Strict blood pressure control following thrombectomy is associated with neuronal injury and poor functional outcome

Objective: Mechanical thrombectomy (MT) has become standard treatment in acute ischemic stroke due to large vessel occlusion (LVO). However, optimal blood pressure (BP) management following successful recanalization remains unclear. We aim to investigate the association of strictly achieving BP targets of ≤160/90 mmHg with the extent of neuronal loss and functional outcome.

Methods: In patients prospectively enrolled in the Gutenberg-Stroke-Study (May 2018-November 2019), BP was measured half-hourly for 24 h following MT. Based on achieving BP target of ≤160/90 mmHg, patients with successful recanalization of LVO were divided into "low-BP" group (BP ≤ 160/90 mmHg) or "high-BP" group (BP > 160/90 mmHg). Neuronal loss was quantified by serum-based measurement of neurofilament light chain (sNfL) after three days. BP groups and association of BP parameters with sNfL were investigated by correlation analyses and multiple regression modeling.

Results: Of 253 enrolled patients (mean age 73.1 ± 12.9 years, 53.4% female), 165 met inclusion criteria. 21.2% (n = 35) strictly achieved "low-BP" target. "low-BP" was associated with unfavorable functional outcome at 90-day follow-up (aOR [95%CI]: 5.88 [1.88-18.32], p = 0.002) and decreased health-related quality of life (mean EQ-5D-index 0.45 ± 0.28 vs 0.63 ± 0.31, p = 0.009). sNfL levels were increased in "low-BP" patients (median [IQR] 239.7 [168.4-303.4] vs 118.8 [52.5-220.5] pg/mL, p = 0.026). Hypotensive episodes were more frequent in the "low-BP" group (48.6% vs 29.2%, p = 0.031). sNfL level could identify patients who had experienced hypotensive episodes with high discriminative ability (AUC [95%CI]: 0.68 [0.56-0.78], p = 0.007).

Interpretation: Strict BP control (≤160/90 mmHg) within 24 h following successful recanalization of LVO by MT is associated with increased neuronal injury, displayed by higher sNfL levels, and poorer functional outcome, potentially indicating hypotension-induced neuronal loss during post-MT phase.