Abstract
BACKGROUND: Significant stenosis without thrombus (SSWT) is sometimes observed in patients with acute coronary syndrome (ACS). However, its incidence and clinical features remains unclear. METHOD: This substudy of the TACTICS registry included patients with ACS (n = 702) undergoing emergency percutaneous coronary intervention using optical coherence tomography. Using this registry data, we compared the clinical features of SSWT in patients with ACS. Major adverse cardiac events were defined as cardiac death, nonfatal myocardial infarction, heart failure, or ischemia-driven revascularization at 1 year. RESULTS: Plaque rupture (PR; n = 411, 59.1%) and plaque erosion (PE; n = 178, 25.6%) were the 2 major morphologies, followed by SSWT (n = 64, 9.1%) and calcified nodule (CN; n = 28, 4.0%). Patients with SSWT were slightly older than those with PR and PE, but younger than those with CN. In the SSWT, non-ST elevation myocardial infarction was the main type of ACS, followed by unstable angina and ST-elevation myocardial infarction (63%, 22%, and 15%, respectively). Lesions were less complex with a lower proportion of type B2 or C, shorter procedure time, lower proportion of multivessel disease, and lower syntax score, which led to a lower incidence of major adverse cardiac events. CONCLUSION: SSWT was the third most common morphology of ACS, with clinical features different from those of PR, PE, and CN.