It has been shown that the sustained PCSK9 release during cardiac I/R could lead to cardiac deleterious effects by inducing cell death and dysfunction.15 In addition, previous studies found that PCSK9 inhibitor causes a decrease in the level of oxidative stress by increased Cu, Zn‐superoxide dismutase (SOD), catalase and C‐reactive protein in patients with coronary artery disease.33, 34 Therefore, PCSK9 inhibitor given prior to ischaemic period might be a prophylactic approach to prevent cardiac adverse effects after I/R injury as we found in this study. Here, CAT is linked to coronary artery disorder.