This Time, Medtronic-Backed Heart-Failure Study Hits Mark

New clinical-trial data released Tuesday showed an expensive implanted device that coordinates beating in erratic hearts helped delay the worsening of symptoms over two years for patients with mild heart failure.

The latest details on 262 patients from the Medtronic Inc. (MDT)-sponsored "Reverse" trial come a year after data on a bigger Reverse group failed to establish this benefit. The fresh results, set for presentation Tuesday at the American College of Cardiology's annual conference, are also a prelude to a bigger study that - if successful later this year - could energize what has become a sluggish market for heart-rhythm devices.

Medtronic is the biggest company in that market, where it competes with Boston Scientific Corp. (BSX) and St. Jude Medical Inc. (STJ).

Their cardiac resynchronization therapy, or CRT, heart devices use power to constantly organize beating. The devices are also often designed to provide high-voltage shocks when hearts beat dangerously fast, and these versions cost about $32,000, which is more than the typical implanted defibrillator.

CRT devices are currently approved for patients with more severe cases of heart failure, as defined by the New York Heart Association, but manufacturers would love to tap the vast pool of less-sick and sometimes asymptomatic patients.

The Reverse study has shown this is challenging, however.

It was designed to see whether CRT devices combined with the best-available drug therapy might help restrain the worsening of symptoms for less-sick patients based on a mix of measurements. All 610 patients in the trial had a device implanted and were on drug therapy, but some patients didn't have the device turned on.

One-year data unveiled last year didn't show a statistically significant benefit when it came to delaying the worsening of symptoms for CRT patients, which meant the trial failed its main goal despite some other benefits, such as improvement for enlarged hearts. Trial investigators hypothesized that because these patients slowly worsen, waiting two years to compare the therapies would have been a better idea.

Per the study's original design, it remained blinded for 262 patients in Europe, and the main goal for them was reached at two years. Specifically, 19% of the 180 patients with their CRT device switched on worsened over that span, compared with 34% of the 82 patients who worsened in the group without their devices on. The difference is considered statistically significant.

The devices don't stop the progression of heart disease, but appeared able to slow the magnitude of that progression.

The latest data also indicated some other benefits from CRT devices, such as reducing enlarged hearts while improving their pumping efficiency. The devices didn't deliver a significant benefit on some other measures, such as quality of life or exercise capacity, perhaps because of these patients' milder symptoms.

The study shows "the longer the time, the greater the benefit," said Cecilia Linde, a cardiologist at Karolinska University Hospital in Stockholm, in an interview. She is also Reverse's world-wide principal investigator and has received research grants from Medtronic.

Leerink Swann analyst Rick Wise said ahead of the results that Reverse is unlikely to be "market-shifting as a standalone trial" due to its early issues. But positive trends could provide insights into a much bigger, upcoming study sponsored by Boston Scientific.

Called Madit-CRT, that study includes 1,820 patients and goes about testing CRT devices in a different way - it focuses on whether they will help prevent death or heart-failure events compared with regular implanted defibrillators. Boston Scientific Chief Executive James Tobin said at a recent financial conference that he expects Madit-CRT to succeed and that results could be ready for release at the Heart Rhythm Society's conference in mid-May.

He downplayed the chances the study will help the heart-rhythm market in the near term, but analyst Wise said it "could be a groundbreaking trial that expands usage."

-By Jon Kamp, Dow Jones Newswires; 617-654-6728; [e-mail]