In-stent Restenosis in an Anomalous Left Main Coronary Artery Arising from the Right Sinus of Valsalva After a Stenting Lesion with Acute Angle.

We describe a 38-year-old male who underwent percutaneous coronary intervention (PCI) using a third-generation drug-eluting stent (DES) with a thin stent for an anomalous left main coronary artery (LMCA) originating from the right coronary sinus with a retro-aortic course. Six months later, in-stent restenosis (ISR) occurred due to stent implantation in angled lesions with significant hinge motion. An intravascular ultrasound (IVUS) revealed significant neointimal hyperplasia. The vessel wall of an angled coronary artery lesion is exposed to mechanical stress from the deployed stent. It has been reported before in the major coronary arteries but not in an anomalous LMCA.