Early and short-term acenocumarine or dalteparin for the prevention of central vein catheter-related thrombosis in cancer patients: a randomized controlled study based on serial venographies.

Background: We evaluated efficacy and safety of early and short-term prophylaxis with acenocumarine or dalteparin in the prevention of non-occlusive or occlusive central vein catheter-related thrombosis (CVCrT).
Patients and Methods: Consecutive cancer patients scheduled for chemotherapy randomly received: acenocumarine 1 mg/day for 3 days before and 8 days after central vein catheter (CVC) insertion; dalteparin 5000 IU 2 h before and daily for 8 days after CVC insertion; no anticoagulant treatment (NT). All patients underwent venography on days 8 and 30, some of them on days 90, 150 and 210 after CVC.
Results: A total of 450 patients were randomized, 348 underwent at least two venography. Both acenocumarine and dalteparin reduced venography-detected CVCrT rate [21.9% acenocumarine versus 52.6% NT, odds ratio (OR) 0.3, P < 0.01; 40% dalteparin versus 52.6% NT, OR 0.6, P = 0.05]. Acenocumarine was more effective than dalteparin (OR 0.4, P = 0.01). The rate of occlusive CVCrT was not different in the three groups (0.9% acenocumarine, 3.3% dalteparin, 1.8% NT; P = 0.40). Most CVCrTs (95.6%) were observed on day 8 after CVC insertion and were non-occlusive.
Conclusions: In this study of early and short-term prophylaxis, acenocumarine was more effective than dalteparin on non-occlusive and asymptomatic CVCrT events. The first days following CVC insertion represent the highest risk for CVCrT.