Abstract 2894: Natural History of First Atrial Fibrillation Complicating Acute Myocardial Infarction
Background: Atrial fibrillation (AF) common occurs in association with myocardial infarction (MI). However, the risk factors associated with the progression to permanent AF have not been well defined.
Methods: We identified the Olmsted County, Minnesota residents who developed first ECG-confirmed AF in 1980–2000 and followed them in medical records to 2004. The patients who developed first AF in the setting of an acute MI constituted the study population. Permanent AF was defined by AF without any evidence of sinus rhythm. Cox proportional hazards modeling was used to identify the risk factors for the progression from initial AF associated with MI to permanent AF.
Results: Of 4,618 residents who developed first AF during the study period, 208 (mean age 75±13, 52% men) were diagnosed with first AF at the time of an acute MI. Of these, 30 (14%) progressed to permanent AF during a mean follow up 4.0±4.6 years, and 164 died. The Kaplan-Meier probability of chronic AF development was 9% at 1 year and 16% at 5 years. The progression to permanent AF was related to advancing age (P=0.011) and a number of other factors (Table⇓), some of which were potentially reversible. Sex was not related to development of permanent AF.
Conclusions: Of the patients who developed first AF in the context of an acute MI, a significant proportion progressed to a permanent form within the ensuing 5 years. Smoking cessation, aggressive weight control and heart failure management may potentially reduce the progression to permanent AF in these patients.