Abstract TP127: Independent Dose-Response Relationships of Nighttime Blood Pressure with Intracranial Atherosclerotic Burden and Ischemic Events

Background: Hypertension is a primary risk factor for intracranial atherosclerotic stenosis (ICAS), yet the role of circadian blood pressure (BP) patterns, particularly nighttime BP, in ICAS burden and related ischemic events remains unclear. We aimed to investigate the associations of ambulatory BP with ICAS burden and ischemic events. Methods: In this multicenter cross-sectional study, 378 patients with radiologically confirmed ICAS underwent 24-hour ambulatory BP monitoring, magnetic resonance angiography, and high-resolution vessel wall imaging. ICAS burden was categorized as low, moderate, or high based on the number of vessels with ≥50% stenosis or occlusion. Symptomatic ICAS (sICAS) was defined by the presence of ischemic events attributable to ICAS lesions. Logistic regression models were used to evaluate associations between BP parameters and ICAS burden or sICAS. Restricted cubic spline (RCS) analyses assessed potential non-linear dose-response relationships. Results: A total of 301 patients were included in the final analysis. All ambulatory BP parameters were positively associated with ICAS burden after adjusting for cardiovascular risk factors. After mutual adjustment between daytime and nighttime BP, only nighttime SBP and mean arterial pressure (MAP) remained independently associated with ICAS burden. RCS analyses showed significant overall associations for all BP parameters, with non-linear relationships identified for 24-hour MAP and daytime SBP, DBP, and MAP. For sICAS, nighttime DBP and MAP remained independently associated, and all associations were predominantly linear. Conclusions: Nighttime BP exhibits independent dose-response associations with ICAS burden and ischemic events, indicating its potential as a target for risk stratification and management.