Time to benefit and harm of direct oral anticoagulants in device-detected atrial fibrillation: A pooled analysis of the NOAH-AFNET 6 and ARTESiA trials

Background: Direct oral anticoagulants (DOACs) reduce stroke risk in patients with device-detected atrial fibrillation (DD-AFib) but increase major bleeding risk. The time to benefit (TTB) and time to harm (TTH) are not well quantified.

Objective: The purpose of this study was to determine TTB and TTH in DOAC-treated patients with DD-AFib.

Methods: Studies were identified from PubMed searching until November 2023. The primary efficacy outcome was the time to the first stroke event, and the primary safety outcome was the time to the first major bleeding event. Pooled hazard ratio (HR) and its confidence interval (CI) were calculated through reconstructed patient-level data and study-level data. Weibull model and Markov chain Monte Carlo simulation were applied to determine time to specific absolute risk change thresholds.

Results: Two trials involving DOACs-NOAH-AFNET 6 (Non-vitamin K antagonist Oral anticoagulants in patients with Atrial High rate episodes) and ARTESiA (Apixaban for the Reduction of Thrombo-Embolism in Patients With Device-Detected Sub-Clinical Atrial Fibrillation)-were identified, which randomized 6548 adults with a mean age of >75 years and a median atrial high-rate episode duration ranging from 1.5 to 2.8 hours. DOACs decreased the risk of stroke (HR 0.67; 95% CI 0.50-0.90) but increased the risk of major bleeding (HR 1.57; 95% CI 1.21-2.04). A TTB of 2.67 years was needed to prevent 1 stroke per 100 DOAC-treated patients, while a TTH of 1.67 years was needed to observe 1 major bleeding.

Conclusion: In elderly patients with low durations of DD-AFib, DOACs result in a delayed and restricted stroke-preventive benefit while posing an early-onset bleeding risk. Our findings offer new insights into the risk-benefit profile and provide clinicians an additional dimension to facilitate shared decision-making discussions with patients.