Although coronary computed tomography angiography (CCTA) offers a valuable alternative for characterizing nonclacified coronary plaques, its value in evaluating noncalcified coronary plaques after an acute cardiac event (ACE) remains uncertain. We investigated the prevalence of ACE and the characteristics of clearly discernible noncalcified coronary plaques using dual-source CCTA. Forty patients with noncalcified coronary plaques demonstrated by dual-source CCTA were studied for 7 to 12 months. The prevalence of ACE with a diameter of the stenotic coronary vessel of more or equal to 50% and of less than 50% of the lumen of the stenotic coronary were grouped and compared. The noncalcified plaque was analyzed. Quantitative CCTA revealed 29 patients were with ≥50% of diameter stenosis (DS) and 9 of them had ACE; 11 patients were with <DS, 1 of them had ACE. The sensitivity of ≥50% DS in predicting ACE was 31.0% (9/29), with specificity of 90.9% (10/11), positive predictive value of 90% (9/10) and negative predictive value of 33.3% (10/30). The average thickness of noncalcified plaques in patients with ACE (3.4±0.9mm) was larger compared to the plaques in patients without ACE (2.5±0.7mm, P<0.01). In conclusion, these data suggest that CCTA plays an important role in evaluating noncalcified plaques. Patients with significant stenoses and thick noncalcified plaques more or equal to 3.4mm in their coronary arteries should be followed up closely.