Hawfield, Amret

Background and objectives It 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, & measurements The 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). Results Over 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. Conclusions Albuminuria did not modify the absolute benefits and risks of intensive systolic BP lowering.

The appropriate target for BP in patients with CKD and hypertension remains uncertain. We report prespecified subgroup analyses of outcomes in participants with baseline CKD in the Systolic Blood Pressure Intervention Trial. We randomly assigned participants to a systolic BP target of <120 mm Hg (intensive group; n =1330) or <140 mm Hg (standard group; n =1316). After a median follow-up of 3.3 years, the primary composite cardiovascular outcome occurred in 112 intensive group and 131 standard group CKD participants (hazard ratio [HR], 0.81; 95% confidence interval [95% CI], 0.63 to 1.05). The intensive group also had a lower rate of all-cause death (HR, 0.72; 95% CI, 0.53 to 0.99). Treatment effects did not differ between participants with and without CKD ( P values for interactions ≥0.30). The prespecified main kidney outcome, defined as the composite of ≥50% decrease in eGFR from baseline or ESRD, occurred in 15 intensive group and 16 standard group participants (HR, 0.90; 95% CI, 0.44 to 1.83). After the initial 6 months, the intensive group had a slightly higher rate of change in eGFR (−0.47 versus −0.32 ml/min per 1.73 m 2 per year; P <0.03). The overall rate of serious adverse events did not differ between treatment groups, although some specific adverse events occurred more often in the intensive group. Thus, among patients with CKD and hypertension without diabetes, targeting an SBP<120 mm Hg compared with <140 mm Hg reduced rates of major cardiovascular events and all-cause death without evidence of effect modifications by CKD or deleterious effect on the main kidney outcome.