Unfractionated Heparin May Cause Higher Risk in Women
Female surgical patients treated with unfractionated heparin at higher risk for heparin-induced thrombocytopenia
FRIDAY, Nov. 10 (HealthDay News) -- Women undergoing surgery who are treated with unfractionated heparin have a high incidence of heparin-induced thrombocytopenia, according to a report in the Nov. 1 issue of Blood. The risk from low-molecular-weight heparin is minimal, regardless of treatment setting.
Theodore E. Warkentin, M.D., of McMaster University in Hamilton, Ontario, Canada, and colleagues noticed a high incidence of heparin-induced thrombocytopenia, or HIT, in women after cardiac or orthopedic surgery, according to national databases. In this study, they set out to examine the link more closely using prospective studies comparing unfractionated heparin with low-molecular-weight heparin (LMWH).
Three separate studies showed overrepresentation of women with HIT. Analysis of the data showed that HIT was more likely to occur in women than men (common odds ratio, 2.37) and in surgical versus medical patients (common OR, 3.25). Unfractionated heparin was also much more likely to cause HIT than LMWH in women versus men (common OR, 9.22 versus 1.83) and in surgical versus medical patients (common OR, 13.93 versus 1.75).
"We conclude that females are at greater risk for HIT and that using LMWH to prevent HIT may have greatest absolute benefit in females undergoing surgical thromboprophylaxis," the authors write. The results should "increase the sensitivity of consultants and critical care personnel to the likelihood of the development of HIT in women in the surgical setting and eventually may lead to specific targeted practices to reduce the frequency of this disorder," according to an accompanying editorial.