Shiyovich A, et al. - Herein, the evaluation of the link between serum calcium levels (sCa) and in-hospital mortality among acute myocardial infarction (AMI) patients was carried out. sCa was identified as an independent predictor of in-hospital mortality in patients with AMI with a U-shaped association. Notably, the association of both increased and decreased sCa levels with increased risk of in-hospital mortality was also apparent.