Association of 24-hour blood pressure parameters post-thrombectomy with functional outcomes according to collateral status

Abstract

IntroductionElevation of blood pressure (BP) after mechanical thrombectomy (MT) can theoretically restore perfusion to the ischemic brain tissue, but it comes at a risk of causing reperfusion injury. We aim to determine the association of 24-h post-MT BP parameters with clinical outcomes depending on the pre-MT collateral status. MethodsWe performed a retrospective chart review of patients who underwent MT at a comprehensive stroke center from 7/2014 to 12/2020. The patients were divided into good versus poor collateral groups depending on their collateral status. A board-certified neuroradiologist, who was blinded to the clinical outcomes, used collateral grading score of Miteff ≥3 to designate good collaterals on the pre-MT CT Angiogram. A binary logistic regression analysis was performed, controlling for baseline parameters, with the 24-h post-MT BP parameters as predictors. The outcomes were functional dependence [3-month mRS (3–6)] and mortality. ResultsA total of 220 met the inclusion criteria. In the multivariable analysis, for patients with poor collaterals, the parameters of higher mean SBP (131.7 ± 12.7 vs. 122.3 ± 14.2; OR, 1.06; 95% CI, 1.01–1.11; P 0.022), higher mean MAP (91.2 ± 8.2 vs. 86.1 ± 6.3; OR, 1.13; 95% CI, 1.03–1.23; P 0.015) and a higher maximum SBP (156.3 ± 13.7 vs. 145.3 ± 19.1; OR, 1.05; 95% CI, 1.01–1.1; P 0.019) were significantly associated with functional dependence at 3-months. For patients with good collaterals, the parameters of lower 24-h mean DBP (69.1 ± 11.1 vs. 73.8 ± 11 95% CI, OR, 0.96; 95% CI, 0.92–1; P 0.025) was significantly associated with higher mortality at 3-months. Conclusion: Our study demonstrates that there is a significant difference with respect to certain 24-h post-MT BP parameters in patients on clinical outcomes depending on their collateral status. In our study, some higher BP parameters were associated with worse outcomes in patients with a poor collateral profile, however, this effect was not replicated in patients with a good collateral profile.