Introduction: The relationship between clinical outcome and arterial occlusive lesion (AOL) location in patients after endovascular therapy is not fully determined. We aimed to investigate if the location of the arterial occlusive lesion (AOL) is an independent predictor of good functional outcome.
Hypothesis: AOL location impacts clinical outcome with distal lesions having higher rates of good functional outcome (GFO) in reperfused patients.
Methods: Using data from the CTP to predict Response to recanalization in Ischemic Stroke Project (CRISP), a multi-center, NIH-sponsored prospective cohort study, we analyzed the effect of AOL location on clinical outcome. Patients were included if they had documented reperfusion on early follow-up MR or CT perfusion imaging (>50% reduction in Tmax>6s lesion volume) or on angiography (TICI 2b or 3). Good functional outcome was defined as mRS score 0-2 at day 90. AOL location was categorized as proximal ICA, distal ICA, MCA-M1, or MCA-M2. Fully automated perfusion software (RAPID) was used to calculate CTP infarct core volume (rCBF<30%) and critically hypoperfused tissue volume (Tmax>6s). We assessed whether age, NIHSS score, infarct core, critically hypoperfused tissue, and AOL are associated with GFO using univariate and multivariate analyses.
Results: The analysis included 167 of 201 patients (proximal ICA=21, distal ICA=32, M1=99, M2=15). Median NIHSS score (IQR) for groups were respectively: 18(14-22), 18(15-23), 17(11-20), 15( 13-19). Mean core volumes (mL) (IQR) were: 24.2(1.1-22.9), 13.0(0.0-17.7), 16.5(0.0-26.2), 10.6(1.1-13.0). Significant independent predictors of GFO were age (OR 0.82 for every 5 year increment, 95% CI 0.72-0.94), NIHSS score (OR 0.86, 95% CI 0.79-0.93), and core volume (OR 0.78 for every 10 mL increase, 95% CI 0.62-0.94), whereas AOL location (p=0.8-0.9) and the volume of critically hypoperfused tissue (p=0.5) were not significant in univariate and multivariate analyses.
Conclusion: Baseline symptom severity, infarct core volume, and age drive functional outcomes in stroke patients with successful endovascular reperfusion. These variables, but not AOL location and volume of critically hypoperfused tissue, should be used for prognostication in the acute setting.