Comparison of ischemic side effects of levosimendan and dobutamine with integrated backscatter analysis.

Background: Levosimendan improves cardiac contractility without increasing oxygen consumption. However, its effects on ischemia were not supported with the utilization of a noninvasive parameter of myocardial characterization.

Hypothesis: The changes observed in integrated backscatter (IBS) may be reflective of change in myocardial ischemia. In this study, the effect of levosimendan on ischemia detected by IBS was evaluated in patients with ischemic heart failure (HF).

Methods: Patients who had LVEF < 40% and NYHA III-IV symptoms of HF were included in this study. Patients were randomized to levosimendan (n = 21), or to dobutamine (n = 25) groups. The cyclic variation of integrated backscatter (CVIBS) was determined as the difference between the maximal and minimal values in a cardiac cycle, average of three consecutive beats. CVIBS was taken from the mid-anteroseptal, mid-inferior, and mid-posterolateral areas of the parasternal short axis images before the drug administration and at the end of the 24-hour infusion period.

Results: Baseline characteristics and concomitant medications were similar in both groups. A significant reduction in CVIBS was detected in anteroseptal (7.6 +/- 1.4 dB versus 5.9 +/- 0.8 dB, p = 0.01), inferior wall (7.4 +/- 0.8 dB versus 6.7 +/- 1.5 dB, p = 0.03), and posterolateral wall (9.0 +/- 1.2 dB versus 8.2 +/- 0.6 dB, p = 0.04) after dobutamine administration, while no significant changes were observed in the levosimendan group in all walls.

Conclusions: Unlike dobutamine, levosimendan may not induce myocardial ischemia as shown by CVIBS at commonly used dosages in the setting of decompensated HF without active ischemia.