Kounis Syndrome in Clinical Practice: Insights from Clinical Case Series and Mechanistic Pathways

Kounis syndrome (KS) is a rare condition where hypersensitivity reactions trigger coronary vasospasm, destabilization of atherosclerotic plaques, or stent thrombosis, posing diagnostic and therapeutic challenges due to its overlap with acute coronary syndrome (ACS) and the absence of specific guidelines. This study reviews cases of KS from the Institute of Cardiovascular Disease to highlight clinical presentations, triggers, and treatment strategies. We analyzed four cases of KS treated at our institution between 2019 and 2024. Detailed clinical histories, laboratory findings, imaging studies, and treatment plans were reviewed. Patients were classified by KS subtype based on coronary anatomy and pathophysiological mechanisms. Management strategies were tailored to each subtype, combining myocardial revascularization, antiplatelet therapy, and treatment for allergic reactions. The series included two cases of Type I KS in patients with structurally normal coronary arteries and two cases of Type II KS involving pre-existing atherosclerosis. No Type III KS was observed. Triggers included insect stings, antibiotics, iodinated contrast agents, and anesthetics. Coronary angiography confirmed the diagnosis in all cases. Treatments included percutaneous coronary interventions, dual antiplatelet therapy, and prophylactic antihistamines or corticosteroids. All patients experienced favorable outcomes, although diagnostic delays were noted in cases with atypical presentations. KS remains underdiagnosed, especially in emergency settings where it mimics ACS. Early recognition and multidisciplinary management involving allergology and cardiology are crucial. Future research should focus on safer diagnostic tools, understanding the pathophysiology, and developing evidence-based preventive strategies. Increasing the awareness of KS and its inclusion in ACS differentials are essential to improving patient outcomes and preventing recurrences.