Systolic blood pressure and future stroke risk by asymptomatic brain lesions in a community MRI cohort: a retrospective study

Asymptomatic brain lesions (ABLs), including white matter hyperintensities (WMHs), silent brain infarcts (SBIs), and cerebral microbleeds (CMBs), are common MRI markers of cerebral small-vessel disease and predictors of future stroke. However, the optimal blood pressure (BP) target for primary prevention in individuals with ABLs remains unclear. We analyzed 2363 neurologically healthy adults (mean age 61.9 ± 10.9 years; 54% men) who underwent brain MRI screening ("Brain Dock") and were followed for incident stroke over a mean of 8.9 years. ABLs were defined as the presence of SBI, WMH (Fazekas grade ≥ 2), or CMBs. The association between systolic BP (SBP) and stroke risk was evaluated using Cox proportional hazards models with restricted cubic splines, stratified by ABL status, and adjusted for age, sex, HbA1c, LDL-C, and antihypertensive use. The interaction between SBP and the ABL status was not significant. Stroke risk increased progressively with increasing SBP in both groups. In the ABL-positive group, the risk appeared to increase at comparatively lower SBP levels; however, this observation was descriptive and should not be interpreted as indicating a specific threshold. Due to limited stroke events and wide confidence intervals, particularly at higher SBP levels, these spline-based patterns should be considered exploratory rather than definitive. However, confirmation in larger prospective cohorts and interventional studies is needed before MRI-defined cerebrovascular markers can inform clinical blood pressure strategies.