Management of New-Onset Postoperative Atrial Fibrillation Utilizing Insertable Cardiac Monitor Technology to Observe Recurrence of AF (MONITOR-AF).

BACKGROUND

New-onset postoperative atrial fibrillation (POAF) occurs in up to 30% of patients undergoing coronary artery bypass grafting (CABG). POAF is associated with short- and long-term mortality.

METHODS

To identify the true incidence and time course of recurrent atrial fibrillation (AF) in patients with POAF, we prospectively assigned 23 patients with POAF to receive an implantable loop recorder (ILR; Medtronic Inc., Minneapolis, MN, USA) for the detection of recurrent AF. Two electrophysiologists independently adjudicated monthly ILR transmissions to classify recurrent AF. We defined AF as any episode lasting ≥6 minutes.

RESULTS

The cohort included 23 subjects averaging 69.1 ± 7.2 years of age. Their mean CHADS2 score averaged 1.9 ± 0.8. Note that 26.1% underwent direct current cardioversion prior to discharge; 95.7% left the hospital taking amiodarone and 26.1% warfarin. A total of 14 patients (60.9%) experienced recurrent AF. AF first recurred within 3 months in nine patients (39.1%), and in 10 patients AF emerged or continued beyond 3 months. Eight of 17 (47.1%) patients followed for at least 1 year experienced AF recurrence beyond 1 year of CABG. The time from surgery to first AF episode averaged 143 ± 22.5 days. Long-term monitoring shows that 60.9% of patients with POAF develop recurrent AF.

CONCLUSION

POAF may represent a propensity for recurrent paroxysmal atrial fibrillation, and not simply a transient consequence of postoperative stress and inflammation. Better detection of recurrent AF might identify patients at risk for stroke who would benefit from continuing anticoagulation.