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.