Abstract TP152: A Comparison Of Thrombus Characteristics In Patients With Anterior Circulation Stroke And Posterior Circulation Stroke In The Mr Clean Registry

Introduction: In posterior circulation stroke (PCS), large artery atherosclerosis at the occlusion site or dissection is most often reported as underlying stroke etiology, while cardio embolism is less common than in anterior circulation stroke (ACS). As thrombus characteristics are related to the underlying stroke etiology, we hypothesized that differences in radiological thrombus characteristics between PCS and ACS are fully explained by differences in underlying etiology. We compared radiological thrombus characteristics between PCS and ACS to gain insight in the differences in order to optimize treatment options for PCS. Methods: In patients treated with endovascular treatment (EVT) for acute ischemic stroke in the MR CLEAN Registry, radiological thrombus characteristics (perviousness, density, and length) were assessed on thin-slice (<2.5mm) non-contrast computed tomography and computed tomography angiography imaging acquired within 30 minutes from each other. Radiological thrombus characteristics between PCS and ACS patients were compared with univariable and multivariable linear regression with adjustments for baseline differences which could influence thrombus characteristics (age, gender, TOAST (Trial of ORG 10172 in Acute Stroke Treatment) criteria and intravenous alteplase treatment. Results: We analyzed 1052 patients: 118 PCS and 934 ACS patients. PCS thrombi were significantly longer and denser than ACS thrombi: median 23 mm vs 18 mm (p<0.001) and median 53 HU vs 50 HU respectively (p=0.04) (Table 1). After adjustments, thrombus length was significantly different: PCS thrombi were 15 mm longer compared with ACS thrombi (aβ 15, 95% CI 12-18), while thrombus density and perviousness did not significantly differ between ACS and PCS (Table 1). Conclusion: PCS thrombi are significantly longer and denser than ACS thrombi. After adjustment for stroke etiology, only thrombus length was significantly different between PCS and ACS patients.