Chronic effects of nebivolol on arterial blood pressure and LV function in patients with moderate to severe arterial hypertension

Abstract

Nebivolol is a highly specific beta-blocking agent with vasodilating properties mediated by endothelial NO release. Aim of the study was to assess by a completely noninvasive approach the effects of Nebivolol on arterial blood pressure and left ventricular systolic function in patients with moderate to severe AH and normal LV mass and function at 2-D echo. Nine patients (4M, 5F) with a resting DP ≥95mmHg, were studied after adequate pharmacological washout and 14 days after oral treatment with Nebivolol 5 mg o.d. Arterial blood pressure was continuously monitored by Finapres and data stored on a computer. The 2D echo was continuously assessed by the apical 4 chamber approach and recorded on videotape; periodic markers on pressure were synchronized with the time display of the echocardiogram. Echo frames for measurement of end-systolic and end-diastolic volumes were selected at different values of arterial pressure during i.v. infusion of nitroprussiate. Relative changes in load-independent measurement of LV inotropism were obtained by comparing slope and intercept values of the end-systolic pressure/volume curves as well as the extrapolated areas under these curves for a constant volume range (0-50 ml) (P/V area). In addition, EF values before and after Nebivolol were compared for the same end-diastolic volume. Heart energy consumption was obtained by mean arterial pressure times cardiac output (CO). Results: significant changes in the clinostatic SBP and DBP after chronic treatment were reported in all pts (-14 and -21%, respectively), associated to a decrease in heart rate (-14%). In conclusion, Nebivolol exerted an hypotensive effect through a reduction of systemic vascular resistance and a mild reduction in CO. The negative inotropic effect, evident from the P/V areas, was counterbalanced by the reduction in SVR with maintained stroke volume. Nebivolol markedly decreased heart energy consumption per beat and per minute. (See Table)