(CCSP048) LONG-TERM RECURRENCE OF NEW-ONSET POST-OPERATIVE AF IN CARDIAC SURGERY PATIENTS AS DETECTED BY AN IMPLANTABLE LOOP RECORDER: A SYSTEMATIC REVIEW AND INDIVIDUAL PARTICIPANT DATA META-ANALYSIS

Background: New-onset post-operative atrial fibrillation (POAF) occurs in 25-50% of patients after cardiac surgery. In some patients, POAF is a transient entity, while in others it represents a first presentation of paroxysmal or persistent AF. The long-term AF recurrence rate in patients with POAF is unknown. This study estimates the AF recurrence rate in patients with new-onset POAF following cardiac surgery as evaluated with an implantable loop recorder (ILR).

METHODS AND RESULTS: We searched MEDLINE, Embase and Cochrane CENTRAL to April 2, 2023 for studies of adult patients without a history of AF, who had POAF detected following cardiac surgery and received an ILR. We defined POAF as AF occurring in the first 30 days postoperatively and AF recurrence as occurring after 30 days.

We contacted authors of eligible studies to request individual participant time-to-event data on AF recurrence. When individual data were not available, we estimated events from study figures. We constructed a Kaplan-Meier curve illustrating the time to first recurrence.

From 8111 screened citations, we identified 8 eligible studies (Table 1). All studies were single-centre prospective cohorts from 7 countries including the United States of America (2), Canada, Denmark, Israel, The Netherlands, Russia and Sweden. Two studies defined AF recurrence as lasting ≥ 30 seconds, four defined AF recurrence as lasting ≥ 2 minutes, one defined AF recurrence as lasting ≥ 5 minutes and one defined AF recurrence as lasting ≥ 6 minutes. We received data from 6 studies and estimated events for one study; data were not available from one study. We pooled data from a total of 186 participants, with a median follow-up of 1.7 (interquartile range (IQR): 1.3 – 2.8) years. Overall, 19.7% of participants were female, 79.8% of participants had isolated CABG, and the median (IQR) CHA2DS2-VASc was 3 (1 – 6).

Rates of AF recurrence beginning after the 30-day post-operative period were: 15.1% (95% CI 10.5% – 21.2%) at 3 months, 23.9% (95% CI 18.1% – 31.0%) at 6 months, 30.7% (95% CI 24.1% – 38.1%) at 12 months and 39.2% (95% CI 32.0% – 47.0%) at 18 months (Figure 1, wherein the shaded area indicates the 95% CI).

Conclusion: For patients with new-onset POAF following cardiac surgery, AF recurrence, as detected by an ILR, is common, with approximately 1 in 3 experiencing recurrence in the first year after surgery. The optimal strategy for monitoring for recurrence, its clinical sequelae, and appropriate management in this population remains uncertain.