Angiotensin converting enzyme inhibition decreases systolic blood pressure more than diastolic pressure as shown by ambulatory blood pressure monitoring.

Non-invasive ambulatory blood pressure monitoring (Spacelabs 5200) was carried out before and 3 months after treatment with perindopril, a new angiotensin converting enzyme (ACE) inhibitor given at 4-8 mg once a day in the morning. Twenty-one patients with sustained essential uncomplicated hypertension were analysed. The 24-h mean values for systolic and diastolic blood pressure, their standard deviations (absolute variability) and their coefficients of variation were compared before and after the administration of perindopril, using a two-way analysis of variance. In order to determine whether perindopril could decrease systolic more than diastolic pressure, we evaluated the relationship between systolic and diastolic blood pressure as recorded by the Spacelabs monitor. The correlation coefficient between these two parameters was calculated before (r = 0.82) and after (r = 0.76) treatment. Comparison between the corresponding slopes indicated that, at any given value of diastolic blood pressure, systolic blood pressure was lower after than before the administration of perindopril.