Outcome of patients with multivessel occlusion stroke after endovascular treatment.

INTRODUCTION: Little is known about the implications of multivessel occlusions (MVO) in large vessel occlusion stroke patients who undergo endovascular treatment (EVT). PATIENTS AND METHODS: We report data from the MR CLEAN Registry: a prospective, observational study on all stroke patients who underwent EVT in the Netherlands (March 2014-November 2017). We included patients with an intracranial target occlusion in the anterior circulation. An MVO was defined as an MCA occlusion (M1/M2) or intracranial ICA/ICA-T occlusion, with a concurrent second occlusion in the ACA or PCA territory confirmed on baseline CTA. To compare outcomes, we performed a 10:1 propensity score matching analysis with a logistic regression model including potential confounders. Outcome measures included 90-day functional outcome (modified Rankin Scale, mRS) and mortality. RESULTS: Of 2946 included patients, 71 patients (2.4%) had an MVO (87% concurrent ACA occlusion, 10% PCA occlusion, 3% ⩾3 occlusions). These patients were matched to 71 non-MVO patients. Before matching, MVO patients had a higher baseline NIHSS (median 18 vs 16, p = 0.001) and worse collateral status (absent collaterals: 17% vs 6%, p < 0.001) compared to non-MVO patients. After matching, MVO patients had worse functional outcome at 90 days (median mRS 5 vs 3, cOR 0.39; 95%CI 0.25-0.62). Mortality was higher in MVO patients (46% vs 27%, OR 2.11, 95%CI 1.24-3.57). DISCUSSION AND CONCLUSION: MVOs on baseline imaging were uncommon in LVO stroke patients undergoing EVT, but were associated with poor functional outcome.

Impact of single phase CT angiography collateral status on functional outcome over time: results from the MR CLEAN Registry.

BACKGROUND: Collateral status modified the effect of endovascular treatment (EVT) for stroke in several randomized trials. We assessed the association between collaterals and functional outcome in EVT treated patients and investigated if this association is time dependent. METHODS: We included consecutive patients from the Multicenter Randomized Clinical Trial of Endovascular Treatment for Acute Ischemic Stroke in The Netherlands (MR CLEAN) Registry (March 2014-June 2016) with an anterior circulation large vessel occlusion undergoing EVT. Functional outcome was measured on the modified Rankin Scale (mRS) at 90 days. We investigated the association between collaterals and mRS in the MR CLEAN Registry with ordinal logistic regression and if this association was time dependent with an interaction term. Additionally, we determined modification of EVT effect by collaterals compared with MR CLEAN controls, and also investigated if this was time dependent with multiplicative interaction terms. RESULTS: 1412 patients were analyzed. Functional independence (mRS score of 0-2) was achieved in 13% of patients with grade 0 collaterals, in 27% with grade 1, in 46% with grade 2, and in 53% with grade 3. Collaterals were significantly associated with mRS (adjusted common OR 1.5 (95% CI 1.4 to 1.7)) and significantly modified EVT benefit (P=0.04). None of the effects were time dependent. Better collaterals corresponded to lower mortality (P<0.001), but not to lower rates of symptomatic intracranial hemorrhage (P=0.14). CONCLUSION: In routine clinical practice, better collateral status is associated with better functional outcome and greater treatment benefit in EVT treated acute ischemic stroke patients, independent of time to treatment. Within the 6 hour time window, a substantial proportion of patients with absent and poor collaterals can still achieve functional independence.

Collateral status and tissue outcome after intra-arterial therapy for patients with acute ischemic stroke.

Intra-arterial therapy (IAT) for ischemic stroke aims to save brain tissue. Collaterals are thought to contribute to prolonged penumbra sustenance. In this study, we investigate the effect of collateral status on brain tissue salvage with IAT. In 500 patients randomized between IAT and standard care, collateral status was graded from 0 (absent) to 3 (good). Final infarct volumes (FIV) were calculated on post-treatment CT. FIVs were compared between treatment groups per collateral grade. Multivariable linear regression with interaction terms was performed to study whether collaterals modified IAT effect on FIV. Four-hundred-forty-nine patients were included in the analysis. Median FIV for the IAT group was significantly lower with 54.5 mL (95% IQR: 21.8-145.0) than for the controls with 81.8 mL (95% IQR: 40.0-154.0) ( p = 0.020). Treatment effect differed across collateral grades, although there was no significant interaction (unadjusted p = 0.054; adjusted p = 0.105). For grade 3, IAT resulted in a FIV reduction of 30.1 mL ( p = 0.024). For grade 2 and 1, this difference was, respectively, 28.4 mL ( p = 0.028) and 28.4 mL ( p = 0.29). For grade 0, this was 88.6 mL ( p = 0.28) in favour of controls. IAT saves substantially more brain tissue as compared to standard care. We observed a trend of increasing effect of IAT with higher collateral grades.