Citations

Thromboangiitis obliterans (TAO), or Buerger's disease, is a nonatherosclerotic segmental vasculitis that affects the small‐ and medium‐sized arteries and veins of the extremities and is strongly associated with tobacco exposure. The immunopathogenesis of TAO remains largely unknown. In the acute phase of the disease, macrophages and occasional giant cells are observed in the characteristic intraluminal thrombus with a relatively mild infiltration of CD4+ and CD8+ T cells and macrophages in the internal lamina. VCAM‐1, ICAM‐1, and E‐selectin expression on the surface of vascular endothelial cells is increased. A variety of circulating autoreactive antibodies targeting endothelial cells and vessel wall components are associated with active disease. One recent report suggests that removal of circulating antibodies by immunoadsorption may decrease disease severity. TAO has been associated positively and negatively with various MHC class 1 and 2 genes; however, genetic testing is not currently used for clinical diagnosis or management. The possible links between tobacco exposure and loss of tolerance for vascular tissues, current management strategy for patients with TAO, and opportunities for translational science are discussed.

Background— Giant cell myocarditis (GCM) typically causes fulminant heart failure, arrhythmias, or heart block, necessitating aggressive immunosuppression, ventricular assist device insertion, or cardiac transplantation. We describe a novel variant of GCM, primarily involving the atria, that displays distinctive clinical features and follows a more benign course than ventricular GCM. Methods and Results— We identified 6 patients (median age 67.5 years, 4 male) with atrial GCM in our pathology consultation practices from 2010 to 2012. Clinical history, imaging, and pathology materials were reviewed. Clinically, 4 patients had atrial fibrillation, 1 had acute heart failure, and 1 had incidental disease at autopsy. Among the 5 living patients, echocardiography revealed severe atrial dilatation (5 cases), mitral/tricuspid regurgitation (5), atrial mural thrombus (3), atrial wall thickening (2), and atrial hypokinesis (2). Ventricular function was preserved in all 5. Histological review of surgically resected atria showed giant cell and lymphocytic infiltrates, lymphocytic myocarditis-like foci, cardiomyocyte necrosis, and cardiomyocyte hypertrophy in all cases. Other features included interstitial fibrosis (5), poorly-formed granulomas (4), eosinophils (4), neutrophils (1), and vasculitis (1). Treatment consisted of steroids and cyclosporine (1), pacemaker placement for sick sinus syndrome (1), and supportive care (3). All 5 living patients returned to baseline exercise tolerance after 6 to 16 weeks of follow-up. Conclusions— Atrial GCM represents a distinct clinicopathologic entity with a more favorable prognosis than classic ventricular GCM. This disorder should be included in the differential diagnosis of atrial dilatation, particularly when associated with atrial wall thickening. The utility of immunomodulatory therapy for this condition remains unknown.

Abstract Acute myocarditis is an inflammatory disease of the heart muscle that may progress to dilated cardiomyopathy and chronic heart failure. A number of factors including the sex hormone testosterone, components of innate immunity, and profibrotic cytokines have been identified in animal models as important pathogenic mechanisms that increase inflammation and susceptibility to chronic dilated cardiomyopathy. The clinical presentation of acute myocarditis is non-specific and mimics more common causes of heart failure and arrhythmias. Suspected myocarditis is currently confirmed using advanced non-invasive imaging and histopathologic examination of heart tissue. However, the diverse presentations of myocarditis and the lack of widely available, safe, and accurate non-invasive diagnostic tests remain major obstacles to early diagnosis and population based research. Recent advances in the understanding of disease pathogenesis described in this review should lead to more accurate diagnostic algorithms and non-invasive tests.

Objectives: The purpose of this study was to describe clinical phenotype and treatment outcomes in lupus myocarditis (LM), an uncommon but serious manifestation of systemic lupus erythematosus (SLE). Methods: The study involved a 10-year retrospective case series of hospitalized patients with LM, with a search of a diagnosis database using systemic lupus erythematosus and either myocarditis, cardiomyopathy, or congestive heart failure, and of a pathology database for biopsy-proved LM. Results: Twenty-four patients met the study criteria, with 79% female and 82% white (age: mean (SD), 47.6 (20.4) years; follow-up: mean (SD), 9.2 (6.1) months). The frequency of antibodies SS-A (69%) and anti-RNP (62%) was greater than in published lupus populations (25%–40%). On echocardiography, the mean initial left ventricular ejection fraction was 33.8%, improving to 49.5% after a mean of 7.2 months. All patients received immunosuppression, most with high-dose corticosteroid treatment and subsequent corticosteroid taper. One patient died of cardiogenic shock during hospitalization; two patients died within one year posthospitalization. Conclusions: A high index of suspicion is necessary in suspected LM. Higher frequency of elevated SS-A and anti-RNP antibody levels in our series than in the literature is suggestive of an LM association. Echocardiography is a useful initial investigation for LM, but patients should be referred early for cardiac magnetic resonance imaging or endomyocardial biopsy to confirm diagnosis if it is clinically indicated in difficult cases.

Median arcuate ligament syndrome (MALS) is often diagnosed when idiopathic, episodic abdominal pain is associated with dynamic compression of the proximal celiac artery by fibers of the median arcuate ligament. The character of the abdominal pain is often postprandial and associated with gradual weight loss from poor food intake, suggestive of chronic mesenteric ischemia. However, the pathognomonic imaging feature of dynamic, ostial celiac artery compression with expiration does not consistently predict clinical improvement from revascularization. Proposed but unproven pathophysiological mechanisms include neurogenic pain from compression of the splanchnic nerve plexus and intermittent ischemia from compression of the celiac artery. Alterations in blood flow and ganglion compression are both associated with delayed gastric emptying, another physiological correlate of the clinical syndrome. Published reports describe a variable response to revascularization and nerve plexus resection suggest a need for translational research to better characterize this poorly understood clinical entity. We illustrate the current gaps in our knowledge of MALS with the case of a 51-year-old woman with a 4-year history of chronic abdominal pain who responded to a combination of ganglion resection and celiac artery reconstruction.

Despite percutaneous intervention after an acute coronary syndrome, patients remain at high risk for recurrent events in the first year. Prior studies have shown that a plaque rupture can occur not only at a single culprit lesion site but also in other atherosclerotic plaques throughout the coronary vasculature in patients with stable angina, silent myocardial ischemia, and during acute coronary syndromes. A 71-year-old man who presented with exertional angina and who had a successful stent in a culprit right coronary artery is described in this article. After 4 weeks, he represented with accelerated angina. A prior lesion in the obtuse marginal artery, remote from the site of the index lesion, had progressed from a 30% to 90% stenosis. This case report demonstrates the systemic nature of acute coronary syndromes, highlights the inherent instability of coronary artery disease, and supports the notion of aggressive secondary prevention in these patients.