On second thought, Boston Scientific will unveil all Watchman data

Boston Scientific is now planning to present the full results of a study on Watchman.--Courtesy of Boston Scientific

After stunning analysts with a contrary announcement this week, Boston Scientific ($BSX) is back on track to present the full results of its latest study on Watchman, a stroke-preventing device that could help the company reverse its cardiac fortunes.

Boston Scientific announced its plans late Wednesday, reversing its earlier decision to disclose just the short-term results from Watchman's Prevail trial at this weekend's American College of Cardiology meeting in San Francisco. Now, the company will unveil data from the trial's three endpoints, looking at rates of stroke, complications and death 7 days and 18 months after the procedure.

When the company first said it would withhold some data, analysts worried that Watchman didn't perform up to expectations, a serious concern for the beleaguered devicemaker with a lot riding on the novel atrial fibrillation device. But it was a question of timing, not efficacy, Boston Scientific said.

"This is truly a late-breaking clinical trial presentation," Kenneth Stein, the company's CMO for Cardiac Rhythm Management, said in a statement. "The last patient 6-month follow-up occurred in January, and the team has been working diligently to complete the preliminary analysis of the data."

A final analysis of Prevail's results will be done in the coming weeks, Stein said, and that data will be rolled in with previous studies and submitted to the FDA as part of Watchman's PMA application.

If nothing else, the back-and-forth over Watchman's efficacy only puts more eyes on this weekend's presentation. The market has thus far given new CEO Mike Mahoney the benefit of the doubt as he promises a return to revenue growth for the company, but yesterday's sky-is-falling snap over a hiccup in disclosure demonstrates that the company still has a lot to prove.

Boston Scientific estimates the market for Watchman, a left atrial appendage closure device designed to capture blood clots, at about $500 million a year. If the tech can prevent strokes in atrial fibrillation patients far better than the standard-of-care warfarin, it could go a long way in making up for Boston Scientific's otherwise sluggish CRM unit.

- read the company's announcement

Special Report: Devicemakers plot paths out of CRM funk