Clot Burden Score on Baseline Computerized Tomographic Angiography and Intra-Arterial Treatment Effect in Acute Ischemic Stroke

Abstract

R ecanalization of the occluded vessel is the major focus of modern treatment for acute ischemic stroke. With the accumulating evidence of the additional benefit of intra-arterial treatment (IAT) in patients with anterior circulation acute ischemic stroke, a new era has started in stroke management. [1][2][3][4][5] However, even after IAT, up to 67% of patients with acute Background and Purpose-A high clot burden score (CBS) is associated with favorable outcome after intravenous treatment for acute ischemic stroke. The added benefit of intra-arterial treatment might be less in these patients. The aim of this exploratory post hoc analysis was to assess the relation of CBS with neurological improvement and endovascular treatment effect. Methods-For 499 of 500 patients in the MR CLEAN study (Multicenter Randomized Clinical Trial of EndovascularTreatment for Acute Ischemic Stroke in the Netherlands), the CBS was determined. Ordinal logistic regression models with and without main baseline prognostic variables were used to assess the association between CBS (continuous or dichotomized at CBS of 6) and a shift toward better outcome on the modified Rankin Scale. The model without main baseline prognostic variables only included treatment allocation and CBS. Models with and without a multiplicative interaction term of CBS and treatment were compared using the χ 2 test to assess treatment effect modification by CBS. Results-Higher CBS was associated with a shift toward better outcome on the modified Rankin Scale; adjusted common odds ratio per point CBS was 1.12 (95% confidence interval, 1.04-1.20]. Dichotomized CBS had an adjusted common odds ratio of 1.67 (95% confidence interval, 1.12-2.51). Both effect estimates were slightly attenuated by adding baseline prognostic variables. The addition of the interaction terms did not significantly improve the fit of the models. There was a small and insignificant increase of intra-arterial treatment efficacy in the high CBS group. Conclusions-A higher CBS is associated with improved outcome and may be used as a prognostic marker. We found no evidence that CBS modifies the effect of intra-arterial treatment. Clinical Trial Registration-URL: http://www.trialregister.nl. Unique identifier: NTR1804. URL: http://www.controlledtrials.com. Unique identifier: ISRCTN10888758.

Predictive value of thrombus volume for recanalization in stent retriever thrombectomy

“…This study showed that the thrombus volume was significantly related to successful recanalization with an SR. Previous studies have shown inconsistent findings in terms of the association between the thrombus burden and recanalization after mechanical thrombectomy by means of an SR 6 , 9 – 15 . The inconsistency between the studies might be partly ascribed to differences in the method used to measure thrombus burden and the number of patients 16 .…”

Does Clot Burden Score on Baseline T2*-MRI Impact Clinical Outcome in Acute Ischemic Stroke Treated with Mechanical Thrombectomy?

“…Amongst factors influencing recanalization success, clot length is an important determinant [10-12], that was scarcely assessed in the recent RCTs. Indeed, if patients were included in case of LVO on computed tomography angiography (CTA), only few studies [13,14] assessed clot length using the CTA-defined clot burden score (CTA-CBS). These analyses demonstrated a direct link between clot length, likelihood of recanalization, final infarct volumes, and 3-month neurological outcome.…”

Computed Tomography-Based Thrombus Imaging for the Prediction of Recanalization after Reperfusion Therapy in Stroke

“…It might be because of the different mechanical devices used, different methods used to determine thrombus size, and small number of cases included [ 21 , 25 - 30 ]. However, in a recent study of a relatively large number of patients who were treated with a stent retriever, higher clot burden scores were associated with increased likelihood of recanalization [ 2 ]. Smaller thrombi may be more easily retrieved with fewer attempts using a Solitaire device.…”

“…This scoring system provides easy and rapid, yet only approximate, information on thrombus burden and can be used for the occlusion in anterior circulation only. The clot burden score is also influenced by the backflow from collateral circulation; hence, clot burden may be overestimated in cases with insufficient collaterals [ 2 ]. However, overestimated clot burden because of the lack of contrast filling due to poor collaterals may strengthen the prognostic value of this clot burden score because poor collaterals are known to be associated with poor outcomes [ 2 ].…”

“…Imaging methods in stroke have been developed and evolved for the accurate diagnosis of infarction/hemorrhage and arterial occlusion and the assessment of perfusion and collateral circulation. Since the successful introduction of reperfusion therapy in stroke, one of the key issues has been the selection of patients who would benefit from the recanalization therapy [ 1 , 2 ]. Thus, the development and use of imaging techniques in acute stroke have been focused on identifying the presence and extent of potentially salvageable areas upon recanalization and the durability of ischemic areas until recanalization.…”