Abstract 3537: First Atrial Fibrillation Following Cardiac Surgery: Risk for Permanent AF and Prognosis
Background: Atrial fibrillation (AF) occurs in a high proportion of patients undergoing cardiac surgery. However, risk of progression to permanent AF and its impact on mortality are poorly understood.
Methods: The Olmsted County, Minnesota residents who developed first ECG-confirmed AF in 1980–2000 were followed in medical records to 2004. Permanent AF was defined by absence of any sinus rhythm. Cox proportional hazards modeling was used to identify the risk factors for the development of permanent AF, and time dependent modeling was used to assess mortality risk.
Results: Of 4618 residents who developed first AF, 235 (mean age 69±11, 70% men) occurred within 15 days of cardiac surgery. Of these, 50 (21%) progressed to permanent AF during a mean follow up time of 7.3±5.5 years, and 135 died. Kaplan-Meier analysis showed a cumulative rate of conversion to permanent AF of 15 % at 5 years. Progression to permanent AF was unrelated to age (P=0.17), sex (P=0.15), or type of surgery (P=0.37). After multiple adjustment, slower heart rate at first AF diagnosis was the only independent variable associated with progression to permanent AF (P=0.008). Permanent AF development was associated with significantly increased mortality risk (HR 1.92, 95% CI 1.26–2.92, P=0.002), even after multiple adjustment (Table⇓).
Conclusions: AF presented initially after cardiac surgery frequently progressed to permanent AF. The development of chronic AF was associated with increased risk of death in these patients.