Recommended Citation
Leef M, Paolella G, Bikeyeva V, et al. Type III Kounis Syndrome Presenting as Inferior STEMI With In-Stent Thrombosis. Presented at Scientific Day; May 21, 2025; Park Ridge, IL.
Abstract
Introduction/Background:
Kounis Syndrome is a hypersensitivity-mediated acute coronary syndrome (ACS) classified into three types: Type I (coronary vasospasm), Type II (plaque rupture with thrombosis), and Type III (stent thrombosis). Type III is the rarest and presents significant challenges in percutaneous coronary intervention (PCI). We report a case of recurrent in-stent thrombosis following PCI, suspected to be due to Type III Kounis Syndrome.
Description:
A 67-year-old female with type 2 diabetes and hyperlipidemia presented with substernal chest pressure radiating to the left shoulder. Symptoms worsened with exertion but were not associated with dyspnea or indigestion. Electrocardiogram (EKG) showed an inferior ST-elevation myocardial infarction (STEMI), with troponin elevated to 1.7K. Emergent coronary angiography demonstrated a 99% stenosis in the mid-right coronary artery stenosis with acute occlusion, treated with a drug-eluting stent. Shortly after PCI, she developed recurrent chest pain, and repeat angiography revealed in-stent thrombosis requiring an additional stent and eptifibatide infusion. Post-procedure transthoracic echocardiogram showed an ejection fraction of 59% with basal inferoseptal and inferior wall hypokinesis. She later developed hypotension, dizziness, and a hemoglobin drop from 13.6 to 7.7 g/dL. CT imaging revealed a retroperitoneal hematoma. Given her history of contrast allergy and recurrent thrombosis, Type III Kounis Syndrome was suspected. She was stabilized on dual antiplatelet therapy with aspirin and prasugrel and managed conservatively, with plans for staged PCI of the left anterior descending artery.
Discussion:
Type III Kounis Syndrome occurs when allergic reactions induce coronary stent thrombosis through mast cell degranulation, leading to platelet activation and thrombus formation. This patient’s contrast allergy suggests a possible allergic trigger, highlighting the need for heightened clinical suspicion in post-PCI patients with recurrent thrombosis. Management involves addressing allergic mechanisms with corticosteroids and antihistamines alongside standard ACS therapy. This case emphasizes the need to recognize allergic reactions as potential contributors to adverse cardiac events, particularly in patients with known hypersensitivities.
Presentation Notes
Presented at Scientific Day; May 21, 2025; Park Ridge, IL.
Full Text of Presentation
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Document Type
Poster
Type III Kounis Syndrome Presenting as Inferior STEMI With In-Stent Thrombosis
Introduction/Background:
Kounis Syndrome is a hypersensitivity-mediated acute coronary syndrome (ACS) classified into three types: Type I (coronary vasospasm), Type II (plaque rupture with thrombosis), and Type III (stent thrombosis). Type III is the rarest and presents significant challenges in percutaneous coronary intervention (PCI). We report a case of recurrent in-stent thrombosis following PCI, suspected to be due to Type III Kounis Syndrome.
Description:
A 67-year-old female with type 2 diabetes and hyperlipidemia presented with substernal chest pressure radiating to the left shoulder. Symptoms worsened with exertion but were not associated with dyspnea or indigestion. Electrocardiogram (EKG) showed an inferior ST-elevation myocardial infarction (STEMI), with troponin elevated to 1.7K. Emergent coronary angiography demonstrated a 99% stenosis in the mid-right coronary artery stenosis with acute occlusion, treated with a drug-eluting stent. Shortly after PCI, she developed recurrent chest pain, and repeat angiography revealed in-stent thrombosis requiring an additional stent and eptifibatide infusion. Post-procedure transthoracic echocardiogram showed an ejection fraction of 59% with basal inferoseptal and inferior wall hypokinesis. She later developed hypotension, dizziness, and a hemoglobin drop from 13.6 to 7.7 g/dL. CT imaging revealed a retroperitoneal hematoma. Given her history of contrast allergy and recurrent thrombosis, Type III Kounis Syndrome was suspected. She was stabilized on dual antiplatelet therapy with aspirin and prasugrel and managed conservatively, with plans for staged PCI of the left anterior descending artery.
Discussion:
Type III Kounis Syndrome occurs when allergic reactions induce coronary stent thrombosis through mast cell degranulation, leading to platelet activation and thrombus formation. This patient’s contrast allergy suggests a possible allergic trigger, highlighting the need for heightened clinical suspicion in post-PCI patients with recurrent thrombosis. Management involves addressing allergic mechanisms with corticosteroids and antihistamines alongside standard ACS therapy. This case emphasizes the need to recognize allergic reactions as potential contributors to adverse cardiac events, particularly in patients with known hypersensitivities.
Affiliations
Advocate Lutheran General Hospital