Ambulatory Blood Pressure Comparison of Amlodipine, Cilnidipine, and Azelnidipine in Hypertension: The AMCILAZ-EH Multicentre, Prospective, Observational Study.

Background Calcium channel blockers (CCBs) are recommended as first-line therapy for hypertension (HTN). Amlodipine is well established, while newer agents such as cilnidipine and azelnidipine possess additional pharmacologic properties that may influence ambulatory blood pressure (BP) and circadian patterns. The clinical relevance of these differences in real-world practice remains uncertain. Methods A multicentric, prospective, observational study included adults with mild-to-moderate essential HTN, in which patients received amlodipine (5-10 mg), cilnidipine (10-20 mg), or azelnidipine (8-16 mg). Ambulatory blood pressure monitoring (ABPM) and clinic BP were recorded at baseline and after eight weeks. Primary endpoints were changes in 24-hour, awake, and asleep BP (systolic blood pressure (SBP)/diastolic blood pressure (DBP)) by ABPM and clinic BP. Secondary endpoints included dipping status, target BP achievement, and pulse rate changes. Continuous variables were analysed using paired t-tests and one-way ANOVA; categorical variables were analysed using Fisher's exact test. Results After screening 113 patients, 50 patients were included in the final analysis (amlodipine n = 17, cilnidipine n = 12, azelnidipine n = 21). All groups demonstrated significant reductions in clinic and ambulatory BP (p < 0.001). Mean 24-hour SBP reductions were -20.2 ± 12.7 mmHg, -14 ± 10.2 mmHg, and -12.8 ± 9.6 mmHg, respectively, with no significant intergroup difference (p = 0.111). However, awake ambulatory SBP (p = 0.047) and DBP (p = 0.034) showed significant intergroup differences, primarily between amlodipine and azelnidipine. All other parameters, including 24-hour and asleep BP, pulse rate, and dipping status, were comparable. Target BP achievement and pulse rate changes were comparable. No significant change in dipping pattern was observed, although azelnidipine showed a numerical improvement. Baseline characteristics between completers and excluded patients were comparable, suggesting minimal attrition bias. Conclusions All three CCBs demonstrated a significant reduction in BP, with comparable short-term efficacy. No consistent intergroup differences were observed across most parameters, except for isolated differences in awake ambulatory BP. However, these findings should be interpreted in the context of the limited sample size and reduced statistical power. Larger randomized studies with possible home BP monitoring are required.