Sun J, Han W, Wu S, et al. - Findings demonstrated an independent association of the combination of hyperhomocysteinemia (HHcy) and smoking with the severity of coronary artery disease (CAD) in young patients ≤ 35 years of age.

• This study involved 989 young CAD patients (18–35 years of age) who had coronary angiography between January 2013 and May 2020.

• According to multivariate liner analysis, both serum Hcy levels and pack-years of smoking were independently related to the severity of coronary artery stenosis post-adjusting for other conventional confounders.

• A higher risk for CAD severity appeared for the combination of HHcy and current smoking, vs HHcy or current smoking alone.