Intracoronary benazeprilat changed the decrease in coronary blood flow induced by cold pressor test and diving into an increase, significantly attenuating coronary vasoconstriction compared to saline.
Does intracoronary benazeprilat attenuate sympathetic coronary vasoconstriction in patients with severe coronary artery disease?
Local cardiac renin-angiotensin system inhibition with intracoronary benazeprilat attenuates sympathetic coronary vasoconstriction in patients with severe coronary artery disease, highlighting the role of tissue RAS.
BACKGROUND: In humans, angiotensin II enhances the sympathetic coronary vasoconstriction elicited by the cold pressor test (CPT) and diving. Whether this enhancement depends on the circulating angiotensin II or on the locally produced angiotensin II is unknown, however. METHODS AND RESULTS: We addressed this issue in 14 patients with severe coronary artery disease by evaluating the effects of a 2-minute CPT (n=14) and a 30-second dive (n=8) on mean arterial pressure (MAP, arterial catheter), heart rate (ECG), coronary sinus blood flow (CBF, thermodilution technique), and coronary vascular resistance (MAP/CBF ratio). The 2 stimuli were applied at the end of left intracoronary infusion of either saline or benazeprilat diluted at the concentration of 25 microgram/mL. The rate of benazeprilat infusion had been preliminarily demonstrated to reduce angiotensin II concentration in the coronary sinus without affecting its arterial concentration. The changes in MAP and heart rate induced by CPT and diving were superimposable during saline and benazeprilat infusions. The decrease in CBF induced by CPT and diving during saline infusion was changed into an increase during benazeprilat infusion with a significant attenuation of the coronary vasoconstrictor response. CONCLUSIONS: In patients with coronary artery disease, an attenuation of sympathetic coronary vasoconstriction can be obtained by reducing cardiac angiotensin II formation without involving circulating angiotensin II. This suggests a role of the tissue renin-angiotensin system in modulating autonomic cardiac drive in humans.
Saino et al. (Tue,) conducted a other in severe coronary artery disease (n=14). Intracoronary benazeprilat vs. Saline was evaluated on Coronary sinus blood flow and coronary vascular resistance. Intracoronary benazeprilat changed the decrease in coronary blood flow induced by cold pressor test and diving into an increase, significantly attenuating coronary vasoconstriction compared to saline.