Effects of Blood Pressure Control on Arterial Stiffness Mechanisms in SPRINT: A Randomized Controlled Trial.

Abstract

BACKGROUND The longitudinal impact of blood pressure (BP) control on the components of arterial stiffness has not been studied. METHODS The SPRINT (Systolic BP Intervention Trial) compared an intensive systolic BP goal (<120 mm Hg) to a standard goal (<140 mm Hg). Carotid-femoral pulse wave velocity (PWV) was measured in a subset of participants (n=605) at 0, 1, 2, and 3 years after randomization. Structural stiffening due to remodeling of the vessel wall and load-dependent stiffening, from changes in BP, were calculated by adjusting PWV to a 120/80 mm Hg reference BP with participant-specific models. The effect of intensive BP control on BP and arterial stiffness components over time was evaluated using generalized least squares regression. RESULTS Intensive BP control slowed the progression of PWV (total stiffness) compared with standard BP control at 3-year follow-up (-0.49 [-0.02 to -0.96] m/s, P=0.042). Differences in total stiffness between treatment groups over 3 years of follow-up were driven by intensive BP control reducing load-dependent PWV (-0.71 [-0.58 to -0.85] m/s, P<0.001), not structural PWV (+0.20 [-0.26 to +0.66], P=0.40). Load-dependent PWV was lower in the intensive treatment group at 1 year and remained lower throughout the follow-up. In contrast, structural PWV was similar between the 2 groups and increased throughout the follow-up period. CONCLUSIONS Intensive BP control slowed the progression of total arterial stiffness by decreasing load-dependent stiffness, but not through reduced structural stiffness. Future investigations are needed to determine if load-dependent PWV may have potential utility as a biomarker to monitor the efficacy of treatment and guide BP management strategies. REGISTRATION URL: https://www.clinicaltrials.gov; Unique identifier: NCT01206062.