Abstract
BACKGROUND: Effect of serum calcium levels on prognosis of patients with coronary artery disease (CAD) is not well evaluated. We aimed to assess the associations of baseline serum calcium levels with both short-term and long-term outcomes in CAD patients. METHODS: This study included 3,109 consecutive patients with angiographically confirmed CAD. Patients were categorized into quartiles according to admission serum calcium. Multivariable regression analysis was used to determine the association of serum calcium with mortality. RESULTS: Compared to patients in the lowest quartile of serum calcium, patients in upper quartiles were presented with lower all-cause mortality (Hazard ratios [HRs] were -0.636 [95% CI: -0.424 to -0.954], -0.545 [95% CI: -0.351 to -0.846] and -0.641 [95% CI: -0.450 to -0.913] for three upper quartiles versus lowest quartile respectively), cardiovascular mortality (HRs 0.594 [0.368-0.961], 0.261 [0.124-0.551] and 0.407 [0.229-0.725]), and in-hospital mortality (Odd ratios [ORs] 0.391 [0.188-0.812], 0.231 [0.072-0.501] and 0.223 [0.093-0.534]). Consistent associations between serum calcium and long-term mortality were also obtained in subgroup analysis of ACS patients, stable CAD patients and discharged patients. CONCLUSIONS: Serum calcium is inversely associated with CAD and can independently predict both in-hospital and long-term mortality among CAD patients.