Effect of Intensive Blood Pressure Control on Aortic Stiffness in the SPRINT-HEART

Abstract

In a subgroup of 337 participants (mean age 64±9 years; 45% women) from the SPRINT (Systolic Blood Pressure Intervention Trial), where participants were randomly assigned to intensive treatment (target systolic blood pressure <120 mm Hg) versus standard treatment (<140 mm Hg), we examined the effect of intensive blood pressure lowering on indexes of aortic stiffness. Carotid-femoral pulse wave velocity, a validated global measure of aortic stiffness, was measured by echo-guided Doppler at baseline and 18-month follow-up visit. Aortic elastance, distensibility, and compliance were measured by cardiac magnetic resonance imaging. During follow-up, the intensive treatment produced a mean between-group reduction in systolic blood pressure of 12.7 mm Hg (95% CI, 11.1–14.3 mm Hg). During follow-up, intensive treatment significantly attenuated the increase in carotid-femoral pulse wave velocity compared with standard treatment (adjusted follow-up least square mean=9.0 m/s [95% CI, 8.7–9.3] versus 10.0 m/s [9.6–10.3]; P <0.001), an effect that persisted even after adjusting for mean arterial pressure. Intensive treatment also decreased the aortic elastance index (least square mean, 1.38 mm Hg/mL per m 2 [95% CI, 1.34–1.41] versus 1.48 mm Hg/mL per m 2 [95% CI, 1.44–1.51], P =0.002) compared with standard treatment. No significant between-group differences were observed for aortic distensibility and compliance. We conclude that intensive treatment significantly attenuated increases in carotid-femoral pulse wave velocity and aortic elastance index. Attenuation of increases in aortic stiffness may be one of the mechanisms contributing to the benefit of intensive blood pressure treatment observed in SPRINT. Registration: URL: https://www.clinicaltrials.gov ; Unique identifier: NCT01206062.