Abstract / Summary
Background: In-stent restenosis (ISR) remains a major limitation of contemporary percutaneous coronary intervention (PCI), particularly in patients with diabetes mellitus and complex coronary anatomy. In addition to anatomical and metabolic factors, inappropriate lesion selection and preparation may contribute to adverse outcomes and repeated revascularization. Case Summary: A 44-year-old man with insulin-treated type 2 diabetes mellitus, arterial hypertension, and dyslipidemia presented with non-ST-segment elevation myocardial infarction. His recent cardiovascular history included multiple PCI procedures with drug-eluting stent (DES) implantation in the left anterior descending and circumflex arteries. Early recurrent ISR developed and progressed to involve the left main coronary artery (LMCA) bifurcation, with rapid evolution toward multilayer restenosis despite repeat drug-coated balloon (DCB) angioplasty and additional stent implantation. Given the complex coronary anatomy (residual SYNTAX score 32) and repeated PCI failure, the Heart Team recommended coronary artery bypass grafting. However, early graft degeneration and progression of native coronary disease led to recurrent angina. Subsequent intravascular ultrasound (IVUS)-guided PCI using a hybrid strategy (DCB and DES) resulted in favorable short-term outcomes, with no significant restenosis at 6- and 12-month follow-up. Conclusions: This case illustrates how recurrent restenosis may develop despite ischemia-supported PCI when complex bifurcation anatomy and mechanical factors such as stent underexpansion remain insufficiently characterized. In complex coronary disease, systematic use of intracoronary imaging and mechanism-based revascularization are essential to prevent repeated target lesion failure.