Title : Recurrent myocardial infarction caused by under-expanded and malpositioned coronary stent identified by OCT
Abstract:
Background: Late stent-related complications such as under-expansion and malapposition are associated with recurrent myocardial infarction and stent thrombosis. These mechanical issues may be angiographically subtle, necessitating intravascular imaging for accurate diagnosis.
Case Summary: We report the case of a 75-year-old woman with a history of multivessel coronary artery disease, previous non-ST elevation myocardial infarctions (NSTEMIs) in 2021 and 2023, and prior drug-eluting stent (DES) implantation in the left anterior descending artery (LAD). She presented in 2025 with recurrent chest pain and dynamic troponin elevation (peak 1500 ng/L). Electrocardiography demonstrated subtle anterior ischemic changes. Coronary angiography revealed patent LAD stents with intraluminal thrombus at the proximal segment, raising suspicion for a mechanical stent issue.
Optical coherence tomography (OCT) identified significant stent under-expansion and incomplete strut apposition, with struts visibly protruding into the vessel lumen. Targeted percutaneous coronary intervention was performed using high-pressure non-compliant balloon dilatation, resulting in improved stent expansion and apposition. Post-procedural OCT confirmed satisfactory mechanical correction. The patient had no recurrent symptoms, demonstrated preserved myocardial function, and was discharged on optimized medical therapy.
Discussion: This case underscores the diagnostic and therapeutic value of OCT in detecting occult stent failure contributing to late thrombotic events. Angiographically inconspicuous mechanical complications can be clarified with high-resolution intravascular imaging, allowing for precision-guided interventions. Adequate stent sizing and expansion at the index PCI remain paramount to long-term success.
Conclusion: Recurrent ischemia in stented segments should prompt a low threshold for intravascular imaging. OCT is an indispensable tool in diagnosing and managing late stent failure, guiding effective re-intervention and improving patient outcomes.
Keywords: Stent Thrombosis, Optical Coherence Tomography, Coronary Artery Disease, Under-Expanded Stent, Intravascular Imaging, PCI Complication.
