Visit-to-Visit Variability of BP and CKD Outcomes

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 <6.63 mmHg) quintile of SD of systolic BP, respectively (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.