Watchman hopes to PREVAIL through U.S. AF trial
Central Baptist Hospital in Lexington, Ky., recently enrolled the first patient into the PREVAIL trial, a U.S. study comparing the Watchman Left Atrial Appendage Closure Device to long-term warfarin therapy in patients with atrial fibrillation at risk for stroke. Atritech, makers of the device, intend to use positive trial results to gain FDA approval.

The Watchman, previously investigated during the PROTECT AF trial, helps to prevent stroke by being percutaneously inserted into the left atrial appendage, essentially occluding blood flow. In the ongoing PROTECT AF, the Watchman reduced the risk of stroke, CV death and embolism by 30 percent at 27 months of follow-up. The trial is designed to follow up patients for five years.

In April 2009, an FDA panel voted 7 to 5 to approve the Watchman "with conditions." The panel noted the positive short-term data of the device during PROTECT AF, but also questioned the lack of long-term evidence.

The PREVAIL trial hopes to close the evidence gap.

The multicenter, prospective trial will enroll 475 patients and randomize them to receive the Watchman or warfarin and evaluate the occurrence of stroke, CV death and embolism.

The PREVAIL study requires all patients be followed up for six months prior to submitting data to the FDA; however, the protocol does require that all patients be followed up for five years.

The patients must be diagnosed with paroxysmal, persistent or permanent AF, be eligible for long-term warfarin therapy and have a calculated CHADS2 score of two or greater.

    Watchman has been approved in Europe and other countries outside the U.S.