Background: Endovascular treatment (EVT) of large vessel anterior circulation stroke has become standard of care. Emerging clinical trials have shown effectiveness of EVT for anterior circulation strokes beyond 6 hours after stroke onset. In addition to imaging criteria, it is important to understand clinical and demographic predictors of poor outcomes in this subgroup.
Methods: A hospital based stroke registry was used for retrospective analysis of 225 consecutive cases of large vessel anterior circulation strokes. Poor outcome was defined as >1/3 middle cerebral artery territory infarct (MCAI) on MRI diffusion weighted imaging or on CT scan performed approximately 24 hours from treatment. Multivariate logistic regression model was used to identify demographic and clinical predictors of poor outcome. IBM - SPSS version 24 was used for data analysis.
Results: In the study cohort, 31.25% patients had <1/3 MCAI. Group of patients with >1/3 MCAI had higher admission NIHSS (National Institute of Health Stroke Scale) (19.37 Vs 15.52, p<0.001) and admission systolic blood pressure (SBP) (153.28 Vs.138.54, p<0.001) compared to <1/3 MCAI group. There was no statistically significant difference noted in time from symptom onset to re-canalization (335.11 Vs 306.04, p=0.24), admission diastolic blood pressure (DBP) (80.19 Vs 80.81, p=0.83) SBP at 24 hour (132.00 Vs.132.61, p=0.84), and DBP at 24 hours 66.97 Vs 64.71, p=0.28). Higher admission SBP [Odds ratio (OR) 1.028; 95% CI (Confidence Interval) 1.002- 1.056, p=0.007) and NIHSS [OR 1.26; 95% CI 1.13 - 1.41, p<0.001) independently predicted >1/3 MCAI after controlling for clinical and demographic variables in multivariate logistic regression analysis.
Conclusion: SBP on initial presentation predicted >1/3 MCAI in large vessel anterior circulation strokes treated with EVT. This finding was in a setting of non-significant difference in DBP on initial presentation, SBP and DBP at 24 hours in >1/3 MCAI versus <1/3 MCAI groups. In addition to the understanding of tissue at risk based on imaging, optimal hemodynamic parameter goals need to be investigated in post thrombectomy care to minimize tissue injury.