Clinical predictive modeling of CK-MB using troponin I/T and CPK in patients post myocardial infarction

INTRODUCTION: Myocardial infarction (MI) continues to be a leading cause of global morbidity and mortality. This study evaluated the predictive relationships between Creatine Kinase-MB (CK-MB) and Troponin I/T (cTnI/T), creatine phosphokinase (CPK), and C-reactive protein (CRP) markers to improve clinical interpretation where CK-MB assays are unavailable. MATERIALS AND METHODS: A retrospective cohort of 102 first-time MI patients from multiple Saudi hospitals was analyzed. Demographic, biochemical, and clinical data were extracted, and univariable and multivariable linear regressions were performed via R (v4.4.2). Subgroup analyses by age, sex, and body mass index were conducted to explore demographic variations. RESULTS: Mean CK-MB levels were 60.85 ± 51.69 U/L in males and 53.71 ± 45.44 U/L in females. cTnI/T, averaged 7.87 ± 12.65 ng/mL, total CPK 370.85 ± 466.99 U/L, and CRP 22.09 ± 14.12 mg/L. Univariable regression revealed strong positive association of CK-MB with cTnI/T, (estimate = 2.98, P < 0.0001, R2 = 0.583), CPK (estimate = 0.082, P < 0.0001, R2 = 0.468), and CRP (estimate = 1.67, P < 0.0001, R2 = 0.202). In the multivariable model, cTnI/T (estimate = 2.33, P < 0.0001) and CPK (estimate = 0.047, P < 0.0001) remained independent predictors, while CRP lost significance (P = 0.192). DISCUSSION AND CONCLUSION: These findings support using cTnI/T and CPK as reliable clinical correlates for CK-MB estimation in post MI evaluation, especially when laboratory access is limited.