Background/aim: Damage to elastin fibres in coronary media might lead to coronary artery ectasia (CAE). This study evaluated whether CAE can be distinguished by detecting circulating soluble elastin (s-elastin), which is a degradation product of elastin fibres, and elastase, which is the main enzyme of elastin fibres.Materials and methods: Fifty-eight patients with CAE, 58 with coronary heart disease (CHD) and 61 with relatively normal coronary arteries, were included. Circulating s-elastin and elastase were measured, and receiver operating characteristic curves were used to demonstrate their respective optimal cut-off values for predicting CAE.Results: The concentrations of s-elastin and elastase were higher in the CAE group than in the CHD and relatively-normal-coronary groups. Their cut-off values for screening of CAE were 13.148 ng/mL and 25.549 ng/mL, respectively; for sensitivity of CAE were 0.690 and 0.773, respectively; and for specificity of CAE were 0.862 and 0.571, respectively. A combination of s-elastin and elastase in series (one of the two higher than its cut-off value) had a better sensitivity for screening for CAE, whereas their combination in parallel (both higher than their cut-off values) had a better specificity. Conclusion:Circulating s-elastin and elastase are promising biomarkers for assisting in CAE diagnosis.