AF monitoring following cardiovascular surgery

In patients who have undergone cardiac surgery and have an elevated risk of stroke with no history of pre-operative or pre-discharge atrial fibrillation (AF), a strategy of continuous rhythm monitoring unveiled a significant persistent burden of unrecognised and potentially actionable post-operative AF (POAF) in the SEARCH-AF trial [1].

The results of the SEARCH-AF trial (NCT02793895) were presented by Prof. Subodh Verma (St. Michael's Hospital; University of Toronto, Canada). He explained that POAF occurs post-operatively in 30–50% of patients, peaking at 3–5 days; whether the risk of POAF persists thereafter is unknown. The SEARCH-AF trial set out to test whether enhanced cardiac rhythm monitoring after cardiac surgery would improve AF detection in high-risk patients. The participants were post-cardiac surgical patients (with isolated coronary artery bypass grafting [CABG] or valve replacement/repair ± CABG) with CHA₂DS₂-VASc ≥4 or ≥2 with additional risk factors for POAF who did not have a history of pre-operative AF. Participants were randomised 1:1 to 30 days of post-discharge continuous cardiac rhythm monitoring with an adhesive monitoring device or usual care. The primary endpoint was cumulative documented AF or atrial flutter lasting ≥6 minutes within 30 days of randomisation.

The analysis was based on results from the 336 patients (85% of the planned sample size) who were randomised before enrolment was suspended due to COVID-19. Mean age was 67±9 years, mean CHA₂DS₂-VASc was 3.7±1.1, and median follow-up was 9 months. The primary outcome occurred in 32 (19.6%) patients of the monitoring group and 3 (1.7%) in the control group. This corresponds to an absolute risk difference of 17.9% (95% CI 11.5–24.3%; P<0.001). The number needed to screen was 6 (95% CI 4–9). AF or atrial flutter lasting ≥6 hours was detected in 8.6% of the monitoring group and 0% of the control group (P<0.001). The rates of oral anticoagulation were lower than the rates of detected AF.

Prof. Verma concluded that POAF after cardiac surgery is not confined to the hospitalisation period. These data should help inform clinical practice guidelines on monitoring for POAF in such patients.

1. 
   
   1. Verma S, et al. Enhanced Monitoring for Atrial Fibrillation Following Cardiac Surgery: Primary Results of the SEARCH-AF Cardiolink Randomized Trial. LBS.06, AHA Scientific Sessions 2020, 13–17 Nov.

 



Posted on 18 February 202118 February 2021