PREVIEW-Devices to take center stage at ACC heart meeting

* Abbott's MitraClip, Medtronic's ablation system featured

* Key data includes products gained through acquisitions

* Phase II data on Merck blood clot preventer anticipated

By Bill Berkrot and Debra Sherman

NEW YORK/CHICAGO, March 11 (Reuters) - Abbott Laboratories and Medtronic Inc will grab a share of the spotlight at this year's American College of Cardiology scientific meeting, as devices and procedures aimed at avoiding traumatic surgeries muscle heart drugs off center stage.

Thousands of cardiologists and researchers will gather in Atlanta for the four-day meeting beginning Saturday at which the latest data on heart drugs and devices, as well as patient care strategies, will be presented and discussed.

Some featured studies will also give companies a chance to demonstrate whether recent acquisitions were worth the expense as key data is unveiled on products picked up through deals.

Pivotal data that could lead to U.S. approval of Abbott's (ABT.N) MitraClip will be presented on Sunday. The study aims to show how the clip, which is delivered via catheter, compares with more invasive traditional valve repair or replacement to address mitral regurgitation.

The condition -- the most common type of heart valve problem -- occurs when the mitral valve does not close tightly, allowing blood to flow backward in the heart.

Abbott added the MitraClip to its portfolio of potential products through its 2009 acquisition of Evalve.

"Should it prove successful, the study would put Abbott's MitraClip on track for FDA approval in 2011 and open up what we believe could ultimately be a $1 billion-plus opportunity for the company," JP Morgan analyst Michael Weinstein said in a research note previewing the meeting.

Medtronic (MDT.N) will be featured on Monday as key safety and efficacy data are presented on its Arctic Front cryoblation catheter to treat paroxysmal atrial fibrillation, or periodic episodes of irregular heartbeat.

The system, which Medtronic gained with its 2008 acquisition of CryoCath, is already in use in Europe and Australia but has not yet been approved in the United States, the world's largest and most lucrative market.

"Expectations are relatively high and consensus assumes success," Morgan Stanley analyst David Lewis said in a note.

Investors and doctors will also get a first look at data from a pilot study comparing St Jude Medical Inc's (STJ.N) catheter ablation system with drug therapy in the treatment of atrial fibrillation, the most common type of arrhythmia.

The prevalence of the condition -- marked by a rapid, irregular heart rhythm -- increases with age and raises the risk of stroke. Catheter ablation involves threading a thin tube through a blood vessel until it reaches the area of the heart causing abnormal rhythms. The tissue is then destroyed.

Cardiovascular device makers see this technology as the next big growth driver for the sector.

A Boston Scientific (BSX.N) study will compare its new generation of drug coated stents based on a platinum chromium alloy with its older stainless steel-based model. The tiny tubular scaffolding props open arteries and are often used as an alternative to open heart bypass surgery.

While drugs that have often dominated major heart meetings in the past take something of a backseat to devices this year, several studies involving pharmaceuticals will get their due.

A trial called Accord will shine a light on whether adding Abbott's triglyceride lowering TriCor to cholesterol fighting statins can reduce heart attacks, strokes and deaths among type 2 diabetes patients.

The results could have implications for success of a pill that combines Abbott's new TriLipix triglyceride lowering medicine with AstraZeneca's (AZN.L) powerful statin Crestor, which is awaiting a U.S. approval decision.

But the pharmaceutical focus has shifted from cholesterol and blood pressure medicines to a new wave of experimental blood thinners used to prevent clots and strokes.

Merck & Co (MRK.N) will have Phase II data on betrixaban, the blood clot preventer it is developing through a licensing deal it recently struck with privately held Portola.

Betrixaban belongs to a highly promising new class of drugs called factor Xa inhibitors. While Merck is well behind factor Xa drugs being developed by rivals, analysts have suggested it could prove to be the best-in-class of the drugs that hope to replace notoriously difficult-to-use warfarin.

Researchers and drugmakers have been searching for decades for an alternative to warfarin, which must be closely monitored to prevent serious bleeding and requires dietary and lifestyle changes. Many patients refuse to take the drug, heightening their risk of stroke.

Medco Health Solutions Inc MHS.N, which administers prescription drug benefits for employers and health plans, will address the warfarin issue with its latest effort to advance the cause of personalized medicine.

Medco will present results from a large study in which it hopes to demonstrate that genetic screening can help determine safe and effective warfarin dosing for individual patients and cut down on hospitalizations. (Reporting by Bill Berkrot and Debra Sherman; editing by Gunna Dickson)