Clinical Features, Course and Prognosis of Kounis Syndrome.

Background: Allergic myocardial infarction, known as Kounis Syndrome (KS), is a significant cause of acute coronary syndrome. However, the management and outcomes of KS are not clear. Thus, we aimed to investigate demographic characteristics, clinical features, laboratory findings, prognosis, and outcomes of patients with KS. Methods: Between January 2018 and December 2024, all consecutive patients who were diagnosed with KS were retrospectively analyzed. The precipitating factors, laboratory, ECG, and echocardiographic findings at presentation, in-hospital, and long-term outcomes were examined. Follow-up data were acquired from the hospital database and telephone interviews. Results: Twenty-eight patients with KS (18 men, mean age 47.7±14.3 years) were included in the study. Allergic symptoms such as pruritus, and cardiac symptoms such as chest pain, palpitation, and dyspnea were the most common presenting symptoms. Type 1 KS was the most frequent form (89.3%) of the disease. The most frequent triggering factor was drugs (71.4%), followed by a bee or insect stings (14.3%). Of the study population, 78.6% had left ventricular (LV) wall motion abnormality at presentation, which completely recovered in 92.9% of the patients within a few weeks. No cases of mortality occurred during the follow-up among patients with KS. Conclusion: This is the largest series of patients with KS. The results of this study showed that drugs and insect/hymenoptera stings were the most common triggering factors in KS. Compared to atherosclerotic acute coronary syndromes, in-hospital and long-term prognosis were better in patients with KS.