Temporal Changes in Near-Infrared Spectroscopy Signals in Recurrent In-Stent Restenosis Attributable to Calcified Nodule.

A 75-year-old man had recurrent in-stent restenosis (ISR) attributable to calcified nodule. Near-infrared spectroscopy (NIRS) showed a gradual decrease in yellow signals during the process of repeated percutaneous coronary intervention for recurrent ISR that eventually halted. The case indicates that NIRS signals may represent lesion instability even in calcified nodule, and may be potentially predictive of recurrent ISR.