Pre-Clinical and Clinical Experience of Telmisartan in Cardiac Remodelling

Abstract

Epidemiological studies have established that left ventricular hypertrophy (LVH) is an independent risk factor for cardiovascular and cerebrovascular morbidity and mortality. In turn, hypertension is a well-established risk factor for LVH. Ambulatory blood pressure monitoring has shown that 24-h mean ambulatory blood pressure is a particularly powerful predictor of LVH, being superior to casual clinic blood pressure measurements. The magnitude of the rise in blood pressure in the early morning correlates with the extent of LVH. Prospective studies have shown the advantageous effects of antihypertensive therapy on LVH in terms of regression of left ventricular mass (LVM) and subsequent reduction in overt cardiovascular disease. Meta-analysis has identified differences in the ability of different classes of anti-hypertensive agents to bring about regression of LVH, with agents that target the renin angiotensin system (RAS) appearing superior to other agents, such as beta-blockers and diuretics. The distinct pharmacological features of telmisartan suggest that it may be a suitable agent for managing hypertensive patients because it provides sustained control of blood pressure and appears to be very effective in reversing cardiac remodelling. Pre-clinical evaluation has demonstrated that telmisartan suppresses angiotensin II-induced collagen production and secretion by cultured fibroblasts, and reduces left ventricular weight in different animal models. Several clinical studies have demonstrated that, as well as reducing blood pressure (including 24-h mean ambulatory values), telmisartan brings about LVM regression in patients with hypertension, and improves left ventricular and left atrial function. Comparative studies have shown telmisartan's superiority compared with both hydrochlorothiazide and carvedilol in regressing LVM, the additional activity probably being explained by the sustained blood pressure control and the non-haemodynamic effects of targeting the RAS. The ultimate proof of the clinical value of telmisartan will be provided by the outcome trials ONgoing Telmisartan Alone and in combination with Ramipril Global Endpoint Trial/Telmisartan Randomized AssessmeNt Study in aCE iNtolerant subjects with cardiovascular Disease (ONTARGET/TRANSCEND) currently being conducted in high-risk patients.