Arterial structure in hypertension and the effects of angiotensin converting enzyme inhibition

In hypertension, structural changes in the cardiovascular system affect not only small arteries and the heart but also the large arteries, particularly in elderly people. It has been suggested that structural alterations to the small arteries are responsible for the elevation in mean arterial pressure seen in hypertension, as a result of increased vascular resistance. However, the amplitude of pressure oscillation (pulse pressure) is influenced by other haemodynamic mechanisms that involve large arteries including a decrease in compliance and an increase in wave reflection.

Structural alterations to the large arteries may, in hypertensive subjects, be responsible for an increase in the amplitude of pressure oscillation, leading to a disproportionate increase in systolic over diastolic blood pressure because of arterial (not arteriolar) changes. These findings not only contribute to a better understanding of the relationship between vascular structure and blood pressure levels but also to a better interpretation of hypertensive complications, particularly those related to the heart and large vessels.

The reversal of structural arterial changes may become a goal in long-term antihypertensive treatment. Angiotensin converting enzyme (ACE) inhibitors in particular can reverse structural arterial changes, increase arterial compliance and produce a more pronounced decrease in systolic than in diastolic blood pressure.