Comparison of two single-pill dual combination antihypertensive therapies in Chinese patients: a randomized, controlled trial

Background Current hypertension guidelines recommend combination of an angiotensin-converting enzyme inhibitor or angiotensin-receptor blocker with a calcium-channel blocker or thiazide diuretic as initial antihypertensive therapy in patients with monotherapy uncontrolled hypertension. However, to what extent these two different combinations are comparable in blood pressure (BP)-lowering efficacy and safety remains under investigation, especially in the Chinese population. We investigated the BP-lowering efficacy and safety of the amlodipine/benazepril and benazepril/hydrochlorothiazide dual therapies in Chinese patients. Methods In a multi-center, randomized, actively controlled, parallel-group trial, we enrolled patients with stage 1 or 2 hypertension from July 2018 to June 2021 in 20 hospitals and community health centers across China. Of the 894 screened patients, 560 eligible patients were randomly assigned to amlodipine/benazepril 5/10 mg ( n = 282) or benazepril/hydrochlorothiazide 10/12.5 mg ( n = 278), with 213 and 212 patients, respectively, who completed the study and had a valid repeat ambulatory BP recording during follow-up and were included in the efficacy analysis. The primary outcome was the change from baseline to 24 weeks of treatment in 24-h ambulatory systolic BP. Adverse events including symptoms and clinically significant changes in physical examinations and laboratory findings were recorded for safety analysis. Results In the efficacy analysis ( n = 425), the primary outcome, 24-h ambulatory systolic BP reduction, was − 13.8 ± 1.2 mmHg in the amlodipine/benazepril group and − 12.3 ± 1.2 mmHg in the benazepril/hydrochlorothiazide group, with a between-group difference of − 1.51 ( p = 0.36) mmHg. The between-group differences for major secondary outcomes were − 1.47 ( p = 0.18) in 24-h diastolic BP, − 2.86 ( p = 0.13) and − 2.74 ( p = 0.03) in daytime systolic and diastolic BP, and − 0.45 ( p = 0.82) and − 0.93 ( p = 0.44) in nighttime systolic and diastolic BP. In the safety analysis ( n = 560), the incidence rate of dry cough was significantly lower in the amlodipine/benazepril group than in the benazepril/hydrochlorothiazide group (5.3% vs 10.1%, p = 0.04). Conclusions The amlodipine/benazepril and benazepril/hydrochlorothiazide dual therapies were comparable in ambulatory systolic BP lowering. The former combination, compared with the latter, had a greater BP-lowering effect in the daytime and a lower incidence rate of dry cough. Trial registration ClinicalTrials.gov, NCT03682692. Registered on 18 September 2018.