Peripheral Embolization of Left Ventricular Thrombus Leading to Acute Bilateral Critical Limb Ischemia: A Rare Phenomenon

Abstract

Left ventricular thrombus (LVT) is a well-known complication of myocardial infarction (MI) leading to significant morbidity and mortality. LVT can also lead to systemic thromboembolic events causing threatening limb ischemia. We report a rare case of critical bilateral limb ischemia that resulted from peripheral embolization of LVT post MI, which was managed successfully by emergent surgical intervention and anticoagulation. A 74-year-old male with a medical history of hypertension, diabetes, hyperlipidemia and coronary artery disease status post stenting of the left anterior descending and left circumflex arteries presented to the emergency department with typical chest pain and progressive shortness of breath. Cardiac troponin levels on admission were 35 ng/mL of blood. The patient subsequently underwent emergent cardiac catheterization which revealed significant triple vessel disease, and was referred for coronary artery bypass grafting (CABG) surgery. Transthoracic and transesophageal echocardiograms revealed the presence of an apical aneurysm with chronic organized mobile thrombus at the apex. Post CABG, the patient complained of excruciating right leg pain. Computed tomography (CT) angiogram of the abdominal aorta and lower extremities revealed a large embolus at the aortic bifurcation occluding the right and nearly occluding the left common iliac arteries and thrombus in the right popliteal artery. He underwent emergent vascular surgery with resolution of his symptoms and remained without further complications. The incidence of LVT remains high in post-MI patients, and complications of LVT are known to include thromboembolic events. Peripheral embolization of acute or chronic LVT leading to bilateral distal embolization and critical limb ischemia remains a rare occurrence. This case report aims to aid clinicians to recognize and promptly manage LVT and related arterial thromboembolic events with anticoagulation and emergent surgical intervention if limb ischemia develops.

Keywords: Ischemia, Ventricular thrombus, Peripheral embolization, Myocardial infarction, Thromboembolism

Introduction

Left ventricular thrombus (LVT) is a well-known complication of left ventricular dysfunction, most commonly occurring post anterior ST-segment elevation myocardial infarction (STEMI) [1, 2]. While the incidence of LVT post myocardial infarction (MI) has decreased over the years due to rapid percutaneous coronary intervention (PCI), it remains a significant cause of morbidity and mortality [3]. LVT is associated with systemic thromboembolism more frequently seen in non-ischemic causes [2, 4, 5]. Acute embolic occlusion of the bilateral lower extremities remains an extremely rare finding. This phenomenon is a medical emergency and requires emergent surgical intervention, which can lead to excellent patient outcomes [6]. We herein report a rare case of critical bilateral limb ischemia that resulted from peripheral embolization of LVT that was managed successfully by emergent surgical intervention.

Case Report

A 74-year-old male with a medical history of hypertension, diabetes, hyperlipidemia and coronary artery disease status post stenting of the left anterior descending and left circumflex arteries presented to the emergency department with typical chest pain and progressive shortness of breath. Physical assessment was unremarkable on admission. Laboratory investigation was normal except for hemoglobin A1c of 8.3% and a cardiac troponin level of 35 ng/mL. The patient was loaded with 325 mg of aspirin and 180 mg of ticagrelor. The patient subsequently underwent emergent cardiac catheterization which revealed significant triple vessel disease, and was referred for coronary artery bypass grafting (CABG) surgery. Preoperative workup included a carotid ultrasound which demonstrated no significant stenosis and a transthoracic echocardiogram (TTE), which showed a mobile left ventricular (LV) apical thrombus associated with an LV aneurysm (Fig. 1). Transesophageal echocardiogram (TEE) was also performed and confirmed the presence of an apical aneurysm with chronic organized mobile thrombus at the apex. He was started on a continuous low-intensity heparin drip (25,000 units in 250 mL D5W) and 81 mg aspirin daily, and the heparin drip was held about 2 h prior to his procedure. He underwent a successful CABG procedure and remained hemodynamically stable. Shortly after awakening from anesthesia, the patient complained of excruciating right leg pain, and was found to have significant discoloration with diminished pulses in both lower extremities. Computed tomography (CT) scan of the abdomen and lower extremities revealed a large embolus at the aortic bifurcation occluding the right common iliac and nearly occluding the left common iliac artery and thrombus in the right popliteal artery (Fig. 2). CT angiogram of the abdominal aorta was also performed confirming the findings (Fig. 3). He was taken emergently back to the operating room for an emergent right and left femoral cut down with repair of common femoral arteries, aortic right iliac artery and right popliteal artery thromboembolectomy. Postoperatively he was started on unfractionated heparin, oral clopidogrel and warfarin. Repeat echocardiogram revealed that the LV apical thrombus was still present but was noted to be smaller in size compared to the preoperative study (Fig. 1). His hospital course thereafter remained unremarkable and he was discharged with a normal physical exam and on warfarin, clopidogrel, and aspirin for anticoagulation.

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Figure 1

(a) Transthoracic echocardiogram (TTE) done pre-CABG surgery showing a mobile left ventricular (LV) apical thrombus associated with an LV aneurysm. (b) TTE done post-CABG surgery and anticoagulation treatment showing decreased size of LV apical thrombus.

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Figure 2

(a) Computed tomography (CT) scan of the abdomen showing a large embolus at the aortic bifurcation. (b) CT scan of the abdomen showing occlusion of the right common iliac and near occlusion of the left common iliac artery.

 

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Figure 3

Computed tomography (CT) angiogram of the abdominal aorta and lower extremities showing right common iliac and right popliteal artery occlusion.

Source: https://www.ncbi.nlm.nih.gov/pmc/

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