Background: Ultrasonographic evidence of increased carotid intima-media thickness (IMT) is known to be associated with generalized atherosclerosis. Therapeutic blockade of the renin-angiotensin system (RAS) with angiotensin-converting enzyme (ACE) inhibitors reportedly reduces carotid IMT in humans. However, there has been no head-to-head comparison of the effects of ACE inhibitor and angiotensin receptor blocker (ARB), a newer type of RAS inhibitor, on carotid IMT.
Methods: 57 hypertensive patients were randomly assigned to treatment with one of two antihypertensive drugs: ACE inhibitor (quinapril; n = 25, group Q) or ARB (losartan; n = 18, group L).
Results: After 1 year of treatment, a similar decrease in mean blood pressure was observed in all groups. Carotid IMT was decreased significantly in group Q (10% decrease, p < 0.05) but did not change in group L. There were no significant changes in other atherosclerotic factors between these two groups.
Conclusion: Our findings suggest that the antiatherosclerotic effect of quinapril is more potent than that of losartan in hypertensive patients. This effect appears unrelated to the drug's antihypertensive action or to traditional atherosclerotic factors.