A higher degree of LMC assessed by PCT-SI predicts good response to iv thrombolysis in MCA ischaemic stroke patients.

Background and Purpose— We aimed to evaluate the impact of brain atrophy on long-term clinical outcome in patients with acute ischemic stroke treated with endovascular therapy, and more specifically, to test whether there are interactions between the degree of atrophy and infarct volume, and between atrophy and age, in determining the risk of futile reperfusion. Methods— We studied consecutive patients with acute ischemic stroke with proximal anterior circulation intracranial arterial occlusions treated with endovascular therapy achieving successful arterial recanalization. Brain atrophy was evaluated on baseline computed tomography with the global cortical atrophy scale, and Evans index was calculated to assess subcortical atrophy. Infarct volume was assessed on control computed tomography at 24 hours using the formula for irregular volumes (A×B×C/2). Main outcome variable was futile recanalization, defined by functional dependence (modified Rankin Scale score >2) at 3 months. The predefined interactions of atrophy with age and infarct volume were studied in regression models. Results— From 361 consecutive patients with anterior circulation acute ischemic stroke treated with endovascular therapy, 295 met all inclusion criteria. Futile reperfusion was observed in 144 out of 295 (48.8%) patients. Cortical atrophy affecting parieto-occipital and temporal regions was associated with futile recanalization. Total global cortical atrophy score and Evans index were independently associated with futile recanalization in an adjusted logistic regression. Multivariable adjusted regression models disclosed significant interactions between global cortical atrophy score and infarct volume (odds ratio, 1.003 [95%CI, 1.002–1.004], P <0.001) and between global cortical atrophy score and age (odds ratio, 1.001 [95% CI, 1.001–1.002], P <0.001) in determining the risk of futile reperfusion. Conclusions— A higher degree of cortical and subcortical brain atrophy is associated with futile endovascular reperfusion in anterior circulation acute ischemic stroke. The impact of brain atrophy on insufficient clinical recovery after endovascular reperfusion appears to be independently amplified by age and by infarct volume.

Background and Purpose— Selection of best responders to reperfusion therapies could be aided by predicting the duration of tissue-at-risk viability, which may be dependant on collateral circulation status. We aimed to identify the best predictor of good collateral circulation among perfusion computed tomography (PCT) parameters in middle cerebral artery (MCA) ischemic stroke and to analyze how early MCA response to intravenous thrombolysis and PCT-derived markers of good collaterals interact to determine stroke outcome. Methods— We prospectively studied patients with acute MCA ischemic stroke treated with intravenous thrombolysis who underwent PCT before treatment showing a target mismatch profile. Collateral status was assessed using a PCT source image–based score. PCT maps were quantitatively analyzed. Cerebral blood volume (CBV), cerebral blood flow, and Tmax were calculated within the hypoperfused volume and in the equivalent region of unaffected hemisphere. Occluded MCAs were monitored by transcranial Duplex to assess early recanalization. Main outcome variables were brain hypodensity volume and modified Rankin scale score at day 90. Results— One hundred patients with MCA ischemic stroke imaged by PCT received intravenous thrombolysis, and 68 met all inclusion criteria. A relative CBV (rCBV) >0.93 emerged as the only predictor of good collaterals (odds ratio, 12.6; 95% confidence interval, 2.9–55.9; P =0.001). Early MCA recanalization was associated with better long-term outcome and lower infarct volume in patients with rCBV<0.93, but not in patients with high rCBV. None of the patients with rCBV<0.93 achieved good outcome in absence of early recanalization. Conclusions— High rCBV was the strongest marker of good collaterals and may characterize durable tissue-at-risk viability in hyperacute MCA ischemic stroke.