Prediction of Non-Cardiac Organ Failure in Acute Myocardial Infarction Patients with Arrhythmia: A Retrospective Case–Control Study

<b>Background:</b> Non-cardiac organ failure is a severe complication following acute myocardial infarction (AMI), particularly among patients with concomitant arrhythmia. This study aimed to identify risk factors at admission that were associated with in-hospital non-cardiac organ failure. <b>Methods:</b> This case-control study enrolled AMI patients hospitalized for treatment with any type of arrhythmia. Patients were divided into the complication group and the control group based on the development of non-cardiac organ failure. Relaxed least absolute shrinkage and selection operator (LASSO) logistic regression and multivariate logistic regression were performed to identify risk factors, which were subsequently used to develop a predictive model. Shapley Additive Explanation (SHAP) values were applied to enhance model interpretability. <b>Results:</b> A total of 668 patients were enrolled, including 59 individuals in the complication group. After LASSO-logistic and multivariate logistic regression, five independent risk factors were identified and ranked by their SHAP values: Killip class III/IV [odds ratio (OR)] = 2.409, 95% confidence interval (CI): 1.246-4.657, <i>p</i> = 0.009], fibrin degradation products [OR = 1.029, 95% CI: 1.009-1.049, <i>p</i> = 0.003], N-terminal pro-B-type natriuretic peptide [OR = 1.000, 95% CI: 1.000-1.000, <i>p</i> = 0.002], type 2 diabetes mellitus [OR = 1.888, 95% CI: 1.005-3.546, <i>p</i> = 0.048], and cardiogenic shock [OR = 3.443, 95% CI: 1.463-8.089, <i>p</i> = 0.005]. The model demonstrated good discriminative ability with an area under the curve of 0.790 (95% CI: 0.720-0.861). Internal validation showed a calibration slope of 0.953 and a Brier score of 0.067, indicating strong overall predictive accuracy. <b>Conclusions:</b> This study identified five independent risk factors associated with in-hospital non-cardiac organ failure in AMI patients with arrhythmia. The nomogram might assist in early risk stratification, ultimately improving clinical outcomes in high-risk AMI patients with arrhythmia.