Ambulatory blood pressure-lowering effects of valsartan and enalapril after a missed dose in previously untreated patients with hypertension: a prospective, randomized, open-label, blinded end-point trial.

BACKGROUND

Approximately 3 days a month, some 15% to 20% of patients with hypertension do not recall having taken their antihypertensive medication. Individuals with this frequency of missed doses may be at increased risk for a cardiovascular event and may have a poorer long-term prognosis.

OBJECTIVE

This study used ambulatory blood pressure monitoring (ABPM) to compare the blood pressure (BP)-lowering effects of valsartan and enalapril over the 24 hours after missing 1 dose in previously untreated patients with mild to moderate essential hypertension.

METHODS

This was a prospective, randomized, open-label, parallel-group, blinded end-point trial in previously untreated patients (age >18 years) with mild to moderate essential hypertension (European Society of Hypertension-European Society of Cardiology guidelines: systolic BP 140-179 mm Hg or diastolic BP 90-109 mm Hg). Patients were randomly assigned to receive 16 weeks of treatment with valsartan 160 mg/d or enalapril 20 mg/d, taken on waking. ABPM was conducted for 48 consecutive hours at baseline and again after 16 weeks of therapy. Patients took a dose of their assigned treatment at the beginning of the final session of ABPM and were instructed to skip the next daily dose.

RESULTS

The study enrolled 148 Spanish patients (84 men, 64 women; mean [SD] age, 45.8 [10.7] years) with previously untreated hypertension. At the end of treatment, there were significant differences between groups during the first 24 hours of ABPM, starting in the final 6 hours of the dosing interval (P < 0.001). There was no significant change in BP reduction between the first and second 24-hour periods of ABPM with valsartan (-2.1/-1.4 mm Hg), whereas enalapril was associated with a significant increase in BP over this period (5.5/3.8 mm Hg; P < 0.001 vs first 24 hours; P = 0.032 vs valsartan).

CONCLUSIONS

In this study in previously untreated patients with mild to moderate essential hypertension, valsartan was associated with a sustained BP-lowering effect beyond the initial 24 hours after dosing, whereas enalapril was not. There was no significant change in the efficacy of valsartan in the 24 hours after a missed dose. At the doses tested, valsartan was more effective than enalapril, both during active treatment and after a missed dose.