FDA Will Evaluate NCDR LAAO Registry Findings on Different Outcomes for Women Versus Men

September 27, 2021—The FDA has issued a letter to health care providers advising of recent findings about the potential for differences in procedural outcomes between women and men undergoing implantation of a left atrial appendage occlusion (LAAO) device. The agency is evaluating a published analysis of real-world data in the National Cardiovascular Data Registry (NCDR) LAAO Registry. The data indicate that procedural outcomes such as major adverse events and lengthened hospital stay may be more common in women compared to men. The causes for these differences are yet to be determined, advised the FDA.

Currently, the FDA believes the benefits continue to outweigh the risks for approved LAAO devices when used in accordance with their instructions for use, noted the FDA letter to health care providers.

“Sex Differences in Procedural Outcomes Among Patients Undergoing Left Atrial Appendage Occlusion: Insights From the NCDR LAAO Registry,” was published on August 11, 2021, by Douglas Darden, MD, et al online in the Journal of the American Medical Association (JAMA): Cardiology.

In the study, the investigators conducted an analysis of 49,357 patients from the LAAO Registry (41.3% women and 58.7% men) treated with the Watchman left atrial appendage closure device (Boston Scientific Corporation) between 2016 to 2019. The investigators found a statistically significant higher rate of adverse procedural events in women compared to men including any adverse events (6.3% vs 3.9%; P < .001), any major adverse events (4.1% vs 2%; P < .001), and hospital stay > 1 day (16% vs 11.6%; P < .001). Among specific procedural adverse events, the rates of pericardial effusion requiring percutaneous drainage was 1.2% versus 0.5% and major bleeding was 1.7% versus 0.8% in women versus men. Procedure-associated death was 0.3% in women and 0.1% in men.

The FDA stated it recognizes the limitations of these data, including that the study was not randomized, only included one LAAO device (the first-generation Watchman device), and did not include longer-term outcomes beyond in-hospital events. However, the analysis provides results from a large registry of patients treated with LAAO implants in the United States. Because the NCDR LAAO Registry captures a large number of patients undergoing LAAO procedures, the number of patients included in this analysis was much larger than the number of patients that were included in the premarket studies of the Watchman device that supported device approval, and the premarket studies for the other approved LAAO devices, noted the agency.

In the letter to health care providers, the FDA stated that the agency 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 manufacturers of the currently approved and marketed LAAO devices in the United States are Boston Scientific (Watchman and Watchman FLX devices) and Abbott (Amplatzer Amulet device).

The FDA outlined its recommendation for health care providers as follows:

• Continue monitoring patients who have been treated with LAAO devices per the current standard of care.
• Discuss the risks and benefits of all available options for stroke prevention in patients with atrial fibrillation as part of shared clinical decision-making.
• Report any adverse events or suspected adverse events experienced with the use of LAAO devices. Prompt reporting of adverse events can help the FDA identify and better understand the risks associated with medical devices.

The FDA will communicate with the public if new or additional information becomes available.