Near-infrared spectroscopy-intravascular ultrasound (NIRS-IVUS) studies have demonstrated that lipid core plaque (LCP) is frequently observed in the culprit segment of myocardial infarction (MI). However, little is known about the impact of clinical presentations such as chronic coronary syndrome (CCS) and acute coronary syndrome (ACS) including unstable angina (UA), non ST-segment elevation MI (NSTEMI), and ST-segment elevation MI (STEMI) on LCP. The present prospective single-center registry included a total of 178 patients who underwent percutaneous coronary intervention under NIRS-IVUS guidance. Patients were divided into CCS and ACS groups, and ACS patients were further sub-divided into the 3 groups according to the clinical presentation. The primary endpoint was coronary LCP in the target lesion assessed by NIRS-IVUS with maximal lipid core burden index over any 4 mm segment (maxLCBI4mm). The study population included 124 and 54 patients with CCS and ACS. MaxLCBI4mm in the target lesion was significantly higher in the ACS group than in the CCS group (503 [284-672] vs. 406 [250-557], p = 0.046). Among ACS patients, MaxLCBI4mm in the target lesion was also significantly different in those with UA (n = 18), NSTEMI (n = 21), and STEMI (n = 15) (288 [162-524] vs. 518 [358-745] vs. 646 [394-848], p = 0.021). In conclusion, LCP assessed by NIRS-IVUS, a surrogate of coronary plaque vulnerability, was significantly different according to the clinical presentations such as CCS, UA, NSTEMI, and STEMI.
Keywords: Acute coronary syndrome; Lipid core plaque; Near-infrared spectroscopy-intravascular ultrasound; Vulnerability.