Admission Blood Pressure and Infarct Volume in Patients With Large Vessel Occlusions. Insights From the ASTER Trial

Background: Higher systolic blood pressure (SBP) has been shown to be associated with worse outcome after mechanical thrombectomy. However, it is still unknown if higher admission SBP is just an epiphenomenon of higher infarct volume leading to the worse outcome or if the SBP association with the outcome is independent of infarct volume. In this study, we aimed to study the correlation between admission SBP and both admission infarct volume and 24 change in infarct volume. Methods: This is a post hoc analysis of the ASTER randomized trial. Cuff admission SBP was measured on presentation prior to thrombectomy. Diffusion-weighted imaging (DWI) infarct volume was measured on admission and at 24-hours post-procedure. Delta volume was measured by calculating the difference between the admission and 24-hour DWI lesions. Results: A total of 126 patients (mean age was 68.9 ± 14.8 years, median NIHSS was 17 (IQR, 11 to 20), 66% received tPA and 87% achieved mTICI 2b-3 at the end of the procedure) had MRI on admission and were included in this study. There was weak and not statistically significant negative correlation between admission SBP and infarct volume (R=-0.15; P=0.08). We did not find any correlation between admission SBP and 24 hours delta infarct volume. On generalized logistic regression analysis adjusting for infarct volume, SBP was associated with 90-day functional independence (modified Rankin Scale <3) (OR,0.84; 95% CI, 0.70-0.99; p=0.049). Conclusion: We did not find a significant correlation between infarct volume on admission and admission SBP. Moreover, the association between admission SBP and functional outcome was independent of infarct volume.