Studies have shown that elevated BPV following EVT for large vessel occlusion ischemic stroke is associated with lower odds of good functional outcome. However, pre-procedural BPV has not been evaluated in this context. 

We included sequential ischemic stroke patients with occlusion of the internal carotid or middle cerebral artery (M1 and M2 segments) who were treated with EVT at the University of Utah after transfer from a regional hospital by helicopter. The primary outcome is 90-day modified Rankin Scale of 0-2, which we termed good outcome. The primary predictor is BPV, defined as the standard deviation (SD) and coefficient of variation (CV=SD/mean) of SBP during helicopter transport. Patients with less than 3 BP measurements were excluded. We fit logistic regression models and adjusted for age, sex, baseline NIHSS, post procedural TICI score, and number of BP measurements.

We included 41 patients with a mean age of 68.9 years, 58.5% male, median NIHSS of 17 (10-23), mean per-patient number of BP measurements of 11.9, and mean duration of interhospital transit of 178.5 minutes. There were 12/41 (29.3%) patients with good outcome. The mean SD was lower in patients with good vs. poor outcome (7.9±3.7 vs. 13.2±5.9, p=0.006), as was CV (5.4±2.6 vs. 9.8±5.6, p=0.014). In the multivariate logistic regression model, we continued to see that lower BPV was associated with good outcome (SD: OR 0.74, 95% CI 0.57-0.96, p=0.025; CV: OR 0.65, 95% CI 0.45-0.95, p=0.026). Mean SBP was not significantly associated with outcome in this analysis (data not shown).

Our analysis suggests that elevated pre-procedural BPV during interhospital transport for EVT is associated with lower odds of good functional outcome at 90 days. Additional research is needed to confirm these preliminary findings.