Long-Term Clinical Outcomes Following the WATCHMAN Device Use in Medicare Beneficiaries

Area of Science:

• Cardiology
• Medical Devices
• Public Health

Background:

• Long-term outcomes of left atrial appendage occlusion (LAAO) are not well-established outside clinical trials.
• Real-world data collection was mandated for US market authorization of the WATCHMAN device.
• This study evaluates stroke, bleeding, and mortality rates in Medicare beneficiaries post-LAAO.

Purpose of the Study:

• To assess the long-term safety and effectiveness of the WATCHMAN device in a large, real-world Medicare population.
• To identify outcomes in important patient subgroups.
• To provide data for post-market surveillance and clinical decision-making.

Main Methods:

• Analysis of Medicare fee-for-service beneficiaries aged 65+ who underwent LAAO (April 2016 - August 2020).
• Utilized ICD-10 and CPT codes for patient identification and outcome assessment.
• Calculated cumulative incidence of mortality, ischemic stroke, and major bleeding over a 5-year follow-up period.

Main Results:

• 48,763 WATCHMAN recipients (median age 77) had 5-year outcomes: 44% mortality, 15% major bleeding, 7% ischemic stroke.
• Outcomes were worse in older and frailer patients, including those with prior stroke or bleeding.
• Male patients had higher mortality but similar stroke/bleeding rates compared to females.

Conclusions:

• Medicare beneficiaries receiving WATCHMAN were older and sicker than trial participants.
• High long-term mortality and bleeding rates reflect the patient population's high-risk profile.
• The annual ischemic stroke rate remained relatively low (<1.5% per year).