Abstract 11476: The Clot Thickens: Massive Left Ventricular Thrombus After Sub-Acute Myocardial Infarction

Abstract

Introduction: Left ventricular thrombus (LVT) following myocardial infarction (MI) can affect up to 19.2% of patients with anterior wall MI. The mechanism is thought to be due to stasis from LV regional wall akinesia, endothelial injury from prolonged ischemia, and hypercoagulability from acute coronary syndrome. In patients with LVT after MI, anticoagulation choice and duration is still a matter of debate. Case Report: A 51-year-old woman with diabetes and prior anterior wall MI with LVT presented with non-healing diabetic leg wounds. One year ago at the time of the MI, transthoracic echocardiogram (TTE) showed a 4.0 x 1.3 cm mural thrombus. She was discharged on prasugrel and apixaban. Apixaban was discontinued after five months, with follow-up TTE showing resolution of LVT, with 30% LV ejection fraction and evidence of LV remodeling. This hospitalization, while awaiting discharge, the patient developed sudden undifferentiated shock requiring norepinephrine and dobutamine. Repeat TTE revealed a 6.0 x 5.5 cm apical LVT filling more than 50% of the LV cavity, with unchanged LV ejection fraction. Heparin drip was started. Prior to evaluation by cardiothoracic surgery, patient became acutely unresponsive, had a cardiac arrest, and expired. Cause of death suspected to be due to cardioembolic events, worsened with mixed shock and low-output heart failure from LVT. Discussion: Management of LVT after MI remains unclear. Current guidelines indicate treatment with vitamin K antagonist (VKA) for at least 3 - 6 months, and consideration of prophylactic anticoagulation with VKA for patients with apical dyskinesis after MI. Retrospectively, this patient may have benefitted from a prolonged course of anticoagulation given the extent of LV remodeling five months after initial event despite resolution of LVT. Anticoagulation must be evaluated on a case-by-case basis weighing propensity of thrombotic events with risk of bleeding.