engleski

Pretreatment with levosimendan improves heart function in off-pump coronary artery bypass grafting

OBJECTIVE. Calcium sensitizer levosimendan induces contractility by binding to intracellular troponin C without increasing intracellular calcium concentration. We used the levosimendan to produce early and prolonged beneficial effect on left ventricular systolic function in patients with preoperative impaired left ventricular function undergoing off-pump coronary artery bypass grafting (OPCABG). METHODS. After induction in anesthesia, by using the computer randomization program, all patients randomized in three groups: low-dose levosimendan, high-dose levosimendan or placebo group. Levosimendan used with loading dose at low-dose (6 mcg/kg), high-dose (12 mcg/kg), or placebo were administered in thirty-five patients. Cardiac output measured with pulmonary artery catheter using bolus thermodilution method in the same time intervals - before infusion, 20 minutes after infusion and 48 hours after the end of surgery. All measurements performed between groups and within each group. Numerical data were described by median. For comparing the data between the independent groups (low-dose levosimendan, high-dose levosimendan or placebo), the Kruskal-Walis test was applied. To compare time points within one group, testing of the differences in time within each group performed with the Friedman test. RESULTS. Increasing of cardiac output was statistically significant and occurred both after low-dose (p = 0.001) and high- dose levosimendan (p < 0.001). Comparing values of cardiac output between groups of patients who received low-dose levosimendan and placebo, cardiac output was higher in low-dose levosimendan group, but statistically differences were not significant. On the other side, in patients who received low-dose levosimendan, compared with baseline measurement, values of cardiac output increased 20 minutes after loading dose (p = 0.080) and 48 h after the end of surgery (p=0.067). Similar changes in cardiac output values have seen in group of patients who received high-dose levosimendan measured in the same time intervals. Significantly higher values of cardiac output were in patients who received high-dose levosimendan compared with those receiving placebo, 20 min after loading (p = 0.021) and 48 h after the end of the surgery (p = 0.006). Finally, patients treated with high-dose levosimendan, had all values of cardiac output significantly higher when compared with baseline measurement (p = 0.005 for all). CONCLUSION. In this study, results shown that levosimendan after loading doses produced significant both early and prolonged favorable effect on left ventricular output in patients with preoperative impaired left ventricular function undergoing OPCABG surgery, and this effect is dose dependent.

levosimendan; OPCABG; coronary artery bypass grafting

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