Defective endothelial function has been shown in dilated cardiomyopathy. Therefore, improvement in endothelial function after low-molecular-weight heparin (LMWH) therapy may be clinically beneficial. Consequently, the effect of adjunct enoxaparin, a LMWH, on standard treatment of dilated cardiomyopathy was investigated.

This was a randomized, standard treatment–controlled, 2-center pilot trial of 102 patients (52 receiving adjunctive therapy with enoxaparin at a dosage of 1.5 mg/kg daily for 3 months and 50 receiving standard therapy with angiotensin-converting enzyme inhibitors, β-blockers, and diuretics alone) with stable chronic heart failure secondary to dilated cardiomyopathy (New York Heart Association [NYHA] class II and III; left ventricular [LV] ejection fraction, ≤40%). All patients underwent coronary angiography and endomyocardial biopsy and were clinically stable for at least 6 months before enrollment. The combined primary end point included mortality, urgent heart transplantation, and readmission to hospital due to heart failure progression. The secondary end point was to determine the severity of heart failure (serum level of N-terminal brain natriuretic peptide), cardiac function (LV ejection fraction by radionuclide ventriculography), LV diameters by echocardiography, exercise capacity (changes in NYHA class, changes in peak oxygen consumption), and changes in quality of life (Minnesota Living with Heart Failure questionnaire). The clinical outcome was assessed after 6 and 12 months of therapy.

Baseline characteristics were comparable in both groups. Five patients dropped out during 12 months of the study. Twelve patients achieved primary end point (8 in the control group and 4 in the LMWH group). The free survival rate was 94% for the LMWH group and 90% for the controls (not statistically significant). After the 12-month period, in the LMWH group, N-terminal brain natriuretic peptide level and LV diameters decreased significantly (P < .001 and P = .006, respectively), whereas LV systolic function increased (P < .001). Changes in exercise capacity and subjective improvement did not differentiate the groups (nonsignificant). Adverse reactions to the enoxaparin therapy were minor and transient.

In patients with chronic heart failure due to dilated cardiomyopathy, adjunct long-term enoxaparin therapy may offer additional clinical benefit without deleterious effects on major cardiac events.