A Randomized Controlled Trial on the Efficacy and Safety of a Calcium-Channel Blocker and an Angiotensin-Converting Enzyme Inhibitor in Chinese and European Patients with Hypertension

Abstract

Background: In a post hoc analysis of a multinational, randomized trial, we investigated whether the efficacy and safety of nifedipine-gastrointestinal therapeutic system (GITS) and ramipril differed between Chinese and European patients with hypertension.

Methods: Previously treated (after 2-week washout) and untreated patients with clinic blood pressure (BP) ≥ 140/90 mmHg (systolic/diastolic), daytime ambulatory BP ≥ 135/85 mmHg and standard deviation of home systolic BP > 7 mmHg, and/or daytime BP > 12 mmHg were randomly assigned to treatment based on nifedipine-GITS 30 mg or ramipril 10 mg for 12 months. Clinic, ambulatory and home BP were measured at baseline, 10 weeks and 12 months after randomization.

Results: A total of 67 Chinese and 101 European patients were analyzed and they differed in age (50.9 vs. 54.6 years, respectively), body mass index (24.5 vs. 27.0 kg/m2), clinic diastolic BP (87.9 vs. 92.5 mmHg), heart rate (75.0 vs. 70.8 beats/minute), and nighttime diastolic BP (79.3 vs. 75.9 mmHg) (all P < 0.05). However, within each ethnicity, patients were comparable for clinical characteristics between the nifedipine-GITS and ramipril groups (P > 0.05). In both the Chinese and European patients, BP was similarly reduced with nifedipine-GITS and ramipril, except that daytime systolic/diastolic BP reductions were 7.4/4.1 mmHg greater in the ramipril than nifedipine-GITS group in Chinese (P = 0.02). The safety profile differed between the Chinese and European patients (P for drug*ethnicity interaction ≤ 0.05) for all adverse events (lower incidence on nifedipine-GITS in Chinese), ankle edema (higher on nifedipine-GITS in Europeans), and dry cough (higher on ramipril in Chinese).

Conclusion: In the Chinese and European patients with hypertension, nifedipine-GITS and ramipril had similar BP lowering efficacy, but different safety profile and tolerability.

Clinical trials registration: Identifier at clinicaltrials.gov NCT02499822 (Registration date: 16 July 2015).

Keywords: angiotensin-converting enzyme inhibitors; blood pressure; calcium-channel blockers; cough; edema; ethnicity; hypertension; racial.