FDA alerts HCPs to higher risk for women with stroke-preventing heart implant

The FDA said it will keep its eye on the safety of left atrial appendage occluders—a small implant that seals off a spare pocket in the heart wall to help cut down a person’s risk of stroke—after a study of nearly 50,000 patients showed major side effects were more common in women than men.

The agency alerted healthcare providers about the real-world study published in JAMA Cardiology, which tracked procedures using Boston Scientific’s Watchman device from 2016 to 2019. The FDA said, though, that the root causes have not yet been determined and that it believes the implants’ benefits continue to outweigh the risks.

Currently, two companies market transcatheter LAAO devices in the U.S.: Boston Scientific, with its Watchman and upgraded Watchman FLX implants, and Abbott with its Amplatzer Amulet. 

The appendage can also be sealed with sutures, staples or other devices during open surgery for another heart condition—however, only the first-generation, minimally invasive Watchman device was covered by the registry study.

Researchers found statistically significant higher rates of adverse events in women compared to men, including the need for hospital stays longer than one day. Cases of major bleeding occurred in 1.7% of women vs. 0.8% in men, while rates of pericardial effusion, or the dangerous build-up of fluid around the heart, were logged at 1.2% vs. 0.5%.

Overall, 6.3% of women had at least one type of adverse event compared to 3.9% of men, while procedure-associated deaths happened in 0.3% of women vs. 0.1% of men. The study did not track longer-term health outcomes, beyond events that happened in-hospital.

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“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 in its notice to providers, stating that the size of the registry study was much larger than the number of patients included in clinical trials leading up to the approval of the Watchman device and other implants. 

In the meantime, the FDA recommended that physicians continue monitoring their patients and report suspected adverse events and discuss the risks and benefits of all available options for preventing stroke in people with atrial fibrillation.

Earlier this year, Boston Scientific delivered new data for its Watchman FLX device, which was approved in mid-2020, showing that zero of 400 patients developed pericardial effusion within two years after the procedure, and only two reported an adverse event within a week of the implantation.

And last month, Abbott received an FDA approval for its Amplatzer Amulet in patients with atrial fibrillation, an irregular heartbeat that can make it easier for blood clots to form within the appendage.

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Shortly after that approval, Abbott delivered late-breaking clinical trial data putting it up against its main competitor, finding that the Amulet performed as well as the Watchman when it came to safety and procedure-related complications.

Additionally, among more than 1,800 patients with an average age of 75, 82% of Watchman patients were discharged with a prescription for blood thinners such as warfarin and aspirin, compared to only 20% of Amulet patients, who were instead largely given a dual antiplatelet therapy regimen of clopidogrel and aspirin in 75% of cases.

The FDA also approved a new device in Abbott’s Amplatzer line, the Talisman occluder, designed to seal off a hole between the heart’s two atria that fails to close after birth. Known as the foramen ovale, the opening may let blood clots pass from the right side of the heart to the left, where they can potentially travel to the brain and cause a stroke.