ASCOT trial and recent meta-analysis suggested that systolic blood pressure variability (SBPV) and central blood pressure (CBP) are important factors for predicting prognosis in hypertensive patients. However, there are little evidences for the effect between calcium channel blocker (CCB) and angiotensin receptor blocker (ARB) in hypertensive patients. The aim of this study is to assess SBPV in essential hypertensive patients treated with amlodipine or losartan.Design and Method:
This is a prospective, open-label, multicenter, randomized study with two parallel study groups. Eligible patients were randomized to either amlodipine 5 mg or losartan 50 mg group. Medication was titrated up according to the protocol, and patients were followed up for 6 months. The primary endpoint was the standard deviation (SD) of visit-to-visit (VV) systolic blood pressure (SBP). The secondary endpoints were mean VV-SBP, coefficient of variation (CV) of VV-SBP, SD of within-visit-SBP, CV of within-visit-SBP, CBP, augmentation index and 24-h ambulatory BP (ABP).Results:
A total of 100 patients (61.7%) completed clinical follow-up among anticipated 162 patients. Male patients were 56(56%) and mean ages were 49.6 ± 10.8years. There were no differences in baseline characteristics between two groups. The rate of up-titration was significantly higher in losartan group at every 4 follow-up visits. The SD of VV-SBP showed no significant difference (10.3 ± 3.8 vs. 10.3 ± 4.0, p = 0.966), but mean VV-SBP was lower in amlodipine group (132.3 ± 7.5 vs. 138.2 ± 8.6, p = 0.001). Mean within-visit-SBPs were significantly lower in amlodipine group at every visit. The SD and CV of within-visit-SBP were significantly lower in amlodipine group at 6 months (3.4 ± 2.2 vs. 5.2 ± 3.1, p = 0.001; 2.7 ± 1.7 vs. 3.9 ± 2.4, p = 0.003). Night-time mean SBP of 24-hr ABP at 6 months was significantly lower in amlodipine group (122.7 ± 13.2 vs. 130.0 ± 14.9, p = 0.025).Conclusions:
In this interim analysis, SD of VV-SBP was not different between two groups. But, mean VV-SBP, mean within-visit-SBP, SD and CV of within-visit-SBP at 6 months and night-time mean SBP of 24-hr ABP at 6 months were significantly lower in amlodipine group.