Device May Offer Alternative to Warfarin for Arrhythmia

FRIDAY, Aug. 14 (HealthDay News) -- Closing the heart's left atrial appendage could offer an alternative to long-term warfarin treatment for people with non-valvular atrial fibrillation who are at risk for stroke, according to a new study.

Atrial fibrillation, the most common type of irregular heartbeat, causes the upper chambers of the heart to quiver. This can cause blood to pool and form clots in the left atrial appendage (LAA), a long, tubular structure connected to the left atrial cavity. More than 90% of atrial blood clots in people with non-valvular atrial fibrillation may originate in the LAA, according to background information in the study.

The study included 463 people who underwent percutaneous implantation of a device, known as the Watchman, to close off the LAA. Their outcomes were compared with those of 244 people who continued long-term treatment with warfarin.

The researchers determined the effectiveness of the treatments by assessing the occurrence, during an average follow-up of 18 months, of strokes, death from cardiovascular causes and systemic embolisms (blood clots that go somewhere other than the brain). They also totaled the occurrence of such serious problems as major bleeding, pericardial effusion (accidental puncture of the heart causing fluid collection in the heart sac) and clots caused by the implanted device.

After 1,065 patient-years of follow-up, there were 3.0 such occurrences per 100 patient-years among those who'd had the device implanted, compared with 4.9 in the warfarin group, for a risk reduction of 38%. But people in the device group had more serious safety events -- 7.4 events per 100 patient-years versus 4.4 events in the warfarin group, the researchers found.

"The efficacy of percutaneous closure of the LAA with this device was non-inferior to that of warfarin therapy," concluded Dr. David R. Holmes, of the Mayo Clinic in Rochester, Minn., and his colleagues. "Although there was a higher rate of adverse safety events in the intervention group than the control group, events in the intervention group were mainly a result of periprocedural complications," they wrote.

"Closure of the LAA might provide an alternative strategy to chronic warfarin therapy for stroke prophylaxis in patients with non-valvular atrial fibrillation," they added.

The study appears this week in The Lancet.

-- Robert Preidt

SOURCE: The Lancet, news release, Aug. 13, 2009

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