Long lasting arterial effects of the ACE inhibitor ramipril

The aim of this study was to determine the acute and chronic arterial effects of the ACE inhibitor, ramipril. Fourteen patients (mean age 47 years) with mild to moderate essential hypertension completed the study. A first haemodynamic examination was performed at the end of a 15-day placebo period (D15) before and 3 hours after oral administration of ramipril, 5 mg. Then all the patients started a 4-week treatment with ramipril, 5 mg/day. At the end of this period (D42) the haemodynamic examination was repeated 24 hours after the last capsule intake, and then 3 hours after administration of ramipril 5 mg. Brachial and carotid artery haemodynamics were evaluated by a bidimensional pulsed Doppler system. Arterial distensibility was non-invasively studied in three different arterial segments (carotido-femoral, brachio-radial, femoro-tibial) by the evaluation of the pulse wave velocity. Ramipril significantly decreased BP after acute or chronic administration. Chronic treatment with ramipril was followed by a long lasting increase in brachial artery diameter, a decrease in forearm vascular resistance, and an improvement in aortic distensibility. The other investigated arterial segments did not show any significant changes. Our results suggest that long lasting arterial effects of the ACE inhibitor ramipril are partly pressure-independent and are related to an effect of this drug on arterial tone. These effects may be able to reduce the hypertensive cardiac and arterial abnormalities.