Hypoplastic coronary artery disease causing sudden death. Report of two cases and review of the literature

Novel Anatomical Variation of Left Coronary Artery Origin at the Sinotubular Junction Level With Coeval Hypoplastic Left Circumflex, Superdominant Right Coronary Artery, and Obstructive Coronary Artery Disease: A Case Report

The isolated origin of the left coronary artery (LCA) ostium at the level of the sinotubular junction (STJ) has been described previously. Congenital absence of the left circumflex (LCx) coronary artery has also been documented with superdominant right coronary arterial circulation, either in the presence or absence of coronary artery obstruction. Earlier literature has linked the association of an absent LCx coronary artery with a superdominant right coronary artery (SRCA) but not with a hypoplastic LCx coronary artery (HLCx). The present case report details the case of a 37-year-old thin, athletic male with the risk factors of diabetes and hypertension who was admitted to the emergency unit of our hospital for losing consciousness while bicycling in the street. The current report establishes a combined association of LCA anomaly origin at STJ level along with HLCx and SRCA condition with the burden of mild to moderate coronary artery disease involving proximal left anterior descending artery, LCx, and mid right coronary artery in the literature for the first time. Further, the case report advocated that the presented case carries the risk of malignancy. Hence, with the advancement of modern imaging technologies, computed tomography angiography should be the first choice of imaging modality rather than coronary angiography to prevent fatal outcomes. Interventional cardiologists, cardiothoracic surgeons, and radiologists should have properly defined knowledge of coronary artery anatomy and associated pathology, as it is important for coronary cannulation or any coronary interventions.

Hypoplastic coronary artery disease, as a cause of sudden death

Hypoplastic coronary artery disease (HCAD) is a rare coronary artery anomaly that may be the cause of sudden death. It can involve a single or all coronary arteries. This anomaly may cause circulatory insufficiency leading to myocardial infarction. HCAD has no symptoms or may exhibit cardiovascular signs like syncope, dyspnea, chest discomfort, or dizziness. It is often diagnosed at autopsy, and early diagnosis is made with a coronary angiogram. We report HCAD as the cause of the sudden death of a 25-year-old female with a history of loss of consciousness following exertion. On autopsy, all the coronary arteries' lumen was narrowed with thin vessel walls. Histopathological examination shows an underdeveloped and missing muscular layer of the left anterior descending and circumflex coronary arteries' vascular wall. Many cases of HCAD diagnosed by radiographic imaging in living patients have been reported in the literature, but a structural anomaly of coronaries leading to HCAD has not been reported. We report a case of HCAD describing the histopathological examination findings of the vascular wall of coronary vessels illustrating the structural difference.

Hypoplastic coronary artery disease and hypertension in a child: a case report

Background

Hypoplastic coronary artery disease (HCAD) is an extremely rare disease associated with a risk of sudden cardiac death. It is rarely recognized in a live paediatric patient.

Case summary

We report a case of HCAD in a patient who first presented with vomiting and poor feeding, suggestive of acute heart failure due to cardiomyopathy or acute myocarditis in infancy. Hypertension and signs of ischaemia became evident on electrocardiography and scintigraphy after his cardiac function fully recovered, and he was diagnosed with HCAD by angiography performed at the age of 8 years. He has remained under close observation with anti-hypertensives, aspirin, and exercise restriction.

Discussion

Although HCAD is a rare disease, it may not only cause ischaemia but may also result in heart failure and sudden cardiac death. It should be considered in any paediatric patient with heart failure. Mid-term follow-up visits might be necessary to detect signs of ischaemia in paediatric patients presenting with features of heart failure.

Hypoplastic Coronary Artery Disease Presenting with Ventricular Fibrillation Cardiac Arrest

Hypoplastic coronary artery disease is a rare congenital anomaly that may present with ischaemic heart disease, heart failure or sudden cardiac death (SCD). We describe a case of cardiac arrest in a healthy young man. Work-up revealed a hypoplastic left anterior descending artery. The patient underwent cardioverter-defibrillator implantation for secondary prevention.

LEARNING POINTS

Hypoplastic coronary artery disease (HCAD) is a rare cause of cardiac arrest and should be suspected in cases of sudden cardiac death (SCD) in young adults.The mechanism in HCAD leading to ventricular fibrillation cardiac arrest is not well understood.Implantable cardioverter-defibrillator (ICD) implantation is recommended for secondary prevention of ventricular fibrillation.

Hypoplastic coronary arteries in a child with a mutation in Notch1: A case report

RATIONALE

Coronary artery abnormalities are usually of major significance in clinical cardiology and cardiac surgery departments due to associated myocardial ischemia, myocardial infarction, and sudden cardiac death. Among them, anatomical malformations account for most coronary artery abnormalities. However, hypoplasia of the coronary artery is a rare type of coronary artery without any genetic screening information.

PATIENT CONCERNS

A 10-year-old boy suffered severe chest pain, and a subsequent syncope occurred.

DIAGNOSIS AND INTERVENTION

The boy complained of significant chest pain with syncope. Computerized tomography (CT) angiography scanning showed that the left coronary artery was dominated by abnormal origins and dramatically narrow artery lesions. Moreover, cardiac magnetic resonance imaging (MRI) confirmed myocardial ischemia. Cardiac catheterization confirmed that this was an extremely rare hypoplastic coronary case. Finally, a mutation was identified in NOTCH1 c.1023C>A for the first time.

OUTCOMES

The boy was discharged after completing all examinations and was forbidden to play any kind of sport activity while waiting for heart transplantation.

LESSONS

Hypoplastic coronary artery diseases have only been reported within very limited cases. This is the only report that has identified hypoplasia in 3 epicardial major coronary arteries. In addition, this is the first case to provide evidence between NOTCH1 genetic disorder and hypoplastic coronary artery disease in the clinic.

A Rare Report of Hypoplastic Coronary Arteries and Pulmonary Veins: A Case Report and Review of the Literature

Congenital coronary artery anomalies are estimated to affect about 1% of the general population. Hypoplastic coronary artery disease is an uncommon subset associated with significant mortality regardless whether another major cardiac anomaly is present. In this case report, we present an extremely rare case of an infant with hypoplastic coronary artery disease and hypoplastic pulmonary veins. A literature review pertinent to the clinical findings is also contained herein.

Sapropterin reduces coronary artery malformation in offspring of pregestational diabetes mice

Endothelial nitric oxide synthase (eNOS) and oxidative stress are critical to embryonic coronary artery development. Maternal diabetes increases oxidative stress and reduces eNOS activity in the fetal heart. Sapropterin (Kuvan®) is an orally active, synthetic form of tetrahydrobiopterin (BH4) and a co-factor for eNOS with antioxidant properties. The aim of the present study was to examine the effects of sapropterin on fetal coronary artery development during pregestational diabetes in mice. Diabetes was induced by streptozotocin to adult female C57BL/6 mice. Sapropterin (10 mg/kg/day) was orally administered to pregnant mice from E0.5 to E18.5. Fetal hearts were collected at E18.5 for coronary artery morphological analysis. Sapropterin treatment to diabetic dams reduced the incidence of coronary artery malformation in offspring from 50.0% to 20.6%. Decreases in coronary artery luminal diameter, volume and abundance in fetal hearts from diabetic mothers, were prevented by sapropterin treatment. Maternal diabetes reduced epicardial epithelial-to-mesenchymal transition (EMT) and expression of transcription and growth factors critical to coronary artery development including hypoxia-inducible factor 1a (Hif1a), Snail1, Slug, β-catenin, retinaldehyde dehydrogenase 2 (Aldh1a2), basic fibroblast growth factor (bFGF) and vascular endothelial group factor receptor 2 (Vegfr2) in E12.5 hearts. Additionally, eNOS phosphorylation was lower while oxidative stress was higher in E12.5 hearts from maternal diabetes. Notably, these abnormalities were all restored to normal levels after sapropterin treatment. In conclusion, sapropterin treatment increases eNOS activity, lowers oxidative stress and reduces coronary artery malformation in offspring of pregestational diabetes. Sapropterin may have therapeutic potential in preventing coronary artery malformation in maternal diabetes.

Coronary Artery Anomalies and Associated Radiologic Findings

Coronary anomalies occur in about 1% of the general population and in severe cases can lead to sudden cardiac death. Coronary computed tomography angiography and magnetic resonance imaging have been deemed appropriate for the evaluation of coronary anomalies by accurately allowing the noninvasive depiction of coronary artery anomalies of origin, course, and termination. The aim of this article is to describe and illustrate a comprehensive array for the classification of coronary artery anomalies.

Pregestational diabetes induces fetal coronary artery malformation via reactive oxygen species signaling

Hypoplastic coronary artery disease is a congenital coronary artery malformation associated with a high risk of sudden cardiac death. However, the etiology and pathogenesis of hypoplastic coronary artery disease remain undefined. Pregestational diabetes increases reactive oxygen species (ROS) levels and the risk of congenital heart defects. We show that pregestational diabetes in mice induced by streptozotocin significantly increased 4-hydroxynonenal production and decreased coronary artery volume in fetal hearts. Pregestational diabetes also impaired epicardial epithelial-to-mesenchymal transition (EMT) as shown by analyses of the epicardium, epicardial-derived cells, and fate mapping. Additionally, the expression of hypoxia-inducible factor 1α (Hif-1α), Snail1, Slug, basic fibroblast growth factor (bFgf), and retinaldehyde dehydrogenase (Aldh1a2) was decreased and E-cadherin expression was increased in the hearts of fetuses of diabetic mothers. Of note, these abnormalities were all rescued by treatment with N-acetylcysteine (NAC) in diabetic females during gestation. Ex vivo analysis showed that high glucose levels inhibited epicardial EMT, which was reversed by NAC treatment. We conclude that pregestational diabetes in mice can cause coronary artery malformation through ROS signaling. This study may provide a rationale for further clinical studies to investigate whether pregestational diabetes could cause hypoplastic coronary artery disease in humans.

The utility of postmortem computed tomography selective coronary angiography in parallel with autopsy

Historically, coronary angiography of the isolated heart has played an important role in the detection of stenotic or occlusive lesions that are difficult to identify by autopsy alone. Meanwhile, although the application of multidetector computed tomography (MDCT) to forensic fields has accelerated recently, isolated single organ angiography with MDCT is rarely performed. In this article, we present an evaluation of postmortem selective coronary CT angiography of the isolated heart with MDCT and discuss its utility for autopsy. First, in a preliminary experiment using pig coronary artery, we examined the behavior of water soluble contrast material on postmortem computed tomography angiography (PMCTA) and found that better angiographic images were acquired when the viscosity of the contrast material was increased and CT was performed under conditions of sustained perfusion. Based on these results, we devised a selective coronary angiography procedure using a pressurized bag for drip infusion that can be performed easily, quickly, and at low cost. The angiographic images obtained provided useful supportive evidence of autopsy findings suggestive of ischemic heart disease. With active discussions underway in forensic fields on the proper use of postmortem computed tomography, PMCTA has also naturally attracted attention as it compensates for some of the shortcomings of CT alone. Although PMCTA typically involves whole-body angiography, if we view PMCTA as one of the many useful and supplementary tools available for autopsy, then isolated heart angiography continues to have utility in autopsy today.

Isolated hypoplastic circumflex coronary artery: a rare cause of haemorrhagic myocardial infarction in a young athlete

Hypoplastic coronary artery disease is a rare condition that may lead to myocardial infarction and sudden death. Here we describe for the first time an isolated hypoplasia of the left circumflex artery (LCX). An otherwise healthy and athletically active 16-year-old boy was admitted to the intensive care unit (ICU) after out-of-hospital cardiac arrest. He died 12 hours after the initial event. Autopsy revealed an isolated hypoplastic LCX and acute haemorrhagic infarction in the posterolateral myocardium. The existence of isolated hypoplasia of the LCX challenges our understanding of coronary artery development. Virtual slides: The virtual slide(s) for this article can be found here: http://www.diagnosticpathology.diagnomx.eu/vs/1558483061962648.

Sudden cardiac death due to arrhythmogenic right ventricular cardiomyopathy and cystic tumor of the AV node

An 18-year-old white male collapsed suddenly in his home and died. At autopsy, the right ventricle of the decedent was noted to be dilated with marked thinning of the wall focally. Microscopically, the myocardium of the right ventricle was noted to be significantly thinned focally, where transmural infiltration with fibroadipose tissue was noted. Depending on the criteria utilized to render such a diagnosis, these findings were consistent with arrhythmogenic right ventricular cardiomyopathy (ARVC). Subsequent microscopic examination of the SA and AV node, however, revealed the presence of a cystic tumor of the AV node (CTAVN), a known cause of sudden death from arrhythmia. The case represents the first reported case of ARVC and CTAVN occurring together in the same individual.

Nitric oxide synthase-3 deficiency results in hypoplastic coronary arteries and postnatal myocardial infarction

AIMS

Hypoplastic coronary artery disease is a rare congenital abnormality that is associated with sudden cardiac death. However, molecular mechanisms responsible for this disease are not clear. The aim of the present study was to assess the role of nitric oxide synthase-3 (NOS3) in the pathogenesis of hypoplastic coronary arteries.

METHODS AND RESULTS

Wild-type (WT), NOS3(-/-), and a novel cardiac-specific NOS3 overexpression mouse model were employed. Deficiency in NOS3 resulted in coronary artery hypoplasia in foetal mice and spontaneous myocardial infarction in postnatal hearts. Coronary artery diameters, vessel density, and volume were significantly decreased in NOS3(-/-) mice at postnatal day 0. In addition, NOS3(-/-) mice showed a significant increase in the ventricular wall thickness, myocardial volume, and cardiomyocyte cell size compared with WT mice. Lack of NOS3 also down-regulated the expression of Gata4, Wilms tumour-1, vascular endothelial growth factor, basic fibroblast growth factor and erythropoietin, and inhibited migration of epicardial cells. These abnormalities and hypoplastic coronary arteries in the NOS3(-/-) mice were completely rescued by the cardiac-specific overexpression of NOS3.

CONCLUSION

Nitric oxide synthase-3 is required for coronary artery development and deficiency in NOS3 leads to hypoplastic coronary arteries.

Ostial plication: a rarely reported cause of sudden death

We report a rare case of ostial plication as a potential cause of sudden death. Very few reports and images are available in the specialized literature regarding this anomaly. Ostial plication may be a source of sudden death or cause of death when no other significant autopsy findings are present.Ostial plication is a congenital severe obstruction/occlusion of the right or left ostium. Plication of the aortic wall leads to a "valve-like" ridge that can act as a door blocking inflow during diastolic filling, with consequent ischemia and a potentially life-threatening arrhythmia. The true incidence of this condition and its relationship to sudden death have not been reported in the literature. We believe that this case will be useful to autopsy pathologists in detecting this infrequent anomaly, thus providing a more accurate estimation of its incidence.