New-onset atrial fibrillation during ST-segment elevation myocardial infarction in an Asian population: Predictors, complications, and prognosis

Introduction Atrial fibrillation (AF) is a common arrhythmia in ST-elevation myocardial infarction (STEMI), which confers greater morbidity and mortality. Currently, treatment strategies and prognosis remain unclear for patient with new-onset AF and STEMI. Methods An observational study was done on 1780 patients from the Singapore Western STEMI network who underwent primary percutaneous coronary intervention for STEMI. Baseline characteristics, cardiac catheterization data, inpatient and follow-up outcomes were obtained from electronic medical records and analyzed. Results 105 (5.9%) patients developed new onset AF during the index admission, and they were more likely to experience acute pulmonary edema (APE) (32.4% vs 9.1%, p<0.001), cardiogenic shock (28.6% vs 10.5%, p<0.001), inotropic support (28.6% vs 10.5%, p<0.001), acute kidney injury (30.5% vs 10.3%, p<0.001), in-hospital stroke (6.7% vs 1.1%, p<0.001), bleeding (20.0% vs 8.9%, p<0.001), ventricular arrhythmias (18.1% vs 9.5%, p=0.004). On multivariate analysis, hypertension, older age, APE and sepsis were independent predictors of new onset AF. Significant predictors of MACE and mortality were APE and cardiogenic shock, but not new-onset AF. Preserved LVEF was a protective factor. Only 45.7% of patients with new-onset AF received anticoagulation, but there was no difference in long-term outcomes of stroke between pre-existing as compared to new-onset AF. Conclusion While AF was associated with higher in-hospital complications, data from our study suggested that AF was not associated with long term outcomes. Further studies are required to first determine if anticoagulation is warranted and justified, and the long-term implications of AF in this subgroup of patients.