UPDATE 2-New Thoratec heart pump beats older model in study

* 46 pct HeartMate II patients meet main study goal

* 11 pct of patients with older model meet goal

* 2-yr survival more than double with new model

* Thoratec shares rise 5 pct (Adds analyst comments, updates shares)

By Ransdell Pierson and Bill Berkrot

ORLANDO, Fla., Nov. 17 (Reuters) - Advanced heart failure patients who received Thoratec Corp's (THOR.O) new pump awaiting U.S. approval as an alternative to heart transplants lived longer and fared far better than those getting the company's older HeartMate XVE device, researchers said on Tuesday.

Thoratec shares rose 5 percent.

After one year, 68 percent of patients with the new pump were still alive, compared with 55 percent in the other group. After two years, the survival advantage was more than double at 58 percent vs. 24 percent.

The results for Thoratec's next-generation HeartMate II unit could prompt twice as many patients who do not have access to heart transplants, or more, to use left ventricular assist devices as a life-extending option, researchers said.

Wedbush Morgan Securities analyst Duane Nash cautioned that the survival data, though impressive, are not as robust as initial findings for a rival pump being developed by HeartWare International Inc (HTWR.O).

"While the HeartMate II's numbers are a clear improvement over the HeartMate XVE, far superior data, albeit early and in small numbers, appears to be coming from HeartWare, where two-year survival in one trial has reached 80 percent," Nash said in a research note.

Gabelli & Co analyst Jeff Jonas said the new HeartMate II data, though perhaps disappointing to some, were praiseworthy.

"It's still a great outcome that will get it approved for destination therapy and really drive the uptake in 2010," Jonas said, referring to use for patients not eligible for heart transplants.

The LVAD device, implanted along the patient's weakened heart and designed to take over the pumping ability of the organ's left ventricle, is only about one-seventh the size of the older model and far quieter.

Unlike the XVE, which pumps blood in pulses that mimic the human heart, the new device pushes blood in a continuous stream and is meant to be more durable because it has only one moving part.

The pumps were compared among 200 end-stage heart failure patients who did not benefit from limited current medical therapies and were ineligible for heart transplants.

The primary trial goal was survival without experiencing a stroke or device failure requiring another operation within two years.

Some 46 percent of patients implanted with the HeartMate II reached the goal, compared with 11 percent receiving the older device. That difference is highly significant, said Dr. Joseph Rogers, a Duke University researcher who helped lead the Thoratec-commissioned study.

Rogers cited an 82-percent reduced need to repair or replace HeartMate II, compared with the older device.

After one year, 68 percent of patients with the new pump were still alive, compared with 55 percent in the other group. After two years, the survival advantage was more than double at 58 percent vs. 24 percent.

"Many doctors think of these devices as a bit space-age, but I think these data could cause an uptick in adoption of the technology," Rogers said in an interview at the American Heart Association's annual scientific meeting in Orlando.

But he noted that the devices' cost -- $70,000 or more, plus tens of thousands of dollars for hospital and surgeon's fees -- had been a hurdle for many patients.

As many as 150,000 Americans have advanced, or end-stage, heart failure, but only a few thousand are eligible each year for heart transplants, Rogers said.

He estimated about 1,000 patients a year have been receiving LVAD devices, either to keep them alive while they wait for a new heart or to extend life for those who are unlikely to receive transplants.

"I think the number should more than double" with the favorable findings for the new device, he said.

The HeartMate II received limited approval in April 2008 for "bridge-to-transplantation," meaning for patients awaiting transplants. If approved for destination therapy, it would become available to the far bigger population of patients ineligible for transplants.

"We had a sense that these smaller devices were going to have better long-term outcomes, and this trial proves it," Dr. Alfred Bove, president of the American College of Cardiology, said in a statement.

"These devices have come a long way in five years," Bove said. "I expect that technology will continue to move things forward, and they will be even better five years from today."

Shares of Pleasanton, California-based Thoratec, which had risen nearly 7 percent this month, were up $1.41 at $29.49 in morning Nasdaq trading. (Reporting by Ransdell Pierson and Bill Berkrot; Editing by Lisa Von Ahn)