Visit-to-Visit Variability of BP and CKD Outcomes

Abstract

Background and objectives Increased visit-to-visit variability of BP is associated with cardiovascular disease risk. We examined the association of visit-to-visit variability of BP with renal outcomes among 21,245 participants in the Antihypertensive and Lipid-Lowering Treatment to Prevent Heart Attack Trial. Design, setting, participants, & measurements We measured mean BP and visit-to-visit variability of BP, defined as SD, across five to seven visits occurring 6–28 months after participants were randomized to chlorthalidone, amlodipine, or lisinopril. The composite outcome included incident ESRD after assessment of SD of systolic BP or ≥50% decline in eGFR between 24 months and 48 or 72 months after randomization. We repeated the analyses using average real variability and peak value of systolic BP and for visit-to-visit variability of diastolic BP. Results Over a mean follow-up of 3.5 years, 297 outcomes occurred. After multivariable adjustment, including baseline eGFR and mean systolic BP, the hazard ratios for the composite end point were 1.29 (95% confidence interval [95% CI], 0.75 to 2.22), 1.76 (95% CI, 1.06 to 2.91), 1.46 (95% CI, 0.88 to 2.45), and 2.05 (95% CI, 1.25 to 3.36) for the second through fifth (SD of systolic BP =6.63–8.82, 8.83–11.14, 11.15–14.56, and >14.56 mmHg, respectively) versus the first (SD of systolic BP P trend =0.004). The association was similar when ESRD and a 50% decline in eGFR were analyzed separately, for other measures of visit-to-visit variability of systolic BP, and for visit-to-visit variability of diastolic BP. Conclusions Higher visit-to-visit variability of BP is associated with higher risk of renal outcomes independent of mean BP.