BACKGROUND: Paradoxical coronary artery embolism (PCAE) may be responsible for up to 25% of acute coronary events in patients under 35 years old. CASES SUMMARY: We report 2 cases of acute myocardial infarction (AMI) caused by suspected PCAE through a patent foramen ovale (PFO). In the first patient, emergency coronary angiography showed a thrombus occluding the distal diagonal branch of the left anterior descending artery in an otherwise normal coronary circulation. No angiographic evidence of coronary embolism or coronary artery disease was present in the second patient, who presented a cryptogenic cerebral ischemic event shortly after AMI. DISCUSSION: The angiographic evidence of coronary artery thrombus without atherosclerotic lesions in one patient and the cryptogenic stroke after AMI in the other patient suggest that PFO was the underlying pathophysiological mechanism of the acute coronary syndrome. TAKE-HOME MESSAGE: Our cases support the pathophysiologic role of PFO in acute coronary syndrome patients with normal coronary arteries.
Onorato et al. (2026) studied this question.