Background Aortic stiffness is an independent predictor of cardiovascular events in patients with arterial
hypertension. Resistant
hypertension is often linked to
hyperaldosteronism and associated with adverse outcomes.
Spironolactone, a
mineralocorticoid receptor antagonist, has been shown to reduce both the arterial blood pressure (BP) and aortic stiffness in resistant
hypertension. However, the mechanism of aortic stiffness reduction by
spironolactone is not well understood. We hypothesized that
spironolactone reduces aortic stiffness in resistant
hypertension independently of BP change. Methods and Results Patients with uncontrolled BP (≥140/90 mm Hg) despite use of ≥3
antihypertensive medications (including
diuretics) were prospectively recruited. Participants were started on
spironolactone at 25 mg/d, and increased to 50 mg/
d at 4 weeks while other
antihypertensive medications were withdrawn to maintain constant mean BP. Phase-contrast cardiac magnetic resonance imaging of the ascending aorta was performed in 30 participants at baseline and after 6 months of
spironolactone treatment to measure aortic pulsatility, distensibility, and pulse wave velocity. Pulse wave velocity decreased (6.3±2.3 m/s to 4.5±1.8 m/s, P<0.001) and pulsatility and distensibility increased (15.9%±5.3% to 22.1%±7.9%, P<0.001; and 0.28%±0.10%/mm Hg to 0.40%±0.14%/mm Hg, P<0.001, respectively) following 6 months of
spironolactone. Conclusions Our results suggest that
spironolactone improves aortic properties in resistant
hypertension independently of BP, which may support the hypothesis of an effect of
aldosterone on the arterial wall. A larger prospective study is needed to confirm our findings.