BackgroundSome patients were detected with coronary artery disease even if the coronary artery calcium score was (CACS)=0. We evaluated the prevalence and predictor of significant stenosis and computed tomography (CT) based vulnerable plaque (CTVP) for patients with CACS=0. MethodsSubjects were 2160 patients (M/F=1110/1050, 64.7±11.6years) who underwent measurement of calcium score and CT coronary angiography. As for CACS=0 group, age, gender, coronary risk factor (family history (FH), hypertension (HT), hyperlipidemia (HL), diabetes (DM), and smoking), body mass index, history of cerebral infarction, the presence of chest symptom, and abnormal rest ECG findings were investigated as predictors for significant stenosis and CTVP by multivariate analysis using logistic regression analysis. ResultsOut of 2160 patients, 1141 (52.8%, M/F=655/486, 68.4±9.8years) were of CACS>0 and 1019 (47.2%, M/F=455/564, 60.5±12.0years) were of CACS=0. In the CACS=0 group, 24 patients (2.4%) were found with significant stenosis and 47 (4.6%) with 2FPP. In 104 patients with spotty calcification (10.2%), 10 (9.6%) out of these 104 had significant stenosis and also had CTVP. Multivariate analysis using logistic regression analysis revealed significant predictor for significant stenosis to be only male (Odds ratio (OR): 3.075, 95%CI 1.166–8.109, p=0.0232) and significant predictor for CTVP to be age (OR: 1.032, 95%CI 1.001–1.063, p=0.0437) and male (OR: 2.386, 95%CI 1.193–4.775, p=0.0140). ConclusionsThe present study suggests that the presence of CTVP must be noted, when patients are male and elderly even if CACS=0 and the presence of spotty calcification increases the prevalence of significant stenosis and CTVP in patients with CACS=0.