Hansen KN, Antonsen L, Maehara A, et al. - Researchers assessed the incidence of ruptured plaques and nonruptured plaques (NRP) and also used optical coherence tomography (OCT) to compare patient features as well as detailed plaque morphology characteristics between the two culprit types in patients experiencing ST-segment elevation myocardial infarction (STEMI). This study involved 52 patients (69.3%) with ruptured plaques and 23 (30.7%) with NRP. Significantly more fibrotic plaque, but less lipidic plaque, less superficial and profound macrophages, were detected in NRP. In addition, NRP had significantly lower prevalence, numbers and lengths of thin-cap fibroatheroma (TCFA), relative to ruptured plaques. In this patient population with STEMI, the presence of culprit lesions without an OCT-detectable ruptured plaque was revealed in one-third of patients. Less vulnerable plaque components, such as lipid plaque, TCFAs and macrophages, were present in culprit lesions with NRP vs ruptured plaques.