Stroke and Bleeding Risk in Long-Term Care Residents With Atrial Fibrillation Who Discontinue Anticoagulation

Importance: Atrial fibrillation (AF) leads to more than 100 000 cases of stroke yearly and is particularly prevalent in long-term care (LTC) residents. Anticoagulation (AC) is the mainstay of stroke prevention, but given its risks, clinicians and residents may consider discontinuation at the time of LTC entry. Objective: To estimate the association between AC discontinuation and stroke and bleeding risk among LTC residents with AF. Design, Setting, and Participants: This comparative effectiveness research study with target trial emulation used claims data (2020-2021) from LTC facilities in the US serving Medicare beneficiaries. Medicare beneficiaries with AF receiving AC who entered LTC between April 1 and December 31, 2020, were included; those with additional indications for AC, including prosthetic heart valve or venous thromboembolism, were excluded. Analysis was performed in August 2026. Exposure: Discontinuer vs continuer assignment. Main Outcomes and Measures: The main outcomes were stroke (including ischemic stroke, transient ischemic attack, and systemic embolism) and bleeding, assessed using Medicare claims. A target trial emulation was conducted with clone censor weighting (CCW) analysis. Specifically, eligible LTC residents were assigned (cloned) to each of 2 strategies: AC discontinuation or AC continuation. Clones were then censored when they deviated from their assigned strategy, and inverse probability of censoring weighting was applied to address informative censoring: residents who deviated differing systematically from those who did not. Subdistribution hazard ratios (sHRs) for stroke and bleeding were then calculated to account for competing mortality and a cause-specific hazard ratio (HR) for death. Results: This study included 15 426 LTC residents (mean [SD] age, 82.6 [7.6] years). Most were female (62.6%). AC discontinuers had 187 strokes, 297 bleeding events, and 3684 deaths over a mean (SD) of 128.9 (177.9) days. AC continuers had 321 strokes, 493 bleeding events, and 5475 deaths over a mean (SD) of 279.6 (204.9) days. Discontinuers had similar stroke risk (sHR, 1.07; 95% CI, 0.93-1.23) and bleeding risk (sHR, 1.02; 95% CI, 0.92-1.13) compared with continuers, but discontinuers had higher mortality risk (HR, 1.27; 95% CI, 1.23-1.31). Conclusions and Relevance: In this target trial emulation with CCW in a cohort of LTC residents with AF, AC discontinuation was not associated with higher stroke or bleeding risk. Very high mortality, unmeasured confounding, and reliance on claims-based outcome ascertainment may have limited the ability to better understand the consequences of AC discontinuation on stroke and bleeding.