Functional Outcome Following Blood Pressure Drops Within 24 Hours After Successful Mechanical Thrombectomy

BACKGROUND AND OBJECTIVES: The optimal target blood pressure (BP) during and after mechanical thrombectomy (MT) for acute ischemic stroke remains uncertain. While BP drops during MT are associated with worse outcomes, evidence on postprocedural BP instability is limited. We aimed to assess the impact of BP drops within the first 24 hours after MT on functional outcome. METHODS: Retrospective observational study analyzing data from 2 tertiary stroke centers, gathered between October 2020 and September 2022 within the German Stroke Registry Endovascular Treatment, a national prospective registry of patients receiving MT for ischemic stroke. High-resolution BP data of patients who reached successful recanalization at the end of MT (modified Thrombolysis in Cerebral Infarction [mTICI] ≥2b) were obtained using stroke unit monitoring. BP drops were defined as systolic BP decreases of ≥40 mm Hg occurring within 1 hour during the first 24 hours after groin puncture. Primary outcome was level of disability at 3 months, assessed on the modified Rankin Scale (mRS shift analysis). Secondary outcomes included early neurologic deterioration (defined as an increase of 4 or more points on the National Institutes of Health Stroke Scale (NIHSS) between admission and 24-hour assessment) and death at 3 months. Associations between BP drops and functional outcomes were evaluated using multivariable ordinal and binary logistic regression. RESULTS: Among 300 patients analyzed (median age 77 years [interquartile range (IQR) 65-83], 46.0% female, median admission NIHSS 13 points [IQR 7-17]), 123 patients (41.0%) had at least 1 drop, including 77 patients (62.6%) with 1 drop and 46 patients (37.4%) with 2 or more drops. BP drops were independently associated with worse functional outcome, both in binary (drops vs no drops; adjusted common odds ratio [OR] 1.66 [95% CI 1.02-2.70]) and count-based analysis (adjusted common OR per +1 drop; 1.33 [95% CI 1.05-1.69]). Patients with drops more often had early neurologic deterioration (22.2% vs 13.4%; adjusted OR 2.22 [95% CI 1.03-4.78]). BP drops were not associated with death at 3 months (adjusted OR 1.25, 95% CI 0.66-2.40). DISCUSSION: BP drops within 24 hours after successful MT are associated with worse functional outcome. Targeted measures to prevent or mitigate BP drops should be explored in future studies.