Intensive Blood Pressure Treatment Reduced Stroke Risk in Patients With Albuminuria in the SPRINT Trial

Abstract

Background and Purpose- Albuminuria is associated with stroke risk among individuals with diabetes. However, the association of albuminuria with incident stroke among nondiabetic patients is less clear. Methods- We performed a post hoc analysis of the SPRINT (Systolic Blood Pressure Intervention Trial), which examined the effect of higher versus lower intensity blood pressure management on mortality in 8913 participants without diabetes. We fit unadjusted and adjusted Cox proportional hazards models to estimate the association of baseline albuminuria (urinary albumin-to-creatinine ratio ≥30 mg/g versus<30 mg/g) with stroke risk. We also assessed effect modification according to treatment arms. Results- Mean age was 68±9 years, 35% were female, and 30% were black. Median follow-up was 3.2 years, and 19% patients had baseline albuminuria. Incident stroke occurred in 129 individuals during follow-up. Albuminuria was associated with increased stroke risk (unadjusted hazard ratio, 2.24; 95% CI, 1.55-3.23; adjusted hazard ratio 1.73; 95% CI, 1.17-2.56). The association of albuminuria with incident stroke differed according to the randomized treatment arm (P interaction=0.03). In the intensive treatment arm, the association of albuminuria and stroke was nonsignificant (unadjusted hazard ratio, 1.25; 95% CI, 0.69-2.28), whereas, in the standard treatment arm, it was significant (unadjusted hazard ratio, 3.44; 95% CI, 2.11-5.61). Conclusions- In a post hoc analysis of SPRINT, baseline albuminuria (versus not) was associated with a higher risk of incident stroke, but this relationship appeared to be restricted to those in the standard treatment arm. Further studies are required to conclusively determine if reduction of albuminuria in itself is beneficial in reducing stroke risk. Clinical Trial Registration- URL: https://www.clinicaltrials.gov. Unique identifier: NCT01206062.

Keywords: albuminuria; blood pressure; diabetes mellitus; hypertension; stroke.

Figures

Figure 1

Incident stroke risk according to the logarithm of baseline urinary albumin-to-creatinine ratio (ACR) as continuous variable. ACR=30 mg/g was used as reference value. Unadjusted(A) and adjusted(B) model.

Figure 2 –

Stroke incidence by treatment arm stratified by baseline albuminuria.