Angiotensin converting enzyme inhibition, pulse wave velocity and ambulatory blood pressure measurements in essential hypertension.

Ambulatory blood pressure measurements are better at predicting the outcome of hypertension than single measurements. Since cardiovascular morbidity and mortality are mainly related to large artery damage in hypertensive patients, non-invasive indices of arterial distensibility, such as pulse wave velocity, have been proposed for the evaluation of cardiovascular risk. Indeed, pulse wave velocity is positively correlated with blood pressure (BP) when measured by ambulatory recordings, while there is no correlation with clinical mercury sphygmomanometer readings. Angiotensin converting enzyme (ACE) inhibitors such as perindopril not only reduce high blood pressure, but also increase arterial compliance and distensibility. This latter effect could lead to a more marked decrease in systolic blood pressure than diastolic blood pressure following long-term treatment with ACE inhibitors. This has been demonstrated using ambulatory blood pressure monitoring in hypertensive patients treated with perindopril for three months. The correlation coefficient between ambulatory systolic and diastolic blood pressure before (r = 0.82) and after (r = 0.76) perindopril was significant. Comparison of the corresponding slopes indicated that, for any given value of diastolic blood pressure, systolic blood pressure was significantly lower after perindopril than before perindopril. The action of the drug on the arterial wall may therefore explain the more marked effect on systolic blood pressure than on diastolic blood pressure.