Rationale, study design, and implementation of the ACS1 study: Effect of azilsartan on circadian and sleep blood pressure as compared with amlodipine

OBJECTIVE: The ACS1 (Azilsartan Circadian and Sleep Pressure - the first study) is a multicenter, randomized, open-label, two parallel-group study carried out to investigate the efficacy of an 8-week oral treatment with azilsartan 20 mg in comparison with amlodipine 5 mg. MATERIALS AND METHODS: The patients with stage I or II primary hypertension will be randomly assigned to either an azilsartan group (n=350) or an amlodipine group (n=350). The primary endpoint is a change in nocturnal systolic blood pressure (BP) as measured by ambulatory BP monitoring at the end of follow-up relative to the baseline level during the run-in period. In addition, we will carry out the same analysis after dividing four different nocturnal BP dipping statuses (extreme-dippers, dippers, nondipper, and risers). CONCLUSION: The findings of this study will help in establishing an appropriate antihypertensive treatment for hypertensive patients with a disrupted circadian BP rhythm.