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

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.