Association of visit-to-visit variability in blood pressure and first stroke risk in hypertensive patients with chronic kidney disease

OBJECTIVE: Data on the association between visit-to-visit variability (VVV) in blood pressure (BP) and the risk of stroke among hypertensive patients with chronic kidney disease (CKD) is limited. We aimed to evaluate the relation of VVV in BP with the risk of stroke, and examine any possible effect modifiers in hypertensive patients with mild-to-moderate CKD. METHODS: This is a post-hoc analysis of the China Stroke Primary Prevention Trial. A total of 3091 patients with estimated glomerular filtration rate 30-60 ml/min per 1.73 m and/or proteinuria at baseline, without occurring stroke and with BP measurements of at least two visits from randomization to the 12-month visit were included. The main VVV in BP was expressed as SD. The primary outcome was first stroke. RESULTS: The median subsequent treatment duration was 3.7 years. After multivariable adjustment, including baseline SBP and mean SBP during the first 12-month follow-up, there was a significantly positive relationship of SD SBP with the risk of subsequent first stroke (per SD increment; odds ratio, 1.41; 95% confidence interval: 1.17-1.69) and first ischemic stroke (odds ratio, 1.55; 95% confidence interval: 1.26-1.90). Results were consistent across various subgroups, including age, sex, baseline SBP, treatment compliance, and mean SBP, concomitant usage of calcium channel blocker during the first 12-month follow-up period. Similar trends were also found for coefficient of variation SBP, and SD or coefficient of variation DBP. However, there was no significant association between BP variability and first hemorrhagic stroke. CONCLUSION: In hypertensive adults with mild-to-moderate CKD, visit-to-visit variability in BP was significantly associated with the risk of subsequent first stroke.