Objective:It is unclear whether carvedilol and nebivolol produce different effects on short-term left ventricle (LV) systolic function in heart failure (HF). These drugs could improve systolic and diastolic functions of the LV. Thus, we aimed to compare their effects on LV systolic functions in patients with non-ischemic HF.Methods:This study included 61 symptomatic non-ischemic HF patients with low ejection fraction (EF) (EF≤40%) between September 2008 and November 2010. The patients were randomized to carvedilol (n=31, 16 males) or nebivolol (n=30, 19 male). They were evaluated clinically and echocardiographically at baseline and 3 and 6 months after target dose; 42% of patients in the carvedilol group and 47% in the nebivolol group achieved the target dose before randomization. LV systolic functions were evaluated with ventricle diameters, EF, ejection time (ET), isovolumic contraction time (IVCT), isovolumic relaxation time (IVRT), and myocardial performance index (MPI).Results:At 6 months, carvedilol and nebivolol similarly improved EF (from 33±4% to 36±5%, p<0.01 and from 34±5% to 37±5%, p<0.01, inter-group p=0.30, respectively) and MPI (from 0.71±0.10 to 0.53±0.07, p<0.01 and from 0.69±0.13 to 0.52±0.08, p<0.01, intergroup p=0.45, respectively). LV diameter was reduced by a similar extent in both groups. In each group, IVCT and IVRT were significantly shortened and ET was prolonged, but there was no inter-group difference. Functional capacity improved similarly (from NYHA Class II-III to Class I-0) in both groups, as did heart rate and blood pressure. Reduction of pro-B-type natriuretic peptide levels was also comparable in both groups (p=0.41).Conclusion:Carvedilol and nebivolol can similarly improve LV systolic functions in non-ischemic HF patients.