Validation of a Score for Predicting Bleeding Events during Acute Coronary Syndromes

Background: Bleeding is a major complication in patients treated for acute coronary syndromes (ACS) with antithrombotic and invasive therapies. Consequently, the benefit of such therapies should be balanced against the potential risk of hemorrhagic complications. Therefore, a score to estimate individual risk of bleeding might represent an important tool in clinical decision-making. Objective: This study aims to create and validate a bleeding risk score for patients with ACS. Methods: Independent predictors of bleeding reported by the GRACE Registry were utilized. Variables with odds ratio (OR) >= 2.5 in that Registry added 3 points (previous history of bleeding), OR = 1.5-2.4 added 2 points (creatinine clearance < 30 ml/min, female gender) and those with OR < 1.5 added 1 point (clearance between 30 and 60 ml/min, each 10 years of age>30, ST-deviation, peripheral artery disease and smoking). The score was validated in a cohort of 383 individuals with ACS. In-hospital bleeding was defined as hematocrit fall >= 10%, blood transfusion >= 2 units, intracerebral bleeding or fatal bleeding. Results: The incidence of bleeding events was 3.1% and the score's C-statistics was 0.66 (95% CI = 0.52-0.80), indicating a predictive ability towards these events. Those with a score >= 7 had 6% incidence of bleeding, compared with 1.9% if the score was < 7 (RR = 3.2; 95%CI = 1.04-9.9; p = 0.03). There was an interaction between a score >= 7 and greater risk imposed by treatment with Clopidogrel (p = 0.02), llb/llla blockers (p = 0.06) and surgical revascularization (p < 0.001). Conclusion: The score discriminates bleeding risk and is potentially useful in clinical decision-making during ACS. (Arq Bras Cardiol 2010; 95(4): 457-463)