The prevalence of HIT may range from 0.1% to 5.0% in patients exposed to heparin, and varies significantly according to a number of host- and drug-related risk factors.[8]Farley S, Cummings C, Heuser W, et al. Prevalence and overtesting of true heparin-induced thrombocytopenia in a 591-bed tertiary care, teaching hospital. J Intensive Care Med. 2019 Jun;34(6):464-71.
http://www.ncbi.nlm.nih.gov/pubmed/28978299?tool=bestpractice.com
[9]Warkentin TE, Levine MN, Hirsh J, et al. Heparin-induced thrombocytopenia in patients treated with low-molecular-weight heparin or unfractionated heparin. N Engl J Med. 1995 May 18;332(20):1330-5.
https://www.nejm.org/doi/full/10.1056/NEJM199505183322003
http://www.ncbi.nlm.nih.gov/pubmed/7715641?tool=bestpractice.com
Postoperative and trauma patients who receive heparin have the highest incidence of HIT (1% to 5%), whereas HIT is very uncommon in medical patients who receive prophylactic doses of heparin (<1%), and is extremely rare in obstetric patients (<0.1%).[10]Warkentin TE, Sheppard JA, Moore JC, et al. Laboratory testing for the antibodies that cause heparin-induced thrombocytopenia: how much class do we need? J Lab Clin Med. 2005 Dec;146(6):341-6.
http://www.ncbi.nlm.nih.gov/pubmed/16310517?tool=bestpractice.com
[11]Warkentin T, Sheppard J, Horsewood P, et al. Impact of the patient population on the risk for heparin-induced thrombocytopenia. Blood. 2000 Sep 1;96(5):1703-8.
http://www.ncbi.nlm.nih.gov/pubmed/10961867?tool=bestpractice.com
[12]Prandoni P, Siragusa S, Girolami B, et al. The incidence of heparin-induced thrombocytopenia in medical patients treated with low-molecular-weight heparin: a prospective cohort study. Blood. 2005 Nov 1;106(9):3049-54.
https://ashpublications.org/blood/article-lookup/doi/10.1182/blood-2005-03-0912
http://www.ncbi.nlm.nih.gov/pubmed/16030191?tool=bestpractice.com
[13]Lubenow N, Hinz P, Thomaschewski S, et al. The severity of trauma determines the immune response to PF4/heparin and the frequency of heparin-induced thrombocytopenia. Blood. 2010 Mar 4;115(9):1797-803.
https://ashpublications.org/blood/article-lookup/doi/10.1182/blood-2009-07-231506
http://www.ncbi.nlm.nih.gov/pubmed/19965682?tool=bestpractice.com
[14]Lindhoff-Last E, Nakov R, Misselwitz F, et al. Incidence and clinical relevance of heparin-induced antibodies in patients with deep vein thrombosis treated with unfractionated heparin or low-molecular-weight heparin. Br J Haematol. 2002 Sep;118(4):1137-42.
http://www.ncbi.nlm.nih.gov/pubmed/12199798?tool=bestpractice.com
The risk of HIT is significantly higher with unfractionated heparin compared with low molecular weight heparin (LMWH).[9]Warkentin TE, Levine MN, Hirsh J, et al. Heparin-induced thrombocytopenia in patients treated with low-molecular-weight heparin or unfractionated heparin. N Engl J Med. 1995 May 18;332(20):1330-5.
https://www.nejm.org/doi/full/10.1056/NEJM199505183322003
http://www.ncbi.nlm.nih.gov/pubmed/7715641?tool=bestpractice.com
[15]Martel N, Lee J, Wells PS. Risk for heparin-induced thrombocytopenia with unfractionated and low-molecular-weight heparin thromboprophylaxis: a meta-analysis. Blood. 2005 Oct 15;106(8):2710-5.
https://ashpublications.org/blood/article-lookup/doi/10.1182/blood-2005-04-1546
http://www.ncbi.nlm.nih.gov/pubmed/15985543?tool=bestpractice.com
[16]Junqueira DR, Zorzela LM, Perini E. Unfractionated heparin versus low molecular weight heparins for avoiding heparin-induced thrombocytopenia in postoperative patients. Cochrane Database Syst Rev. 2017 Apr 21;4:CD007557.
https://www.cochranelibrary.com/cdsr/doi/10.1002/14651858.CD007557.pub3/full
http://www.ncbi.nlm.nih.gov/pubmed/28431186?tool=bestpractice.com
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How does low molecular weight heparin compare with unfractionated heparin for avoiding heparin-induced thrombocytopenia in people undergoing surgery?/cca.html?targetUrl=https://cochranelibrary.com/cca/doi/10.1002/cca.1760/fullShow me the answer Women appear to have a 1.5- to 2-fold increased risk of HIT compared with men.[17]Warkentin TE, Sheppard JA, Sigouin CS, et al. Gender imbalance and risk factor interactions in heparin-induced thrombocytopenia. Blood. 2006 Nov 1;108(9):2937-41.
https://ashpublications.org/blood/article-lookup/doi/10.1182/blood-2005-11-012450
http://www.ncbi.nlm.nih.gov/pubmed/16857993?tool=bestpractice.com