Ambulatory Blood Pressure Monitoring (ABPM) in the VALUE Trial

Abstract

The VALUE Trial evaluated the cardiac outcomes in a large group of high-risk, elderly hypertensive patients randomized to either a valsartan-based (VAL) or amlodipine-based (AML) antihypertensive regimen. During the entire 4.2 year study period office blood pressure (BP) at trough remained significantly lower in the AML group. The present substudy aimed to demonstrate similar BP reductions in the two groups over 24 hours. ABPM was performed after one year of randomized treatment in 47 centres in Italy, USA and Denmark. Measurements were carried out with Spacelab 90202 or 90207 monitors hooked up before the morning dose of medicine. 659 patients were available for ITT analysis. The two treatment groups were generally well balanced concerning BP and other demographic data at baseline. However, ECG-verified left ventricular hypertrophy was more prevalent in patients randomized to valsartan (15.7 vs. 8.0%, p=0.002). The mean doses of VAL and AML employed were 131±36 and 8±2 mg respectively. 34% were on monotherapy with VAL and 43% had AML alone. The average 24-SBP difference at one year was 1.1 mmHg in favour of AML (131.8 vs. 132.9 mmHg, ns), and the DBP difference was 0.4 mmHg in favour of VAL (75.0 vs. 75.4 mmHg, ns). Similar trends were seen both during day- and nighttime with a tendency for AML to be more effective during the late night hours. The number of combined cardiovascular endpoints (cardiac morbidity, mortality and stroke) were not different in the two groups, but correlated significantly with the level of 24-h SBP and DBP. Thus for the ITT-population a 10 mmHg increase in 24-h SBP translated into a 37% increase in combined risk (p<0001). The difference between office DBP at trough and mean 24-h DBP tended to be less pronounced in the AML group than in the VAL treated patients (4.2 vs.5.4 mmHg). A tendency to more advanced BP-dipping during nighttime was observed in the VAL-treated patients. After one year 24-h BP was similarly reduced by the valsartan and the amlodipine based regimen. Endpoints were strongly related to 24-h BP levels. Night BP during the last hours of the dosing interval tended to be lower on amlodipine.