Abstract 177: Absent Collateral Flow on CT Angiogram Predicts Acute Hemorrhagic Transformation in Ischemic Stroke
Background: In patients with a large vessel occlusion, the degree of collateral vascular supply to an ischemic territory has been shown to be a predictor of stroke outcome. Prior studies have focused on the correlation between collateral flow measured on conventional digital subtraction angiography and outcome measures, including the presence of hemorrhagic conversion. CT/CTA is more widely available and more quickly accomplished than MR or conventional angiography. In this work we demonstrate that the absence of CT angiographic collaterals predicts hemorrhage transformation in acute ischemic stroke patients that have persistent vessel occlusion.
Methods: Retrospective review of patient data from a prospectively acquired database identified acute ischemic stroke patients who underwent CT angiography followed by cerebral angiography, and post procedure non-contrast CT scans. Blinded evaluators independently assessed CT angiogram collaterals, angiographic TICI scores, and the presence and severity of post procedure hemorrhagic transformation. Fishers exact test was used to compare proportions between groups.
Results: 146 patients were included. The mean age was 67. The median NIHSS was 15.5 (range 0-32). 34% of patients had any type of hemorrhagic conversion. Of patients with no collaterals on CT angiography, 63% had hemorrhagic conversion versus 23%, 33%, and 38% for patients with grades 1, 2, and 3 collaterals (p<0.05 for comparisons). Patients with TICI scores of 0 or 1 and no CTA collaterals all had hemorrhagic transformation.
Conclusion: The absence of collateral flow on CT angiography in patients without recanalization strongly predicts the acute development of hemorrhagic conversion.
- © 2012 by American Heart Association, Inc.