Prediction of Hemorrhagic Transformation and Functional Outcome Using HAT Score in Acute Ischemic Stroke Patients Treated with Intravenous Alteplase

ABSTRACT

BACKGROUND: Intravenous thrombolysis with alteplase is the most effective therapy for acute ischemic stroke, but hemorrhagic transformation (HT) is a potentially dangerous complication of such thrombolysis. Few studies have investigated the predictors of HT after thrombolysis in Korean stroke patients. METHODS: From 2003 to 2009, acute ischemic stroke patients who received intravenous alteplase were included from the prospective stroke registry of Kyung Hee University Hospital. Patients submitted to CT or MRI scans with gradient echo sequences within 12-36 hours of thrombolysis. The Hemorrhage After Thrombolysis (HAT) score [ranging from 0 (minimum risk) to 5 (maximum risk)] was calculated retrospectively for each patient. The predictive ability of the HAT score for HT and symptomatic intracranial hemorrhage (sICH) was calculated using C statistics. RESULTS: Among 151 consecutive patients, HT was confirmed in 35 on follow-up brain imaging. Atrial fibrillation (OR=2.709, 95%CI=1.118-6.567) and low one-third CT scan (OR=3.419, 95%CI=1.281-9.121) increased the risk of HT after intravenous thrombolysis in multivariate logistic regression analysis. HT, sICH (based on the National Institute of Neurological Disorders and Stroke and the Safe Implementation of Treatment in Stroke-Monitoring Study definitions), unfavorable [modified Rankin Scale (mRS) score of 2-6] and poor (mRS score of 3-6) outcomes at 3 months, and mortality at 3 months were increased with higher HAT scores (C statistic=0.632, 0.637, 0.843, 0.670, 0.689, and 0.659, respectively; p=0.018, 0.036, 0.042, 0.002, 0.015, and <0.001). CONCLUSIONS: The HAT score can be used to predict the risk of sICH following intravenous thrombolysis and the long-term clinical outcome.