Background: Endovascular therapy (EVT) has been demonstrated to be beneficial regardless of baseline blood pressure (BP). However, questions concerning optimal BP management during EVT remain unanswered. Lowering BP may reduce penumbral perfusion resulting in increased infarct volume and poor outcomes. In this study, we examined the relationship between reductions in intra-procedural BP during EVT and functional outcome.
Methods: We prospectively enrolled patients with acute large-vessel occlusion ischemic stroke undergoing EVT at Yale-New Haven Hospital. Baseline BP was measured at the start of EVT and monitored throughout the procedure. Reductions in BP were calculated as the difference between baseline systolic BP (SBP) and lowest SBP during the intervention. In addition, to distinguish between one time SBP reductions and sustained hypotension, we measured the area between baseline SBP and continuous measurements of intra-procedural SBP. Functional outcome was assessed using the modified Rankin scale (mRS) at discharge and 90 days. Associations between BP reduction and outcome were assessed using ordinal logistic regression.
Results: 68 patients (mean age 73+/-16.7, 36F, mean NIHSS 17) were included in the study. Mean baseline BP was 152/82 mmHg. The median SBP reduction among patients with favorable outcome (mRS ≤2) was 23 mmHg (IQR 11-52) compared to 54 mmHg (IQR 28-86) in the group with poor outcome (p=0.03). A decrease in SBP from initial levels during EVT was independently associated with an increased likelihood for higher (worse) scores on the mRS at discharge (p=0.02) and 3 months (p=0.03) after adjusting for age and admission NIHSS. Every 10 mmHg reduction in SBP from baseline was associated with a 1.4 fold increase in the odds of an unfavorable outcome at 90 days.
Conclusions: BP reduction during EVT may be harmful and lead to worse functional outcomes for patients affected by large-vessel stroke. Even modest, one time reductions in SBP, as frequently occurs during induction of anesthesia, appear to be associated with increased risk for worsened functional status. These results underline the importance of BP management during EVT, and highlight the need for further investigation of active BP management strategies to optimize clinical outcomes.