What is the incidence of stroke following the Watchman (Left Atrial Appendage Closure) procedure?

From the Guidelines

The incidence of stroke following the Watchman procedure is approximately 1-2% per year, as demonstrated by the PROTECT-AF and PREVAIL trials 1. This rate represents a significant reduction compared to the expected stroke risk in patients with atrial fibrillation not taking anticoagulation. After Watchman implantation, patients typically follow a specific antithrombotic regimen: warfarin plus aspirin for 45 days, followed by dual antiplatelet therapy (clopidogrel 75mg daily plus aspirin 81-325mg daily) for 4.5 months, and then aspirin alone indefinitely. For patients who cannot take warfarin, the alternative regimen is dual antiplatelet therapy for 6 months followed by aspirin alone. The Watchman device works by occluding the left atrial appendage, where most stroke-causing blood clots form in atrial fibrillation patients. While the procedure reduces stroke risk, it doesn't eliminate it entirely since strokes can occur from other mechanisms. Some key points to consider include:

• The Watchman device has been shown to be noninferior to warfarin for the composite endpoint of stroke, systemic embolism, and cardiovascular death 1.
• A patient-level meta-analysis of the PROTECT-AF and PREVAIL trials showed that LAA closure was associated with a comparable rate of the composite primary efficacy outcome and significantly lower hemorrhagic stroke and cardiovascular death 1.
• The American Heart Association/American Stroke Association 2014 Guidelines suggest that LAA closure may be considered for high-risk patients with AF who are deemed unsuitable for prolonged anticoagulation 1. Patients should continue regular follow-up with their cardiologist after the procedure to monitor for any complications and ensure optimal management of their overall cardiovascular health. The most recent and highest quality study, the 2016 update on antithrombotic therapy in patients with atrial fibrillation undergoing percutaneous coronary intervention, provides the best evidence for the incidence of stroke following the Watchman procedure 1.

From the Research

Incidence of Stroke Following Watchman Procedure

The incidence of stroke following the Watchman (Left Atrial Appendage Closure) procedure has been studied in several research papers.

• The ASAP study 2 reported an all-cause stroke or systemic embolism rate of 2.3% per year, with ischemic stroke occurring in 1.7% per year and hemorrhagic stroke in 0.6% per year.
• The EWOLUTION trial 3 found an ischemic stroke rate of 1.1% at 1-year follow-up, which is lower than the estimated historical rate.
• A network meta-analysis 4 indirectly compared the Watchman device with new oral anticoagulants (NOACs) and found that both were superior to warfarin in preventing hemorrhagic stroke, but there was a trend toward higher rates of ischemic stroke with the Watchman device compared to NOACs.
• A 5-year retrospective study 5 compared stroke rates in patients with nonvalvular atrial fibrillation who received the Watchman device or direct oral anticoagulants (DOACs) after a major bleeding event, and found that the Watchman cohort had significantly lower rates of major bleeding events, transient ischemic attacks, and ischemic strokes, but no significant difference in hemorrhagic strokes.

Key Findings

• The Watchman procedure has been shown to be effective in reducing the risk of stroke in patients with atrial fibrillation, particularly those with contraindications to oral anticoagulation.
• The incidence of stroke following the Watchman procedure varies across studies, but overall, the rates of ischemic and hemorrhagic stroke are lower than expected based on the patients' CHADS2 or CHA2DS2-VASc scores.
• The Watchman device has been compared to NOACs and warfarin in several studies, with mixed results, but overall, it appears to be a safe and effective alternative for stroke prevention in patients with atrial fibrillation.