The HAS-BLED Score Identifies Patients with Acute Venous Thromboembolism at High Risk of Major Bleeding Complications during the First Six Months of Anticoagulant Treatment

Objective The HAS-BLED score enables a risk estimate of major bleeds in patients with atrial fibrillation on vitamin K-antagonists (VKA) treatment, but has not been validated for patients with venous thromboembolism (VTE). We analyzed whether the HAS-BLED score accurately identifies patients at high risk of major bleeds during VKA treatment for acute VTE. Methods Medical records of 537 patients with acute VTE (primary diagnosis pulmonary embolism in 223, deep vein thrombosis in 314) starting VKA treatment between 2006-2007 were searched for items on the HAS-BLED score and the occurrence of major bleeds during the first 180 days of follow-up. The hazard ratio (HR) for the occurrence of major bleeds comparing non-high with high-risk patients as defined by a HAS-BLED score ≥ 3 points was calculated using Cox-regression analysis. Results Major bleeds occurred in 11/537 patients (2.0%, 5.2/100 person years, 95% CI 2.8-9.2). Cumulative incidences of major bleeds were 1.3% (95% CI 0.1-2.5) in the non-high (HAS-BLED < 3) and 9.6% (95%CI 2.2-17.0) in the high-risk group (HAS-BLED ≥ 3), (p <0.0001 by Log-Rank test), with a HR of 8.7 (95% CI 2.7-28.4). Of the items in the HAS-BLED score, abnormal renal function (HR 10.8, 95% CI 1.9-61.7) and a history of bleeding events (HR 10.4, 95% CI 2.5-42.5) were independent predictors of major bleeds during follow-up. Conclusion Acute VTE patients with a HAS-BLED score ≥ 3 points are at increased risk of major bleeding. These results warrant for correction of the potentially reversible risk factors for major bleeding and careful International Normalized Ratio monitoring in acute VTE patients with a high HAS-BLED score.