Aim: In patients with ST-segment elevation myocardial infarction (STEMI), it is uncertain whether atrial fibrillation has prognostic implications. There may be a difference between atrial fibrillation before and after reperfusion therapy.
Methods and results: In patients with STEMI treated with primary percutaneous coronary intervention (PCI), ECGs were analysed before and after primary PCI. Of the 1623 patients with electrocardiographic data before primary PCI, 53 patients (3.3%) had atrial fibrillation. Patients with atrial fibrillation were older, were more often female, and less often had anterior MI location. Of the 1728 patients with electrocardiographic data after primary PCI, 52 patients (3.0%) had atrial fibrillation. Atrial fibrillation was more common in older patients and in those with Killip class >1. Also patients with occlusion of the right coronary artery or TIMI flow 0 before primary PCI more commonly had AF after the procedure. Not successful reperfusion was also associated with a higher incidence of AF after primary PCI. Although both atrial fibrillation before and after primary PCI were associated with increased mortality, multivariable analyses, adjusting for differences in age, gender and Killip class on admission, revealed that atrial fibrillation after PCI (OR 3.69, 95% CI 1.87-7.29) but not before PCI (OR 1.86, 95% CI 0.89-3.90) was independent and statistically significantly associated with long-term mortality.
Conclusion: In patients with STEMI, atrial fibrillation after but not before primary PCI has independent prognostic implications. Possibly, atrial fibrillation after the PCI is a symptom of failed reperfusion and a sign of heart failure.