Stroke and Bleeding Risk Co-distribution in Real-world Patients with Atrial Fibrillation: The Euro Heart Survey

BACKGROUND: The choice to recommend antithrombotic therapy to patients with atrial fibrillation should rely on cardioembolic and bleeding risk stratification. Sharing some risk factors, schemes to predict thrombotic and bleeding risk are expected not to be independent, yet the degree of their association has never been clearly quantified. METHODS: We described the cardioembolic (Congestive heart failure, Hypertension, Age >75, Diabetes mellitus, and prior Stroke or transient ischemic attack [CHADS(2)]/Congestive heart failure, Hypertension, Age >75, Diabetes mellitus, and prior Stroke or transient ischemic attack, Vascular disease, Age 65-75, Sex category i.e. females [CHA(2)DS(2)-VASc]) and bleeding risk (Hypertension, Abnormal renal/liver function, Stroke, Bleeding history or predisposition, Labile international normalized ratio, Elderly (>65 years), Drugs/alcohol concomitantly [HAS-BLED]) co-distribution among patients of the Euro Heart Survey on atrial fibrillation. We measured the within-patient correlation (Spearman) and concordance between the 2 types of score and score-based risk categorization (low, intermediate, high). The score-based predicted risk co-classification was then related to the observed 1-year stroke and bleeding occurrence. RESULTS: In 3920 patients, we found a between-scores correlation of 0.416 (P <.001) between HAS-BLED and CHADS(2), and 0.512 (P <.001) between HAS-BLED and CHA(2)DS(2)-VASc. In 89% (CHADS(2)/HAS-BLED) and 97% (CHA(2)DS(2)-VASc/HAS-BLED) of patients, the bleeding risk category was equal to or lower than their cardioembolic risk category (P <.001 for symmetry test). A complete concordance between risk categories was found in 39.6% (CHADS(2)/HAS-BLED) and 21.7% (CHA(2)DS(2)-VASc/HAS-BLED) of patients; 4.4% (CHADS(2)/HAS-BLED) and 7.7% (CHA(2)DS(2)-VASc/HAS-BLED) of patients had high cardioembolic risk/low bleeding risk or vice versa. A tendency for an increasing frequency of stroke was observed for increasing bleeding risk within cardioembolic risk categories and vice versa. CONCLUSIONS: In a real-world population with atrial fibrillation, we confirmed that the cardioembolic and bleeding risk classifications are correlated but not exchangeable. It is then worth verifying the advantages of a strategy adopting a combined risk assessment over a strategy relying only on the cardioembolic risk evaluation.