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 disease has been reported. Using intravascular ultrasound it was demonstrated that arterial compliance decreases with increasing distance from the heart. Until now changes in the elastic profile have not been investigated after a stepwise blood pressure (BP) reduction induced by antihypertensive agents. The local viscoelastic properties of the aortic tree were analyzed before and after a mean arterial BP reduction of about 5 and 15 mm Hg below baseline by the steady-state infusion of increasing doses of nisoldipine in 15 patients with coronary artery disease. Intravascular ultrasound imaging combined with arterial pressure measurements were performed at five sites along the aortic tree to determine the viscoelastic profile before nisoldipine administration and again after the 5 and 15 mm Hg nisoldipine-induced blood pressure reductions. The elasticity parameters varied depending on the distance from the heart and on the BP level. At both BP reduction levels nisoldipine infusion led to an increase in arterial compliance at the abdominal aorta and at the aortic bifurcation. A dissociation between the 5 and the 15 mm Hg BP reduction was found at the common iliac artery and at the external iliac artery. Our results provide direct quantitative evidence that stepwise BP reductions exhibit different and, in part, contrary effects on the elastic profile, depending on the aortic tree location. The results also suggest that nisoldipine infusion can significantly 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.