Eosinophilic coronary periarteritis (vasospastic angina and sudden death), a new type of coronary arteritis: report of seven autopsy cases and a review of the literature

What Is New in Spontaneous Coronary Artery Dissection?

Spontaneous coronary artery dissection (SCAD) is a condition that leads to tearing of the coronary vessel wall in the absence of trauma, iatrogenic injury, or atherosclerosis. SCAD is an important cause of myocardial infarction in young women, leading to significant cardiovascular morbidity and mortality. Within cohorts of women aged around 50 years on average, who experience acute coronary syndrome, the prevalence of SCAD is 22.5%- 35%. Over the past decade, SCAD research has expanded rapidly, leading to improved understanding of this condition. In this review, we provide a summary of the current body of knowledge, highlight areas of ongoing research, and identify existing knowledge gaps. Specifically, we provide a focused update on the pathogenesis of SCAD, including genetic and associated conditions, clinical presentation and diagnosis, prognosis, and short-term and long-term management. Highlighted areas include the following: insights from recent genome-wide association studies; intracoronary imaging for the diagnosis of SCAD; the role of cardiac computed tomography angiography to assess for vessel healing; revascularization strategies and challenges; cardiogenic shock in SCAD; and the increasingly recognized burden of anxiety, depression, and posttraumatic stress disorder among SCAD patients.

MINOCA biomarkers: Non-atherosclerotic aspects

Myocardial infarction in the absence of obstructive coronary artery disease (MINOCA) is an important subtype of myocardial infarction. Although comprising less than 50% stenosis in the main epicardial coronary arteries, it constitutes a severe health risk. A variety of approaches have been recommended, but definitive diagnosis remains elusive. In addition, the lack of a comprehensive understanding of underlying pathophysiology makes clinical management difficult and unpredictable. This review highlights ongoing efforts to identify relevant biomarkers in MINOCA to improve diagnosis, individualize treatment and better predict outcomes.

TyG index as a predictor of spontaneous coronary artery dissection in young women

OBJECTIVE

Spontaneous coronary artery dissection (SCAD) is a rare but potentially life-threatening pathology and cases are especially seen in women under 50 years of age and with relatively fewer cardiovascular risk factors. Although risk factors facilitating the development of SCAD have been defined in the literature, modifiable risk factors remain unclear. In this study, it was aimed to investigate the relationship between the triglyceride glucose index (TyG) and the development of SCAD in the population of young women.

METHODS

The results of 281 patients were analyzed and compared with each other in terms of clinical, demographic, laboratory parameters, and coronary angiography results.

RESULTS

The mean age was 45 years and all of them were female. When the groups were compared, the TyG and inflammatory parameters were higher in the SCAD group (p < 0.001). When these two groups with low cardiovascular risk factors were compared in logistic regression analysis, high TyG was found to be an independent predictor of SCAD development in young women (p < 0.001).

CONCLUSION

As a result, our study shows that the development of these non-atherosclerotic conditions can be predicted by simple biochemical tests in young women with low atherosclerotic cardiovascular risk factors.

Precipitating factors in patients with spontaneous coronary artery dissection: Clinical, laboratoristic and prognostic implications

BACKGROUND

Spontaneous coronary artery dissection (SCAD) often presents with acute coronary syndrome and underlying pathophysiology involves the interplay between predisposing factors and precipitating stressors, such as emotional and physical triggers. In our study we sought to compare clinical, angiographic and prognostic features in a cohort of patients with SCAD according to the presence and type of precipitating stressors.

METHODS

Consecutive patients with angiographic evidence of SCAD were divided into three groups: patients with emotional stressors, patients with physical stressors and those without any stressor. Clinical, laboratoristic and angiographic features were collected for each patient. The incidence of major adverse cardiovascular events, recurrent SCAD and recurrent angina was assessed at follow-up.

RESULTS

Among the total population (64 subjects), 41 [64.0%] patients presented with precipitating stressors, including emotional triggers (31 [48.4%] subjects) and physical efforts (10 [15.6%] subjects). As compared with the other groups, patients with emotional triggers were more frequently female (p = 0.009), had a lower prevalence of hypertension (p = 0.039] and dyslipidemia (p = 0.039), were more likely to suffer from chronic stress (p = 0.022) and presented with higher levels of C-reactive protein (p = 0.037) and circulating eosinophils cells (p = 0.012). At a median follow-up of 21 [7; 44] months, patients with emotional stressors experienced higher prevalence of recurrent angina (p = 0.025), as compared to the other groups.

CONCLUSIONS

Our study shows that emotional stressors leading to SCAD may identify a SCAD subtype with specific features and a trend towards a worse clinical outcome.

Coronary Artery Vasospasm in Patients With Eosinophilia

Coronary vasospasm is a relatively well-documented cause for ischemia and myocardial infarction in patients with nonobstructive coronary artery disease. Patients with coexisting eosinophilia present with severe manifestations and are often refractory to traditional therapies. There are few reported cases in the literature. We describe 3 cases occurring within 10 months. (Level of Difficulty: Intermediate.).

Eosinophilic Lung Diseases

The eosinophilic lung diseases may manifest as chronic eosinophilic pneumonia, acute eosinophilic pneumonia, or as the Löffler syndrome (generally of parasitic etiology). The diagnosis of eosinophilic pneumonia is made when both characteristic clinical-imaging features and alveolar eosinophilia are present. Peripheral blood eosinophils are generally markedly elevated; however, eosinophilia may be absent at presentation. Lung biopsy is not indicated except in atypical cases after multidisciplinary discussion. The inquiry to possible causes (medications, toxic drugs, exposures, and infections especially parasitic) must be meticulous. Idiopathic acute eosinophilic pneumonia may be misdiagnosed as infectious pneumonia. Extrathoracic manifestations raise the suspicion of a systemic disease especially eosinophilic granulomatosis with polyangiitis. Airflow obstruction is frequent in allergic bronchopulmonary aspergillosis, idiopathic chronic eosinophilic pneumonia, eosinophilic granulomatosis with polyangiitis, and hypereosinophilic obliterative bronchiolitis. Corticosteroids are the cornerstone of therapy, but relapses are common. Therapies targeting interleukin 5/interleukin-5 are increasingly used in eosinophilic lung diseases.

Spontaneous coronary artery dissection in a patient with recent COVID-19 infection: A case report

We report a spontaneous coronary artery dissection (SCAD) case in a lady with a history of recent COVID-19 and without any known predisposing factors. We also highlight the value of CMR as a noninvasive tool for tissue characterization, which can also be more applicable during the COVID-19 pandemic.

Cardiovascular disease in women: A review of spontaneous coronary artery dissection

Research has demonstrated the disproportionate quality of care for women with cardiovascular disease. These findings have prompted a renewed focus on cardiovascular disease awareness and disease prevention in women. Spontaneous coronary artery dissection (SCAD) is a significant cause of myocardial infarction (MI) and sudden death that primarily affects women. ongoing research has led to improved diagnostic capabilities and changes in approaches to initial and long-term management most importantly this research has provided evidence that SCAD is more common than previously thought and must be evaluated and treated differently from atherosclerotic MI. The difference between SCAD and atherosclerotic MI is highlighted in high rates of recurrent disease, gender distribution, association with exogenous hormones, pregnancy, migraine, physical and emotional stress triggers, concurrent systemic arteriopathies, and connective tissue disease. In this review, we provide updated insights and a summary of the epidemiology, risk factors, clinical presentation, diagnosis, treatment options, prognosis, and recurrence prevention of SCAD. We aim to provide a review of SCAD as a focus on cardiovascular disease awareness and disease prevention in women.

The presence of thrombus in spontaneous coronary artery dissection: A systematic review of autopsy findings

Background

Spontaneous coronary artery dissection (SCAD) is an important cause of acute coronary syndrome in young women. There is no consensus on optimal treatment, though a conservative approach including antiplatelet agents is commonly used. We hypothesized that most cases of SCAD would not demonstrate true lumen thrombus in the dissected artery, suggesting that anti-platelet agents might not have a role in the treatment of SCAD.

Methods

We conducted a systematic review of the published literature through March 2022 to identify pathology images from individuals who died of SCAD. The images were independently reviewed by a pathologist to assess for the presence of thrombus and inflammatory cells.

Results

We identified 40 cases from 34 publications with available pathology images and found only one case of true lumen thrombus. Additionally, we found that 53% of cases involved eosinophilic inflammation.

Conclusion

The role of antiplatelet agents in the treatment of SCAD should be re-evaluated. Further studies are needed to better understand the significance and treatment implications of eosinophilic inflammation.

Spontaneous Coronary Artery Dissections: A Systematic Review

Myocardial infarction with nonobstructive coronary artery disease due to spontaneous coronary artery dissection (SCAD) accounts for 5–8% of acute coronary syndrome (ACS) presentations. The demographic characteristics, risk factors, and management of patients with SCAD differ from those with atherosclerotic disease. The objective of this review is to provide a contemporary understanding of the epidemiology, pathophysiology, clinical presentation, and management of SCAD.

Vascular histopathology and connective tissue ultrastructure in spontaneous coronary artery dissection: pathophysiological and clinical implications

Aims 

Spontaneous coronary artery dissection (SCAD) is a cause of acute coronary syndromes and in rare cases sudden cardiac death (SCD). Connective tissue abnormalities, coronary inflammation, increased coronary vasa vasorum (VV) density, and coronary fibromuscular dysplasia have all been implicated in the pathophysiology of SCAD but have not previously been systematically assessed. We designed a study to investigate the coronary histological and dermal collagen ultrastructural findings in SCAD.

Methods and results

Thirty-six autopsy SCAD cases were compared with 359 SCAD survivors. Coronary and myocardial histology and immunohistochemistry were undertaken. Transmission electron microscopy (TEM) of dermal extracellular matrix (ECM) components of n = 31 SCAD survivors and n = 16 healthy volunteers were compared. Autopsy cases were more likely male (19% vs. 5%; P = 0.0004) with greater proximal left coronary involvement (56% vs. 18%; P < 0.0001) compared to SCAD survivors. N = 24 (66%) of cases showed no myocardial infarction on macro- or microscopic examination consistent with arrhythmogenic death. There was significantly (P < 0.001) higher inflammation in cases with delayed-onset death vs. sudden death and significantly more inflammation surrounding the dissected vs. non-dissected vessel segments. N = 17 (47%) cases showed limited intimal fibro-elastic thickening but no features of fibromuscular dysplasia and no endothelial or internal elastic lamina abnormalities. There were no differences in VV density between SCAD and control cases. TEM revealed no general ultrastructural differences in ECM components or markers of fibroblast metabolic activity.

Conclusions 

Assessment of SCD requires careful exclusion of SCAD, particularly in cases without myocardial necrosis. Peri-coronary inflammation in SCAD is distinct from vasculitides and likely a reaction to, rather than a cause for SCAD. Coronary fibromuscular dysplasia or increased VV density does not appear pathophysiologically important. Dermal connective tissue changes are not common in SCAD survivors.

An Autopsy Case of Spontaneous Coronary Artery Dissection With Eosinophilic Coronary Periarteritis and Degeneration of Medial Smooth Muscles

ABSTRACT

A 45-year-old woman with no known medical history died suddenly shortly after complaining of anterior chest discomfort. The autopsy revealed a dissection at the anterior descending branch of the left coronary artery, and eosinophilic adventitial inflammation was observed both in the right coronary artery and in the vicinity of the dissection. Furthermore, there was degeneration of the tunica media in the right coronary artery, and this was thought to be a predissection lesion. In the degenerated area of the tunica media, probable apoptosis of smooth muscle cells was noted, suggesting that the degeneration was not due only to the effect of eosinophilic lytic enzymes. These findings also indicated that eosinophilic infiltration preceded the dissection. Eosinophilic infiltration around the coronary arteries is occasionally observed in cases of sudden death, but although it might be associated with the death, the pathological mechanism is yet to be elucidated. Eosinophilic periarteritis has also been observed around the site of spontaneous coronary artery dissection, although a causal relationship is unproven. The histopathology of this case indicated that the eosinophilic infiltration preceded the dissection. Detailed pathological findings are presented, together with a review of the literature.

Kounis Syndrome Following Hypnale zara (Hump-Nosed Pit Viper) Bite in Sri Lanka

A 47-y-old man was bitten by a hump-nosed viper (Hypnale zara) and gradually developed retrosternal chest pain associated with ST segment elevation on electrocardiogram. He had normal troponin I levels and no evidence of coagulopathy. Initially, he was managed as having anterior ST elevation myocardial infarction with thrombolysis. Later, because troponin levels were normal, he was suggested to have the type I variant of Kounis syndrome (allergic coronary artery spasm). This was supported by high eosinophil counts in peripheral blood. He was successfully managed with supportive treatment and discharged 6 d after the snakebite. Cardiac complications are rarely reported after hump-nosed viper bites, and clinical reports of coronary vasospasm after snakebites are extremely rare in the literature. This is the first known report of Kounis syndrome after a hump-nosed viper bite.

Fatal eosinophilic coronary periarteritis leads to dissection in a young patient: A case report

Eosinophilic coronary periarteritis (ECPA) is a poorly studied type of coronary arteritis. It causes myocardial ischemia and most cases are diagnosed at autopsy. We report the case of a 35-year-old woman who presented with sudden unexpected cardiac arrest and was brought to the emergency ward. Cardiopulmonary resuscitation was started by ambulance paramedic. On arrival, the patient was transferred to the catheterization laboratory due to sudden aborted cardiac death. The angiography was performed and dissection of the left main coronary artery, extended to the left anterior descending artery was detected. Pathological study confirmed ECPA. It appears that young and healthy patients with a history of intermittent vasospastic angina should be evaluated for ECPA. <Learning objective: Young and healthy patients with a history of intermittent Prinzmetal vasospastic angina should be evaluated for eosinophilic coronary periarteritis (ECPA) prior to sudden cardiac death. Since ECPA is an unexpected and life-threatening condition, developing a diagnostic tool amongst suspicious young and healthy patients is demanded. Positron emission tomography-computed tomography might be an interesting tool, since it can detect infiltrative cells in early stages of cardiac inflammatory disease.>.

"Idiopathic Eosinophilic Vasculitis": Another Side of Hypereosinophilic Syndrome? A Comprehensive Analysis of 117 Cases in Asthma-Free Patients

BACKGROUND

The absence of asthma may rule out a diagnosis of eosinophilic granulomatosis with polyangiitis in patients with hypereosinophilic syndrome (HES) and features of vasculitis.

OBJECTIVE

To describe eosinophilic vasculitis (EoV) as a possible manifestation of HES in asthma-free patients.

METHODS

We screened our hospital database and the literature for patients with HES who met the following 4 criteria: (1) histopathological or clinical features of EoV (biopsy-proven vasculitis with predominant eosinophilic infiltration of the vessel wall and/or features of vasculitis with tissue and/or blood hypereosinophilia [absolute eosinophil count >1.5 G/L]); (2) no other obvious causes of reactive eosinophilia, organ damage, and vasculitis; (3) the absence of antineutrophil cytoplasmic antibodies; and (4) the absence of current asthma.

RESULTS

Ten of our 83 (12%) asthma-free patients with HES and 107 additional cases in the literature met the criteria for EoV. After a critical analysis of the patients' clinical and laboratory characteristics and outcomes, we identified 41 cases of single-organ EoV (coronary arteritis, n = 29; temporal arteritis, n = 8; cerebral vasculitis, n = 4). Of the remaining 76 patients with EoV, the most frequent manifestations (>10%) were cutaneous vasculitis (56%), peripheral neuropathy (24%), thromboangiitis obliterans-like disease (16%), fever (13%), central nervous system involvement (13%), deep venous thrombosis (12%), and nonasthma lung manifestations (12%). Blood hypereosinophilia more than 1.5 G/L was observed in 79% of patients, and necrotizing vasculitis was observed in 44%.

CONCLUSIONS

Our results suggest that idiopathic EoV (HES-associated vasculitis) can be classified as an eosinophilic-rich, necrotizing, systemic form of vasculitis that affects vessels of various sizes in asthma-free patients.

Kounis syndrome uncovers severe coronary disease: an unusual case of acute coronary syndrome secondary to allergic coronary vasospasm

Acute coronary syndrome occurring during the course of a type I hypersensitivity reaction constitutes Kounis syndrome. We report a case of a 64-year-old man who presented with a non-ST elevation myocardial infarction and peripheral blood eosinophilia. He had rhinitis and constitutional symptoms for several days prior to presentation. Blood investigations revealed moderate eosinophilia and elevated IgE levels. A cardiac MRI showed generalised oedema with a subtle wall motion abnormality in basal inferior/inferolateral wall, and subendocardial high signal on late gadolinium enhancement suggesting a localised myocardial infarction. A coronary angiogram then revealed triple vessel disease. A diagnosis of Kounis syndrome was made. Within days of starting appropriate treatment, the patient’s eosinophil count returned to normal with improvement of clinical picture.

An autopsy case of sudden unexpected death with loxoprofen sodium-induced allergic eosinophilic coronary periarteritis

Although the cause of eosinophilic coronary periarteritis (ECPA) remains unclear, an allergic background is present in fewer patients than expected. A 50-year-old man with no history of allergy or symptoms suggestive of cardiac or respiratory disorders suddenly died shortly after oral administration of loxoprofen sodium. Autopsy showed eosinophilic coronary periarteritis in three main branches of the coronary arteries, characterized by eosinophil-predominant inflammation without fibrinoid necrosis or granulomatous change in the adventitia and its surroundings of the three main branches of the coronary arteries, in addition to the localized sign of bronchial asthma in the lung. Immunohistochemical examination showed that many mast cells positive for human mast cell tryptase were evident in the perivascular tissue containing peripheral nerve trunks. Whereas the blood concentration of loxoprofen sodium was within the therapeutic range, significant elevation of the serum histamine and tryptase levels was found. The present case suggests that eosinophilic coronary periarteritis may be caused by a type I allergic reaction in some patients and that loxoprofen sodium can trigger a life-threatening type I allergic reaction, including eosinophilic coronary periarteritis, leading to sudden unexpected death.

Clinicopathological complexity in the application of the universal definition of myocardial infarction

A universal definition of myocardial infarction (UDMI) has been established, periodically updated, and refined over the past twenty years. The primary purpose of the UDMI is to bring uniformity and accuracy to clinical diagnosis. Herein, a review and analysis of the UDMI is presented with emphasis on clinicopathological correlation. Determination of the presence of myocardial injury is based on the detection of abnormal serum cardiac biomarkers, particularly cardiac troponin (cTn), and in the current fourth iteration of the UDMI, high sensitivity (hs)-cTn. Differentiation of myocardial infarction from other causes of myocardial injury requires the documentation of clinical evidence of myocardial ischemia. In this review, difficulties in applying the UDMI in actual practice are discussed, based on the experience and perspective of those of us who face these problems as part of our own practice of pathology. The complexity in application of the UDMI is highlighted by the presentation of five illustrative cases involving the differential diagnosis of myocardial injury and myocardial infarction due to atherothrombotic and nonatherothrombotic coronary artery disease. The cases include myocardial infarction due to severe coronary atherosclerosis, supply-demand mismatch, coronary artery dissection associated with an eosinophilic coronary periarteritis, and coronary thromboembolism, and a case with a differential diagnosis of myocarditis and myocardial infarction. These cases illustrate how pathological findings can contribute to more accurate application of the UDMI and how, when critically applied, the UDMI can be used to better characterize myocardial infarcts in clinical practice.

How to Diagnose and Manage Angina Without Obstructive Coronary Artery Disease: Lessons from the British Heart Foundation CorMicA Trial

Patients with symptoms and/or signs of ischaemia but no obstructive coronary artery disease (INOCA) present a diagnostic and therapeutic challenge. Microvascular and/or vasospastic angina are the two most common causes of INOCA; however, invasive coronary angiography lacks the sensitivity to diagnose these functional coronary disorders. In this article, the authors summarise the rationale for invasive testing in the absence of obstructive coronary disease, namely that correct treatment for angina patients starts with the correct diagnosis. They provide insights from the CORonary MICrovascular Angina (CorMicA) study, where an interventional diagnostic procedure was performed with linked medical therapy to improve patient health. Identification of these distinct disorders (microvascular angina, vasospastic angina or non-cardiac chest pain) is key for stratifying INOCA patients, allowing prognostic insights and better patient care with linked therapy based on contemporary guidelines. Finally, they propose a framework to diagnose and manage patients in this common clinical scenario.

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.

Systemic inflammatory activation in patients with acute coronary syndrome secondary to nonatherosclerotic spontaneous coronary artery dissection

OBJECTIVE

Pathological studies have suggested that local inflammation, particularly eosinophilic infiltration of the adventitia, could be related to nonatherosclerotic spontaneous coronary artery dissection (NA-SCAD). However, the role of systemic inflammation in the pathogenesis of NA-SCAD remains unknown. Our aim was to investigate systemic inflammatory activation in patients with an acute coronary syndrome (ACS) secondary to NA-SCAD.

METHODS

The institutional electronic medical database was reviewed, and 22 patients with NA-SCAD-ACS were identified after the review. Furthermore, 30 random patients with CAD-ACS and 30 random subjects without any history of CAD or ACS with demographic and clinical characteristics similar to those of NA-SCAD-ACS patients were identified from the institutional database to be included in the study.

RESULTS

Patients with NA-SCAD-ACS and those with CAD-ACS both had higher white blood cell and neutrophil counts than controls. Neutrophil-lymphocyte ratio (NLR) and C-reactive protein (CRP) levels were only significantly higher in the NA-SCAD-ACS group [2.01 (1.54-6.17) for NLR and 0.70 (0.13-2.70) for CRP] than in the controls [1.55 (1.27-2.13), p=0.03 for NLR and 0.15 (0.10-0.43), p=0.049 for CRP]; however, there were no differences between the NA-SCAD-ACS and CAD-ACS groups [1.91 (1.41-2.78) for NLR and 0.41 (0.09-1.10) for CRP, p>0.05 for both comparisons] regarding all tested parameters.

CONCLUSION

The degree of inflammatory activation in NA-SCAD-ACS patients was similar to, or even greater than, that in CAD-ACS patients; thus, suggesting a role of inflammation in the pathophysiology of NA-SCAD-ACS.

Protective Role of Mast Cells in Primary Systemic Vasculitis: A Perspective

Mast cells are important cells of the immune system. Although traditionally considered as key players in allergic and hypersensitivity reactions, emerging evidence suggests that mast cells have many complex roles in vascular disease. These include regulation of vasodilation, angiogenesis, activation of matrix metalloproteinases, apoptosis of smooth muscle cells, and activation of the renin angiotensin system. Mast cells are also known to play an immunomodulatory role via modulation of regulatory T-cell (Treg), macrophage and endothelial cell functions. This dual role of the mast cells is evident in myeloperoxidase anti-neutrophil cytoplasmic antibodies-mouse model of glomerulonephritis in which mast cell deficiency worsens glomerulonephritis, whereas inhibition of mast cell degranulation is effective in abrogating the development of glomerulonephritis. Our previous work demonstrated that mast cell degranulation inhibits lipopolysaccharide-induced interleukin 6 (IL-6) production in mice. This effect was not seen in histamine-1-receptor knockout (H1R^-/-) mice suggesting a role for histamine in IL-6 homeostasis. In addition, mast cell degranulation-mediated decrease in IL-6 production was associated with an upregulation of suppressor of cytokine signaling-1 protein in the aorta. We propose that mast cells regulate large artery inflammation through T-cells, shifting a primarily Th1 and Th17 toward a Th2 response and leading to enhanced IL-10 production, activation Treg cells, and the inhibition of macrophage functions.

Eosinophilic Lung Diseases

Eosinophilic lung diseases especially comprise eosinophilic pneumonia or as the more transient Löffler syndrome, which is most often due to parasitic infections. The diagnosis of eosinophilic pneumonia is based on characteristic clinical-imaging features and the demonstration of alveolar eosinophilia, defined as at least 25% eosinophils at BAL. Peripheral blood eosinophilia is common but may be absent at presentation in idiopathic acute eosinophilic pneumonia, which may be misdiagnosed as severe infectious pneumonia. All possible causes of eosinophilia, including drug, toxin, fungus related etiologies, must be thoroughly investigated. Extrathoracic manifestations should raise the suspicion of eosinophilic granulomatosis with polyangiitis.

Recurrent chest pain after treatment of spontaneous coronary artery dissection: An enigma

Spontaneous coronary artery dissection (SCAD) is a rare entity. It has been described in various settings like pregnancy, collagen vascular diseases, cocaine abuse, heavy exercise, variant angina, eosinophilic arteritis, or fibro muscular dysplasia. It is also easy to miss a dissection during angiography, as the typical radiolucent lumen seen in coronary angiography may be absent in many cases. In this report, we describe the case of a 35-year-old female who presented with acute ST elevation myocardial infarction due to spontaneous coronary dissection. She had been having episodic chest pain for one year and had been seen by two different cardiologists but was thought to have non-cardiac symptoms. Even during the index hospitalization, she underwent coronary angiography three times before coronary dissection could be identified as the cause of her symptoms. She underwent coronary artery bypass graft surgery uneventfully. However, even after myocardial revascularization, she has had multiple episodes of chest pain requiring hospitalization. However, we have not been able to find a specific cause for it and the cause of her recurrent chest pain remains an enigma. This case highlights the problems, which arise while managing a case of SCAD. More research is needed to find the exact etiology and long-term prognosis of this condition.

Allergy in extremis: a case of sudden unexpected death due to an allergy-associated disease

Allergy-associated diseases have a multitude of confirmed or suspected etiologies and associations affecting organs and organ systems. The hyper-reactivity of the immune system in which the eosinophils are prominent plays a central role in organ-specific and systemic effects in these diseases. Patients may be plagued with nonspecific, episodic, or progressive signs and symptoms. Patients may also exhibit signs and symptoms that mimic more common conditions. Recognition of certain patterns of clinical signs and symptoms may lead to definitive clinical diagnosis and effective treatment, particularly of less common but potentially lethal disease entities. The lack of clinical recognition of these patterns, whether due to "red herring" historical information, lack of sign/symptom specificity, clinical presentation at early stage, or unfamiliarity with the constellation of disease presentation, may delay or preclude diagnosis and treatment. The forensic pathologist must also have an awareness of varied clinical presentations of diseases because these can provide us with direction toward the ultimate determination of cause and manner of death.The importance and contribution of the practice of forensic pathology are highlighted in the instance of sudden and unexpected death, whereby the previously unrecognized or unconfirmed disease entity that leads to the death is revealed via analysis of scene information, autopsy performance, and review of medical history and history of the most recent illness. Through this comprehensive approach, a greater understanding of the extent and potential lethality of disease with reiteration of the importance of early clinical diagnosis and treatment is reinforced. This benefits the medical community involved in diagnosis and treatment, clinicians and pathologists alike, with the ultimate goal of reduction of morbidity and mortality.Reported is a case of sudden unexpected death with historical, gross, and microscopic findings consistent with a multisystem, inflammatory, allergic disease entity.

Spontaneous coronary artery dissection: Case series from two institutions with literature review

Spontaneous coronary artery dissection (SCAD) is a rare cause of acute coronary syndrome (ACS). Consequently, its presentation and optimal treatment are yet to be clearly defined. In the current literature, all case series report less than 50 patients, most of whom are either young peripartum women or women who have used oral contraceptives over long periods. All information in this study was compiled by the database service from two hospitals, the first one between 2003 and 2012 and the second one between 2007 and 2012, to include the clinical characteristics, angiography. and treatment approaches in the study population. The study population consisted in four women (50%) and four men (50%) whose ages ranged between 28 and 57 years. Two women had a history of oral contraceptive use and three women presented during peripartum. None of the patients had traditional cardiovascular risk factors or previous heart disease. In 88% of the cases, the principal diagnoses were non-ST segment elevation myocardial infarction and unstable angina. All patients underwent emergency coronary angiography and percutaneous coronary intervention. Half of them were treated with drug-eluting stents and the other half with bare metal stents. The most frequent type of dissection was NIHBL Type E, and the right coronary artery was the most frequently compromised. SCAD is a rare cause of ACS; however, its identification has improved due to the availability of angiography and new complementary techniques. Regarding treatment, PCI seems effective with adequate long-term results.

Eosinophilic Coronary Periarteritis with Arterial Dissection: The Mast Cell Hypothesis

A subset of coronary arterial dissections is associated with eosinophilic coronary periarteritis (ECPA); however, the pathogenesis of the process remains unclear. Mast cells normally reside in coronary arterial adventitia and are known mediators of eosinophilic inflammatory conditions such as type I hypersensitivity reactions. We report two cases in which coronary arterial dissection with ECPA was detected at autopsy. Tryptase, CD68, CD4, CD8, and CD1a immunohistochemical staining was performed to better characterize inflammation. While eosinophils represented a prominent periadventitial inflammatory cell, there were slightly more lymphocytes: CD4/CD8 ratios were within expected reference ranges. There were moderate numbers of macrophages, and few neutrophils or dendritic cells. Numbers of mast cells in dissected versus nondissected sections were compared: adventitial mast cell densities were threefold higher in dissected portions and showed a trend toward increased degranulation. These findings suggest that mast cells may play a role in orchestrating inflammation in cases of ECPA.

Eosinophilic Pneumonia

Eosinophilic pneumonia may manifest as chronic or transient infiltrates with mild symptoms, chronic idiopathic eosinophilic pneumonia, or the frequently severe acute eosinophilic pneumonia that may be secondary to a variety of causes (drug intake, new onset of tobacco smoking, infection) and that may necessitate mechanical ventilation. When present, blood eosinophilia greater than 1 × 10⁹ eosinophils/L (and preferably greater than 1.5 × 10⁹/L) is of considerable help for suggesting the diagnosis, however it may be absent, as in the early phase of idiopathic acute eosinophilic pneumonia or when patients are already taking corticosteroids. On bronchoalveolar lavage, high eosinophilia (>25 %, and preferably >40 % of differential cell count) is considered diagnostic of eosinophilic pneumonia in a compatible setting, obviating the need of video-assisted thoracic surgical lung biopsy, which is now performed only on very rare occasions with inconsistency between clinical, biological, and imaging features. Inquiry as to drug intake must be meticulous (www.pneumotox.com) and any suspected drug should be withdrawn. Laboratory investigations for parasitic causes must take into account the travel history or residence and the epidemiology of parasites. In patients with associated extrathoracic manifestations, the diagnosis of eosinophilic granulomatosis with polyangiitis or of the hypereosinophilic syndromes should be raised. Presence of airflow obstruction can be found in hypereosinophilic asthma, allergic bronchopulmonary aspergillosis, idiopathic chronic eosinophilic pneumonia, eosinophilic granulomatosis with polyangiitis, or in the recently identified syndrome of hyperosinophilic obliterative bronchiolitis. Corticosteroids remain the cornerstone of symptomatic treatment for eosinophilic pneumonias, with a generally dramatic response. Relapses are common when tapering the doses or after stopping treatment especially in idiopathic chronic eosinophilic pneumonia. Cyclophosphamide is necessary only in patients with eosinophilic granulomatosis with polyangiitis and poor-prognostic factors. Imatinib is very effective in the treatment of the myeloproliferative variant of hypereosinophilic syndromes. Anti-interleukin-5 monoclonal antibodies are promising in the spectrum of eosinophilic disorders.