Atrial fibrillation (AF) occurs frequently in advanced heart failure. The prognostic significance of AF remains controversial. To determine the relation of AF to survival in patients with advanced heart failure, 234 consecutive patients referred for heart transplantation evaluation from January 1993 to June 1996 were studied to determine the effect of AF on event-free survival (freedom from death, heart transplantation, or placement of a left ventricular assist device). Clinical characteristics of the study population included: age, 51 +/- 17 years; maximum exercise oxygen consumption, 14.2 +/- 5.3 ml/kg/min; left ventricular ejection fraction, 24 +/- 11%; pulmonary capillary wedge pressure, 23 +/- 9 mm Hg; and ischemic etiology, 52%. Medical therapy included: diuretics (86%), angiotensin-converting enzyme inhibitors (80%), digoxin (80%), and anticoagulation therapy (72%). Mean duration of follow-up was 1.1 +/- 1.0 years. Sixty-two patients (27.4%) had AF. One-year event-free survival of the study population was 48%. No difference in event-free survival between patients with and without AF was observed. Univariate predictors of decreased event-free survival included: (1) advanced New York Heart Association class; (2) higher pulmonary capillary wedge pressure; (3) lower cardiac index; (4) lower maximum exercise oxygen consumption; (5) use of inotropic therapy; and (6) greater pulmonary artery systolic pressure. By multivariate analysis, independent predictors of decreased event-free survival included advanced New York Heart Association class (p <0.002) and higher pulmonary capillary wedge pressure (p = 0.02). Thus, AF in patients with advanced heart failure is not associated with decreased event-free survival.