my personal edition > hypertension > news


  E-Mail this DGDispatch to a colleague

DGDispatch

Valsartan Significant Better Than Amlodipine for Improving Long-term Heart-rate Variability in Patients With LVH: Presented at EMH

By Chris Berrie

MILAN, ITALY -- June 20, 2005 -- The angiotensin II receptor blocker (ARB) valsartan provides a positive effect on heart-rate variability (HRV) that is significant better than the calcium channel blocker (CCB) amlodipine in patients with left ventricular hypertrophy (LVH).

The finding, from a substudy analysis of the Valsartan Antihypertensive Long-Term Use Evaluation (VALUE), was presented here June 18^th at the 15^th European Meeting on Hypertension (EMH) by Eric S. Nielsen, MD, Research Fellow, and principal investigator Ole Pedersen, MD, DMSci, Consultant, Division of Cardiology, Department of Medicine, Sygehus Viborg, Viborg, Denmark.

According to the researchers, advanced hypertensive diseases such as LVH are associated with a higher risk of complex cardiac arrhythmias and sudden death. The echocardiographic (ECG) QT-dispersion (QTd) is associated to the degree of LVH and strongly correlates with complex ventricular arrhythmias in hypertensive patients.

Similarly, impaired cardiac autonomic function assessed as heart-rate variability through Holter monitoring is associated with an increased risk of sudden death in patients with ischaemic heart disease, while arterial hypertension has shown a negative correlation between heart-rate variability and degree of LVH.

The randomised, double-blind VALUE trial, previously found that treatment regimens based on valsartan and amlodipine achieved similar blood pressure levels after 2 years of maintained therapy.

The researchers performed their substudy analysis to determine the effect of the two agents on QTd and measures of heart-rate variability in hypertensive patients with a high risk of cardiac morbid events.

The two treatment arms were similar with respect to body mass index, incidence of diabetes, systolic/diastolic blood pressure, heart rate, and other medications used.

Patients were evaluated with 12-lead ECG recordings on the same day as the Holter recording, and they were analysed by a single investigator before unblinding. The corrected QT (QTc), QTd, Sokolov-Lyon and Cornell voltage indices were calculated manually.

The Holter recording was performed by a single operator before unblinding; the raw data was cleaned visually, and arrhythmias were analysed on an hour-by-hour basis. These data provided standard measures of heart-rate variability from representative 2-hour periods during both day and night.

Analysis of the ECG recordings showed no significant differences between the two treatment groups for all variables recorded, although with the groups combined, the ECG signs of LVH correlated positively with diastolic blood pressure and QTd, but not QTc.

The valsartan group showed increased, and thus beneficial, Holter results compared to amlodipine for the 24-hour triangle index (32.2 vs. 28.3; P = .02) and night-time standard deviation of normal-to-normal intervals in all 5-minute segments of the recording (37.8 vs. 31.7 ms; P = .02).

However, when the researchers removed the data for patients on beta blockers they observed stronger results, with a significant difference in heart-rate variability in favour of valsartan on both the long-term (P = .02) and total (P < .01) variabilities, Dr. Nielsen said.

Dr. Pedersen concluded that these significant effects on total heart-rate variability measures in favour of the valsartan-based regimen seen after 2 years of treatment indicate that, "Valsartan may have some prognostic abilities which were not seen in the main [VALUE] study because it did not last for more than 4 years, and this might only have become apparent later on in the study."


[Study title: Heart Rate Variability and ECG Changes in 148 Danish Patients After Two Years in the VALUE Trial. Abstract P1.330]

E-Mail this DGDispatch to a colleague

To print, use this version