UPDATE 1-Molecular Insight imaging agent passes heart trial

* Imaging agent meets primary, secondary goals of study

* Says product better identifies true heart-risk patients

* Company says product may help transform chest-pain care

* Says Zemiva has blockbuster sales potential

* Shares of Molecular Insight jump nearly 19 percent (Adds share price gains, CEO view of sales potential)

By Ransdell Pierson

NEW YORK, March 26 (Reuters) - A radioactive imaging agent developed by Molecular Insight Pharmaceuticals Inc MIPI.O was better able than standard emergency room tests to pinpoint which patients with chest pains had true heart symptoms, the company said on Thursday, citing data from a mid-stage study.

The company, whose shares rose almost 19 percent, said its injectable product, called Zemiva, met its primary goal in the 510-patient phase II study of better showing which patients are experiencing blocked flow to the heart. Such interrupted blood flow can lead to heart attacks.

"Our imaging agent met our pre-specified goal of finding disease and ruling out disease" among patients admitted to emergency rooms for chest pains, John Babich, chief executive officer of Molecular Insight Pharmaceuticals, said in an interview. Secondary trial goals were also met.

Emergency room doctors must quickly assess whether patients having chest pains are experiencing interrupted blood flow to the heart and therefore need invasive medical procedures or surgery to restore vital blood flow.

To make such assessments, doctors typically ask for the patient's medical history, give the patient a medical exam and an electrocardiogram, as well as a blood test for a protein complex called troponin that can help confirm a heart attack has occurred.

But standard tests must be done while symptoms are still present and are inconclusive for about two-thirds of chest pain patients, Babich said. Because of that uncertainty, about 3.5 million such U.S. patients are hospitalized annually for continued observation even though many have no real heart issues.

One group of patients in the study received standard assessments, while others received standard assessments along with injections of the Zemiva imaging agent.

"(Standard assessments) were able to find disease 52 percent of the time when disease was present, but when Zemiva was added, the sensitivity of finding disease rose to 85 percent," Babich said, thereby meeting the primary goal of the study.

"These are very exciting results, which show that by adding Zemiva you can quickly identify which patients need intervention," said Babich.

Based on the favorable data, the Cambridge, Massachusetts-based company now plans to move the product into larger phase III studies.

Babich said Zemiva, if approved, would likely cost $1,500 to $2,000 per treatment and have blockbuster sales potential.

Zemiva has advantages over several other imaging agents sometimes used in the emergency room, including Cardiolite, an imaging agent developed by DuPont (DD.N) but now owned and marketed by privately held Lantheus Medical Imaging.

But while those agents must be given while sypmtoms are still present, Babich said Zemiva works for as long as 30 hours after blood flow is interrupted and subjects patients to considerably less radiation than currently approved agents.

Shares of Molecular Insight Pharmaceuticals rose 54 cents to $3.45 in morining trading on the Nasdaq.

(Editing by Andre Grenon, Dave Zimmerman)