Dalteparin for prevention of catheter-related complications in cancer patients with central venous catheters: final results of a double-blind, placebo-controlled phase III trial

Background: Cancer patients receiving chemotherapy experience thromboembolic complications associated with the use of long-term indwelling central venous catheters (CVCs). This prospective, double-blind, placebo-controlled, multicenter study evaluated whether prophylactic treatment with a low molecular weight heparin could prevent clinically relevant catheter-related thrombosis. Patients and methods: Patients with cancer undergoing chemotherapy for at least 12 weeks (n = 439) were randomly assigned, in a 2:1 ratio, to receive either dalteparin (5000IU) or placebo, by subcutaneous injection, once daily for 16 weeks. Patients underwent upper extremity evaluation with either venography or ultrasound at the time of a suspected catheter-related complication (CRC) or upon completion of study medication. The primary end point, as determined by a blinded adjudication committee, was the occurrence of a CRC, defined as the first occurrence of any one of the following: clinically relevant catheter-related thrombosis that was symptomatic or that required anticoagulant or fibrinolytic therapy; catheter-related clinically relevant pulmonary embolism; or catheter obstruction requiring catheter removal. Results: There was no significant difference in the frequency of CRCs between the dalteparin arm (3.7%) and the placebo arm (3.4%; P = 0.88), corresponding to a relative risk of 1.0883 (95% confidence interval 0.37–3.19). No difference in the time to CRC was observed between the two arms (P = 0.83). There was no significant difference between the dalteparin and placebo groups in terms of major bleeding (1 versus 0) or overall safety. Conclusions: Dalteparin prophylaxis did not reduce the frequency of thromboembolic complications after CVC implantation in cancer patients. Dalteparin was demonstrated to be safe over 16 weeks of treatment in these patients.