Incidence, clinical predictors, and clinical effect of new-onset atrial fibrillation in myocardial infarction patients: A retrospective cohort study

OBJECTIVES: To calculate the incidence of new-onset atrial fibrillation (NOAF) in myocardial infarction (MI) patients and examine associated predictors and clinical outcomes of NOAF patients. METHODS: A retrospective cohort study was used to carry out this study. All MI patients admitted to King Khaled University Hospital, Riyadh, Saudi Arabia, between January 2015 to 2020 were eligible for inclusion. The study excluded those with a previous diagnosis of atrial fibrillation and patients who died at presentation. RESULTS: A total of 281 patients were analyzed with a mean age of 58.7±12.7. Incidence of NOAF was 7.8%. Significant predictors identified by multivariate logistic regression analysis included older age (p=0.004), history of MI (p=0.012), and undergoing coronary artery bypass graft surgery (CABG) as treatment (p=0.016). New-onset atrial fibrillation was associated with higher odds of major adverse cardiovascular event (p=0.039), ventricular tachycardia (p=0.001), and mortality (p=0.031). CONCLUSION: New-onset atrial fibrillation is a relatively common complication of MI, and in our study, it was associated with higher odds of further complications including death. Therefore, identification of MI patients at risk of developing NOAF is crucial. Our study suggests that older age, a previous history of MI, and undergoing CABG are significant predictors of NOAF development.