Factors Influencing the Improvement of Left Ventricular Systolic Function in Patients with Idiopathic Dilated Cardiomyopathy

ABSTRACT

BACKGROUND AND OBJECTIVES: Idiopathic dilated cardiomyopathy (IDC) is a disease entity with no known specific curative measures. However, significant improvement in the left ventricular (LV) systolic function, during the management course for IDC, is frequently observed. In this study we tried to ascertain associated factors for the improvement of the LV function in patients with IDC. SUBJECTS AND METHODS: Thirty-three patients, newly diagnosed as IDC between Jan. 1999 and Jan. 2001, on whom a 6-month follow-up echocardiography was performed, were included in the study. Improvement in the LV systolic function was defined as an increase in the LV ejection fraction greater than 10% from the baseline. The subjects were divided into two groups; the improved group (IG) and the unimproved group (UG). The clinical characteristics and management methods were evaluated, and compared between the two groups. RESULTS: Seventeen patients (M/F15/2) were included in the IG, and 16 (M/F7/9) were included in the UG. There were no significant differences in the baseline LV systolic function (IG23.4+/-1.5% vs. UG28.9+/-2.3%), age, NYHA functional class or resting heart rate on admission between the two groups. b-blocker therapy (p=0.002), the absence of diabetes mellitus (p=0.046) and male sex (p=0.007), were all significantly associated with an improvement in the LV systolic function from the univariate analyses. With the multivariate analyses, only b-blocker therapy was significantly associated with an improvement in the LV systolic function. The 6-month event-free survival rate was significantly better in the IG compared with UG (94+/-5% vs. 63+/-13%, p=0.031). CONCLUSION: b-blocker therapy exerts a considerable effecs on the improvement in the LV systolic function of patients with IDC.