Effects of Intensive Systolic Blood Pressure Control on Kidney and Cardiovascular Outcomes in Persons Without Kidney Disease

Abstract

BACKGROUND: The public health significance of the reported higher incidence of chronic kidney disease (CKD) with intensive systolic blood pressure (SBP) lowering is unclear. OBJECTIVE: To examine the effects of intensive SBP lowering on kidney and cardiovascular outcomes and contrast its apparent beneficial and adverse effects. DESIGN: Subgroup analyses of SPRINT (Systolic Blood Pressure Intervention Trial). (ClinicalTrials.gov: NCT01206062). SETTING: Adults with high blood pressure and elevated cardiovascular risk. PARTICIPANTS: 6662 participants with a baseline estimated glomerular filtration rate (eGFR) of at least 60 mL/min/1.73 m2. INTERVENTION: Random assignment to an intensive or standard SBP goal (120 or 140 mm Hg, respectively). MEASUREMENTS: Differences in mean eGFR during follow-up (estimated with a linear mixed-effects model), prespecified incident CKD (defined as a >30% decrease in eGFR to a value <60 mL/min/1.73 m2), and a composite of all-cause death or cardiovascular event, with surveillance every 3 months. RESULTS: The difference in adjusted mean eGFR between the intensive and standard groups was -3.32 mL/min/1.73 m2 (95% CI, -3.90 to -2.74 mL/min/1.73 m2) at 6 months, was -4.50 mL/min/1.73 m2 (CI, -5.16 to -3.85 mL/min/1.73 m2) at 18 months, and remained relatively stable thereafter. An incident CKD event occurred in 3.7% of participants in the intensive group and 1.0% in the standard group at 3-year follow-up, with a hazard ratio of 3.54 (CI, 2.50 to 5.02). The corresponding percentages for the composite of death or cardiovascular event were 4.9% and 7.1% at 3-year follow-up, with a hazard ratio of 0.71 (CI, 0.59 to 0.86). LIMITATION: Long-term data were lacking. CONCLUSION: Intensive SBP lowering increased risk for incident CKD events, but this was outweighed by cardiovascular and all-cause mortality benefits. PRIMARY FUNDING SOURCE: National Institutes of Health.