Allergic Reactions to Current Available COVID-19 Vaccinations: Pathophysiology, Causality, and Therapeutic Considerations

Vaccines constitute the most effective medications in public health as they control and prevent the spread of infectious diseases and reduce mortality. Similar to other medications, allergic reactions can occur during vaccination. While most reactions are neither frequent nor serious, anaphylactic reactions are potentially life-threatening allergic reactions that are encountered rarely, but can cause serious complications. The allergic responses caused by vaccines can stem from activation of mast cells via Fcε receptor-1 type I reaction, mediated by the interaction between immunoglobulin E (IgE) antibodies against a particular vaccine, and occur within minutes or up to four hours. The type IV allergic reactions initiate 48 h after vaccination and demonstrate their peak between 72 and 96 h. Non-IgE-mediated mast cell degranulation via activation of the complement system and via activation of the Mas-related G protein-coupled receptor X2 can also induce allergic reactions. Reactions are more often caused by inert substances, called excipients, which are added to vaccines to improve stability and absorption, increase solubility, influence palatability, or create a distinctive appearance, and not by the active vaccine itself. Polyethylene glycol, also known as macrogol, in the currently available Pfizer-BioNTech and Moderna COVID-19 mRNA vaccines, and polysorbate 80, also known as Tween 80, in AstraZeneca and Johnson & Johnson COVID-19 vaccines, are excipients mostly incriminated for allergic reactions. This review will summarize the current state of knowledge of immediate and delayed allergic reactions in the currently available vaccines against COVID-19, together with the general and specific therapeutic considerations. These considerations include: The incidence of allergic reactions and deaths under investigation with the available vaccines, application of vaccination in patients with mast cell disease, patients who developed an allergy during the first dose, vasovagal symptoms masquerading as allergic reactions, the COVID-19 vaccination in pregnancy, deaths associated with COVID-19 vaccination, and questions arising in managing of this current ordeal. Careful vaccine-safety surveillance over time, in conjunction with the elucidation of mechanisms of adverse events across different COVID-19 vaccine platforms, will contribute to the development of a safe vaccine strategy. Allergists’ expertise in proper diagnosis and treatment of allergic reactions is vital for the screening of high-risk individuals.

White blood cell counts, leukocyte ratios, and eosinophils as inflammatory markers in patients with coronary artery disease

Inflammation is a key feature of atherosclerosis and its clinical manifestations. The leukocyte count has emerged as a marker of inflammation that is widely available in clinical practice. Since inflammation plays a key role in atherosclerosis and its end results, discovering new biomarkers of inflammation becomes important in order to help diagnostic accuracy and provide prognostic information about coronary cardiac disease. In acute coronary syndromes and percutaneous coronary intervention, elevated levels of almost all subtypes of white blood cell counts, including eosinophils, monocytes, neutrophils, and lymphocytes, and neutrophil-lymphocyte ratio and eosinophil-leukocyte ratio constitute independent predictors of adverse outcomes. Eosinophil count and eosinophil-leukocyte ratio, in particular, emerge as novel biomarkers for risk stratification in patients with coronary artery disease. Since the presence of eosinophils denotes hypersensitivity inflammation and hypersensitivity associated with Kounis syndrome, this reality is essential for elucidating the etiology of inflammation in order to consider predictive and preventive measures and to apply the appropriate therapeutic methods.

Kounis syndrome: A concise review with focus on management

Kounis syndrome is defined as the co-incidental occurrence of an acute coronary syndrome with hypersensitivity reactions following an allergenic event and was first described by Kounis and Zavras in 1991 as an allergic angina syndrome. Multiple causes have been described and most of the data in the literature are derived from the description of clinical cases - mostly in adult patients - and the pathophysiology remains only partly explained. Three different variants of Kounis syndrome have been defined: type I (without coronary disease) is defined as chest pain during an acute allergic reaction in patients without risk factors or coronary lesions in which the allergic event induces coronary spasm that electrocardiographic changes secondary to ischemia; type II (with coronary disease) includes patients with pre-existing atheromatous disease, either previously quiescent or symptomatic, in whom acute hypersensitive reactions cause plaque erosion or rupture, culminating in acute myocardial infarction; more recently a type-III variant of Kounis syndrome has been defined in patients with preexisting coronary disease and drug eluting coronary stent thrombosis. The pathogenesis of the syndrome is discussed, and a therapeutic algorithm is proposed.

Kounis Syndrome—not a Single-organ Arterial Disorder but a Multisystem and Multidisciplinary Disease

Coronary symptoms associated with conditions related to mast cell activation and inflammatory cell interactions, such as those involving T-lymphocytes and macrophages, further inducing allergic, hypersensitivity, anaphylactic, or anaphylactic insults, are currently referred to as the Kounis syndrome. Kounis syndrome is caused by inflammatory mediators released during allergic insults, post-inflammatory cell activation, and interactions via multidirectional stimuli. A platelet subset of 20% with high- and low-affinity IgE surface receptors is also involved in this process. Kounis syndrome is not just a single-organ but also a complex multisystem and multi-organ arterial clinical condition; it affects the coronary, mesenteric, and cerebral arteries and is accompanied by allergy–hypersensitivity–anaphylaxis involving the skin, respiratory, and vascular systems in the context of anesthesia, surgery, radiology, oncology, or even dental and psychiatric medicine; further, it has significantly influences both morbidity and mortality. Kounis syndrome might be caused by numerous and continuously increasing causes, with broad clinical symptoms and signs, via multi-organ arterial system involvement, in patients of any age, thereby demonstrating predominant anaphylactic features in terms of a wide spectrum of mast cell-association disorders. Cardiac symptoms, such as chest pain, coronary vasospasm, angina pectoris, myocardial infarction, stent thrombosis, acute cardiac failure, and sudden cardiac death associated with subclinical, clinical, acute, or chronic allergic reactions, constitute the clinical manifestations of this syndrome. Since its first description, a common pathway between allergic and non-allergic coronary events has been demonstrated. The hypothesis is based on the existence of a much higher degree of mast cell degranulation at plaque erosion or rupture sites compared with at the adjacent areas or even more distant segments in post-acute myocardial infarction of non-allergic etiology. Although mast cell activation, differentiation, and mediator release takes days or weeks, the mast cell degranulation may occur just before any acute coronary event, further resulting in coronary artery vasoconstriction and atheromatous plaque rupture. It seems that medications and natural molecules stabilizing the mast cell membrane as well as monoclonal antibodies protecting the mast cell surface can emerge as novel therapeutic modalities for acute coronary and cerebrovascular event prevention.

Anaphylactic cardiovascular collapse and Kounis syndrome: systemic vasodilation or coronary vasoconstriction?

The first reported human anaphylactic death is considered to be the Pharaoh Menes death, caused by a wasp sting. Currently, anaphylactic cardiovascular events represent one of most frequent medical emergencies. Rapid diagnosis, prompt and appropriate treatment can be life saving. The main concept beyond anaphylaxis lies to myocardial damage and ventricular dysfunction, thus resulting in cardiovascular collapse. Cardiac output depression due to coronary hypoperfusion from systemic vasodilation, leakage of plasma and volume loss due to increased vascular permeability, as well as reduced venous return, are regarded as the main causes of cardiovascular collapse. Clinical reports and experiments indicate that the human heart, in general, and the coronary arteries, in particular, could be the primary target of the released anaphylactic mediators. Coronary vasoconstriction and thrombosis induced by the released mediators namely histamine, chymase, tryptase, cathepsin D, leukotrienes, thromboxane and platelet activating factor (PAF) can result to further myocardial damage and anaphylaxis associated acute coronary syndrome, the so-called Kounis syndrome. Kounis syndrome with increase of cardiac troponin and other cardiac biomarkers, can progress to heart failure and cardiovascular collapse. In experimental anaphylaxis, cardiac reactions caused by the intracardiac histamine and release of other anaphylactic mediators are followed by secondary cardiovascular reactions, such as cardiac arrhythmias, atrioventricular block, acute myocardial ischemia, decrease in coronary blood flow and cardiac output, cerebral blood flow, left ventricular developed pressure (LVdp/dtmax) as well as increase in portal venous and coronary vascular resistance denoting vascular spasm. Clinically, some patients with anaphylactic myocardial infarction respond satisfactorily to appropriate interventional and medical therapy, while anti-allergic treatment with antihistamines, corticosteroids and fluid replacement might be ineffective. Therefore, differentiating the decrease of cardiac output due to myocardial tissue hypoperfusion from systemic vasodilation and leakage of plasma, from myocardial tissue due to coronary vasoconstriction and thrombosis might be challenging during anaphylactic cardiac collapse. Combined antiallergic, anti-ischemic and antithrombotic treatment seems currently beneficial. Simultaneous measurements of peripheral arterial resistance and coronary blood flow with newer diagnostic techniques including cardiac magnetic resonance imaging (MRI) and myocardial scintigraphy may help elucidating the pathophysiology of anaphylactic cardiovascular collapse, thus rendering treatment more rapid and effective.

Epidemiology of acute coronary syndrome co-existent with allergic/hypersensitivity/anaphylactic reactions (Kounis syndrome) in the United States: A nationwide inpatient analysis

BACKGROUND

The nationwide epidemiological data on Kounis Syndrome (KS), still remains indistinct in the United States (US) after it was first reported in 1991.

METHODS

We assessed the prevalence of KS among patients primarily hospitalized for allergic/hypersensitivity/anaphylactic reactions. We then compared baseline demographics, comorbidities, and outcomes of KS with patients with only allergic/hypersensitivity/anaphylactic reactions using the National Inpatient Sample, 2007-2014.

RESULTS

The cohort comprised of 235,420 patients primarily hospitalized with allergy/hypersensitivity/anaphylactic reactions. Of these, 2616 [1.1%; 0.2% unstable angina, 0.2% ST-elevation myocardial infarction & 0.7% non-ST-elevation myocardial infarction] patients experienced ACS and were identified as having KS. Patients with KS were older (mean 65.9 ± 14.1 vs. 57.2 ± 17.8 yrs), more often White (71.1% vs. 58.6%), male (46.4% vs. 39.9%) and Medicare enrollees (58.9% vs. 41.5%) admitted non-electively (96.8% vs. 95.3%) as compared to non-KS group (p < 0.001). The hospitalizations with KS demonstrated higher all-cause in-hospital mortality (7.0% vs. 0.4%, p < 0.001), prolonged hospitalization stay (mean 5.8 ± 6.0 vs. 3.0 ± 3.9 days, p < 0.001), higher hospitalization charges ($52,656 vs. $20,487, p < 0.001) and more frequent transfers to other facilities. The rates of stroke (1.0% vs. 0.2%), arrhythmias (30.4% vs. 12.4%), venous thromboembolism (1.6% vs. 1.0%), and diagnostic and therapeutic coronary interventions were also found to be significantly higher in patients with KS (p < 0.05). Patients with KS had increased odds of in-hospital mortality [unadjusted OR: 18.52; 95% CI: 15.74-21.80, p < 0.001 & adjusted OR: 9.74, 95% CI: 8.08-11.76, p < 0.001] compared to non-KS group.

CONCLUSIONS

Overall US prevalence of KS among patients hospitalized for allergic/hypersensitivity/anaphylactic reactions is 1.1% with a subsequent all-cause inpatient mortality rate of 7.0%.

Thrombotic responses to coronary stents, bioresorbable scaffolds and the Kounis hypersensitivity-associated acute thrombotic syndrome

Percutaneous transluminal coronary angioplasty with coronary stent implantation is a life-saving medical procedure that has become, nowadays, the most frequent performed therapeutic procedure in medicine. Plain balloon angioplasty, bare metal stents, first and second generation drug-eluting stents, bioresorbable and bioabsorbable scaffolds have offered diachronically a great advance against coronary artery disease and have enriched our medical armamentarium. Stented areas constitute vulnerable sites for endothelial damage, endothelial dysfunction, flow turbulence, hemorheologic changes, platelet dysfunction, coagulation changes and fibrinolytic disturbances. Implant surface attracts several proteins such as albumin, fibronectin, fibrinogen, and complement that lead to complement system activation. Macrophages recognize the implant as foreign substance due to protein adsorption and its continuous presence results in macrophage differentiation and fusion into foreign body giant cells. Polymer coating, stent metallic platforms and the released drugs can act as strong antigenic complex that apply continuous, repetitive, persistent and chronic hypersensitivity irritation to the coronary intima. The concomitant administration of oral antiplatelet drugs and environmental exposures can induce hypersensitivity inflammation. A class of platelets, activated via high-affinity and low-affinity IgE hypersensitivity receptors FCγRI, FCγRII, FCεRI and FCεRII, can induce Kounis hypersensitivity-associated thrombotic syndrome inside the stented coronaries. Type III variant of this syndrome is diagnosed when coronary artery stent thrombosis is associated with thrombus infiltrated by eosinophils or mast cells and/or when coronary intima, media and adventitia adjacent to stent, is infiltrated by eosinophils or mast cells. Careful history of hypersensitivity reactions to all implanted materials and concomitant drugs with monitoring of inflammatory mediators as well as lymphocyte transformation studies to detect hypersensitivity must be undertaken in order to avoid disastrous consequences. Food and Drug Administration recommendations for coronary stent implantation should be applied also to bioresorbable scaffolds. Further studies with inert and non-allergenic implants are necessary.

Mast Cells in Cardiovascular Disease: From Bench to Bedside

Mast cells are pluripotent leukocytes that reside in the mucosa and connective tissue. Recent studies show an increased prevalence of cardiovascular disease among patients with mastocytosis, which is a hematological disease that is characterized by the accumulation of mast cells due to clonal proliferation. This association suggests an important role for mast cells in cardiovascular disease. Indeed, the evidence establishing the contribution of mast cells to the development and progression of atherosclerosis is continually increasing. Mast cells may contribute to plaque formation by stimulating the formation of foam cells and causing a pro-inflammatory micro-environment. In addition, these cells are able to promote plaque instability by neo-vessel formation and also by inducing intraplaque hemorrhage. Furthermore, mast cells appear to stimulate the formation of fibrosis after a cardiac infarction. In this review, the available data on the role of mast cells in cardiovascular disease are summarized, containing both in vitro research and animal studies, followed by a discussion of human data on the association between cardiovascular morbidity and diseases in which mast cells are important: Kounis syndrome, mastocytosis and allergy.

Anaphylactic Shock: Kounis Hypersensitivity-Associated Syndrome Seems to be the Primary Cause

Experiments have shown that anaphylaxis decreases cardiac output; increases left ventricular end diastolic pressure; induces severe early acute increase in respiratory resistance with pulmonary interstitial edema; and decreases splanchnic, cerebral, and myocardial blood flow more than what would be expected from severe arterial dilation and hypotension. This is attributed to the constrictive action of inflammatory mediators released during anaphylactic shock. Inflammatory mediators such as histamine, neutral proteases, arachidonic acid products, platelet-activating factor (PAF), and a variety of cytokines and chemokines constitute the pathophysiologic basis of Kounis hypersensitivity-associated acute coronary syndrome. Although the mechanisms of anaphylactic shock still remain to be elucidated, myocardial involvement due to vasospasm-induced coronary blood flow reduction manifesting as Kounis syndrome should be always considered. Searching current experimental and clinical literature on anaphylactic shock pathophysiology, causality, clinical appearance, and treatment via PubMed showed that differentiating global hypoperfusion from primary tissue suppression due to mast cell mediator constrictive action on systemic arterial vasculature is a challenging procedure. Combined tissue suppression from arterial involvement and peripheral vasodilatation, perhaps, occur simultaneously. In cases of anaphylactic shock treatment targeting the primary cause of anaphylaxis together with protection of coronary vasculature and subsequently the cardiac tissue seems to be of paramount importance.

The more allergens an atopic patient is exposed to, the easier and quicker anaphylactic shock and Kounis syndrome appear: Clinical and therapeutic paradoxes

Kounis syndrome is a condition that combines allergic, hypersensitivity, anaphylactic or anaphylactoid reactions with acute coronary syndromes including vasospastic angina, acute myocardial infarction and stent thrombosis. This syndrome is a ubiquitous disease affecting patients of any age, involving numerous and continuously increasing causes, with broadening clinical manifestations and covering a wide spectrum of mast cell activation disorders. Drugs, environmental exposures and various conditions are the main offenders. Clinical and therapeutic paradoxes concerning Kounis syndrome therapy, pathophysiology, clinical course and causality have been encountered during its clinical course. Drugs that counteract allergy, such as H2-antihistamines, can induce allergy and Kounis syndrome. The more drugs an atopic patient is exposed to, the easier and quicker anaphylaxis and Kounis syndrome can occur. Every anesthetized patient is under the risk of multiple drugs and substances that can induce anaphylactic reaction and Kounis syndrome. The heart and the coronary arteries seem to be the primary target in severe anaphylaxis manifesting as Kounis syndrome. Commercially available adrenaline saves lives in anaphylaxis but it contains as preservative sodium metabisulfite and should be avoided in the sulfite allergic patients. Thus, careful patient past history and consideration for drug side effects and allergy should be taken into account before use. The decision to prescribe a drug where there is a history of previous adverse reactions requires careful assessment of the risks and potential benefits.

Kounis syndrome, a disease to know: Case report and review of the literature

The case deals with an anaphylactoid reaction to intravenous ampicillin/sulbactam resulting in cardiogenic syncope and myocardial damage. Symptoms and ECG modifications promptly disappeared after corticosteroids administration. The Kounis syndrome is an acute coronary syndrome, including coronary spasm, acute myocardial infarction and stent thrombosis, resulting from an anaphylactic or anaphylactoid or allergic or hypersensitivity insult. First described in 1991, it can be caused by a lot of substances, particularly antibiotics. The management should be directed to both the allergic reaction and the myocardial damage. The Kounis syndrome is a not rare disease that every physician should know because of the wideness of triggers and the possible fatal evolution if not promptly recognized.

The Role of Mast Cells in the Induction and Maintenance of Inflammation in Selected Skin Diseases

Under physiological conditions, skin mast cells play an important role as guardians that quickly react to stimuli that disturb homeostasis. These cells efficiently support, fight infection, and heal the injured tissue. The substances secreted by mast cells allow for communication inside the body, including the immune, nervous, and blood systems. Pathologically non-cancerous mast cells participate in allergic processes but also may promote the development of autoinflammatory or neoplastic disease. In this article, we review the current literature regarding the role of mast cells in autoinflammatory, allergic, neoplastic skin disease, as well as the importance of these cells in systemic diseases with a pronounced course with skin symptoms.

Type 1 Kounis Syndrome Induced by Inactivated SARS-COV-2 Vaccine

Background Vaccination is the most important way out of the novel coronavirus disease 2019 (COVID-19) pandemic. Vaccination practices have started in different countries for community immunity. In this process, health authorities in different countries have preferred different type of COVID-19 vaccines. Inactivated COVID-19 vaccine is one of these options and has been administered to more than 7 million people in Turkey. Inactivated vaccines are generally considered safe. Kounis syndrome (KS) is a rare clinical condition defined as the co-existence of acute coronary syndromes and allergic reactions.

Case Report We present the case of a 41-year-old woman with no cardiovascular risk factors who was admitted at our emergency department with flushing, palpitation, dyspnea, and chest pain 15 min after the first dose of inactivated CoronaVac (Sinovac Life Sciences, Beijing, China). Electrocardiogram (ECG) showed V4-6 T wave inversion, and echocardiography revealed left ventricular wall motion abnormalities. Troponin-I level on arrival was elevated. Coronary angiography showed no sign of coronary atherosclerosis. She was diagnosed with type 1 KS. The patient's symptoms resolved and she was discharged from hospital in a good condition.

Why Should an Emergency Physician Be Aware of This? To the best of our knowledge, this is the first case of allergic myocardial infarction secondary to inactivated coronavirus vaccine. This case demonstrates that KS can occur after inactivated virus vaccine against COVID-19. Although the risk of severe allergic reaction after administration of CoronaVac seems to be very low, people who developed chest pain after vaccine administration should be followed by ECG and troponin measurements.

Kounis syndrome induced by contrast media: A case report and review of literature

Kounis syndrome (KS) is an acute coronary disorder associated with anaphylactic reactions. The purpose of this report is to identify the features of KS triggered by contrast media on the basis of our experience and from literature review.

We have described a case and literature review of KS triggered by injection of contrast media. Including the present case, we reviewed eleven cases of KS. Six cases developed KS in diagnostic radiology departments.

KS could be induced by intravenous injection of contrast media in the radiology department. Radiologists should recognize this critical condition to ensure appropriate management.

Adverse cardiac events to monoclonal antibodies used for cancer therapy: The risk of Kounis syndrome

Monoclonal antibodies are currently used in the treatment of neoplastic, hematological, or inflammatory diseases, a practice that is occasionally associated with a variety of systemic and cutaneous adverse events. Cardiac adverse events include cardiomyopathy, ventricular dysfunction, arrhythmias, arrests, and acute coronary syndromes, such as acute myocardial infarction and vasospastic angina pectoris. These events generally follow hypersensitivity reactions including cutaneous erythema, pruritus chills, and precordial pain. Recently, IgE specific for therapeutic monoclonal antibodies have been detected, pointing to the existence of hypersensitivity and Kounis hypersensitivity-associated syndrome. Therefore, the careful monitoring of cardiovascular events is of paramount importance in the course of monoclonal antibody-based therapies. Moreover, further studies are needed to elucidate the pathophysiology of cardiovascular adverse events elicited by monoclonal antibodies and to identify preventive, protective, and therapeutic measures.

Management of Kounis syndrome: two case reports

Background

Kounis syndrome corresponds to the occurrence of myocardial injury following an allergic insult. This syndrome is infrequent, and is not well known. In consequence, it is usually misdiagnosed leading to inappropriate treatment. The current literature is limited to case studies and there are no international recommendations concerning this topic.

Case presentation

We discussed, through two case reports, the clinical presentation and the management of a 60-year-old North African man and a 45-year-old North African man presenting with chest pain suggesting acute coronary syndrome following anaphylactic reaction. Triggering factors were a drug in the first case and herbal dermal exposure in the second. A clinical examination and electrocardiogram revealed anaphylactic reaction associated with myocardial infarction. Appropriate management of these two life-threatening conditions allowed an improvement in our patients’ condition and their transfer to specialized units.

Conclusions

Although Kounis syndrome is a rare phenomenon, physicians should be aware of its physiopathological mechanisms in order to treat it appropriately. The difficulty lies in the fact that the treatment of either of the two associated entities may worsen the other injury.

Electronic supplementary material

The online version of this article (doi:10.1186/s13256-017-1310-7) contains supplementary material, which is available to authorized users.

COVID-19 Disease, Women's Predominant Non-Heparin Vaccine-Induced Thrombotic Thrombocytopenia and Kounis Syndrome: A Passepartout Cytokine Storm Interplay

Coronavirus disease 2019 (COVID-19) and severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) constitute one of the deadliest pandemics in modern history demonstrating cardiovascular, gastrointestinal, hematologic, mucocutaneous, respiratory, neurological, renal and testicular manifestations and further complications. COVID-19-induced excessive immune response accompanied with uncontrolled release of cytokines culminating in cytokine storm seem to be the common pathogenetic mechanism of these complications. The aim of this narrative review is to elucidate the relation between anaphylaxis associated with profound hypotension or hypoxemia with pro-inflammatory cytokine release. COVID-19 relation with Kounis syndrome and post-COVID-19 vaccination correlation with heparin-induced thrombocytopenia with thrombosis (HITT), especially serious cerebral venous sinus thrombosis, were also reviewed. Methods: A current literature search in PubMed, Embase and Google databases was performed to reveal the pathophysiology, prevalence, clinical manifestation, correlation and treatment of COVID-19, anaphylaxis with profuse hypotension, Kounis acute coronary syndrome and thrombotic events post vaccination. Results: The same key immunological pathophysiology mechanisms and cells seem to underlie COVID-19 cardiovascular complications and the anaphylaxis-associated Kounis syndrome. The myocardial injury in patients with COVID-19 has been attributed to coronary spasm, plaque rupture and microthrombi formation, hypoxic injury or cytokine storm disposing the same pathophysiology with the three clinical variants of Kounis syndrome. COVID-19-interrelated vaccine excipients as polysorbate, polyethelene glycol (PEG) and trometamol constitute potential allergenic substances. Conclusion: Better acknowledgement of the pathophysiological mechanisms, clinical similarities, multiorgan complications of COVID-19 or other viral infections as dengue and human immunodeficiency viruses along with the action of inflammatory cells inducing the Kounis syndrome could identify better immunological approaches for prevention, treatment of the COVID-19 pandemic as well as post-COVID-19 vaccine adverse reactions.

An Acute Adverse Reaction with ST Elevation Induced by Magnetic Resonance Contrast Media: Kounis Syndrome

A 78-year-old man with mild coronary arteriosclerosis on coronary CT angiography underwent MRI of the prostate with the administration of Gadolinium-based contrast agent (GBCA) (gadopentetate dimeglumine). He developed acute coronary syndrome immediately after the intravenous injection of GBCA, and recovered after the administration of nitroglycerine, atropine sulfate, and hydrocortisone. He was discharged on the ninth day of hospitalization without recurrent chest symptoms. This is the second reported case of Kounis syndrome caused by GBCA. Kounis syndrome caused by MR contrast media is rare, but we should recognize that all contrast agents have the potential to cause Kounis syndrome.

The utility of cardiac magnetic resonance imaging in Kounis syndrome

Introduction

Current diagnostic measurements used to assess myocardial involvement in Kounis syndrome, such as electrocardiography (ECG), cardiac enzymes, and troponin levels, are relatively insensitive to small but potentially significant functional change. According to our review of the literature, there has been no study using magnetic resonance imaging (MRI) on Kounis syndrome except for one case report.

Aim

To identify the findings of dynamic contrast-enhanced magnetic resonance imaging (CE-MRI) in patients with Kounis syndrome (KS) type 1.

Material and methods

We studied 26 patients (35 ±11.5 years, 53.8% male) with known or suspected KS type 1. The patients underwent precontrast, first-pass, and delayed enhancement cardiac MRI (DE-MRI). Contrast enhancement patterns, edema, hypokinesia, and localization for myocardial lesions were evaluated in all KS type 1 patients.

Results

Contrast-enhanced magnetic resonance imaging demonstrated an early-phase subendocardial contrast defect, and T2-weighted images showed high-signal intensity consistent with edema in lesion areas. None of the lesion areas was found upon contrast enhancement on DE-MRI. The area of early-phase subendocardial contrast defect was reported as follows: the interventricular septum in 14 (53.8%) patients, the left ventricular lateral wall in 8 (30.7%), and the left ventricular apex in 4 (15.4%).

Conclusions

Dynamic cardiac MR imaging is a reliable tool for assessing cardiac involvement in Kounis syndrome. Delayed contrast-enhanced images show normal washout in the subendocardial lesion area in patients with Kounis syndrome type 1.

Some Perspectives on Hypersensitivity to Coronary Stents

The development of coronary stents has represented a revolution in the treatment of coronary heart disease. Beyond their many advantages, stents also have their limitations and complications. Allergic reactions to coronary stents are more common than acknowledged. These stented patients are exposed to foreign substances inserted in direct contact with the coronary intima. Hypersensitivity to stent components and drugs prescribed after stent insertion together with any environmental exposure seem to contribute to these adverse reactions. Patients can present to the hospital with a wide range of symptoms and multiple complications, the most important ones being instent restenosis and stent thrombosis. Although not very common (and not always easy to identify), allergic reactions after coronary or peripheral stents should be taken into account. Careful selection of patients (for elective stent implantation) depending on the propensity to allergies, although hard to achieve, represents a key factor in reducing the number of these complications.

Contrast Media Induced Kounis Syndrome: A Case Report

Kounis syndrome is a rare anaphylactic reaction leading to coronary spasm, acute plaque rupture, or intrastent stenosis. Many types of medicine or environmental factors can potentially trigger Kounis syndrome by mast cell allergic reactions. In severe Kounis syndrome, reduced blood pressure or cardiac arrest may be accompanying symptoms. The treatment strategy for Kounis syndrome is usually difficult due to both cardiac dysfunction and allergic reactions. The delay to intervention to break the vicious circle may cause catastrophic complications. Therefore, early diagnosis is critical for physicians to outline detailed etiology for prevention and treat the cardiac and allergic symptoms in a timely manner. Here, we describe a case presenting rare severe Kounis syndrome with cardiac arrest which occurred after the administration of a contrast media.

Capecitabine-induced ventricular fibrillation arrest: Possible Kounis syndrome

We report the case of capecitabine-induced ventricular fibrillation arrest, possibly secondary to type I Kounis syndrome. A 47-year-old man with a history of T3N1 moderately differentiated adenocarcinoma of the colon, status-post sigmoid resection, was started on adjuvant capecitabine approximately five months prior to presentation of cardiac arrest secondary to ventricular fibrillation. An electrocardiogram (EKG) revealed ST segment elevation on the lateral leads and the patient was taken emergently to the cardiac catheterization laboratory. The catheterization revealed no angiographically significant stenosis and coronary artery disease was ruled out. After ruling out other causes of cardiac arrest, the working diagnosis was capecitabine-induced ventricular fibrillation arrest. As such, an inflammatory work up was sent to evaluate for the possibility of a capecitabine hypersensitivity, or Kounis syndrome, and is the first documented report in the literature to do so when evaluating Kounis syndrome. Immunoglobulin E (IgE), tryptase, and C-reactive protein were normal but histamine, interleukin (IL)-6, and IL-10 were elevated. Histamine elevation supports the suspicion that our patient had type I Kounis syndrome. Naranjo adverse drug reaction probability scale indicates a probable adverse effect due to capecitabine with seven points. A case of capecitabine-induced ventricular fibrillation arrest is reported, with a potential for type 1 Kounis syndrome as an underlying pathology supported by immunologic work up.

Kounis syndrome resulting from anaphylaxis to diclofenac

“Kounis syndrome” refers to acute coronary syndromes of varying degree (myocardial ischaemia to infarction) induced by mast cell activation as a result of allergic and anaphylactic reactions. ST-segment elevated myocardial infarction is a rare complication that can occur even in patients with normal coronary arteries due to anaphylactic reactions. We present a case that developed acute myocardial infarction following a diclofenac sodium-induced anaphylaxis. The patient did not have any previous coronary artery disease, but there was a temporal relationship with development of the anaphylactic reaction due to diclofenac sodium and the cardiac event. The patient was managed conservatively and the recovery was uneventful.