Left Ventricular Apical Thrombus in a Post-Heart Transplant Patient With Preserved Ejection Fraction

BACKGROUND: Left ventricular (LV) thrombus is typically associated with systolic dysfunction. Its occurrence after heart transplantation (HTx) with preserved ejection fraction (EF) is rare. CASE SUMMARY: A 58-year-old man, 3 years post-HTx, was incidentally found to have an LV apical mass on routine echocardiography with preserved EF. Cardiac magnetic resonance and computed tomography suggested thrombus. The lesion persisted after direct oral anticoagulant therapy but resolved after transition to a vitamin K antagonist. Retrospective review revealed an apical false tendon, likely serving as a nidus for thrombus formation. DISCUSSION: This case highlights LV thrombus formation post-HTx despite normal EF with no clinical evidence of rejection, possibly related to subtle structural anomalies. Multimodality imaging was essential for differentiating thrombus from tumor and guiding optimal anticoagulation therapy. TAKE-HOME MESSAGES: Subtle LV structural variants may predispose to thrombus despite normal EF. Vitamin K antagonists may be more effective than direct oral anticoagulant in selected cases, underscoring its value in evaluating cardiac masses in complex posttransplant patients.