Anticoagulant Bridge Comparison in Mechanical Circulatory Support Patients.

Maintaining mechanical circulatory support (MCS) device patients in a specified therapeutic range for anticoagulation remains challenging. Subtherapeutic international normalized ratios (INRs) occur frequently while on warfarin therapy. An effective anticoagulant bridge strategy may improve the care of these patients. This retrospective review of MCS patients with subtherapeutic INRs compared an intravenous unfractionated heparin (UFH) strategy with a subcutaneous enoxaparin or fondaparinux strategy. Native thromboelastography (n-TEG) was used to evaluate anticoagulant effect with coagulation index (CI) as the primary outcome measure. Enoxaparin 0.5 mg/kg subcutaneously (SC) every 12 hours or fondaparinux 2.5-5 mg SC daily were compared with an initial UFH rate of 5 units/kg/hr and titrated to stated n-TEG goal range. The anticoagulant groups UFH, enoxaparin, and fondaparinux were found to be statistically similar with regard to frequency in n-TEG goal range, above range (hypercoagulability), or below range (hypocoagulability). Clinical outcomes were similar among groups with three gastrointestinal bleeds in UFH, one in enoxaparin, and one in fondaparinux groups. Device thrombosis occurred in one UFH patient, while UFH and fondaparinux groups had one ischemic cerebrovascular accident event each. These strategies provided comparable n-TEG results and clinical outcomes when compared with intravenous UFH. Low-dose enoxaparin or fondaparinux may provide an alternative anticoagulant bridging option in MCS patients presenting with subtherapeutic INR.

Improved cancer mortality with low-molecular-weight heparin treatment: a review of the evidence.

Work with low-molecular-weight heparins (LMWHs) continues to provide suggestions for survival advantages among patients with cancer diagnoses. Momentum is building in support of this theory through reports, the vast majority of which are derived from secondary analyses of clinical trials on the treatment of thromboembolism. The data retrieved from such studies that compare unfractionated heparin (UFH) with LMWH indicate that LMWH is equally beneficial if not more beneficial to cancer patients in terms of survival. In retrospective analysis, this improved life expectancy is not considered a result of reduced complications from thromboembolism. Thus, theories of antitumor effects of LMWH have developed, supported by evidence that most of the survival benefits are during long-term comparisons. Reports describing the effects of heparin in the setting of cancer have existed for over a half-century, although specific mechanisms for the marginal results seen thus far have yet to surface. Proposals for the most likely targets of the effective heparins include enzyme interaction, cellular growth modifications, and antiangiogenesis.