Prevention of catheter-related venous thrombosis with nadroparin in patients receiving chemotherapy for hematologic malignancies: a randomized, placebo-controlled study

Background: Hemato-oncology patients treated with intensive chemotherapy usually require the placement of a central venous catheter (CVC). CVCs are frequently complicated by catheter-related central venous thrombosis (CVT), which has been associated with an increased risk of pulmonary embolism and catheter-related infection. Objectives: To determine the efficacy and safety of thromboprophylaxis with s.c. low-molecular-weight heparin (nadroparin) administered once daily in a randomized placebo-controlled, double-blind trial in patients with hematologic malignancies. Patients and methods: Consecutive patients with hematologic malignancies requiring intensive chemotherapy including autologous stem cell transplantation were eligible. The patients were randomized to receive nadroparin 2850 antifactor Xa units once daily or placebo s.c. for 3 weeks. Venography was performed on day 21 after CVC insertion. Secondary outcomes were bleeding and catheter-related infection. Results: In total, 113 patients were randomized to nadroparin or placebo, and 87 patients (77%) underwent venography. In total, I I venographically proven catheter-related CVTs were diagnosed. The frequency of catheter-related CVT was not significantly different between study groups, namely four catheter-related CVTs in the placebo group [9%; 95% CI: 0.002-0.16] vs. seven catheter-related CVTs in the nadroparin group (17%; 95% Cl: 0.06-0.28). In addition, no difference in the incidence of catheter-related infection or bleeding was observed between the groups. Conclusion: This study showed that the actual risk for catheter-related CVT in patients with hematologic malignancies is lower than suggested in earlier studies in cancer patients. Although prophylactic administration of nadroparin appeared to be safe in this group of patients with a high risk of bleeding, it cannot be recommended for the prevention of catheter-related CVT or catheter-related infection in patients with hematologic malignancies.