Successful Treatment of Fulminant Myocarditis with Intracardiac Thrombus in COVID-19

The treatment of pediatric patients with COVID-19 associated myocardial injury and prothrombotic coagulation derangements remains to be established. We cared for an adolescent with COVID-19 and fulminant myocarditis who required veno-arterial extracorporeal membrane oxygenation (VA-ECMO). Her course was complicated by a large intracardiac thrombus, which was successfully treated with systemic tissue plasminogen activator (tPA). A 17 year old unvaccinated female presented with fever and chest pain 7 days after testing positive for COVID-19. She had a peak troponin of 21.48 ng/ml, elevated brain natriuretic peptide (629 pg/ml), and severely diminished left ventricular systolic function. She progressed to cardiogenic shock and was cannulated to VA-ECMO via the neck. On ECMO day 2 while therapeutic on unfractionated heparin (UFH), a large thrombus was noted in the left ventricular apex, extending toward the aortic valve (Figure 1). Prior to this, she had no evidence of a deep vein thrombosis. Given the concern for an impending stroke upon restoration of ventricular function, a continuous systemic high-dose tPA infusion (0.1mg/kg/hr) was initiated, while she was continued on UFH. A twenty-fold increase in D-dimer levels and serial echocardiograms indicated a thrombolytic effect. After 22 hours of thrombolysis, the patient developed bleeding complications and tPA was discontinued. By ECMO day 4, the thrombus completely resolved. Once her bleeding was controlled, she was transitioned to bivalirudin. Cardiac function recovered by day 11 allowing for separation from ECMO. 25 days later, she was discharged without any neurologic deficits. The coagulopathic derangements associated with COVID -19 pose significant challenges to the management of fulminant myocarditis. There are no guidelines regarding management of an intracardiac thrombus on ECMO. However, with careful monitoring, systemic tPA can be used to provide life-saving therapies with excellent neurological outcomes.