Antiphospholipid syndrome leading to myocardial infarction in a Fontan patient 17 years after Norwood palliation

Myocardial infarction due to thrombosis of native aorta late after Fontan procedure for hypoplastic left heart syndrome

Patients with single ventricle physiology who have undergone the Fontan procedure are at risk for long-term complications such as thrombus formation. Thrombus formation in the native aortic root (NAR) can be life-threatening if retrograde filling of the coronary arteries (CAs) is impaired. We present three cases of NAR thrombus with embolization to the CA, resulting in myocardial infarction. Thromboembolic events are well-documented complications of Fontan physiology, and optimal prevention and treatment strategies are poorly defined.

Coronary artery embolism in a patient with Fontan palliation: a rare complication

Coronary artery embolism is extremely rare in children with Fontan palliation. We report a 10-year-old boy with hypoplastic left heart syndrome post-Fontan procedure who presented with acute onset chest pain and ST-segment changes on electrocardiogram. Cardiac catheterisation revealed coronary artery emboli requiring stent placement. Our case highlights the importance of evaluating chest pain in a systematic manner in Fontan patients as acute coronary artery embolism can be a part of the spectrum of well-known thromboembolic complications.

Percutaneous coronary intervention following Fontan procedure

Fontan procedure is known to increase the risk of thromboembolic events. However, coronary artery thrombotic occlusion is rarely reported in patients with Fontan procedure. We present a case of a 10-year-old boy with hypoplastic left heart syndrome palliated with a Fontan procedure who presented with myocardial infarction secondary to thrombotic occlusion of the left circumflex coronary artery. He underwent successful percutaneous coronary intervention with thrombus aspiration, balloon angioplasty, and stent placement, highlighting the necessity of collaboration between congenital and adult cardiologists to treat acute coronary syndrome among this challenging young population.

A Rare Case of Embolic ST-Elevation Myocardial Infarction in an Adult Patient With Repaired Hypoplastic Left Heart Syndrome

A 24-year-old male with past medical history of hypoplastic left heart syndrome and staged reconstructive surgery in infancy culminating in the Fontan circulation presented to the hospital with a chief complaint of chest pain described as an "elephant sitting" on his chest. Initial 12-lead electrocardiogram revealed 2-mm ST segment elevation in inferior leads, 3-mm ST-segment elevation in anterolateral precordial leads V3 and V4, and 2-mm ST-segment elevation in V5 and V6, with right axis deviation. He was transported emergently to the cardiac catheterization laboratory where coronary angiography revealed complete occlusion of multiple anomalous branches of the right coronary system with hazy appearance suggesting the presence of thrombotic material. An aspiration catheter was used successfully to reestablish TIMI grade III flow. The patient was treated with aspirin, brilinta (ticagrelor), and anticoagulation with vitamin K antagonism to prevent recurrent thromboembolic complications.

Embolic myocardial infarction in a patient with a Fontan circulation

Coronary artery embolism is an uncommon cause of acute myocardial infarction (MI). We present a patient with pulmonary atresia and severe right heart hypoplasia who underwent a lateral tunnel Fontan procedure in childhood and presented with an acute ST-segment elevation MI at 19 years of age. In addition to the known risk of thrombotic complications associated with a Fontan circulation, potential predisposing factors to thromboembolism in this patient included a right ventricle to left anterior descending coronary connection and a Fontan baffle leak. The patient was treated with device closure of the baffle leak and anticoagulation. This is one of the first reports of an embolic MI in a patient with a Fontan circulation. The optimal method of reducing thromboembolic risk in this patient, and those with a Fontan circulation in general, is complicated and no consensus exists.