Myocardial infarction associated with eosinophilia and plasma extravasation at multiple sites. A variant of Kounis syndrome

Kounis Syndrome Secondary to Medicine-Induced Hypersensitivity

Introduction

Kounis syndrome is the concurrence of an acute coronary syndrome (ACS) caused by coronary vasospasms, acute myocardial infarctions, or stent thromboses in case of allergic or hypersensitivity reactions. Kounis syndrome is mediated by mast cells that interact with macrophages and T-lymphocytes, causing degranulation and inflammation with cytokine release. It is a life-threatening condition that has many trigger factors and is most commonly caused by medicines. Case Presentation. A 71-year-old male was admitted with a fever of five days' duration associated with cellulitis, for which he had been treated with clindamycin and flucloxacillin before admission. He was a diagnosed patient with hypertension and dyslipidemia five years ago. After taking the antibiotics, he had developed generalized itching followed by urticaria suggesting an allergic reaction. Therefore, he was admitted to the hospital. After admission, he developed an ischaemic-type chest pain associated with autonomic symptoms and shortness of breath. An immediate ECG was taken that showed ST-segment depressions in the chest leads V4–V6, confirmed by a repeat ECG. Troponin I was 8 ng/mL. Acute management of ACS was started, and prednisolone 10 mg daily dose was given. After complete recovery, the patient was discharged with aspirin, clopidogrel, atorvastatin, metoprolol, losartan, isosorbide mononitrate, and nicorandil. Prednisolone 10 mg daily dose was given for five days after discharge.

Conclusion

In immediate hypersensitivity, with persistent cardiovascular instability, Kounis syndrome should be considered, and an electrocardiogram and other appropriate assessments and treatments should be initiated. Prompt management of the allergic reaction and the ACS is vital for a better outcome of Kounis syndrome.

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.

Postmortem IgE determination in coronary artery disease

Allergic, IgE-mediated inflammation is thought to play a role in atherogenesis and atherosclerotic disease progression. In this study, total IgE and mast cell tryptase were measured in a series of forensic autopsy cases including non-allergic cardiac deaths (14 cases with minimal or no coronary atherosclerosis, 14 cases with significant coronary artery atherosclerosis without acute coronary thrombosis, and 14 cases with significant coronary artery atherosclerosis and acute coronary thrombosis or myocardial infarction) and non-allergic non-cardiac deaths (21 cases with death due to hanging and 21 cases with death due to intracranial gunshot wounds), in order to correlate laboratory results with morphological findings and compare them to conclusions reported in the clinical setting. In cardiac death cases, postmortem serum total IgE levels were increased in 7 out of 42 cases and mast cell tryptase levels were increased in 3 out of 42 cases. In non-cardiac death cases, postmortem serum total IgE levels were not increased in 39 out of 42 cases and mast cell tryptase levels were not increased in any of these cases. These preliminary findings seem to indicate that a portion of coronary deaths characterized by coronary artery atherosclerosis of various severities are also characterized by increased total IgE and mast cell tryptase levels, thus corroborating the data previously reported in both clinical and forensic literature on this topic as well as the necessity of combining morphological investigations focusing on the heart and coronary arteries with biochemical analyses.