Antiatherosclerotic effects of antihypertensive drugs: recent evidence and ongoing trials.

The issue as to whether antihypertensive drugs may exert some antiatherosclerotic effect, at least partly independent of blood pressure lowering, has been explored in several experimental models of atherosclerosis, and a large body of evidence has been obtained in favor of a specific antiatherosclerotic action of calcium antagonists and ACE-inhibitors. On the clinical side, several studies are investigating the problem in hypertensive patients in whom progression of carotid intima-media thickness (IMT) and atherosclerotic plaques is explored by sensitive quantitative B-mode ultrasound techniques. The MIDAS has indicated a slower progression, at least in the first six months, of carotid plaques in isradipine treated patients than in diuretic-treated ones. However, MIDAS as a pioneer study has been particularly valuable in giving information on the rate of growth of IMT in hypertensive patients and on the best end-point to use in carotid ultrasound trials. Baseline data of the ongoing studies ELSA and VHAS have so far provided evidence of the very high prevalence of carotid atherosclerosis among hypertensive patients, an observation that makes the evaluation of the antiatherosclerotic action of some antihypertensive agents even more important. Finally, the PHYLLIS trial using a factorial design, beside exploring the antiatherosclerotic action of an ACE-inhibitor vs a diuretic, intends to evaluate the possible benefits of associating antihypertensive therapy with lipid lowering by a statin on the progression of carotid atherosclerosis.