Serum calcium-magnesium ratio at admission predicts adverse outcomes in patients with acute coronary syndrome

Abstract

Background Evidence from observational studies suggests that increased calcium exposure may elevate the risk of adverse events in patients with coronary artery disease, while magnesium may exert a protective effect on disease risk. However, there have been limited investigations into the relationship between these minerals and acute coronary syndrome (ACS). Therefore, this study aimed to explore the association between the Serum calcium-magnesium ratio (Ca/Mg ratio) in patients with acute coronary syndrome and their clinical outcomes. Methods This retrospective analysis reviewed the clinical data of 1,775 patients with ACS who underwent coronary angiography and/or percutaneous coronary intervention (PCI) at the Fujian Heart Center between May 2017 and December 2022. The patients were categorized into four groups based on their Ca/Mg ratio at admission (Group 1, ≤2.373, n = 443; Group 2, 2.374–2.517, n = 442; Group 3, 2.518–2.675, n = 446; Group 4, ≥2.676, n = 444). Single-factor analysis and multivariate logistic regression were employed to analyze the clinical characteristics and postoperative clinical outcomes of patients in different groups. The primary outcome included major adverse cardiovascular and cerebrovascular events (MACCEs), while the secondary outcomes included contrast-induced nephropathy (CIN)、all-cause rehospitalization raten and hematorrhea. Results Univariate analysis showed that the patients had a mean age of 64.50±10.79 years, with 370 female patients (20.8%). Additionally, 1,158 patients had hypertension (65.2%), and 710 patients had diabetes (40.5%). Univariate analysis showed an inverse relationship between the serum calcium-to-magnesium ratio and all-cause in-hospital mortality, with patients in the lowest quartile having the highest mortality rate. Multivariate analysis showed that the Ca/Mg ratio at admission was independently associated with MACCEs. Among them, this ratio was inversely associated with all-cause mortality [adjusted odds ratio (aOR) 0.07; 95% CI 0.01–0.63; P<0.05] and positively associated with new-onset atrial fibrillation (aOR 1.86; 95% CI 1.08–3.21; P<0.05). Additionally, the Ca/Mg ratio was positively correlated with an increased risk of postoperative major bleeding (aOR 6.58; 95% CI 1.43–30.29; P<0.05). Conclusion In this large retrospective study, serum calcium and magnesium levels at admission were significantly associated with adverse outcomes in patients with ACS. The Ca/Mg ratio was identified as a reliable predictor of poor prognosis in ACS patients.