Abstract WP3: Decreases in Blood Pressure During Endovascular Stroke Therapy are Associated With Larger Infarct Volumes and Poor Functional Outcome

Abstract

Background: After large-vessel occlusion (LVO), the fate of the ischemic penumbra, and ultimately final infarct volume, largely depends on compensatory collateral perfusion. Blood pressure (BP) management is critical for avoiding cerebral hypoperfusion and further secondary neurological injury. In this study, we examined the effect of BP reductions and sustained relative hypotension during endovascular therapy (EVT) on infarct volume and functional outcome. Methods: We retrospectively studied patients with LVO stroke who underwent mechanical thrombectomy. Intra-procedural MAP was monitored using a non-invasive BP cuff or an intra-arterial catheter. ΔMAP was calculated as the difference between admission MAP and lowest MAP during EVT. Sustained hypotension (aMAP) was measured as the area between admission MAP and continuous measurements of intra-procedural MAP until recanalization was achieved or procedure was completed. Final infarct volume was measured on MRI at 24hrs. Functional outcome was assessed using the modified Rankin Scale (mRS) at discharge and 90 days. Associations with outcome were analyzed using linear and ordinal regressions and adjusted for age, gender, admission NIHSS and TICI score. Results: 262 patients (mean age 71±16, 58% F, mean NIHSS 17) were included in the analysis. Mean admission MAP was 106 mmHg. 86% of patients experienced ΔMAP reductions during EVT (mean 25±24 mmHg). ΔMAP was associated with larger final infarct volume (n=189, p=0.042). Median ΔMAP among patients with favorable outcomes (mRS 0-3) was 19 mmHg (IQR 3-39) compared to 33 mmHg (IQR 8-49) among patients with poor outcome (p=0.024). ΔMAP was independently associated with higher (worse) mRS scores at discharge (n=255, OR 1.013, 95% CI 1.004-1.023, p=0.008) and at 90 days (n=156, OR 1.014, 95% CI 1.001-1.023 p=0.034). The association between aMAP and outcome was highly significant at discharge (p=0.003) and 90 days (p=0.018). Conclusions: BP reduction prior to recanalization may lead to larger infarct volumes and worse functional outcomes for patients affected by LVO stroke. 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.