EFFECTS OF BLOOD-PRESSURE REDUCTION ON THE ELASTIC PROFILE OF THE AORTIC TREE IN PATIENTS WITH CORONARY HEART-DISEASE

Decreased arterial compliance of large arteries in coronary heart dise ase has been reported. Using intravascular ultrasound it was demonstra ted that arterial compliance decreases with increasing distance from t he heart. Until now changes in the elastic profile have not been inves tigated after a stepwise blood pressure (BP) reduction induced by anti hypertensive agents. The local viscoelastic properties of the aortic t ree were analyzed before and after a mean arterial BP reduction of abo ut 5 and 15 mm Hg below baseline by the steady-state infusion of incre asing doses of nisoldipine in 15 patients with coronary artery disease . Intravascular ultrasound imaging combined with arterial pressure mea surements were performed at five sites along the aortic tree to determ ine the viscoelastic profile before nisoldipine administration and aga in after the 5 and 15 mm Hg nisoldipine-induced blood pressure reducti ons. The elasticity parameters varied depending on the distance from t he heart and on the BP level. At both BP reduction levels nisoldipine infusion led to an increase in arterial compliance at the abdominal ao rta and at the aortic bifurcation. A dissociation between the 5 and th e 15 mm Hg BP reduction was found at the common iliac artery and at th e external iliac artery. Our results provide direct quantitative evide nce that stepwise BP reductions exhibit different and, in part, contra ry effects on the elastic profile, depending on the aortic tree locati on. The results also suggest that nisoldipine infusion can significant ly ameliorate local viscoelastic properties at the abdominal aorta and at the aortic bifurcation, an effect that was associated or caused by a change in BP attributable to a decrease in peripheral resistance.