Collateral Circulation Predicts the Size of the Infarct Core and the Proportion of Salvageable Penumbra in Hyperacute Ischemic Stroke Patients Treated with Intravenous Thrombolysis

Abstract

Background: We studied the impact of collateral circulation on CT perfusion (CTP) parametric maps and the amount of salvaged brain tissue, the imaging and clinical outcome at 24 h and at 3 months in a retrospective acute (<3 h) stroke cohort (105 patients) with anterior circulation thrombus treated with intravenous thrombolysis. Methods: Baseline clinical and imaging information were collected and groups with different collateral scores (CS) were compared. Binary logistic regression analyses using good CS (CS ≥2) as the dependent variable were calculated. Results: CTP Alberta Stroke Program Early CT Score (ASPECTS) was successfully assessed in 58 cases. Thirty patients displayed good CS. Poor CS were associated with more severe strokes according to National Institutes of Health Stroke Scale (NIHSS) at arrival (15 vs. 7, p = 0.005) and at 24 h (10 vs. 3, p = 0.003) after intravenous thrombolysis. Good CS were associated with a longer mean onset-to-treatment time (141 vs. 121 min, p = 0.009) and time to CTP (102 vs. 87 min, p = 0.047), better cerebral blood volume (CBV) ASPECTS (9 vs. 6, p < 0.001), better mean transit time (MTT) ASPECTS (6 vs. 3, p < 0.001), better noncontrast CT (NCCT) ASPECTS (10 vs. 8, p < 0.001) at arrival and with favorable clinical outcome at 3 months (modified Rankin Scale ≤2, p = 0.002). The fraction of penumbra that was salvageable at arrival and salvaged at 24 h was higher with better CS (p < 0.001 and p = 0.035, respectively). In multivariate analysis, time from the onset of symptoms to imaging (p = 0.037, OR 1.04 per minute, 95% CI 1.00-1.08) and CBV ASPECTS (p = 0.001, OR 2.11 per ASPECTS point, 95% CI 1.33-3.34) predicted good CS. In similar multivariable models, MTT ASPECTS (p = 0.04, OR 1.46 per ASPECTS point, 95% CI 1.02-2.10) and NCCT ASPECTS predicted good CS (p = 0.003, OR 4.38 per CT ASPECTS point, 95% CI 1.66-11.55) along with longer time from the onset of symptoms to imaging (p = 0.045, OR 1.03 per minute, 95% CI 1.00-1.06 and p = 0.02, OR 1.05 per minute, 95% CI 1.00-1.09, respectively). CBV ASPECTS had a larger area under the receiver operating characteristic curve for good CS (0.837) than NCCT ASPECTS (0.802) or MTT ASPECTS (0.752) at arrival. Conclusions: Favorable CBV ASPECTS, NCCT ASPECTS and MTT ASPECTS are associated with good CS along with more salvageable tissue and longer time from the onset of symptoms to imaging in ischemic stroke patients treated with intravenous thrombolysis.

Stroke etiology and collaterals: atheroembolic strokes have greater collateral recruitment than cardioembolic strokes

“…This may be due to frequent use of extracranial stenting in the CASOD population (70%) as well as the fact that chronically ischaemic tissues have a greater tendency for reperfusion injury. Moreover, our study confirms historical data, showing that patients with poor collaterals have lower ASPECTS, larger CTP core at baseline, lower rates of successful reperfusion, worse functional outcomes and larger FIVs .…”

“…Conversely, other studies of unique features and determinants of stroke mechanism (cardioembolic versus atherosclerotic) failed to demonstrate an association between stroke etiology and collateral flow [25,26]. Similarly, two recently published small series evaluated the impact of collaterals on clinical and imaging outcomes in LVOS [3,17]. While they confirmed good collaterals were associated with favorable outcomes, both failed to demonstrate that stroke etiology was a predictor of collateral status.…”

Collateral grade of the Willis' circle predicts outcomes of acute intracranial internal carotid artery occlusion before thrombectomy

“…Collateral status, beyond age, diabetes, NIHSS onset, ASPECTS, and recanalization, can be used to determine infarction and ischemic penumbra volumes (Rusanen, Saarinen, & Sillanpaa, ) and was demonstrated to be positively associated with favorable functional outcomes in both the MR CLEAN trial (Berkhemer et al, ) and the ESCAPE trial (Goyal et al, ). Furthermore, after correcting for stroke severity, Agarwal found that good collateral status was the only independent predictor of improvement in clinical status (Agarwal, Bivard, Warburton, Parsons, & Levi, ).…”

First Automated Stroke Imaging Evaluation via Electronic Alberta Stroke Program Early CT Score in a Mobile Stroke Unit

“…The ASPECTS value has been shown to be associated with vascular pathology [21,22] and is a simple and accurate predictor of functional outcome after thrombolytic treatment [20,23,24]. Patients with an ASPECTS value higher than 7 will probably respond to treatment, whereas those with a value lower than 5 are much less likely to benefit [25].…”