The chicken or the egg? Mycoplasma pneumoniae complicated by left ventricle thrombus and anterior myocardial infarction: a case report

Mycoplasma pneumoniae can be associated with extrapulmonary manifestations, including vasculitis, myocarditis, and thrombosis. In rare cases, it has also been implicated in intracardiac thrombus formation.

A previously healthy 25-year-old male presented with worsening abdominal pain, an episode of acute chest pain, new lightheadedness, and gait instability in the setting of M. pneumoniae. Initial blood tests were notable for mild coagulopathy, thrombocytosis, transaminitis, and elevated high-sensitivity troponin. Further, workup revealed systematic emboli to the cerebellum, kidneys, spleen, anterior myocardial infarction, and a left ventricular multilobular mural mass. Due to the unknown composition of the mass with concern for further embolic events, the patient underwent successful surgical excision with the mass ultimately defined as a thrombus. Hypercoagulable workup was notably inconclusive and intraoperative myocardial biopsies revealed organizing infarction without inflammation or healed myocarditis. Post-operative course was complicated by left ventricular dysfunction and acute kidney injury, both with eventual improvement. Patient has remained on guideline-directed medical therapy and prophylactic anticoagulation.

We presume that the formation of the ventricular thrombus in this case was a result of transient thrombophilia in the setting of M. pneumonia resulting in coronary obstruction and subsequent myocardial injury. This case underscores the challenge of determining the pathophysiological sequence of events in patients with mycoplasma who develop systemic embolism and the management of a large residual thrombus, particularly in regard to surgical consideration.