Heparin-induced thrombocytopenia during multiple extracorporeal mechanical supports for fulminant myocarditis: a case with literature review

Background Heparin-induced thrombocytopenia (HIT) is a relatively rare complication associated with heparin therapy. HIT can cause fatal thromboembolic events. However, bleeding complications are critical issues during mechanical support therapies such as extracorporeal membrane oxygenation and continuous renal replacement therapy, both of which require anticoagulation. Case presentation We report a case of HIT complicated with acute kidney injury due to fulminant myocarditis. A 57-year-old female with acute fulminant myocarditis was transferred to our hospital while receiving extracorporeal membrane oxygenation and continuous renal replacement therapy anticoagulated with unfractionated heparin. After transfer, based on the rapid decrease in platelets and circuit occlusion, HIT was strongly suspected according to the 4Ts score. Heparin was discontinued and replaced with nafamostat mesilate or argatroban. On day 4 after transfer, the HIT antibody test was positive. During her stay in the intensive care unit, bleeding tendency was observed as a mild retroperitoneal hematoma and oozing from catheter insertion sites. Additionally, hypercoagulability was also observed as frequent occlusion of the hemodialysis circuit and pallor of the soles. Conclusion HIT can be complicated during extracorporeal life support. In critically ill patients, multiple conditions that cause thrombocytopenia can coexist, and it is always important to carefully consider the possibility of HIT.