Supplementary Material for: Relative hypotension is not associated with rapid progressor phenotype in anterior circulation large vessel occlusion acute ischaemic stroke: A retrospective cohort study

Introduction: We aimed to determine whether relative hypotension, defined as a systolic blood pressure (SBP) threshold of below 140mmHg or 160mmHg at the time of neuroimaging, was associated with rapid infarct progressor phenotype, as defined by a high hypoperfusion intensity ratio on MISTAR imaging software (DT6/DT2>0.318) during anterior circulation large vessel occlusion (LVO) acute ischaemic stroke (AIS).
Methods: In a retrospective cohort study, consecutive patients admitted to a metropolitan comprehensive stroke centre within South Australia between January 2017 to January 2024 with anterior circulation LVO AIS were included. LVO was defined as either carotid terminus or M1 occlusion. Univariable and multivariable logistic regression were performed.
Results: A total of 477 patients were included (253 (53.0%) female), of whom 163 (34.2%) had elevated hypoperfusion intensity ratio (HIR). Hypotension, as defined by either SBP<160mmHg (OR 1.2, 95%CI 0.8-1.8) or SBP<140mmHg (OR 1.7, 95% CI 0.8-1.7) was not associated with elevated HIR. Insular cortex ischaemia (OR 6.1, 95% CI 1.7-38.9) and ischaemic heart disease (OR 2.0, 95% CI 1.3-3.1) were associated with elevated HIR. Smoking history (OR 0.5, 95% CI 0.3-0.9) and obesity (OR 0.4, 95% CI 0.2-0.8) were associated with lower HIR.
Conclusion: Relative hypotension was not significantly associated with rapid infarct progressor phenotype in anterior circulation LVO AIS. Insular cortex ischaemia and ischaemic heart disease were associated with rapid progression phenotype, whilst smoking history and obesity were associated with slower progression phenotype. Further mechanistic studies to elucidate how systemic comorbidities and regional brain vulnerability contribute to infarct evolution are needed.