Purpose: To compare the long-term effects of olmesartan combined with either azelnidipine or amlodipine on central blood pressure (CBP), left ventricular (LV) mass index (LVMI), LV diastolic function (e' velocity, E/e' ratio, E/A ratio) and arterial stiffness (brachial-ankle pulse wave velocity [baPWV] and augmentation index normalized for a heart rate of 75 bpm [AIx]).
Patients and methods: Patients with systolic BP ≥ 140 mmHg and/or diastolic BP ≥ 90 mmHg received olmesartan monotherapy (20 mg/day) for 12 weeks. They were then randomly assigned to fixed-dose add-on therapy with azelnidipine (16 mg/day; n = 26) or amlodipine (5 mg/day; n = 26) for a further 2 years. CBP, LVMI, e' velocity, E/e' ratio, E/A ratio, baPWV, and AIx were measured at baseline, 6 months, and 2 years.
Results: Baseline characteristics of both groups were similar. The decrease in brachial BP over 2 years was similar in both groups. CBP, LVMI, E/e' ratio, baPWV, and AIx decreased significantly, and the E/A ratio and e' velocity increased significantly in both groups. The decreases in CBP (P < 0.001), AIx (P < 0.001), baPWV (P < 0.001), LVMI (P < 0.001), and E/e' (P = 0.002) as well as the increase in E/A ratio (P = 0.03) over 2 years were significantly greater in the olmesartan/azelnidipine group than in the olmesartan/amlodipine group. Multivariate linear regression analyses showed that the changes in baPWV (β = 0.41, P < 0.001) and CBP (β = 0.47, P = 0.01) were independently associated with the change in LVMI, the change in baPWV (β = 0.25, P < 0.001) was independently associated with the change in E/e' ratio, and the changes in baPWV (β = 0.21, P = 0.001) and AIx (β = 0.25, P = 0.03) were independently associated with the change in E/A ratio.
Conclusion: Treatment with olmesartan/azelnidipine for 2 years resulted in greater improvements in CBP, LVMI, and LV diastolic function, and arterial stiffness compared with olmesartan/amlodipine. Improvements in LV diastolic function were associated with improvements in arterial stiffness.
Keywords: arterial stiffness; central blood pressure; left ventricular diastolic function; left ventricular mass index; olmesartan/azelnidipine.