Abstract WP88: Volumetric Measures of Hemorrhagic Transformation After Acute Ischemic Stroke Predicts Neurological Deterioration Better Than Radiologic Classification

Abstract

Introduction: Hemorrhagic transformation (HT) after acute ischemic stroke (AIS) may contribute to neurologic deterioration. The current radiologic classification of HT is qualitative and distinguishes petechial hemorrhagic infarction from parenchymal hematoma (PH-1 and PH-2). However, this grading scheme is subjective and may not accurately reflect the impact of HT on neurological status and outcome. We sought to evaluate whether the volume of hemorrhage was a better marker of deterioration. Methods: We evaluated AIS patients with follow-up CT imaging from a prospective stroke genetics study. HT seen within 36 hours of AI was classified using ECASS criteria. In addition, we outlined all confluent areas of hemorrhage to derive hemorrhage volume (HV). We calculated ΔNIHSS as the difference between baseline and 24-hour NIHSS. Early neurological deterioration (END) was defined as ΔNIHSS of -4 points or more. Association of radiologic HT grade and HV with ΔNIHSS and END were analyzed using linear regression and receiver-operating-curve testing. Results: We analyzed 948 stroke patients with median NIHSS 7 (IQR 4-14), 64% receiving tPA and ΔNIHSS +2 (IQR 0-5). 294 (31%) had HT (146 HI1, 63 HI2, 42 PH1 and 43 PH2). HT was associated with higher baseline NIHSS but not with tPA treatment or ΔNIHSS. END occurred in 113 (12%) including 46 with HT (16%) vs. 67 (10%) without HT (p=0.02). Amongst those with HT, the radiologic grade was not associated with ΔNIHSS or END (20% of PH2, 20% of PH1 vs. 15% of HI1/HI2, p=0.40). However, greater HV was associated with ΔNIHSS (adjusting for baseline NIHSS and tPA, estimate -1.5 point per 10-ml, p=0.0001) and with END (those with END had median HV 7 vs. 3-ml, p=0.001). A cut-off of 12-ml had 45% sensitivity and 90% specificity for END (AUC of 0.72). Conclusion: We demonstrated that while HT was associated with a higher risk of END, the ECASS classification alone did not distinguish those who worsened. It appears that hemorrhage volume may better predict worsening NIHSS and END with moderate sensitivity.