How Well Does Physician Risk Assessment Predict Stroke and Bleeding in Atrial Fibrillation? Results from the Outcomes Registry for Better Informed Treatment of Atrial Fibrillation (ORBIT-AF)

• Published in: The American heart journal 2016-11, Vol.181, p.145-152
• Main Authors: Steinberg, Benjamin A., MD, MHS, Shrader, Peter, MA, Kim, Sunghee, PhD, Thomas, Laine, PhD, Fonarow, Gregg C., MD, Ansell, Jack, MD, Kowey, Peter R., MD, Singer, Daniel E., MD, Gersh, Bernard J., MB, Ch.B., DPhil, Mahaffey, Kenneth W., MD, Peterson, Eric D., MD, MPH, Piccini, Jonathan P., MD, MHS
• Format: Article
• Language: English
• Subjects: Aged; Aged, 80 and over; Anticoagulants - therapeutic use; Atrial Fibrillation - complications; Atrial Fibrillation - drug therapy; Cardiovascular; Embolism - epidemiology; Embolism - etiology; Embolism - prevention & control; Female; Hemorrhage; Hemorrhage - chemically induced; Hemorrhage - epidemiology; Humans; Male; Middle Aged; Mortality; Patients; Physicians; Proportional Hazards Models; Prospective Studies; Risk assessment; Risk Assessment - methods; Stroke; Stroke - epidemiology; Stroke - etiology; Stroke - prevention & control; Studies; United States - epidemiology
• ISSN: 0002-8703; 1097-6744
• DOI: 10.1016/j.ahj.2016.07.026

Abstract Background Assessments of stroke and bleeding risks are essential to selecting oral anticoagulation (OAC) in patients with atrial fibrillation (AF). We aimed to assess outcomes according to physician assessed risk, with comparison to empirical risk scores. Methods This was a prospective, observational study of 9715 outpatients with AF enrolled in ORBIT-AF, a US national registry. Stroke and bleeding risks were quantified by physician-assignment, CHADS2 and CHA2 DS2 -VASc stroke scores, and ATRIA and HAS-BLED bleeding scores. Outcomes were stroke or systemic embolism and major bleeding during median follow-up of 28 months. Results Physician-assigned risk was associated with thromboembolic events: low risk (0.71 per 100-patient-years [95% CI 0.56–0.91], n = 3991), intermediate risk (0.98 [0.79–1.20], n = 4148) and high risk (1.84 [1.43–2.37], n = 1576; P < .0001); and major bleeding: low (3.43 [3.07–3.82], n = 4250), intermediate (4.55 [4.03–5.15], n = 2702), and high (5.76 [4.42–7.50], n = 468; P < .0001). Discrimination of stroke risk was similar with CHADS2 (c = 0.59, 95% CI: 0.57–0.61) versus physician assessment (c = 0.58, 0.55–0.62). Among patients on OAC, bleeding risk discrimination was higher with ATRIA (c = 0.63, 0.61–0.65) and HAS-BLED (c = 0.60, 0.59–0.62) than with physician assessment (0.55, 0.53–0.57). Physician-assessed risk categories did not add significantly to empirical risk scores, in Cox models for outcomes (padjusted > 0.05 for all physician assessments vs. padjusted < 0.05 for empirical scores). Conclusion Physician-assigned risk showed a graded relationship with outcomes and both physician-based and empirical scores yielded only moderate discrimination. While empirical scores provided valuable risk stratification information (with or without physician judgement), physician-assessment added little to existing scores. These data support the use of empirical scores for stroke and bleeding risk stratification, and the need for novel approaches to risk stratification in this population.