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

Case Report: A case of Kounis syndrome induced by iodine contrast agent during coronary angiography

Kounis Syndrome (KS), a seldom-seen adverse reaction to iodine contrast agents, has an incidence that remains unclear. At present, there are no unified guidelines for managing KS either nationally or internationally. Ioversol, a new triiodinated hypotonic nonionic contrast agent, is commonly used in cardiovascular Computed Tomography (CT) and vascular imaging for diagnostic purposes. Its principal adverse reactions encompass fever, dermatological responses, convulsions, respiratory distress, hypersensitivity reactions including KS, and acute renal injury. This paper documents a case of KS induced by an iodine contrast agent during coronary angiography and, at the same time, searches for related literature and carries out a summary analysis in an attempt to provide a dependable reference for clinicians to make accurate diagnoses and treatments.

Adrenaline, Takotsubo, Anaphylaxis, and Kounis Syndrome (ATAK) Complex Unveiled: Integrating Takotsubo and Kounis Syndromes in the Context of Chemotherapy-Related Anaphylaxis

The convergence of takotsubo and Kounis syndromes, collectively referred to as the "ATAK complex" (short for adrenaline, takotsubo, anaphylaxis, and Kounis syndrome), poses a unique and challenging clinical scenario, especially in the context of chemotherapy-related anaphylaxis. We present a case report involving a 63-year-old woman undergoing chemotherapy for endometrial adenocarcinoma who experienced anaphylactic symptoms during treatment. Immediate administration of epinephrine was followed by the emergence of ST elevation, a reduced left ventricular ejection fraction, and wall motion abnormalities indicative of stress-induced cardiomyopathy. Detailed investigations revealed normal coronary arteries, prompting further exploration into the intricacies of the ATAK complex. Notably, the administration of intravenous rather than intramuscular epinephrine was identified as a contributing factor. This case underscores the critical importance of recognizing and managing the ATAK complex promptly, emphasizing the need for refined diagnostic and treatment guidelines. The interplay between adrenaline, takotsubo, anaphylaxis, and Kounis syndrome necessitates a nuanced approach, urging healthcare professionals to exercise caution and adhere to recommended administration routes. Increased awareness of the ATAK complex is imperative for optimizing patient outcomes and guiding therapeutic interventions in similar clinical scenarios. Further research is warranted to elucidate the underlying mechanisms and refine strategies for the effective management of this intricate syndrome.

Kounis syndrome: ST elevations in the setting of anaphylaxis

Acute coronary syndrome in the presence of an allergic reaction is known as Kounis syndrome, which is an underdiagnosed disorder and has nuances regarding management. We present a patient brought to the hospital as an ST segment elevation myocardial infarction (STEMI) alert in the setting of an allergic reaction triggered by food.

A Rare Case of Kounis Syndrome Secondary to Infliximab

Kounis syndrome (KS) is an acute coronary syndrome triggered by allergic or anaphylactic reactions. It manifests as coronary artery vasospasm, acute myocardial infarction, or coronary stent thrombosis, resulting from inflammatory cytokine release and inappropriate activation of platelets and mast cells. We present a case of an 85-year-old male with Crohn's disease who suffered anaphylaxis during infliximab infusion, culminating in non-ST myocardial infarction (NSTEMI). The patient's symptoms were effectively managed with epinephrine and diphenhydramine, and KS secondary to infliximab was diagnosed. Diagnosing KS can be challenging due to the overlapping signs of an allergic reaction and myocardial infarction. Timely recognition and appropriate management of KS are crucial to enhance patient outcomes. Therefore, healthcare providers should maintain a high index of suspicion for KS in patients with acute coronary syndromes linked to allergic reactions to optimize care and minimize potential risks. This case report underscores the significance of prompt intervention and awareness of Kounis syndrome in clinical practice.

Refractory cardiac arrest caused by type I Kounis syndrome treated with adrenaline and nicorandil: A case report

RATIONALE

Kounis syndrome is a rare but life-threatening anaphylactic reaction that can lead to acute coronary syndrome and cardiac arrest, and requires prompt diagnosis. Adrenaline, which is used to treat anaphylaxis, may cause coronary vasoconstriction and worsen ischemia, whereas coronary vasodilators may dilate systemic vessels and exacerbate hypotension. Delayed diagnosis of Kounis syndrome and inadequate therapeutic intervention may thus lead to a poor outcome.

PATIENT CONCERNS

A 59-year-old man was treated for sepsis due to a liver abscess. Following administration of daptomycin, the patient developed severe anaphylactic shock leading to refractory cardiac arrest. Because conventional cardiopulmonary resuscitation was ineffective, extracorporeal cardiopulmonary resuscitation was considered as an alternative approach.

DIAGNOSES

On bedside monitoring during cardiopulmonary resuscitation, unexpected ST-segment elevation was found on lead II electrocardiogram. Accordingly, the patient was clinically diagnosed with Kounis syndrome.

INTERVENTIONS

Nicorandil (6 mg/h), a coronary vasodilator with minimal blood pressure effects, was administered along with high doses of vasopressors, including adrenaline 0.2 µg/kg/min.

OUTCOMES

After the initiation of nicorandil administration, the patient achieved return of spontaneous circulation and did not require extracorporeal cardiopulmonary resuscitation. Based on the elevated serum tryptase level, normal creatine kinase-MB range, and lack of stenosis on coronary angiography, the patient was definitively diagnosed with type I (coronary vasospasm) Kounis syndrome. He was subsequently transferred to the referring hospital without neurological sequelae.

LESSONS

If anaphylaxis leads to refractory shock and cardiac arrest, ischemic changes on the electrocardiogram should be investigated to identify underlying Kounis syndrome. In addition to adrenaline, coronary dilators are the definitive treatment. Nicorandil may be a useful treatment option because of its minimal effect on blood pressure.

Identification of the biological processes, immune cell landscape, and hub genes shared by acute anaphylaxis and ST-segment elevation myocardial infarction

Background: Patients with anaphylaxis are at risk for ST-segment elevation myocardial infarction (STEMI). However, the pathological links between anaphylaxis and STEMI remain unclear. Here, we aimed to explore shared biological processes, immune effector cells, and hub genes of anaphylaxis and STEMI. Methods: Gene expression data for anaphylactic (GSE69063) and STEMI (GSE60993) patients with corresponding healthy controls were pooled from the Gene Expression Omnibus database. Differential expression analysis, enrichment analysis, and CIBERSORT were used to reveal transcriptomic signatures and immune infiltration profiles of anaphylaxis and STEMI, respectively. Based on common differentially expressed genes (DEGs), Gene Ontology analysis, cytoHubba algorithms, and correlation analyses were performed to identify biological processes, hub genes, and hub gene-related immune cells shared by anaphylaxis and STEMI. The robustness of hub genes was assessed in external anaphylactic (GSE47655) and STEMI (GSE61144) datasets. Furthermore, a murine model of anaphylaxis complicated STEMI was established to verify hub gene expressions. The logistic regression analysis was used to evaluate the diagnostic efficiency of hub genes. Results: 265 anaphylaxis-related DEGs were identified, which were associated with immune-inflammatory responses. 237 STEMI-related DEGs were screened, which were involved in innate immune response and myeloid leukocyte activation. M0 macrophages and dendritic cells were markedly higher in both anaphylactic and STEMI samples compared with healthy controls, while CD4⁺ naïve T cells and CD8⁺ T cells were significantly lower. Enrichment analysis of 33 common DEGs illustrated shared biological processes of anaphylaxis and STEMI, including cytokine-mediated signaling pathway, response to reactive oxygen species, and positive regulation of defense response. Six hub genes were identified, and their expression levels were positively correlated with M0 macrophage abundance and negatively correlated with CD4⁺ naïve T cell abundance. In external anaphylactic and STEMI samples, five hub genes (IL1R2, FOS, MMP9, DUSP1, CLEC4D) were confirmed to be markedly upregulated. Moreover, experimentally induced anaphylactic mice developed impaired heart function featuring STEMI and significantly increased expression of the five hub genes. DUSP1 and CLEC4D were screened as blood diagnostic biomarkers of anaphylaxis and STEMI based on the logistic regression analysis. Conclusion: Anaphylaxis and STEMI share the biological processes of inflammation and defense responses. Macrophages, dendritic cells, CD8⁺ T cells, and CD4⁺ naïve T cells constitute an immune cell population that acts in both anaphylaxis and STEMI. Hub genes (DUSP1 and CLEC4D) identified here provide candidate genes for diagnosis, prognosis, and therapeutic targeting of STEMI in anaphylactic patients.

Kounis syndrome in a patient with multivessel coronary artery disease and DRESS

A 68-year-old man was admitted with ST-elevation myocardial infarction and intense rash. He was diagnosed with type 2 Kounis syndrome elicited by drug reaction with eosinophilia and systemic symptoms (DRESS) syndrome and received complete revascularization with percutaneous coronary intervention. This case highlights the complex pathophysiology of acute coronary syndrome, and the elusive link between coronary occlusion and ST-segment deviations at ECG.

Kounis Syndrome Associated With the Use of Diclofenac

BACKGROUND

Diclofenac is a widely used analgesic, anti-inflammatory, antipyretic drug. In several case reports, its use was associated with the occurrence of Kounis syndrome. The aim of this review was to investigate and summarize published cases of Kounis syndrome suspected to be associated with the use of diclofenac.

METHODS

Electronic searches were conducted in PubMed/MEDLINE, Scopus, Web of Science, Google Scholar, and the Serbian Citation Index.

RESULTS

Twenty publications describing the 20 patients who met inclusion criteria were included in the systematic review. Specified patient ages ranged from 34 to 81 years. Eighteen (90.0%) patients were male. Five patients (25.0%) reported a previous reaction to diclofenac. Reported time from the used dose of diclofenac to onset of the first reaction symptoms ranged from immediately to 5 hours. Diclofenac caused both type I and type II Kounis syndrome, with the presence of various cardiovascular, gastrointestinal, dermatologic, and respiratory signs and symptoms. Most patients experienced hypotension (n = 15 [75.0%]) and chest pain (n = 12 [60.0%]). The most frequently reported finding on electrocardiogram was ST-segment elevations (n = 17 [85.0%]). Coronary angiogram showed normal coronary vessels in 9 patients (45.0%), with some pathologic findings in 8 patients (40.0%).

CONCLUSION

Clinicians should be aware that Kounis syndrome may be an adverse effect of diclofenac. Prompt recognition and withdrawal of the drug, with treatment of both allergic and cardiac symptoms simultaneously, is important.

Kounis Syndrome: A Sting to the Heart

A 67-year-old woman experienced pruritus, an urticarial rash, and acute, pressure-like chest pain following an insect sting. Initial electrocardiographic findings were notable for ST-segment elevations in the inferior leads without reciprocal changes, but a follow-up electrocardiogram showed pronounced ST-segment elevations in the inferior leads with reciprocal changes. Her troponin I level peaked at 3,053 pg/mL, and she was transferred to a large academic center for percutaneous coronary intervention. Balloon angioplasty was performed for 95% thrombotic occlusion of the mid-right coronary artery, and a drug-eluting stent was placed. The patient's presentation was consistent with type II Kounis syndrome.

Is Adrenaline Always the First Choice Therapy of Anaphylaxis? An Allergist-cardiologist Interdisciplinary Point of View

Worldwide, adrenaline is considered the first choice therapy in the international guidelines for the management of anaphylaxis. However, the heart and cardiovascular apparatus are strongly involved in anaphylaxis; for that reason, there are some cardiac conditions and certain anaphylaxis patterns that make epinephrine use problematic without adequate heart monitoring. The onset of Kounis syndrome, takotsubo cardiopathy, or the paradoxical anaphylaxis require great attention in the management of anaphylaxis and adrenaline administration by clinicians, who should be aware of the undervalued evolution of anaphylaxis and the potential cardiologic complications of epinephrine administration. Numerous case reports and studies describe the unexpected onset of cardiac diseases following epinephrine treatment, despite the latter being the recommended therapy for anaphylaxis. Our review suggests that future anaphylaxis guidelines should incorporate cardiovascular specialists since the treatment of Kounis syndrome or takotsubo cardiopathy requires cardiologist skills.

Angina and Arrhythmia Symptoms Following Multiple Bee Stings: Kounis Syndrome

Kounis syndrome (KS) is an acute coronary syndrome including coronary spasm, acute myocardial infarction, and stent thrombosis preceded by an anaphylactic, anaphylactoid, allergic, or hypersensitivity injury. In this case presentation, we discussed Type I and Type II KS. Case 1 was a 72-y-old man who presented to the emergency department with allergic symptoms and chest pain that developed after multiple bee stings. Electrocardiography showed ST depression in the lateral leads. Case 2 was a 42-y-old woman who presented to the emergency department with complaints of chest pain, dizziness, and presyncope that developed after multiple bee stings. Mobitz Type II Block with right bundle branch block was observed in 42 beats·min-1 in the electrocardiography. Both patients were first treated for allergic reaction. Although early percutaneous coronary intervention was performed for graft thrombosis in Case 1, a permanent pacemaker was inserted in Case 2. The patients were discharged without any complications. Increasing physician awareness towards the existence of KS can prevent fatal outcomes with early diagnosis and treatment.

Case report: Cefoperazone-sulbactam induced Kounis syndrome and cardiogenic shock

Background

Kounis syndrome is a hypersensitive coronary artery disease caused by the body's exposure to allergens, which is induced by various drugs and environmental factors. This entity has been described primarily in isolated case reports and case series. We report a case of type III Kounis syndrome caused by cefoperazone-sulbactam.

Case presentation

A 79-year-old man who received an infusion of cefoperazone-sulbactam in Respiratory Department of our hospital for recurrent infections. 28 minutes later, he developed skin flushing of the trunk and extremities, soon followed by loss of consciousness and shock. With antianaphylaxis, pressor therapy, and fluid rehydration, the patient was admitted to the ICU for treatment. During which, he experienced recurrent ventricular fibrillation and a progressive increase in troponin I levels. The ECG of the patient showed that the ST segment elevation of lead II, III, avF, and V3R–V5R was 0.10–0.20 MV. An urgent coronary angiography showed an in-stent thrombosis in the middle part of the right coronary artery, occlusion of the distal flow with TIMI grade 0. The diagnosis was type III Kounis syndrome with cardiogenic shock. Despite aggressive treatment, the patient died on day 7 after ICU admission.

Conclusion

Kunis syndrome is a life-threatening disease, and therefore allergic reactions in patients with a history of cephalosporin allergy and coronary stent implantation should be considered and treated promptly.

Acute myocardial infarction due to Kounis syndrome: A case report

BACKGROUND

Acute myocardial infarction (AMI) can be induced by several factors. However, AMI induced by Kounis syndrome (an allergic reaction) is extremely rare and is highly susceptible to misdiagnosis.

CASE SUMMARY

A 70-year-old man presented after suffering an allergic reaction that caused chest pain triggered upon eating ice cream. Troponin I was found to be elevated, and an electrocardiogram showed ST-segment elevation. The diagnosis was AMI. He underwent two coronary angiographies, with one intravascular ultrasound during hospitalization showing no evidence of atherosclerotic coronary artery disease. The final diagnosis was vasospastic myocardial infarction due to Kounis syndrome. The patient was then treated with hydrocortisone and intravenous antihistamines, and his chest pain symptoms resolved.

CONCLUSION

Allergic reactions (such as Kounis syndrome) can cause serious damage to the heart. Physicians should be alert to the consequences and avoid misdiagnosis.

Recurrent Coronary Vasospasm: A Case of Kounis Syndrome from Anaphylaxis to Contrast Dye

Kounis syndrome is characterized by acute coronary syndrome due to coronary vasospasm or thrombosis following exposure to an allergic stimulus. The presentation can be compounded by cardiovascular collapse due to cardiogenic shock from coronary vasospasm and associated vasodilatory shock from anaphylaxis. A high index of suspicion is crucial for prompt initiation of treatment, which focuses on managing the allergic or anaphylactic process. Here we present a case of coronary vasospasm and anaphylactic shock due to contrast dye exposure during percutaneous coronary intervention of an unstable coronary lesion and its associated diagnostic and therapeutic challenges.

Allergy Associated Myocardial Infarction: A Comprehensive Report of Clinical Presentation, Diagnosis and Management of Kounis Syndrome

Kounis syndrome (KS) has been defined as acute coronary syndrome (ACS) in the context of a hypersensitivity reaction. Patients may present with normal coronary arteries (Type I), established coronary artery disease (Type II) or in-stent thrombosis and restenosis (Type III). We searched PubMed until 1 January 2020 for KS case reports. Patients with age <18 years, non-coronary vascular manifestations or without an established diagnosis were excluded. Information regarding patient demographics, medical history, presentation, allergic reaction trigger, angiography, laboratory values and management were extracted from every report. The data were pulled in a combined dataset. From 288 patients with KS, 57.6% had Type I, 24.7% Type II and 6.6% Type III, while 11.1% could not be classified. The mean age was 54.1 years and 70.6% were male. Most presented with a combination of cardiac and allergic symptoms, with medication being the most common trigger. Electrocardiographically, 75.1% had ST segment elevation with only 3.3% demonstrating no abnormalities. Coronary imaging was available in 84.8% of the patients, showing occlusive lesions (32.5%), vascular spasm (16.2%) or normal coronary arteries (51.3%). Revascularization was pursued in 29.4% of the cases. In conclusion, allergic reactions may be complicated by ACS. KS should be considered in the differential diagnosis of myocardial infarction with non-obstructive coronary arteries.

A Case of Kounis Syndrome Presenting as Coronary Artery Spasm Associated with Acetaminophen Infusion

Patient: Male, 38-year-old

Final Diagnosis: Myocardial Infarction

Symptoms: Chest discomfort • dyspnea • hypotension

Medication: —

Clinical Procedure: —

Specialty: Allergology • Cardiology

Should beta-blockers be continued as a treatment for myocardial infarction in the case of Kounis syndrome?

A 71-year-old male patient reported to our hospital with anaphylactic shock, and the following two issues were focused in this case. First, he was resistant to adrenaline because of taking beta-blocker, and shock was repeated until glucagon administration was initiated. Second, he developed acute coronary syndrome. Two mechanisms contributing to Kounis syndrome were differentiated: 1) adrenaline induced coronary spasm and platelet activation or 2) a mismatch between oxygen supply and demand due to an allergic reaction. Beta-blocker therapy was discontinued because his cardiac function was preserved. Secondary preventive beta-blockers in recovering myocardial infarction with severe anaphylaxis history should be carefully considered.

Bee Attack or Heart Attack: Kounis Syndrome

Kounis syndrome (KS) is defined as an allergic or hypersensitivity reaction leading to coronary vasospasm and acute coronary syndrome. The inflammatory mediators released during the body's reaction to an allergen causes vasoconstriction, plaque rupture, platelet aggregation, and even thrombosis of an existing coronary stent. Over the years, many allergens including drugs, environmental exposures, and animal and insect bites have been implicated in KS. Patients may present with elevated cardiac enzymes and electrocardiographic changes. We describe a case of a patient with no prior cardiac history who presented to the emergency department seeking treatment after multiple bee stings. The patient had non-specific electrocardiogram (ECG) changes and elevated cardiac enzymes consistent with a non-ST-elevation myocardial infarction. The patient underwent a pharmacologic stress test and myocardial perfusion imaging, which showed a perfusion defect consistent with ischemia. Selective right and left coronary angiography revealed a critical lesion at the proximal left circumflex artery. This was managed with percutaneous coronary intervention utilizing a bare-metal stent.

Therapeutic Efficacy and Safety of Safflower Injection in the Treatment of Acute Coronary Syndrome

Background

Safflower injection (SFI), a popular Chinese patent drug, is commonly used to treat acute coronary syndromes (ACSs) in China. The research seeks to scientifically estimate the clinical efficacy of SFI for ACS patients.

Methods

Eight electronic databases were retrieved for eligible research from the founding date to September 8, 2020. Odds ratio (OR) was adopted to assess the total effective rate, ECG improvement, and adverse reaction, and mean difference (MD) was used for assessing the hemorheology indexes as well as the LVEF.

Results

Sixteen randomized controlled trials involving 1620 sufferers with ACS were incorporated. The outcomes showed that, in comparison to conventional medication alone, SFI combined with conventional treatment remarkably enhanced the total effective rate (OR = 3.66, 95% CI [2.73, 4.90], P < 0.00001), ECG improvement (OR = 2.85, 95% CI [2.04, 3.99], P < 0.00001), and LVEF (MD = 5.13, 95% CI [3.73, 6.53], P < 0.00001). Moreover, SFI combined with conventional treatment significantly decreased hemorheology indexes including BV (MD = −0.95, 95% CI [−1.76, −0.13], P=0.02), HCT (MD = −2.37, 95% CI [−3.25, −1.50], P < 0.00001), FIB (MD = −0.44, 95% CI [−0.60, −0.29], P < 0.00001), and PAR (OR = −7.65, 95% CI [−10.16, −5.14], P < 0.00001). However, no notable contrast was observed to link the experimental and the control team for PV (MD = −0.42, 95% CI [−0.83, 0.00], P=0.05) and adverse reactions (OR = 0.59, 95% CI [0.13, 2.74], P=0.50).

Conclusion

Despite the limitations that existed in this meta-analysis, the outcomes demonstrated that SFI and conventional combined medication is an effective and relatively safe therapy for ACS sufferers.

Delayed Acute Coronary Syndrome Caused by Multiple Bee Stings: A Rare Case of Kounis Syndrome

A 51-year-old female patient was admitted to our hospital for medical evaluation and treatment of a syncopal episode following multiple bee stings. The syncopal episode was attributed to an allergic reaction and the patient was treated with intravenous hydration and anti-histamines. Twenty-four hours later, the patient manifested an acute coronary syndrome with chest discomfort, electrocardiographic disorders, and myocardial enzyme motility (including troponin). Coronary angiography was performed without revealing pathological findings and she was diagnosed with Kounis syndrome type I. The management of the patient included administration of single antiplatelet therapy combined with a calcium channel blocker (CCB). The patient follow-up was uncomplicated. In patients with Kounis syndrome type I undergoing a normal coronary angiography, in the absence of specific guidelines, single antiplatelet therapy and CCB may be a reasonable approach.

Epirubicin-induced Kounis syndrome

Background

Kounis syndrome is an acute coronary syndrome that appears in the setting of anaphylactic reaction or hypersensitivity. Many drugs and environmental exposures have been identified as potential offenders, and diagnosis and treatment can be challenging.

Case presentation

A 62-year-old man with recurrent bladder cancer underwent an intra-iliac artery epirubicin injection. After the injection, he developed chest pain and a systemic allergic reaction, with electrocardiographic alterations and elevated troponin-I levels. Emergent coronary angiography showed right coronary artery spasm and no stenosis of the other coronary arteries. This reaction was considered compatible with an allergic coronary vasospasm. A diagnosis of Kounis syndrome was made.

Conclusions

Kounis syndrome is common, but a prompt diagnosis is often not possible. This case is the first to suggest that an intraarterial epirubicin injection could potentially be one of its triggers. All physicians should be aware of the pathophysiology of this condition to better recognize it and start appropriate treatment; this will prevent aggravation of the vasospastic cardiac attacks and yield a better outcome.

Kounis Syndrome Leading to Cardiac Arrest After Iodinated Contrast Exposure

Immune-mediated coronary spasm, called Kounis syndrome (KS), is not rare but is underdiagnosed. In this report, we present a case of KS induced by iodinated contrast resulting in cardiac arrest, requiring temporary mechanical circulatory support. We show angiographic evidence of KS and outline commonly associated clinical features that may predict KS. (Level of Difficulty: Beginner.).

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.