FDA Investigating Possible Sex Differences in LAAO Outcomes

On Monday, the US Food and Drug Administration issued a letter alerting clinicians to potential sex differences in the outcomes of left atrial appendage occlusion (LAAO), citing a recent study indicating worse short-term results in women versus men.

The agency said it’s looking into data published in JAMA Cardiology last month showing that women were more likely to have major adverse events, including pericardial effusion requiring drainage and major bleeding, as well as a hospital stay lasting more than a day. The in-hospital mortality rate was low overall, but it was significantly higher in women (0.3% vs 0.1%; P < 0.001). The analysis had a large sample size—more than 49,000 patients from the LAAO Registry, part of the National Cardiovascular Data Registry—but it was not randomized, included only one device (the first-generation Watchman from Boston Scientific), and didn’t assess outcomes beyond discharge.

“The FDA will work with the manufacturers of approved LAAO devices to evaluate information from several sources, including premarket studies, mandated postmarket studies, and real-world data to provide additional information on this issue,” the agency said. “Currently, the FDA believes the benefits continue to outweigh the risks for approved LAAO devices when used in accordance with their instructions for use.”

As the review continues, clinicians should continue monitoring patients undergoing LAAO according to standard of care and continue discussing the risks and benefits of all options for stroke prevention with patients through shared decision-making, the FDA said, adding that all adverse events or suspected events related to use of LAAO devices should be reported.

In the United States, approved LAAO devices include the first-generation Watchman and next-generation Watchman FLX (Boston Scientific), as well as the recently approved Amplatzer Amulet device (Abbott).