Effects of Intensive Blood Pressure Control in Patients with and without Albuminuria

Abstract

Background and objectivesIt is unclear whether the presence of albuminuria modifies the effects of intensive systolic BP control on risk of eGFR decline, cardiovascular events, or mortality.Design, setting, participants, & measurementsThe Systolic Blood Pressure Intervention Trial randomized nondiabetic adults ≥50 years of age at high cardiovascular risk to a systolic BP target of <120 or <140 mm Hg, measured by automated office BP. We compared the absolute risk differences and hazard ratios of ≥40% eGFR decline, the Systolic Blood Pressure Intervention Trial primary cardiovascular composite outcome, and all-cause death in those with or without baseline albuminuria (urine albumin-creatinine ratio ≥30 mg/g).ResultsOver a median follow-up of 3.1 years, 69 of 1723 (4%) participants with baseline albuminuria developed ≥40% eGFR decline compared with 61 of 7162 (1%) participants without albuminuria. Incidence rates of ≥40% eGFR decline were higher in participants with albuminuria (intensive, 1.74 per 100 person-years; standard, 1.17 per 100 person-years) than in participants without albuminuria (intensive, 0.48 per 100 person-years; standard, 0.11 per 100 person-years). Although effects of intensive BP lowering on ≥40% eGFR decline varied by albuminuria on the relative scale (hazard ratio, 1.48; 95% confidence interval, 0.91 to 2.39 for albumin-creatinine ratio ≥30 mg/g; hazard ratio, 4.55; 95% confidence interval, 2.37 to 8.75 for albumin-creatinine ratio <30 mg/g; P value for interaction <0.001), the absolute increase in ≥40% eGFR decline did not differ by baseline albuminuria (incidence difference, 0.38 events per 100 person-years for albumin-creatinine ratio ≥30 mg/g; incidence difference, 0.58 events per 100 person-years for albumin-creatinine ratio <30 mg/g; P value for interaction =0.60). Albuminuria did not significantly modify the beneficial effects of intensive systolic BP lowering on cardiovascular events or mortality evaluated on relative or absolute scales.ConclusionsAlbuminuria did not modify the absolute benefits and risks of intensive systolic BP lowering.

Intensive Blood Pressure Lowering Should Be the Goal for Most Individuals at High Risk of Cardiovascular Disease Irrespective of Albuminuria

“…SPRINT was adequately powered to demonstrate both cardiovascular disease and mortality benefits with intensive BP-lowering therapy overall, with similar results in the CKD subgroup. Chang et al (5) now demonstrate that these benefits seem consistent regardless of the presence of baseline albuminuria. In contrast, the MDRD study and AASK were designed with primary kidney outcomes without central adjudication of cardiovascular disease, leading to few such events (Table 1).…”

“…In summary, the most important and novel finding provided by Chang et al (5) is that intensive BP lowering in SPRINT reduces the risk of cardiovascular disease and mortality irrespective of albuminuria. It should be noted that, because of SPRINT's exclusion criteria, this finding may not be generalizable to individuals with diabetes, advanced CKD, or severe albuminuria.…”

“…Reassuringly, additional studies in SPRINT support the hypothesis that greater eGFR decline following intensive BPlowering therapy is often related to hemodynamic changes rather than intrinsic injury (7-9). Chang et al (5) were also limited in the ability to use ESKD events. Few ESKD events occurred in SPRINT as a result of the trial excluding individuals with baseline eGFR ,20 ml/min per 1.73 m 2 and then providing only a mean of 3.1 years of follow-up.…”

“…Third, a particularly important discovery by Chang et al (5) relates to SPRINT's design as a cardiovascular disease end point trial. SPRINT was adequately powered to demonstrate both cardiovascular disease and mortality benefits with intensive BP-lowering therapy overall, with similar results in the CKD subgroup.…”

SPRINT—A Kidney-Centric Narrative Review: Recent Advances in Hypertension

“…Beyond eGFR considerations, albuminuria is also an independent risk factor for cardiovascular disease. 15 A post hoc analysis by Chang et al 16 stratified SPRINT participants by baseline albuminuria (UACR< or ≥30 mg/g). A UACR of 30 mg/g is a well-established cutoff above which increases in albuminuria is directly correlated with an increase in the risk of cardiovascular death and all-cause mortality.…”