Abstract 81: Translesional Pressure Gradient Alters the Relationship Between Blood Pressure and Stroke Recurrence in Symptomatic Intracranial Atherosclerotic Disease

Abstract

Objective: Patients with symptomatic intracranial atherosclerotic stenosis (sICAS) have a high risk of stroke recurrence. There is debate over an optimal blood pressure (BP) lowering target in secondary stroke prevention in such patients, when some factors (e.g., impaired cerebral perfusion) may alter the relationship between BP and risk of stroke recurrence. In this study, we investigated whether translesional pressure gradient across sICAS lesions would also alter such relationship. Methods: We recruited patients with sICAS (50-99% stenosis) confirmed in CT angiography (CTA). Computational fluid dynamics (CFD) models were built based on CTA to simulate blood flow across sICAS and calculate the translesional pressure ratio (PR, the ratio of pressures distal and proximal to a lesion). PR ≤ median was defined as low PR, indicating larger translesional pressure gradient and hence restricted downstream perfusion. The primary outcome was recurrent ischemic stroke in the same territory in 1 year. We investigated the interaction of PR and mean systolic BP (SBP) during follow-up in determining the risk of the primary outcome. Results: Among 157 patients, the median PR was 0.93. Multivariate Cox regression revealed significant PR-SBP interaction on the primary outcome (p=0.025): in patients with normal PR, the risk of primary outcome significantly decreased with lower SBP during follow-up (for 10 mmHg decrement: HR 0.46; p=0.018); however, in those with low PR, mean SBP ≤130 mmHg was associated with significantly increased risk of primary outcome, compared with 130<SBP<150mmHg (HR 5.08; p=0.043) (Figure). Conclusion: Intensive BP lowering may increase the risk of stroke recurrence in sICAS patients with a large translesional pressure gradient, warranting further investigation. PR by CFD models may yield a promising indicator to differentiate sICAS patients for different BP management strategies for better secondary stroke prevention.