Beneficial effects of a Ca 2+ sensitizer, MCI-154, on the myocardial oxygen consumption–cardiac output relation in patients with left ventricular dysfunction after myocardial infarction: Comparison with dobutamine and phosphodiesterase inhibitor, , ,

Although conventional inotropic agents such as catecholamines increase myocardial oxygen consumption, a newly developed inotropic agent, a Ca 2+ sensitizer, may be able to increase cardiac output with less myocardial oxygen consumption. By using right-side heart catheterization, we assessed the ratio of the increase in myocardial oxygen consumption per unit increase in cardiac output during β-adrenergic receptor stimulation (dobutamine, n = 15), phosphodiesterase inhibition (E-1020, n = 10), and Ca 2+ sensitization (MCI-154, n = 17) in patients with coronary artery disease. Dobutamine increased cardiac output and myocardial oxygen consumption. E-1020 increased cardiac output but did not change myocardial oxygen consumption. MCI-154 increased cardiac output and decreased myocardial oxygen consumption. The oxygen cost of increasing cardiac output with dobutamine and with E-1020 was different from that with dextran infusion ( n = 18); in contrast, the oxygen cost with MCI-154 was significantly smaller. Thus a newly developed Ca 2+ sensitizer, MCI-154, may be beneficial for the treatment of heart failure. (Am Heart J 1997;133:283-9.)