Background: Kounis syndrome is an acute coronary syndrome triggered by hypersensitivity reactions, which may result in coronary vasospasm, thrombosis, or stent-related complications. Case Summary: A 64-year-old male smoker with dyslipidemia and recently diagnosed urothelial carcinoma presented with exertional angina and underwent coronary angiography. Percutaneous coronary intervention was performed for a critical proximal–mid left anterior descending artery lesion using a drug-eluting stent. Immediately after stent deployment, the patient developed diffuse multivessel coronary vasospasm involving the left main stem, left anterior descending, and left circumflex arteries, accompanied by slow-flow/no-reflow phenomena and subsequent acute in-stent thrombosis. The clinical course rapidly progressed to ventricular arrhythmias and cardiogenic collapse. Despite transient return of spontaneous circulation after cardiopulmonary resuscitation, the patient developed fatal asystole during a repeat angiographic attempt. No cutaneous or respiratory allergic manifestations were observed. The abrupt onset of diffuse coronary dysfunction immediately following contrast exposure was suggestive of suspected Kounis syndrome, although mechanical causes and chemotherapy-related vasospasm could not be entirely excluded. Conclusions: Diffuse coronary vasospasm with multivessel dysfunction occurring abruptly after contrast exposure should raise suspicion for Kounis syndrome, even in the absence of overt allergic manifestations. Early recognition is essential to avoid misattribution to procedural complications and may be particularly important in patients with malignancy undergoing invasive coronary procedures.
Abdullah et al. (Thu,) studied this question.