Objectives: Measurement of central blood pressure provides prognostic information beyond conventional peripheral blood pressure (BP). However, few studies have directly compared the effects of antihypertensives on central hemodynamics. This study investigated the effects of a low-dose combination of nifedipine Gastrointestinal Therapeutic System (GITS) and valsartan versus high-dose monotherapy with either agent in reducing central BP in essential hypertension inadequately controlled by low-dose monotherapy.
Materials and methods: In this prospective, open-label, randomized, active-controlled, multicenter 8-week study, patients not meeting the target BP after 4 weeks of treatment with low-dose monotherapy were randomized to receive nifedipine GITS 30 mg plus valsartan 80 mg (N30+V80), nifedipine GITS 60 mg (N60), or valsartan 160 mg (V160) for a further 4 weeks. Central hemodynamics were measured by applanation tonometry.
Results: A total of 391 patients were enrolled. Reduction in central systolic BP from baseline to week 8, the primary efficacy variable, was significantly greater in the N30+V80 group (-27.2±14.7 mmHg) and the N60 group (-27.1±16.5 mmHg) compared with V160 group (-14.4±16.6 mmHg). Decrease in the augmentation index in the N60 group was significantly greater compared with V160 alone, without differences between combination therapy and either high-dose monotherapy. Decreases in brachial systolic BP were significantly greater in the N30+V80 and N60 groups than in the V160 group. By multiple regression analysis, most differences in drug effects on central hemodynamics disappeared after controlling for changes in peripheral BP. A low rate of adverse events occurred in all treatment groups.
Conclusion: A low-dose combination of nifedipine GITS plus valsartan or high-dose nifedipine was more effective in improving central hemodynamics than high-dose valsartan in patients with hypertension, mostly because of the improvement in peripheral (brachial) hemodynamics.