Abstract 17137: Renal Dysfunction is a Potent Predictor of Stroke and Systemic Embolism Among Individuals with Atrial Fibrillation: Results from the ROCKET AF Trial

Abstract

Background: Stroke is a disabling and frequently lethal complication of atrial fibrillation (AF). Risk stratification is an essential first step in effective stroke prevention. We investigated what factors are associated with the occurrence of stroke and systemic embolism in a large, international AF trial. Methods: In ROCKET AF, 14,264 patients with nonvalvular AF and creatinine clearance (CrCl) ≥30 mL/min were randomized to rivaroxaban or dose-adjusted warfarin. The primary endpoint was stroke or systemic embolism analyzed according to intention to treat. Cox proportional hazards modeling was used to identify the factors at randomization independently associated with the occurrence of stroke or systemic embolism. Results: At randomization, the median age was 73 yrs, median CHADS2 score was 3.0, median CHA 2 DS 2 VASc score was 5, and 52% had a history of prior stroke or TIA. Over a median follow-up of 1.94 years, 575 (4.0%) patients had a primary endpoint event. Among these patients, the median age was 74, median CHADS 2 score was 4, median CHA 2 DS 2 VASc score was 5, and 64% had prior stroke or TIA. Reduced CrCl was a strong independent predictor of stroke and systemic embolism, second only to prior stroke or TIA (Table). Additional factors associated with stroke and systemic embolism included increased diastolic BP and heart rate, and vascular disease of the heart and limbs; (C-index 0.635). This model demonstrated improved discrimination compared with the CHA 2 DS 2 VASc model (0.578), and the CHADS 2 model (0.575). The inclusion of eGFR <60 and prior stroke or TIA in a model without any other covariates led to a C-index of 0.591. Conclusions: In a population of patients with non-valvular AF at moderate to high risk of stroke, impaired renal function is a potent predictor of stroke and systemic emboli. Risk stratification for stroke prevention in AF should incorporate renal function into risk estimates and potentially, subsequent therapeutic decisions.