Aim: to compare effects of fixed-dose combinations of antihypertensive drugs that block renin-angiotensin-aldosterone system (RAAS) with hydrochlorothiazide (HCT) on parameters of ambulatory blood pressure monitoring (ABPM).
Material and methods: Patients (n=50; 25 women, 25 men aged 40-75 years) with stage II essential hypertension who received no antihypertensive therapy for 12 weeks were randomized to receive once daily fixed-dose combinations of either valsartan/HCT (Val/HCT - group I) or quinapril/HCT (Quin/HCT - groupII) in starting doses of 80/12.5 or 10/12.5 mg, respectively. If target BP (<140 and 90 mm Hg) was not achieved after 2 weeks, doses were increased to 160/12.5 and 20/12.5 mg, respectively. Patients in whom target BP was not achieved after another 2 weeks were excluded from the study. Follow - up after achieving target BP was 12 weeks.
Results: Both combinations significantly (p<0.001) reduced office systolic and diastolic BP (SBP and DBP), however, BP decrease in group I was significantly (p<0.01) greater (-42.0+/-2,7 /-22.2+/-1.2 mm Hg) than in group II (-26,4+/-2,1/-6.6+/-0.4 mm Hg). Significant reduction of day- and night-time BP (p<0.001) observed in both groups was also more pronounced (p<0.01) in group I. In both groups we recorded significant (p<0.01) decreases of BP variability and morning BP rise. Variability of DBP at night (-3.3+/-0.2 mm Hg), magnitude and speed of morning DBP surge (-20.9+/-0.3 mm Hg and -3.4+/-0.2 mm Hg/hour, respectively) in group I decreased significantly (p<0.05) greater compared with same parameters in group II (-2.5+/-0.2 mm Hg, -17.7+/-0.3 mm Hg, -2.6+/-0.2 mm Hg/hour, respectively).
Conclusion: Fixed-dose combinations of RAAS blockers and HCT provided reliable reduction of BP, BP variability, morning BP rise, and high percentage of achievement of target BP. Val/HCT combination was more effective in terms of reducing SBP, DBP and pulse BP levels at routine measurement, and day- and night-time SBP and DBP, night-time DBP variability, and rate of morning DBP rise.
Keywords: ambulatory blood pressure monitoring; angiotensin II receptor antagonists; angiotensin converting enzyme inhibitors; antihypertensive drugs; fixed-dose combinations; hydrochlorothiazide; hypertension; quinapril; valsartan.