Heparin-platelet factor 4 antibodies in patients presenting to the ED with thrombosis

Heparin-PF4 antibody prevalence is 7.4% in ED patients with chest pain or thrombosis, with ∼1 in 3 seropositive patients having platelet-activating antibodies. Alternative, nonheparin anticoagulation would be prudent in these at-risk patients.