Interventional study of diltiazem in dilated cardiomyopathy: a report of multiple centre clinical trial in China: Chinese cooperative group of diltiazem intervention trial in dilated cardiomyopathy

The aim of this study was to determine the interventional effects of diltiazem on autoantibody mediated myocardial damage in dilated cardiomyopathy (DCM). 221 patients with DCM in 16 hospitals were included in the multiple centre clinical trial from January 1995 to November 1996, using the diltiazem or placebo based on the background therapy for heart failure. Patients were randomly divided into groups for a single blind trial, followed by observation for an average of 7.4 months. After treatment, the heart function of 84% of patients in the diltiazem group recovered to grade I or II, but this occured for 64% of patients in the placebo group. Heart–thorax ratio was decreased from 0.59±0.07 to 0.56±0.07 and the left ventricular end-diastolic dimension (LVEDd) from 65.40±8.60 mm to 61.12±9.86 mm, the left ventricular ejection fraction (EF) was increased from 35.75±10.78% to 42.52%±11.41% (P<0.01) in the diltiazem group (n=114). The above parameters were not significantly changed in the placebo group (n=107). Mortality was 3.5% in the diltiazem group and 11.2% in the placebo group (P<0.05). Further analysis also shows that LVEDd were reduced and EF were obviously elevated in patients with DCM of LVEDd <70 mm, but the above parameters werenʹt improved in patients of LVEDd >70 mm. The study suggests that diltiazem is safe and effective in the treatment of DCM, the action mechanism might be intervention in antibody-mediated myocardial damage and protection of myocardium. Diltiazem is suitable for the treatment of the early stage in DCM.