Effect of antihypertensive treatment with a combination of telmisartan and amlodipine on vascular structure and function

Abstract

Purpose: Various antihypertensive combination therapies are available to treat arterial hypertension. Aim of the present study was to comparatively assess the effects of two usual combinations with an ARB, either combined with a thiazide diuretic or a CCB, on vascular function and structure phenotypes beyond blood pressure reduction. Methods: The <> Study (TEAMSTA protect I Study) is a randomised, double blind, controlled, single centre study. Patients with controlled or uncontrolled hypertension were included in the trial receiving either the a combination of either telmisartan and amlodipine (T/A) or olmesartan and hydrochlorothiazide (O/H) for 26 weeks. Primary endpoint was the change in flow mediated dilation (FMD) after 6 months compared to baseline examination. Secondary endpoints were the change of intermediate phenotypes of cardiovascular disease including structural and functional vascular parameters. Results: Between August 2010 and 2011, 576 subjects (68% males) aged 35 to 82 years have been enrolled into the trial. Treatment groups were concordant concerning the cardiovascular risk profile. Blood pressure reduction was comparable in both treatment groups after 26 weeks (O/H -12 mmHg, T/A -13 mmHg; p =0,805). Both, T/A and O/H did not affect flow mediated dilation (FMD), the primary endpoint, in a post-hoc prevasodilation-adjusted calculation. However, T/A reduced the Augmentation Index (AI) measured by digital volume plethysmography and ultrasound-based Intima Media thickness, whereas O/H had no effect (T/A vs O/H: DAI, p for difference=0,025; DIMT, p for difference=0,011). Stiffness Index by digital photoplethysmography was reduced in the T/A group (D -0,868 m/s, P=0,000); however, there was no difference between treatment groups (p=0,104) as well as NTproBNP was significantly reduced in the T/A group (DT/A p=0,002, D O/H p=0,055; p for difference = 0,447). Conclusion: Both combination therapies reduced blood pressure effectively and without observed differences between the treatment groups. Although the trial failed to show effects on endothelial function of the brachial artery after 6 months, T/A seems to have beneficial effects on arterial stiffness beyond blood pressure lowering which suggests additive cardioprotective effects. Further efforts are needed to elucidate the biological mechanisms of these findings and the impact on the outcome