Boston Scientific hesitates to release full safety results for Watchman heart implant

March 6, 2013 by Arezu Sarvestani

Some Wall Street analysts are wary of Boston Scientific's decision to hold back some of the safety results from a trial of its Watchman stroke prevention implant.

Boston Scientific's Watchman heart implant

Officials at Boston Scientific (NYSE:BSX) announced this week that they would reveal only limited patient safety results when they present data from a clinical trial of the Watchman stroke prevention implant at the American College of Cardiology conference this week.

The Massachusetts-based medical device giant revealed in a press release that it plans to "present the acute procedural safety results of the PREVAIL clinical trial," keeping 2 other safety endpoints under wraps for the time being.

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"We find this highly unusual given that Prevail is one of the featured late-breaking trials at ACC," Wells Fargo analyst Larry Biegelsen said in a note to investors. The hesitation to reveal the full safety results may indicate that the Watchman device failed to meet the other endpoints, he speculated. "Given the unusual nature of this development, i.e. only one of 3 primary endpoints being presented, we would not be surprised to see this decision change by Saturday."

Representatives for the ACC conference, which begins this weekend, said they were "surprised" by Boston Scientific's announcement and that they would investigate further.