Intravenous pimobendan (5 mg) reduced systemic resistance by 22% and left ventricular end-diastolic pressure by 50%, and improved isovolumetric contractility and relaxation parameters by 30%.
Does intravenous pimobendan improve hemodynamics, myocardial energetics, and neurohormonal profiles in patients with mild to moderate heart failure due to ischemic cardiomyopathy?
Intravenous pimobendan provides positive inotropic and lusitropic effects while reducing preload, afterload, and myocardial oxygen consumption in patients with ischemic cardiomyopathy.
p-value: p=<0.05
In contrast to cyclic AMP-dependent positive inotropes, the calcium-sensitizer and partial phosphodiesterase (PDE) inhibitor pimobendan may induce beneficial effects in heart failure. However, its effect on relaxation, myocardial energetics and neurohormones are unknown. Twelve patients with heart failure, New York Heart Association (NYHA) classification II-III, due to ischemic cardiomyopathy, were studied for 1 h after they received 5 mg pimobendan intravenously (i.v.). Pimobendan progressively reduced systemic resistance and left ventricular end-diastolic pressure (LVEDP) (22 and 50%, respectively) and improved isovolumetric contractility and relaxation parameters by 30% (all p < 0.05 vs. control). LV end-diastolic and end-systolic volumes (LVEDV, LVESV) decreased significantly by 20 and 19%, respectively. Cardiac output (CO) increased by 17% due to a simultaneous increase in heart rate (HR) from 75 +/- 3 to 86 +/- 5 beats/min (mean +/- SEM, p < 0.05). Pimobendan did not change coronary hemodynamics, but myocardial O2 extraction and consumption were decreased significantly by 18 and 20%, respectively. Catecholamines, angiotensin II (AII), and aldosterone levels did not change significantly. In contrast, arterial and coronary venous renin increased significantly from 57 +/- 17 and 53 +/- 14.7 microM/h at control to 69 +/- 20 and 69 +/- 20 microM/h, respectively, 60 min after pimobendan administration. Simultaneously, cardiac renin uptake at baseline (0.449 +/- 0.185 mumol/min) changed to release (-0.071 +/- 0.145 mumol/min, p < 0.05). Serious side effects did not occur. Thus, pimobendan had progressive positive inotropic and lusitropic effects, diminished preload and afterload despite modest stimulation of plasma renin activity (PRA), and reduced systemic vascular resistance.(ABSTRACT TRUNCATED AT 250 WORDS)
Remme et al. (Tue,) conducted a other in Mild to moderate heart failure (n=12). Pimobendan vs. Baseline was evaluated on Hemodynamic, neurohumoral, and myocardial energetic parameters (p=<0.05). Intravenous pimobendan (5 mg) reduced systemic resistance by 22% and left ventricular end-diastolic pressure by 50%, and improved isovolumetric contractility and relaxation parameters by 30%.