Randomized comparison of systolic blood pressure variability (COMPASS-BPV) and central blood pressure in essential hypertensive patients treated with a calcium channel blocker (amlodipine) or angiotensin II receptor blocker (losartan)

Background: Current hypertension treatment guidelines are focused on controlling mean blood pressure (BP). However, BP variability is a strong predictor of cardiovascular events, independent of mean BP. In addition, central BP may have a better predictive value for cardiovascular events, compared to brachial BP. A calcium channel blocker (CCB) or angiotensin converting enzyme inhibitor (ACEi) [or angiotensin II receptor blocker (ARB)] is recommended as the first-line drug for essential hypertension, although comparison studies of these anti-hypertensive drugs on BP variability and central BP are lacking. Therefore, the aim of this study is to assess systolic BP variability and central BP in essential hypertensive patients treated with a CCB or ARB. Methods and design: Eligible hypertensive patients will be randomized to either a CCB (amlodipine, 5 mg) or ARB (losartan, 50 mg) group. Medication will be titrated up according to the protocol, and patients will be followed up for 6 months. The primary efficacy endpoint will be the standard deviation of visit-to-visit systolic BP variability. The secondary efficacy endpoints will be central BP, central BP augmentation index, standard deviation of within-visit systolic BP variability, visit-to-visit systolic BP variability coefficient of variation, variability independent of the mean visit-to-visit systolic BP variability, 24-h ambulatory BP monitoring parameters (mean BP and daytime, nighttime, and daily systolic BP standard deviation), and at home systolic BP. Discussion: This prospective, open-label, multicenter, randomized study will compare the effects of a CCB (amlodipine) with ARB (losartan) on systolic BP variability and central BP. The results may guide the choice of anti-hypertensive drugs regarding these novel cardiovascular event predictive parameters. Trial registration number: Clinical Trials.gov: NCT01964079.