Medtronic Resolute stent matches Abbott's in study

* Both stents deemed safe, effective in high-risk patients

* 8.2 pct event rate for Resolute vs 8.3 pct for Xience

* Resolute stent has higher rate of blood clot formation

By Susan Kelly

CHICAGO, May 25 (Reuters) - Medtronic Inc's (MDT.N) new Resolute drug-coated stent led to a similar number of deaths, heart attacks and repeat procedures as Abbott Laboratories' (ABT.N) market-leading Xience stent in a large head-to-head study of high-risk patients.

Both stents were found to be safe and effective, and researchers characterized the rate of adverse events -- 8.2 percent for Resolute and 8.3 percent for Xience -- as relatively low. The study met its main goal of demonstrating the Resolute stent's "non-inferiority" to Xience, researchers said.

Stents are wire mesh tubes inserted into arteries to prop them open after they have been cleared of blockages. The drug coating helps prevent the diseased artery from reclogging.

The European study of 2,292 patients, presented Tuesday at a meeting of cardiologists in Paris, was dubbed "All Comers" because it enrolled people whose risk factors limited their participation in previous stent studies.

Those risk factors, including diabetes, a smoking habit, high blood pressure and prior heart bypass surgery or stent procedure, are more typically seen in routine clinical practice.

Both stents "were associated with a relatively low frequency of adverse events even in this complex, all-comers patient population," researchers at Erasmus University Medical Center in the Netherlands said in a presentation. The study was sponsored by Medtronic.

Medtronic's Resolute follows its Endeavor stent and is intended to treat more complex cases such as small arteries or multi-vessel disease. It has been sold in European countries since 2007.

Data from the study will be used to seek U.S. Food and Drug Administration approval for Resolute, which Medtronic expects to receive in the second half of 2012.

Safety concerns about dangerous blood clots forming long after stents were implanted led device manufacturers to develop a second generation of stents with new designs as well as polymers that help the anti-clotting drugs adhere to the stent.

Medtronic said patients who received its Resolute stent in the study had a higher rate of stent thrombosis, or clots, at one year -- 1.6 percent compared with 0.7 percent for those who got the Xience stent.

The company said most of those clots occurred within the first 30 days of implantation, suggesting a correlation with the procedure rather than the device, and the clotting did not have an impact on the overall rate of adverse events.

Medtronic competes against Boston Scientific Corp (BSX.N) and Johnson & Johnson (JNJ.N) in addition to Abbott in the nearly $5 billion worldwide drug-coated stent market.

JP Morgan analyst Michael Weinstein, in a note to clients ahead of the Paris meeting, said the Resolute data could help Medtronic gain market share in Europe if the study met its primary endpoint of non-inferiority to Xience.

Endeavor, Medtronic's first drug-eluting stent, was introduced in the United States in 2008 and holds a 20 percent global market share, according to the company. (Reporting by Susan Kelly; Editing by Derek Caney)