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 remodelling’.
This review summarizes work aimed at determining the extent to which angiotensin converting enzyme (ACE) inhibitor treatment is able to normalize these abnormalities, and whether this is desirable.
In essential hypertension, the changes seen in subcutaneous resistance vessels appear to be mainly due to eutrophic remodelling and only a small portion to growth. In addition, rat studies indicate that eutrophic remodelling, rather than growth, is found in all vascular beds. Antihypertensive treatment of hypertensive rats with ACE inhibitors causes a dose-dependent regression of the media: lumen ratio. Clinical studies have now confirmed these findings, showing that when previously untreated essential hypertensive patients are treated with the ACE inhibitor perindopril, the abnormal structure of resistance vessels regresses towards normal values; in contrast, treatment with a β-blocker does not affect the abnormal vascular structure.
The available evidence indicates that ACE inhibitors are able to normalize the abnormal resistance vessel structure seen in essential hypertension, and suggests that this effect may not only be dependent on their ability to reduce blood pressure.