Increased Cardiovascular Hospitalizations Associated With Presence of Atrial Fibrillation in Acute Coronary Syndrome Patients: A Double Trouble Situation.

BACKGROUND: In previous studies, atrial fibrillation (AF) has been reported to be common among patients with acute coronary syndrome (ACS), and the presence of AF has been associated with increased mortality and morbidity. However, treatment strategies for both ACS and AF have been continuously updated. AIMS: The aim of the present study was to determine the prevalence of AF in ACS patients treated according to the most recent guideline recommendations and to evaluate the prognostic significance of AF in this population. METHODS: In this retrospective cohort study, 285 patients diagnosed with and treated for ACS between 2024 and 2025 were included. The prevalence of AF was determined in this cohort. All patients were followed for at least 1-year. The study endpoint was the occurrence of cardiovascular (CV) mortality and CV-related hospitalizations. RESULTS: AF was identified in 79 patients (28%) with ACS. The mean follow-up duration was 16.5 ± 7.4 months. During follow-up, CV mortality occurred in 37 patients (13%), and CV-related hospitalizations were observed in 97 patients (34%). In regression analysis, left atrial (LA) dimension and smoking status were independently associated with the presence of AF (OR = 1.264, 95% CI: 1.164-1.372, p < 0.001 and OR = 2.318, 95% CI: 1.251-4.295, p = 0.008, respectively). Left ventricular ejection fraction and LA dimension were independently associated with CV mortality (HR = 0.964, 95% CI: 0.936-0.992, p = 0.014 and HR = 1.080, 95% CI: 1.012-1.152, p = 0.020, respectively). In addition, the presence of AF and hypertension were independently associated with CV-related hospitalizations (HR = 1.564, 95% CI: 1.091-2.240, p = 0.015; and HR = 1.686, 95% CI: 1.246-2.240, p = 0.001, respectively). CONCLUSION: Although the presence of AF in patients with ACS was not independently associated with CV mortality, it was independently associated with CV-related hospitalizations despite contemporary treatment strategies. Therefore, closer follow-up and more intensive management of ACS patients with AF may be necessary to reduce the frequency of CV-related hospitalizations.