Effects of angiotensin-converting enzyme inhibition on vascular remodeling of resistance vessels in hypertensive patients.

Essential hypertension is known to be associated with a decrease in the lumen diameter and an increase in the wall thickness to lumen diameter ratio of the resistance vessels. Recently, it has been clarified that this alteration does not necessarily involve vascular growth, but could be due to a rearrangement of the same amount of material, a phenomenon now termed "eutrophic remodeling." These changes are found both in human essential hypertension and in animal models of genetic hypertension. Antihypertensive treatment with angiotensin-converting enzyme (ACE) inhibitors causes a dose-dependent regression of the media to lumen ratio in rats. Clinical studies have now confirmed these findings, showing that when previously untreated essential hypertensive patients are treated with the ACE inhibitor perindopril (PE), the abnormal structure of resistance vessels regresses toward normal values; in contrast, treatment with a beta-blocker does not affect the abnormal vascular structure. The available evidence thus indicates that ACE inhibitors are able to normalize the abnormal resistance vessel structure in essential hypertension, and suggest that this effect may not only be dependent on their ability to reduce blood pressure. This review summarizes these findings, and discusses the extent to which this is desirable.