Effect of angiotensin receptor blockade on central haemodynamics in essential hypertension: results of a randomised trial.

Objective: Angiotensin-converting enzyme (ACE) inhibitors have been shown to lower central augmentation index (cAI), an index of arterial wave reflection, more than beta-blockers. We tested whether this is also true for long-term treatment with an angiotensin receptor blocker (ARB).

Methods: One-hundred and fifty-six subjects with essential hypertension were randomised to treatment with either irbesartan or atenolol. cAI and central blood pressure (BP) were determined by pulse wave analysis from the radial and the carotid artery after six and after 18 months treatment.

Results: Peripheral and central systolic and diastolic BP were reduced to a similar extent in the two groups. cAI was reduced with irbesartan, but increased with atenolol (derived from the carotid artery: -6+/-10 vs. -4+/-12% after six months, p<0.001; -4+/-12 vs. +1+/-11% after 18 months; p=0.011). Furthermore, central to peripheral pulse pressure (PP) amplification was unaffected by treatment with irbesartan, but decreased with atenolol.

Conclusions: Although treatment with irbesartan and atenolol similarly decreased peripheral and central BP, only treatment with irbesartan had beneficial effects on arterial wave reflection and preserved PP amplification. These haemodynamic effects may at least partly explain the reported differential effects of ARB versus beta-blocker treatment on cardiovascular mortality in patients with essential hypertension.