CathMasters (Drs. Amit Goyal, Daniel Ambinder, Nazli Okumus, and Salman Allana) discuss a challenging case of recalcitrant focal in-stent restenosis (ISR) within two layers of stent in a right coronary artery. The panel walks through a systematic approach to ISR: guide selection and access strategy; the role of intracoronary imaging…