Dermatan sulfate versus unfractionated heparin for the prevention of venous thromboembolism in patients undergoing surgery for cancer. A cost-effectiveness analysis.

BACKGROUND: In a recent clinical trial, dermatan sulfate was found to be more effective than unfractionated heparin (UFH), but equally well tolerated, for the prevention of deep vein thrombosis (DVT) after major surgery for cancer. OBJECTIVE: To perform a cost-effectiveness analysis of dermatan sulfate versus UFH in this clinical setting. DESIGN AND SETTING: This was a retrospective economic analysis using data from a randomised clinical trial, and was performed from the hospital perspective. METHODS: Clinical event rates were extrapolated from the observed venographic DVT rates, using appropriate assumptions from the scientific literature. The economic effects of switching DVT prophylaxis from UFH to dermatan sulfate and the potential lives saved were assessed by a predictive decision model. RESULTS: The per patient cost, including the burden of residual thromboembolic events and major bleeding complications, was estimated to be 154 euros (EUR) for dermatan sulfate and EUR185 for UFH (1998 values). With reference to a potential target population of 60,000 patients/year undergoing surgery for cancer in Italy, the total prophylaxis-associated cost was EUR9,258,000 for dermatan sulfate and EUR11,096,000 for UFH, whereas the potential deaths from prophylaxis failure were 204 and 392, respectively. This represented a saving of EUR1,838,000 and 188 potential lives per year with the dermatan sulfate option. The final costs and effects were mainly sensitive to variations in the rates of DVT and pulmonary embolism, and to the possible need for 1 extra day of hospitalisation because of the earlier preoperative initiation of dermatan sulfate prophylaxis. CONCLUSION: Dermatan sulfate is more cost effective than UFH for the prevention of postoperative venous thromboembolism in patients with cancer. If the hospital stay needs to be prolonged, then the dermatan sulfate option may involve a small additional cost (EUR47) per potential life saved.

Danaparoid sodium.

Danaparoid sodium (Orgaran, Organon) is a heparinoid glycosamino-glycuronan antithrombotic agent approved for the prophylaxis of post-operative deep vein thrombosis (DVT), which may lead to pulmonary embolism (PE) in patients undergoing elective hip replacement surgery. Danaparoid is a low molecular weight heparinoid consisting of a mixture of heparan sulphate (84%), dermatan sulphate (12%) and small amounts of chondroitin sulphate (4%), whose antithrombotic activity has been well established. Its pharmacological effect is exerted primarily by inhibiting Factors Xa (FXa) and IIa (FIIa) at a ratio greater than heparin, with a minimal effect on platelet function. Danaparoid exhibits low cross-reactivity with heparin-induced antibodies when compared with heparin or low molecular weight heparins (LMWH), thereby making it an excellent choice for the management of heparin-induced thrombocytopenia (HIT). It has excellent bioavailability following s.c. injection. Danaparoid has little effect on routine coagulation tests (activated partial thromboplastin time [aPTT], prothrombin time [PT], and thrombin time [TT]). Patients with elevated serum creatinine should be monitored carefully. For its FDA approved indication (DVT prophylaxis during hip replacement surgery), its cost per day is approximately eight times more than LMWH. Even though monitoring is not routinely necessary according to the manufacturer for its approved indication, monitoring is frequently necessary when it is used in other clinical scenarios. Its higher cost than comparable therapies for DVT prophylaxis and the low availability of the FXa assay in most non-tertiary care hospitals has limited the widespread use of danaparoid. Danaparoid has been found to be effective in the treatment of HIT although this is an off label use, despite being the most frequent reason why danaparoid is used.