RESUMEN
Essential In patients on treatment with direct anticoagulants (DOACs) variation of renal function is common. The effect of variations of renal function over time on major bleeding is not well defined. Variation of renal function over time is an independent predictor of major bleeding. Identifying conditions associated with variation of renal function may increase safety of DOACs. SUMMARY: Background Chronic kidney disease is a risk factor for major bleeding in patients with atrial fibrillation (AF) treated with warfarin. Objective To assess the effect of variations in renal function over time on the risk of major bleeding during treatment with direct oral anticoagulants (DOACs) in patients with non-valvular AF. Methods Consecutive AF patients were prospectively followed after they had received the first DOAC prescription. Estimated glomerular filtration rate (eGFR) was periodically assessed, and the incidence of major bleeding was recorded. A joint survival model was used to estimate the association between variation in eGFR and the risk of major bleeding. Results During a mean follow-up of 575 days, 44 major bleeds occurred in 449 patients (6.1% per patient-year). eGFR over time was inversely and independently associated with the risk of major bleeding; every 1 mL min-1 absolute decrease in eGFR was associated with a 2% increase in the risk of major bleeding (hazard ratio [HR] 1.02, 95% confidence interval [CI] 1.01-1.04). A similar effect of the variation in eGFR over time was observed on the risk of clinically relevant non-major bleeding (HR 1.02, 95% CI 1.01-1.03). Deterioration of renal function leading to a change in eGFR staging was associated with an increase in the risk of major bleeding (HR 2.43, 95% CI 1.33-4.45). Conclusions Variation in renal function over time is associated with the risk of major bleeding in AF patients treated with DOACs in real life. Identification of intervening clinical conditions associated with variation in renal function is essential to reduce the risk of major bleeding and to make DOAC treatment more safe.