The contribution of intermittent handheld electrocardiogram and continuous electrocardiogram monitoring with an implantable loop recorder to detect incident and recurrent atrial fibrillation during 1 year after coronary artery bypass graft surgery: A prospective cohort study

Abstract

Background: Atrial fibrillation (AF) is common after coronary artery bypass graft (CABG) surgery.

Objective: To evaluate the incidence and recurrence rate of AF during 1 year after CABG surgery. We also aimed at calculating the AF burden and compare long-term intermittent vs continuous electrocardiogram (ECG) monitoring.

Methods: Forty patients scheduled for CABG surgery were equipped with an implantable loop recorder (ILR). After discharge, they carried out handheld ECG 3 times daily during the first 30 postoperative days and during 2 weeks at 3 and 12 months. During hospital stay they were monitored with telemetry.

Results: Altogether 27 of 40 (68%) patients were diagnosed with AF, 24 during the first month (21 in-hospital and 3 after discharge) and 3 during months 2-12. Three patients progressed into persistent AF. In addition, 17 patients had AF recurrence, 9 of them after the first 30 days. In patients with paroxysmal AF, the AF burden was low, 0.1% (interquartile range [IQR] 0.02%-0.3%). Patients with AF had higher CHA₂DS₂-VASc scores than non-AF patients: median 4 (IQR 3-4) and 3 (IQR 2-3.5), respectively, P = .006. The handheld ECG identified 45% (9/20) of the patients with AF episodes identified with continuous ECG monitoring with the ILR after discharge from hospital, P = .001.

Conclusions: Patients with AF during the postoperative hospitalization showed a high likelihood of recurrent AF, usually within 30 days. Continuous ECG monitoring with an ILR was superior to the handheld ECG for detecting patients with AF. The AF burden was low.

Keywords: Atrial fibrillation; Coronary artery bypass graft surgery; ECG monitoring; Handheld ECG; Implantable loop recorder.

Graphical abstract

Figure 1

Incident and recurrence of atrial fibrillation (AF) captured by any method. In total 27 of 40 patients had incident AF. Three progressed into persistent AF and a further 17 had 1 or more recurrences of AF during follow-up.

Figure 2

Number of patients with incident and/or recurrent atrial fibrillation (AF) detected by the implantable loop recorder (ILR) and the handheld electrocardiogram (ECG), respectively, during month 1 and months 2–12 of monitoring. One patient with incident AF found by the handheld ECG during the first month was not detected by the ILR, since the ILR had not been activated at discharge. The detection rate was significantly higher for the ILR than the handheld ECG for month 1 and months 2–12, 94% (16/17) vs 47% (8/17), P = .007 and 100% (12/12) vs 33% (4/12), P = .001, respectively. The error bars show the 95% confidence interval for the detected proportion. Statistical test used: Fisher’s exact test.

Figure 3

The atrial fibrillation (AF) burden was low except for the 3 patients (colored in red) who developed persistent AF, and it gradually decreased during the 12-month follow-up.