Utility of near‐infrared spectroscopy to detect the extent of lipid core plaque leading to periprocedural myocardial infarction

Objectives The aim of this study was to investigate whether lipid core plaque (LCP) in the entire stented segment detected by near‐infrared spectroscopy‐intravascular ultrasound (NIRS‐IVUS) could predict procedural myocardial infarction (PMI) in patients undergoing percutaneous coronary artery intervention (PCI). Background NIRS‐IVUS can identify LCP, described as high lipid core burden index (LCBI). Previously, the highest LCBI contained only in the 4‐mm segment (maxLCBI4mm) was reported to predict PMI. Methods Patients who underwent NIRS‐IVUS examination during PCI for coronary artery disease at Chiba University Hospital were included. The extent of LCP in the stented segment derived from NIRS‐IVUS analysis was presented as LCBI, maxLCBI4mm, and LCP area index (LAI), reflecting the total amount of LCP in the entire stented segment calculated as LCBI×lesion length. PMI was defined as an elevation of creatine kinase MB > 3 times upper reference level (URL), and periprocedural myocardial injury (PMInj) was defined as an elevation of troponin I>5 times URL within 12 to 24 h after PCI. Results Out of 141 enrolled patients, PMI occurred in 20 (14.2%) and PMInj occurred in 62 (44.0%) patients. Receiver‐operating characteristic curve analysis revealed LAI was the strongest predictor for both PMI and PMInj (area under curve 0.771, p