Does intensive systolic blood pressure lowering in older patients increase the likelihood of renal dysfunction?

In this post-hoc analysis of the previously published SPRINT trial, lowering the systolic blood pressure of patients who are at increased risk of cardiovascular events (average age 66 years) will decrease their risk of cardiovascular disease but increase their likelihood of developing moderate renal dysfunction. It will not, at least over 3 years, increase their likelihood of developing end-stage renal disease. (LOE = 1b)

Beddhu S, Rocco MV, Toto R, et al, for the SPRINT Research Group. Effects of intensive systolic blood pressure control on kidney and cardiovascular outcomes in persons without kidney disease. A secondary analysis of a randomized trial. Ann Intern Med 2017;167(6):375-383.  [PMID:28869987]

Randomized controlled trial (nonblinded)

Government

Uncertain

Outpatient (any)

This report is a subgroup analysis of the SPRINT (Systolic blood Pressure INtervention Trial), which enrolled patients with high blood pressure and elevated cardiovascular risk. This analysis was limited to the 6662 participants, mean age 66 years, with a baseline estimated glomerular filtration rate (GFR) of at least 60 mL/min/1.73 m2, who represented approximately 70% of the total original cohort. The participants were randomly assigned, allocation concealment unknown, to be treated to reach an intensive (120 mm Hg or lower) or standard (140 mm Hg or lower) systolic blood pressure. The actual blood pressure difference between the 2 groups was an average 15 mm Hg. Significantly more people in lower blood pressure group experienced a significant decline in kidney function, defined as a 30% or greater decline in GFR to less than 60 mL/min/1.73 m2 (number needed to treat to harm = 38; 95% CI 29 - 53). But, as in the full SPRINT report, the risk of death or cardiovascular event over 3 years was lower with lower systolic blood pressure. None of the participants developed end-stage renal disease. Post-hoc analyses such as this one are risky to interpret, but in this case the results echo the analysis in the original report.