The role of angiotensin-converting enzyme inhibitors in the treatment of hypertension.

Angiotensin-converting enzyme (ACE) inhibitors continue to find new uses. The Heart Outcomes Prevention Evaluation study has demonstrated their wide application as a preventive measure for patients at high risk of cardiovascular disease, but the available clinical trials in hypertensive subjects do not so far suggest any clear superiority over conventional treatment. The available trials may have been underpowered to detect non-blood pressure-related benefits on smooth muscle growth, endothelial function, left ventricular hypertrophy, and plaque rupture, when used in relatively low-risk subjects with uncomplicated hypertension. Clinical trials have also shown that two or more drugs are needed to lower blood pressure even to 140/90. Few patients have uncomplicated hypertension, so the choice of their drugs will be powerfully influenced by their other clinical problems. Nevertheless, there is a strong case for an attack on the renin-angiotensin system. Whether this will be by ACE inhibition, angiotensin-II receptor blockade, or both, is the subject of current clinical trials.