Predictors of Atrial Fibrillation During Long‐Term Implantable Cardiac Monitoring Following Cryptogenic Stroke

BACKGROUND: Following cryptogenic stroke, guidelines recommend cardiac monitoring for occult atrial fibrillation (AF). We aimed to evaluate predictors of AF during long‐term implantable cardiac monitoring. METHODS AND RESULTS: We studied 293 consecutive patients who underwent implantable cardiac monitor implant (Medtronic LINQ) following hospitalization for cryptogenic stroke at the University of Rochester Medical Center from January 2013 to September 2018. Multivariable Cox proportional hazards regression modeling was used to identify predictors of AF during long‐term monitoring. At 36 months of follow‐up, the cumulative rate of implantable cardiac monitor–detected AF events was 32% in the total study population. Multivariable analysis identified age ≥70 years as the most powerful predictor of the development of AF events during follow‐up (hazard ratio, 2.28 [95% CI, 1.39–3.76]; P=0.001). Replacing age with the CHA(2)DS(2)‐VASc (congestive heart failure, hypertension, age, diabetes mellitus, stroke, vascular disease, age, sex category) score resulted in a weaker association, for which each 1‐point increment in the CHA(2)DS(2)‐VASC score was associated with an 18% increased risk of developing AF (95% CI, 1.00–1.38; P=0.047). Consistent results were shown using Kaplan–Meier analysis by age and by the CHA(2)DS(2)VASc score. CONCLUSIONS: Cryptogenic stroke patients continue to develop AF episodes during 36 months of implantable cardiac monitoring following the index event. Age is the most powerful predictor of occult AF in this population.