The Impact of Angiotensin Converting Enzyme Inhibitors on the Arterial Wall

There is recent interest in the possibility that angiotensin converting enzyme inhibitors (ACE inhibitors) may reduce the damage inflicted on the arterial wall by common cardiovascular risk factors such as hypertension, hyperlipidaemia and ageing. The efficacy of these drugs in blood pressure reduction is accepted, but whether there is an excess benefit on arterial structure and function, conferred by use of ACE inhibitors over more traditional antihypertensives, is still under debate. There is also evidence in animal models to suggest that ACE inhibition is effective in reduction of arterial damage due to experimental hyperlipidaemia. ACE inhibitors not only reduce the conversion of angiotensin I and angiotensin II, which can interact with the sympathetic nervous system, but also prevent the degradation of bradykinin. This means that ACE inhibitors have several potential mechanisms through which they could suppress intimal hypertrophy and prevent endothelial dysfunction, which is believed to precede arteriosclerosis in man. Although much further work is needed to clarify the mechanism underlying the beneficial effects on the arterial wall of this group of drugs, they do appear to have significant potential in the effort to reduce cardiovascular mortality and morbidity, especially in high risk groups.