The Role of Topographic Collaterals in Predicting Functional Outcome after Thrombolysis in Anterior Circulation Ischemic Stroke

BACKGROUNDThe Alberta Stroke Program Early CT (ASPECTS) leptomeningeal collaterals score on CT-angiography helps in prognosticating functional outcome in acute ischemic stroke (AIS) patients treated with intravenous thrombolysis. We evaluated whether a simplified topological ASPECTS collaterals scoring could serve as a rapid biomarker for early prediction in thrombolyzed AIS patients. METHODSConsecutive patients from 2010 to 2014 with anterior circulation AIS treated with intravenous thrombolysis were included. The primary outcome was good functional outcome (modified Rankin scale score 0-1 at 3-months). Collaterals were scored according to the extent of contrast opacification in arteries distal to the acute occlusion. Prognostic value of individual ASPECTS leptomeningeal collateral regions was determined by multivariate logistic regression. RESULTSA total of 283 patients were included (mean National Institutes of Health Stroke Scale [NIHSS] score 19.0 6.3 points). Using multivariate logistic regression, good M5 region (parietal)-collaterals (OR 2.62, 95%CI 1.215-5.682, P = .014), younger age (OR .97 per year, 95%CI .943-.990, P = .006), nondiabetics (OR .44, 95%CI .224-.889, P = .021), and lower NIHSS (OR .89 per point, 95%CI .842-.935, P < .001) were independently associated with good functional outcome. The receiver operating characteristic curve showed NIHSS as a good predictor of functional outcome (area under the curve .718, 95%CI .656-.780, P < .001). However, a better predictive value was achieved when M5 collateral score was added to the NIHSS (area under the curve .752, 95%CI .694-.809, P < .001). CONCLUSIONSGood collaterals in the M5 region are associated with good functional outcome. Addition of this simple neuroimaging tool to the pretreatment NIHSS may serve as a reliable biomarker for prognosis.