The Legacy Effect of Intensive versus Standard BP Control on the Incidence of Needing Dialysis or Kidney Transplantation

Abstract

Key Points In the Systolic Blood Pressure Intervention Trial (SPRINT), the longer-term incidence of needing dialysis or transplantation was low and primarily associated with baseline kidney function.Rates of dialysis or transplantation were higher with intensive versus standard treatment, though the differences were not statistically significant. Background The Systolic Blood Pressure Intervention Trial (SPRINT) showed that intensive lowering of systolic BP increased the risk of incident CKD and episodes of AKI. Whether intensive treatment changes the risk of kidney failure is unknown. The goal of this study was to estimate the legacy effect of intensive versus standard systolic BP lowering on the longer-term incidence of kidney failure. Methods This study is a secondary analysis of a randomized, open-label clinical trial with observational follow-up. Between 2010 and 2013, patients 50 years and older with hypertension and higher cardiovascular risk excluding those with diabetes mellitus, history of stroke, proteinuria >1 g/d, or polycystic kidney disease were recruited from 102 clinic sites in the United States and Puerto Rico. Participants were randomized to a systolic BP goal of <120 mm Hg (intensive treatment) or <140 mm Hg (standard treatment group). We linked participants with the United States Renal Data System to ascertain kidney failure (initiation of dialysis therapy or transplantation) and the US National Death Index to ascertain all-cause mortality through 2020. Results Based on analysis of 9279 (99.1%) of 9361 randomized participants, 101 cases of kidney failure occurred over a median follow-up of 8.6 years (interquartile range, 8.0–9.1 years), with the majority occurring in 74 (73.3%) participants with an eGFR <45 ml/min per 1.73 m2 at baseline. Intensive treatment did not significantly increase the risk of kidney failure either overall (cause-specific hazard ratio, 1.20; 95% confidence interval, 0.81 to 1.78) or in the subgroup of participants with baseline eGFR <45 ml/min per 1.73 m2 (cause-specific hazard ratio, 1.43; 95% confidence interval, 0.89 to 2.30). Conclusions Overall, and in patients with eGFR <45 ml/min per 1.73 m2, there were higher rates of dialysis or transplantation among SPRINT participants randomized to intensive treatment, but the modest differences observed were not statistically significant. Clinical Trial registry name and registration number: SPRINT, NCT01206062.