones said.

-By Jon Kamp, Dow Jones Newswires; 312-750-4129; jon.kamp@dowjones.com

  (END) Dow Jones Newswires
  03-31-08 0915ET
  Copyright (c) 2008 Dow Jones & Company, Inc.