Study population
We prospectively screened 139 consecutive outpatients with non-ischaemic
DCM who were referred to our echocardiography department. DCM was
defined using the following criteria: (1) end-diastolic left ventricular
(LV) volume index > 74 ml/m2 in males and
> 61 ml/m2 in females, according to
cut-offs from the current guidelines of chamber quantification [14]
and (2) LV ejection fraction (EF) <40% by two-dimensional
(2D) Simpson biplane method. We excluded patients with atrial
fibrillation (15 patients), poor acoustic window or inability to hold
breath (10 patients), conduction disturbances (3 patients) and cor
pulmonale (6 patients), leaving a final study population of 105
patients. Included patients were clinically stable (i.e., with no change
in diuretic dose for at least 2 weeks prior to enrollment).
Three investigators collected basic demographic and clinical data.
Patients’ clinical status was assessed by a physician using the New York
Heart Association (NYHA) classification. Severe symptoms of HF were
defined by NYHA class III or IV. BNP serum levels were available in 62
patients. Informed consent was obtained from all patients and the study
protocol was approved by the local human research committee.