Can low molecular weight heparins circumvent the problem of coumadine and chemotherapy interaction in cancer patients with prosthetic heart valves?

In the everyday routine practice of a medical oncologist, it is not so infrequent that a patient with prosthetic heart valve who is on warfarine therapy has to receive chemotherapy, . This is a problematic situation for a medical oncologist since, drug interactions of warfarine with various chemotherapeutics are unpredictable, the result may either be thrombosis or bleeding. Furthermore, chemotherapeutic agents are given mostly on an intermittent basis, meaning that these unpredictable interactions occur when chemotherapy is given and then thrombocytopenia follows. The data on how to continue anti-coagulation therapy in such patients are sparse and in major guidelines, it is not involved (Holbrook et al., 2012; Vahanian et al., 2012). Low molecular weight heparins (LMWH) are superior to warfarine in patients with cancer in the prophylaxis of deep vein thrombosis, probably owing to lack of significant drug interactions with chemotherapeutic agents. There is also no need for INR (International normalized ratio) monitorization. They are also safe as bridging therapy in patients with prosthetic heart valves peri-operatively instead of warfarine (Holbrook et al., 2012; Vahanian et al., 2012). For the reasons above, we tend to follow such patients on chemotherapy with LMWH instead of warfarine. Here, we wanted to share our experience on nine patients with prosthetic heart valves treated with LMWH during chemotherapy (Table 1). During our follow up, we had not observed neither any thrombotic complications nor LMWH associated bleeding LETTER to the EDITOR