Monday, March 11 07:36:44
A tiny upside down umbrella-shaped device implanted on the heart to prevent stroke in patients with a dangerous irregular heart rhythm known as atrial fibrillation appeared to be safe in a highly anticipated clinical trial, providing an alternative to clot-preventing blood thinners.
The device, called Watchman and made by Boston Scientific Corp, could potentially spare heart patients a lifetime of taking anticoagulant drugs, such as warfarin, that carry a high risk of bleeding.
The Watchman, which Boston Scientific acquired when it bought Atritech in 2011, has been available in Europe for several years. But U.S. regulators wanted another safety study, testing it in higher risk patients, before considering approval in the world's biggest market.
"In this experience focusing on safety, we were very, very pleased," Dr. David Holmes, a cardiologist at the Mayo Clinic who led the study, said in an interview.
People with atrial fibrillation, the most common type of arrhythmia, are five times more likely to suffer a stroke than those without the condition. It affects nearly 3 million people in the United States and that number is expected to increase.
The study, dubbed Prevail, was a follow-up to a previous study called Protect-AF, which demonstrated that Watchman works as well as warfarin in preventing clots that cause strokes.
But the U.S. Food and Drug Administration raised concerns about complications, such as build-up of fluid around the heart and stroke around the time of the procedure, explained Holmes, who also led the earlier trial. The latest study compared safety data between the two trials.
"Absolute stroke rates were low, but statistically they were less in this group of patients treated in Prevail" even though they were higher risk patients, Holmes said.
The 407-subject Prevail trial enrolled more diabetics than the previous study, patients who were older and were deemed at higher risk of stroke or had suffered a previous stroke. And still, stroke rates were statistically significantly lower in the Prevail study, procedural success was higher and vascular complications were lower, Holmes said. ( C) Reuters