OS 19-02 RELATIONSHIP BETWEEN VISIT-TO-VISIT BLOOD PRESSURE VARIABILITY (BPV) AND KIDNEY FUNCTION IN PATIENTS WITH HYPERTENSION.

OBJECTIVE: High blood pressure variability (BPV) and worsening kidney function have both independently been linked to a higher risk for cardiovascular events. We aimed to investigate the impact of kidney function on BPV (using estimated glomerular filtration rate, eGFR), via a retrospective post hoc analysis of patients with hypertension.

DESIGN AND METHOD: Subject level data were extracted from the ASCOT-BPLA (N = 18,852) and ALLHAT (N = 26,441) databases; both were randomized, active controlled studies, and treatment duration for hypertension was at least 4-years. Visit-to-visit BPV was assessed using standard deviation (SD) and coefficient of variation of systolic blood pressure (SBP) across visits from 12 weeks. Baseline GFR, estimated by the simplified Modification of Diet in Renal Disease equation, was stratified into ≤ 60, 61-90, and > 90 ml/min per 1.73 m. The relationship between BPV and eGFR was analyzed using an analysis of covariance (ANCOVA), with baseline factors (see Table) considered as covariates. The square root of the coefficient of variation of BP was utilized. Studies were assessed individually and together.

RESULTS: Patient characteristics were largely consistent between studies. In the overall population (n = 38,133) there were 19.1%, 62.9% and 18.0% patients, with eGFR ≤60, 61-90, and >90 ml/min/1.73 m, respectively. Patients with lower baseline eGFR had higher BPV, in both the pooled population and each study analyzed separately. Other baseline predictors included higher SBP and age, being male, and a smoker. Being on amlodipine vs. other antihypertensive treatments was a negative predictor of BPV (Table).

CONCLUSIONS: Patients with declining renal function tend to have higher BPV compared with those without, even after adjusting for known risk factors or potential risk factors for BPV. Therefore, when treating patients with hypertension who are also renally compromised, strategies for managing BP should be carefully considered in light of their effect on BPV.