Nonatherosclerotic causes of coronary artery narrowing--Part III

Non-ST-segment elevation myocardial infarction with non-obstructive coronary arteries due to a type-A thymoma: A case report

Introduction

Myocardial infarction with non-obstructive coronary arteries (MINOCA) has become an increasingly recognized subgroup in patients with acute myocardial infarction, with a recent cohort study reporting a prevalence of 8.8%. This report describes a patient who presented with non-ST-segment elevation myocardial infarction (NSTEMI) due to an incidental anterior mediastinal mass.

Case presentation

An 80-year-old woman presented to our emergency department with a chief complaint of progressive shortness of breath associated with retrosternal chest pain for one day duration. Computed tomography (CT) angiogram of the chest was conducted, which revealed an anterior mediastinal mass. Upon admission, the patient developed an acute episode of recurrent severe chest pain, which was diagnosed as an NSTEMI. Emergent cardiac catheterization was performed because of unstable vital signs; however, the results showed no evidence of atherosclerotic changes in the major coronary arteries, compatible with the diagnosis of MINOCA. The mediastinal mass was later confirmed to be a type A thymoma on CT-guided biopsy.

Conclusion

Myocardial infarction in patent coronary arteries due to an anterior mediastinal mass is rare. Further studies are needed to standardize the diagnosis and management protocols for the potential etiologies of MINOCA.

Anatomical reconstruction of proximal coronary artery stenosis in children

OBJECTIVES

Timing and method of surgical reconstruction for non-sclerotic proximal coronary artery stenosis, occuring de-novo or post coronary artery transfer, are evolving. We have pursued a technique of anatomical reconstruction of ostial and short segment proximal coronary artery stenosis and atresia in children, using patch plasty or interposition vein graft. Herein, we discuss the medium- to long-term outcome.

METHODS

Nine consecutive children undergoing ten left main coronary artery reconstructions using autologous great saphenous vein patch (n = 4), autologous pericardium (n = 4), xenopericardium (n = 1) or great saphenous vein interposition graft (n = 1) were retrospectively analysed. Complementary wedge resection of the stenotic coronary ostium was performed in chronic cases.

RESULTS

The aetiology of coronary artery stenosis was post arterial switch operation (n = 6), Takayasu`s arteritis (n = 1), idiopathic left main coronary artery atresia (n = 1) and anomalous origin of the left coronary artery from the pulmonary artery (n = 1). Median age and weight at operation were 0.15 (range 0.01-13.1) years and 4.4 (range 3 -13.1) kilograms, respectively. Survival was 100% at median follow-up of 12.6 (range 1-19.2) years. All patients showed normal left ventricular ejection fraction on transthoracic echocardiogram. In one patient, kinking of the proximal left circumflex artery resulted in non-significant obstruction. In all other cases, follow-up catheter angiography revealed unobstructed coronary arteries. Cardiac magnetic resonance tomography showed no significant perfusion deficit in any child.

CONCLUSIONS

Anatomical reconstruction of the proximal left coronary artery using autologous saphenous vein may allow optimal restoration of physiological coronary blood flow, keeping the option of future coronary bypass operation open.

Typical angina in a patient with Takayasu arteritis

Takayasu arteritis (TA) is a well-reported form of large-vessel vasculitis that primarily affects the aorta and its major branches. Cardiac manifestations of TA have been reported and can include typical angina secondary to coronary artery involvement; however, typical angina in the setting normal coronary arteries is uncommon. We describe a case of typical angina in a patient with TA with normal coronary arteries secondary to diastolic hypotension, in the absence of significant aortic regurgitation, likely from poor aortic distensibility and elevated left ventricular end-diastolic pressure.

CAD-RADS: Pushing the Limits

Coronary CT angiography is now established as the first-line diagnostic imaging test to exclude coronary artery disease (CAD) in the population at low to intermediate risk. Wide variability exists in both the reporting of coronary CT angiography and the interpretation of these reports by referring physicians. The CAD Reporting and Data System (CAD-RADS) is sponsored by multiple societies and is a collaborative effort to provide standard classification of CAD, which is then integrated into patient clinical care. The main goals of the CAD-RADS are to decrease variability among readers; enhance communication between interpreting and referring clinicians, allowing collaborative determination of the best course of patient care; and generate consistent data for auditing, data mining, quality improvement, research, and education. There are several scenarios in which the CAD-RADS guidelines are ambiguous or do not provide definite recommendations for further management of CAD. The authors discuss the CAD-RADS categories and modifiers, highlight a variety of complex or ambiguous scenarios, and provide recommendations for managing these scenarios. Online supplemental material is available for this article. ^©RSNA, 2020 See discussion on this article by Aviram and Wolak.

Sudden unexpected death due to coronary thrombosis associated with isolated necrotizing vasculitis in the coronary arteries of a young adult

Coronary arteritis is an uncommon cause of sudden death in non-atherosclerotic coronary diseases, and is mostly associated with systemic vasculitis or systemic autoimmune diseases; therefore, sudden death due to isolated coronary arteritis rarely occurs. The case described in this report is that of a 34-year-old man with no significant personal medical history who died suddenly after presenting with nausea. Postmortem examination revealed a significant infiltration of lymphocytes predominantly on the adventitia and periadventitial tissues of the coronary arteries in the epicardium. The lymphocytic infiltrate partially extended to the thickened intima with fibrosis, destructing the media and internal elastic lamina, and the lumen was occluded by a thrombus in the left main stem and left anterior descending branch. The arterial walls exhibited focal fibrinoid necrosis with regression in the intima and fibrous scars with angiogenesis in the media and adventitia. Focal myocardial infarction was detected in the left ventricle as a fibrotic change of the myocardium. No findings associated with vasculitis were discerned in the aorta, other peripheral arteries, or major organs. Laboratory tests of postmortem blood samples returned negative results for antinuclear antibodies, cryoglobulin, immunoglobulin G4, and cytoplasmic anti-neutrophil cytoplasmic antibodies for myeloperoxidase and proteinase 3. These autopsy findings suggest that the sudden death was caused by isolated necrotizing vasculitis that is assumed to be polyarteritis nodosa localized at the coronary arteries. However, pathological characteristics may not be exactly the same between isolated necrotizing vasculitis in the coronary arteries and polyarteritis nodosa.

[Unusual cause of acute coronary syndrome: Horton's disease]

The pathophysiology of acute coronary syndromes is in most cases due to the erosion or rupture of a plaque with consequent thrombotic obstruction of coronary artery. In a few cases, the mechanism is different, this not modifying the initial management but imposing special techniques for diagnosis and therapeutic management. We report a clinical case of a patient supported for an acute coronary syndrome, in a context of impaired general condition and biological inflammatory syndrome revealing a Horton's disease.

A rare cause of myocardial infarction with non-obstructive coronary arteries-case report of ST-segment elevation myocardial infarction caused by a mediastinal mass

INTRODUCTION

ST-segment elevation myocardial infarction (STEMI) is attributable to an occluded coronary artery in almost 90% of patients. Accordingly, restoration of coronary perfusion as early as possible, preferably with primary percutaneous coronary intervention, is the recommended treatment by the European Society of Cardiology, to maximise myocardial salvage. However, not all cases of STEMI are because of coronary artery occlusion. ST-segment elevation myocardial infarction that occurs in the absence of obstructive coronary artery disease on angiography has been termed myocardial infarction with non-obstructive coronary arteries (MINOCA).

CASE PRESENTATION

A 44-year-old man was admitted with retrosternal chest pain radiating to the left arm and jaw, and electrocardiography showed extensive anterior ST-segment elevation. Emergency coronary angiography showed all three coronary arteries were patent with Thrombolysis in Myocardial Infarction-3 flow and no evidence of dissection or thrombus. The ST-elevation and pain resolved spontaneously. Troponin-T level rose from <3 ng/L on arrival to 549 ng/L at 12 h. Subsequent cardiac magnetic resonance imaging (MRI) showed a structurally normal heart (without late gadolinium enhancement) but detected an incidental large, lobulated (90 × 31 × 71 mm) mediastinal mass containing multiple cysts in the anterior mediastinum with inflammation and oedema of the parietal pericardium. Tissue biopsy confirmed Hodgkin's lymphoma and the patient was initiated on chemotherapy.

DISCUSSION

Some 3% of ST-segment myocardial infarctions occur in the absence of obstructive coronary disease (MINOCA), is more frequent in younger patients. Cardiac MRI is a useful tool to both identify some of the potential causes of MINOCA and also to confirm the diagnosis of infarction. Some 26% of MINOCA patients have significant biochemical evidence of myocardial injury but have a normal cardiac MRI. This case illustrates a very rare cause of myocardial infarction in a young patient with unobstructed coronary arteries, and highlights the need in such cases for further detailed imaging of the myocardium and thorax to establish the diagnosis and initiate appropriate treatment.

Mechanisms of unexpected death and autopsy findings in Friedreich ataxia

A 36-year-old woman with a clinical history of Friedreich ataxia and hypertrophic cardiomyopathy was found unexpectedly dead at her home. The heart showed asymmetric left ventricular hypertrophy, with an interventricular septal thickness of 20-25 mm (the remainder of the left ventricular wall measured 15 mm). Histologically, both ventricles had irregular areas of marked myocyte hypertrophy with associated interstitial fibrosis and focal myofibre disarray. There was neuronal loss within the dentate nucleus of the cerebellum, with vacuolation and axonal loss in the dorsal columns and spinocerebellar tracts of the upper cervical spinal cord. Death was due to hypertrophic cardiomyopathy complicating Friedreich ataxia. Other causes of death in this condition include embolic stroke, cerebral haemorrhage, aspiration pneumonia, renal failure, diabetic ketoacidosis, myocardial infarction, generalised inanition and trauma. Sudden death due to cardiac disease, resulting in presentation for medicolegal autopsy, may be the presenting feature at all ages, including childhood.

Acute coronary syndrome due to coronary artery compression by a metastatic cardiac tumor

A 60-year-old female without coronary risk factors was admitted to the hospital with ST-elevation acute coronary syndrome (ACS). She had previously suffered breast cancer and received radical mastectomy followed by chemotherapy and radiation. Emergent coronary angiography showed an occlusion of the proximal left anterior descending coronary artery (LAD) and coronary angioplasty was performed. Coronary computed tomography (CT) angiography (CTA) disclosed a tumor invading the left ventricular anterior wall and surrounding the coronary artery. Myocardial single-photon-emission CT (SPECT) using 123I-BMIPP showed a defect in the same portion. A fusion image of the CTA and the SPECT delineated a tumor surrounding the coronary artery. She finally died two months later from a terminal condition. Autopsy demonstrated a tumor involving the left ventricular anterior wall and surrounding the LAD. Pathology of the affected LAD showed only fibrous plaque without vulnerable plaque, thrombus, or tumor invasion to the coronary wall. Thus, compression of the coronary artery by the metastatic tumor was the most likely mechanism of ACS.

Staphylococcal coronary arteritis as a complication of septicemia

We describe a case of staphylococcal coronary arteritis in the setting of sepsis due to arteriovenous fistula and dialysis catheter infection. The left circumflex coronary artery was the only vessel involved. The patient was a 77-year-old, insulin-dependent diabetic man with chronic renal failure. The immunosuppressed state in diabetes with subsequent septicemia may have facilitated a large number of bacteria to lodge in the atheromatous plaque of the coronary artery. We briefly review previously reported cases and suggest that bacterial arteritis may be an underrecognized cause of acute coronary occlusion.

Arterial thromboembolic events in patients with the factor V Leiden mutation

BACKGROUND

The factor V Leiden mutation affects 6% of the United States population and is known to be associated with venous thrombosis. We identify, herein, 30 individuals with the Leiden mutation and known arterial thromboembolic events.

METHODS

The factor V mutation was assessed using polymerase chain reaction.

RESULTS

In the 16 patients sustaining a cerebrovascular accident, the mean age was 44.1 and 11 (69%) were younger than 50. Similarly, the 13 patients presenting with an acute myocardial infarction were relatively young with a mean age of 45.5, and 9 (65%) patients presented at less than 50 years of age. Radiographic information was available for 19 patients in this study. No significant arterial atherosclerotic disease was demonstrated in 18 (95%) of these patients.

CONCLUSIONS

This study demonstrates an association between the factor V Leiden mutation and the development of unexplained arterial thromboembolic events, especially in younger patients without existing atherosclerotic disease.