COMPARATIVE VALIDATION OF A NOVEL RISK SCORE FOR PREDICTING BLEEDING RISK IN ANTICOAGULATED PATIENTS WITH ATRIAL FIBRILLATION

Title: Comparative Validation of a Novel Risk Score for Predicting Bleeding Risk in Anticoagulated Patients With Atrial Fibrillation: The HAS-BLED (Hypertension, Abnormal Renal/Liver Function, Stroke, Bleeding History or Predisposition, Labile INR, Elderly, Drugs/Alcohol Concomitantly) Score
Date Posted: January 6, 2011
Authors: Lip GY, Frison L, Halperin JL, Lane DA.
Citation: J Am Coll Cardiol 2011;57:173-180.

Study Question:
What are the predictors of bleeding events among patients with atrial fibrillation (AF)?

Methods:
A total of 7,329 patients with AF who were enrolled in SPORTIF (Stroke Prevention Using an ORal Thrombin Inhibitor in Atrial Fibrillation) III and V clinical trials were included in this analysis. Predictive risk stratification schemas were evaluated to examine predictors of bleeding events. Patients were anticoagulated orally with either adjusted-dose warfarin (target international normalized ratio [INR] 2-3) or fixed-dose ximelagatran 36 mg twice daily. Major bleeding was the primary outcome of interest. Concurrent aspirin therapy was allowed in patients with clinical atherosclerosis.

Results:
In this cohort, patients who experienced a major bleeding event (n = 217) were more likely to be elderly, nonsmokers, diabetics, have left ventricular dysfunction, prior stroke (or transient ischemic attack), and impaired renal function. Patients with higher CHADS2 scores had higher risk of bleeding. In multivariate analyses, significant predictors of bleeding were concurrent aspirin use (hazard ratio [HR], 2.10; 95% confidence interval [CI], 1.59-2.77; p < 0.001); renal impairment (HR, 1.98; 95% CI, 1.42-2.76; p < 0.001); age 75 years or older (HR, 1.63; 95% CI, 1.23-2.17; p = 0.0008); diabetes (HR, 1.47; 95% CI, 1.10-1.97; p = 0.009), and heart failure or left ventricular dysfunction (HR, 1.32; 95% CI, 1.01-1.73; p = 0.041). Of the tested schemas, the new HAS-BLED (Hypertension, Abnormal Renal/Liver Function, Stroke, Bleeding History or Predisposition, Labile INR, Elderly, Drugs/Alcohol Concomitantly) score performed best, with a stepwise increase in rates of major bleeding with increasing HAS-BLED score (p for trend < 0.0001). The c statistic for bleeding varied between 0.50 and 0.67 in the overall entire cohort, and 0.68 among patients naïve to warfarin at baseline (n = 769).

Conclusions:
The authors concluded that factors including diabetes and heart failure or left ventricular dysfunction are potential risk factors for bleeding in AF. In addition, the HAS-BLED scheme offers a useful predictive capacity for identification of patients at increased risk for bleeding.

Perspective:
The study uses a large cohort to identify risk factors of major bleeding among patients with AF. Given the significant increase in AF projected over the next several decades, identification of a predictive scheme is clinically important.

POSTED BY STEVEN ALMANY, MD