The monocyte-to-HDL-cholesterol ratio predicts new-onset atrial fibrillation in patients with acute STEMI.

Objective: Newly diagnosed AF (NOAF) associated with acute STEMI holds significant relevance in clinical practice. This study seeks to assess the role of the monocyte to HDL-C ratio (MHR) in predicting NOAF in these patients.

Methods: Between July 2017 and May 2018, 663 patients who underwent primary PCI for STEMI were retrospectively analyzed. NOAF was identified in 34 patients (5.1%), and this group was compared with those without AF.

Results: The NOAF group experienced a longer hospitalization duration and a higher mortality rate (11.8 vs. 4.3%,  = 0.044) compared to the non-AF group. In a multivariable analysis, increased MHR (OR: 1.413, 95% CI: 1.203-1.657,  = 0.005), advanced age, decreased LVEF, Killip class 2-4, diabetes mellitus, hypertension, and left atrial enlargement emerged as independent predictors for the development of NOAF in STEMI. ROC curve analysis revealed that MHR values exceeding 26.54 strongly predict NOAF, achieving sensitivity and specificity above 70% (AUC: 0.768, 95%CI: 0.734-0.801,  < 0.001).

Conclusion: The present study revealed that increased MHR robust indicator for NOAF in STEMI patients and can be easily assessed in clinical practice. Incorporating MHR alongside established traditional risk factors may enhance the identification of patients at risk for AF in those with STEMI.