How Well Do Stroke Risk Scores Predict Hemorrhage in Patients With Atrial Fibrillation?

Abstract

<p class="first" id="P1">The decision to use anticoagulants for atrial fibrillation depends on comparing a patient's estimated risk of stroke to their bleeding risk. Several of the risk factors in the stroke risk schemes such as overlap with hemorrhage risk. We compared how well two stroke risk scores (CHADS ₂ and CHA ₂DS ₂-VASc) and two hemorrhage risk scores (the ATRIA bleeding score and the HAS-BLED score) predicted major hemorrhage on and off warfarin in a cohort of 13,559 community-dwelling adults with AF. Over a cumulative 64,741 person-years of follow up, we identified a total of 777 incident major hemorrhage events. The ATRIA bleeding score had the highest predictive ability out of all of the scores in patients on-warfarin (c-index of 0.74 [0.72-0.76] compared to 0.65 [0.62-0.67] for CHADS ₂, 0.65 [0.62-0.67] for CHA ₂DS ₂-VASc, and 0.64 [0.61-0.66] for HAS-BLED) as well as in patients off-warfarin (0.77 [0.74-0.79] compared to 0.67 [0.64-0.71] for CHADS ₂, 0.67 [0.64-0.70] for CHA ₂DS ₂-VASc, and 0.68 [0.65-0.71] for HAS-BLED). In conclusion, although CHADS ₂ and CHA ₂DS ₂-VASc stroke scores were better at predicting hemorrhage than chance alone, they were inferior to the ATRIA bleeding score. Our study supports the use of dedicated hemorrhage risk stratification tools to predict major hemorrhage in atrial fibrillation. </p>