Background and purpose: Angiotensin receptor blocker (ARB)-based treatment reduces cardiovascular events and stroke more than does beta-blocker-based treatment despite similar blood pressure (BP) reduction. We investigated whether these treatments have different effects on cardiac and large-artery remodelling and evaluated the relation of arterial remodelling to hemodynamic changes in subjects with hypertension.
Methods: We compared the treatment effects of an ARB (candesartan cilexetil)-based regimen and a beta-blocker (atenolol)-based regimen for 52 weeks on common carotid artery (CCA) and left ventricular structure in hypertensive patients in a randomized, double-blind study. Clinic brachial BP and 24-hour ambulatory BP, carotid BP, left ventricular mass index, CCA intima-media thickness, lumen diameter, intima-media area, and carotid blood flow were measured. Distensibility, circumferential tensile stress, Young's elastic modulus (E(m)), and shear stress (tau) in the CCA were also calculated.
Results: Both candesartan and atenolol reduced intima-media thickness and intima-media area and increased distensibility to similar extents after 52 weeks of treatment. Despite similar reductions in BP, treatment with atenolol resulted in a lesser reduction in left ventricular mass index, a decrease in lumen diameter, and a reduction in carotid blood flow compared with candesartan.
Conclusions: BP-independent effects of ARB on cardiac and arterial structure may contribute to the beneficial effects of these agents on cardiovascular disease.