Abstract
INTRODUCTION: Acute coronary syndrome (ACS) remains a leading cause of mortality and disability worldwide. Vulnerable plaques constitute a key pathological substrate underlying ACS. Although lipid-lowering therapy (LLT) is central to plaque stabilization and secondary prevention in ACS, a substantial proportion of patients fail to achieve recommended lipid targets, underscoring a persistent gap between guideline recommendations and real-world outcomes. Serial assessment of plaque morphology using high-resolution intracoronary imaging may provide clinically actionable guidance for individualized management. Here, we report a case in which a ruptured coronary plaque in a patient with acute myocardial infarction underwent progressive healing, remaining phenotypically vulnerable at early follow-up before ultimately evolving into a stable plaque under intensive lipid-lowering and dual antiplatelet therapy, as documented by serial optical coherence tomography (OCT). CASE PRESENTATION: A 52-year-old patient presented with acute chest pain and was diagnosed with ST-segment elevation myocardial infarction. Coronary angiography (CAG) and thrombus aspiration restored coronary flow, after which OCT evaluation was performed. A deferred stenting strategy was adopted, combined with intensive lipid-lowering therapy and dual antiplatelet therapy. At the 1-month follow-up, repeat CAG and OCT supported continued conservative management, and stent implantation was not performed. Over the subsequent year, the patient achieved sustained lipid control under close follow-up, without recurrent chest pain or other cardiac-related symptoms. Conservative management was continued without stent implantation. Serial OCT at 1 month and 1 year demonstrated a stepwise morphological transition of the culprit lesion: from an initially ruptured plaque to a healed but still vulnerable phenotype at early follow-up, and ultimately to a stable plaque phenotype at 1 year. CONCLUSION: Vulnerable plaques represent a principal pathological driver of acute coronary events. Sustained and effective LLT promotes plaque stabilization and regression, while serial OCT, owing to its high resolution and reproducibility, enables dynamic assessment of plaque morphology and supports individualized management in patients with ACS.