Risk profiles for acute health events after incident atrial fibrillation in patients with end-stage renal disease on hemodialysis

Background: Little is known about the cardiovascular risks of incident atrial fibrillation/flutter (AF) in patients with end-stage renal disease (ESRD) undergoing hemodialysis (HD). Methods: We studied older US patients who newly initiated HD for ESRD (2006-11) and who had not previously been diagnosed with AF, stroke, myocardial infarction (MI) or hip fracture. We used Cox regression with AF as a time-varying covariate, adjusted for socio-demographic characteristics and comorbidities to estimate hazard ratios [HRs (95% confidence intervals)] for the events of ischemic stroke, MI and death. Hip fracture served as a negative control outcome. Results: We identified 85 377 older patients (mean age: 76.5 years) who initiated HD; of these, 14.3% were subsequently diagnosed with AF (14.9% thereof as primary diagnosis) and 49.8% died during follow-up. Incident AF was associated with nine times higher adjusted mortality during the first 30 days [9.2 (8.8-9.6)], 5-fold higher mortality between 31 and 90 days [4.6 (4.3-4.8)] and double the mortality beyond 90 days from first AF diagnosis [2.2 (2.1-2.3)]. Incident AF was similarly associated with higher adjusted risk of ischemic stroke: 2.1 (1.6-2.7) during the first 30 days, 2.5 (2.0-3.0) between 31 and 90 days and 1.5 (1.3-1.7) beyond 90 days. Similar findings were obtained for MI. However, the risk of hip fracture was only marginally increased following AF diagnosis [≤30 days: 1.1 (0.7-1.6); 31-90 days: 1.4 (1.0-1.8); >90 days: 1.2 (1.1-1.4)]. All associations were attenuated and the association with hip fracture was null when incident AF was defined by a primary diagnosis code. Conclusions: AF was strongly associated with increased risks of ischemic stroke, MI and death, with risks highest soon after AF diagnosis but extending beyond 90 days.