Higher Blood Pressure during Endovascular Thrombectomy in Anterior Circulation Stroke Is Associated with Better Outcomes

Abstract

Background and purpose: Reports investigating the relationship between in-procedure blood pressure (BP) and outcomes in patients undergoing endovascular thrombectomy (EVT) due to anterior circulation stroke are sparse and contradictory.

Methods: Consecutive EVT-treated adults (modern stent retrievers, BP managed in line with the recommendations, general anesthesia, invasive BP measurements) were evaluated for associations of the rate of in-procedure systolic BP (SBP) and mean arterial pressure (MAP) excursions to >120%/<80% of the reference values (serial measurements at anesthesia induction) and of the reference BP/weighted in-procedure mean BP with post-procedure imaging outcomes (ischemic lesion volume [ILV], hemorrhages) and 3-month functional outcome (modified Rankin Scale [mRS], score 0 to 2 vs. 3 to 6).

Results: Overall 164 patients (70.7% pharmacological reperfusion, 80.5% with good collaterals, 73.8% with successful reperfusion) were evaluated for ILV (range, 0 to 581 cm3) and hemorrhages (incidence 17.7%). Higher rate of in-procedure SBP/MAP excursions to >120% was independently associated with lower ILV, while higher in-procedure mean SBP/MAP was associated with lower odds of hemorrhages. mRS 0-2 was achieved in 75/155 (48.4%) evaluated patients (nine had missing mRS data). Higher rate of SBP/MAP excursions to >120% and higher reference SBP/MAP were independently associated with higher odds of mRS 0-2, while higher ILV was associated with lower odds of mRS 0-2. Rate of SBP/MAP excursions to <80% was not associated with any outcome.

Conclusion: s In the EVT-treated patients with BP managed within the recommended limits, a better functional outcome might be achieved by targeting in-procedure BP that exceeds the preprocedure values by more than 20%.

Keywords: Anesthesia, general; Blood pressure; Mechanical thrombolysis; Stroke.

Figure 1.

(A) Patient flow. (B) Steps in data analysis. We analyzed relationships between blood pressure (BP) during endovascular thrombectomy (EVT) with or without recombinant tissue plasminogen activator (rtPA) with (1) post-procedure computed tomography (CT) findings: ischemic lesion volume (ILV) and visible hemorrhages; (2) functional outcome at 3 months. We explored a possibility of a mediated association: in-procedure BP → ILV/visible hemorrhage → 3-month functional outcome.

Figure 2.

Model selection strategy. All models were fitted separately for systolic blood pressure (BP) and mean arterial pressure. TICI, Thrombolysis in Cerebral Infarction; EVT, endovascular thrombectomy; NIHSS, National Institutes of Health Stroke Scale; mRS, modified Rankin Scale.

Figure 3.

Disposition of patients. EVT, endovascular thrombectomy; BP, blood pressure; TOAST, Trial of Org 10172 in Acute Stroke Treatment classification; CE, cardioembolic; unk., unknown etiology; LAA, large artery atherosclerosis; MCA, middle cerebral artery, segment 1, segment 2; rtPA, recombinant human tissue plasminogen activator; TICI, Thrombolysis in Cerebral Infarction; CT, computed tomography; ILV, ischemic lesion volume; mRS, modified Rankin Scale.

Figure 4.

Mediation analysis: association of in-procedure systolic blood pressure (SBP) and mean arterial pressure (MAP) excursions to >120% of their reference values with 3-month modified Rankin Scale (mRS) score 0-2 is mediated through their association with the ischemic lesion volume (ILV). (A) Outline of associations. All associations are adjusted for all other model effects. Effects are from models analyzing ILV (Table 2) and mRS (Table 3). (B) Mediation model for SBP. (C) Mediation model for MAP. Higher rate of blood pressure (BP) excursions, Thrombolysis in Cerebral Infarction (TICI) scale grade 2b-3 and good collaterals are each directly associated with lower ILV; lower ILV is directly associated with higher odds of mRS 0-2; direct association of these predictors with mRS 0-2 is uncertain; each is associated with mRS 0-2 indirectly, via ILV. Effects are expressed as percent change in ILV or odds of mRS 0-2 with 95% confidence interval. NIHSS, National Institute of Stroke Scale.