Anticoagulants Could Be Post-Operative Killers

Potent anticoagulants used in thromboprophylaxis protocols are associated with a higher all-cause mortality rate after hip and knee arthroplasty, according to a new study.

Researchers from the Hospital for Special Surgery (New York, NY, USA) reviewed and compared 20 studies published from 1998 to 2007 that included 6-week or 3-month incidence of all-cause mortality and symptomatic, nonfatal pulmonary embolism, and compared between three frequently-used prevention protocols worldwide in over 28,000 patients. Patients in group A received potent anticoagulants such as low molecular weight heparin, ximelagatran, fondaparinux, or rivaroxaban; those in group B received local spinal or epidural anesthesia, pneumatic compression, and aspirin; and patients in group C were prescribed slow-acting oral anticoagulants such as warfarin.

The results showed that the lowest number of deaths occurred in patients in group B; all-cause mortality was higher in Group A than in Group B (0.41% versus 0.19%) and the incidence of clinical nonfatal pulmonary embolus was higher in Group A than in Group B (0.60% versus 0.35%). The incidences of all-cause mortality and nonfatal pulmonary embolism in Group C were similar to those in Group A (0.4 and 0.52, respectively). Patients in group A were also at 60-70% greater risk of non-fatal pulmonary embolism than those in group B, indicating that pulmonary embolism occurs despite the use of powerful anticoagulants. The study was published in the March 2008 issue of Clinical Orthopaedics and Related Research.

"Pulmonary embolism occurs despite the use of potent anticoagulants and may, in fact, expose patients to increased mortality after surgery,” concluded lead author Dr. Nigel Sharrock and colleagues of the department of anesthesiology. "Current US guidelines for the prescription of potent anticoagulants by surgeons who perform joint replacement operations could be doing patients more harm than good.”


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