A Clot in Transit: A Cause of Death or a Bystander?

Introduction: The clot in transit is a rare manifestation of thromboembolic disease occurring usually in the setting of PE and frequently associated with poor outcomes. The best therapeutic option is not well established. We describe a series of 35 patients diagnosed with clots in transit including their therapeutic interventions and outcome between the period January 2016 to December 2020. Methods: a retrospective chart review of all patients with an Echocardiogram showing thrombi in the right heart chambers including patients with thrombus in the presence of central lines or other devices. We exclude patients where masses were described as tumors or vegetation and masses in the presence of bacteremia. Results: There were 35 patients with echocardiographic evidence of a thrombus in the right heart chambers. In 12 of those patients, the thrombus was related to an intracardiac catheter. 37.1% of CT chest was done along with Echocardiogram and showed a concomitant PE in 77%. On echocardiogram, 66% of the thrombi were mobile. RV strain was present in 17% while abnormal RVSP (>30 mmHg) was present in 74%. Respiratory support was required in 37.1% and only 17% required inotropic support. There was a total or partial resolution in 80% those who had repeated echocardiogram after four weeks of therapy. Heparin was started in the majority of patients (74%). Warfarin was the most frequently used follow-up anti-coagulant in 51.4%. The mortality rate was significantly higher in those patients with RVSP >50, UFH group, O2 or inotropic support. 26% of patients died within the first 28 days after the diagnosis, while first 7 days mortality was 6% only. Conclusion: a clot in transit in our study was not directly associated with poor outcomes in the first week of therapy, UFH is still the most frequently used initial method to treat clots in transit. However, only 26% had a total resolution of clot within 4 weeks of treatment.