INTRODUCTION
Atrial fibrillation (AF) is the most common cardiac arrhythmia. Despite
advancements in screening, diagnosis and management, the presence of AF
is still associated with an increased risk of stroke, heart failure and
death. New-onset AF is frequent after any cardiac surgery, but evidence
suggests it has no significant impact on survival if sinus rhythm (SR)
is effectively restored early after the onset of the arrhythmia. In
contrast, several studies have suggested that preoperative AF is
associated with increased morbidity and mortality in patients undergoing
cardiac surgery. Management of preoperative AF is often overlooked
during or after cardiac surgery despite several proposed protocols.
Concomitant surgical AF ablation is recommended to improve left
ventricular ejection fraction, exercise tolerance, and long-term
survival, and to reduce the risk of stroke and thromboembolic events.
However, the presumed additional risk of atriotomy and subsequent
surgical ablation still precludes its routine use in a large subset of
patients.
AF is common in patients with aortic valve disease, especially aortic
stenosis. This is, at least in part, because the incidence of both
conditions increases with age. Furthermore, chronically elevated left
ventricular afterload secondary to aortic stenosis precipitates impaired
diastolic relaxation with resultant upstream transfer of pressure to the
left atrium, which provokes left atrial dilatation, fibrosis and
arrhythmogenesis . A recent metanalysis suggested an association between
preoperative AF and adverse outcomes after surgical aortic valve
replacement (AVR). Of note, patients with AF are usually older with
multiple comorbidities. They also often require concomitant cardiac
surgeries such as coronary artery bypass graft and other valve
surgeries. Thus, there is still some debate whether AF is an independent
predictor of adverse prognosis after surgical AVR or whether the worse
prognosis among AF patients rather reflects increased age and associated
comorbidities and/or concomitant surgeries. The AF-TRACER study sought
to evaluate the sole impact of preoperative AF on mortality in a large
cohort of patients undergoing isolated surgical AVR.