Levosimendan had neutral effects on myocardial oxygen consumption and cardiac efficiency in healthy male volunteers, whereas dobutamine increased oxygen requirement.
Dynamic positron emission tomography (PET) with 11Cacetate allows noninvasive assessment of myocardial oxygen consumption. In combination with echocardiography, PET enables determination of cardiac efficiency (defined as useful cardiac work per unit of oxygen consumption). We used this approach to compare the effects of levosimendan, a Ca(2+)-dependent calcium sensitizer, with dobutamine and sodium nitroprusside in healthy male volunteers. The effects of levosimendan on k(mono), an index of oxygen consumption, and cardiac efficiency were neutral, whereas the hemodynamic profile was consistent with balanced inotropism and vasodilatation. Dobutamine enhanced cardiac efficiency at the expense of increased oxygen requirement, but the effects of nitroprusside on k(mono) and cardiac efficiency were neutral. This study shows the feasibility of PET in phase 1 pharmacodynamic studies and suggests potential energetical advantages of calcium sensitization with levosimendan.
Ukkonen et al. (Thu,) conducted a other in Healthy volunteers. Levosimendan vs. Dobutamine and sodium nitroprusside was evaluated on k(mono) (index of oxygen consumption) and cardiac efficiency. Levosimendan had neutral effects on myocardial oxygen consumption and cardiac efficiency in healthy male volunteers, whereas dobutamine increased oxygen requirement.