Introduction: Although beta-blockers are highly effective in the treatment of heart failure (HF), many patients with HF receiving a beta-blocker continue to become decompensated and require hospitalization for worsening HF. Levosimendan and dobutamine are used to manage decompensated HF, but their comparative effects on left ventricular (LV) function in patients prescribed beta-blockers are unknown.
Aims: The aim of this study was to compare the effects of dobutamine and levosimendan on LV systolic and diastolic functions in chronic HF patients treated chronically with carvedilol. Forty patients with chronic HF who had NYHA class III to IV symptoms, a LV ejection fraction (LVEF) <40%, and ongoing treatment with carvedilol were enrolled in this randomized (1:1), dobutamine controlled, open-label study. Before and 24 h after treatment, LVEF, mitral inflow peak E and A wave velocity, E/A ratio, the deceleration time of the E wave (DT), isovolumic relaxation time (IVRT), peak systolic (Sm) and early diastolic (Em) mitral annular velocity, and systolic pulmonary artery pressure (SPAP) were measured by echocardiography.
Results: Levosimendan produced a statistically significant increase in LVEF (28+/-5% vs. 33+/-3%), Sm (6.5+/-1.2 cm/s vs. 7.4+/-0.9 cm/s), DT (120+/-10 ms vs. 140+/-15 ms), and Em (7.5+/-0.4 cm/s vs. 8.1+/-0.5 cm/s) and significant decrease in E/A ratio (2.1+/-0.3 vs. 1.7+/-0.4) and SPAP (55+/-5 mmHg vs. 40+/-7 mmHg). No significant change occurred in LV systolic and diastolic function parameters, or SPAP with dobutamine treatment. Levosimendan did not significantly alter the heart rate (72+/-4 bpm vs. 70+/-3 bpm), systolic (105+/-5 mmHg vs. 102+/-4 mmHg), or diastolic blood pressure (85+/-5 mmHg vs. 83+/-5 mmHg) whereas with dobutamine treatment, all these parameters significantly increased.
Conclusions: Dobutamine and levosimendan have different effects on LV functions in patients treated chronically with carvedilol. These differences should be considered when selecting inotropic therapy for decompensated HF receiving long-term carvedilol.