Association between Admission Hypocalcemia and In-hospital Mortality among Patients Presenting with ST-Segment Elevation Myocardial Infarction: A Prospective Cohort Study

Abstract

Objectives: To evaluate the association between admission hypocalcemia and in-hospital mortality among patients presenting with ST-segment elevation myocardial infarction (STEMI). Methodology: This prospective cohort study was conducted in the cardiology department of Jinnah Hospital Lahore over a six-month period. A total of 120 adult patients with STEMI were enrolled and categorized into hypocalcemic and normocalcemic groups based on admission serum calcium levels. In-hospital mortality was recorded as the primary outcome. Demographic and clinical variables including age, gender, body mass index (BMI), and diabetes mellitus status were assessed as potential confounders. Results: A total of 36 patients (30%) experienced in-hospital mortality. Mortality was higher in the hypocalcemia group compared with the normocalcemia group, with 23/60 patients (38.3%) versus 13/60 patients (21.7%) dying during hospitalization, respectively. The unadjusted relative risk for mortality associated with hypocalcemia was 1.769 (95% CI: 0.99–3.15, p = 0.054). Stratified subgroup analysis demonstrated a statistically significant association only among patients aged 25–50 years (RR = 5.087, 95% CI: 1.31–19.72, p = 0.004), although this finding should be interpreted cautiously due to small subgroup size and wide confidence intervals. Multivariable logistic regression analysis showed that admission hypocalcemia was associated with increased odds of mortality (adjusted odds ratio [AOR] = 2.137, 95% CI: 0.929–4.916, p = 0.074), but the association did not reach statistical significance. Conclusion: Admission hypocalcemia was associated with numerically increased in-hospital mortality among patients presenting with STEMI; however, the observed association was not statistically significant after adjustment for confounding variables. Reduced serum calcium may therefore reflect underlying illness severity rather than functioning as an independent predictor of mortality.