P200 - VALVULAR SURGERY IS ASSOCIATED WITH AN INCREASED RISK OF POST-OPERATIVE ATRIAL FIBRILLATION: SECONDARY ANALYSIS OF THE SEARCH-AF CARDIOLINK-1 RANDOMIZED TRIAL

Thursday, October 27, 2022

3:52 PM – 4:00 PM EDT

Location: Room 210

Presenter(s)

Makoto Hibino

Division of cardiac surgery
University Hospitals Harrington Heart & Vascular Institute
Case Western Reserve University
Cleveland, Ohio, United States

First Author(s)

Makoto Hibino

Division of cardiac surgery
University Hospitals Harrington Heart & Vascular Institute
Case Western Reserve University
Cleveland, Ohio, United States

Senior Author(s)

Subodh Verma, MD PhD

Cardiac Surgeon
St Michael's Hospital, University of Toronto, ON
Toronto, United States

Author(s)

AP

Arjun Pandey, BHSc

Waterloo, Ontario, Canada
AQ

Adrian Quan, MPhil

Toronto, Ontario, Canada
PP

Pankaj Puar

Toronto, Ontario, Canada
RV

Raj Verma

Toronto, Ontario, Canada
Avinash Pandey, MD

Internal Medicine Resident
Department of Medicine, University of Ottawa
Department of Medicine, University of Ottawa
Waterloo, Ontario, Canada
GB

Gianluigi Bisleri

Cardiac Surgeon
Toronto, Ontario, Canada
Atul Verma

Director of Cardiology
McGill University Health Centre
McGill University Health Centre
Montreal, Quebec, Canada
C David Mazer, MD, FRCPC

Professor of Anesthesia and Physiology
St. Michael's Hospital
St. Michael's Hospital, University of Toronto
Toronto, Ontario, Canada

Senior Author(s)

AH

Andrew C.T. C. Ha

Cardiac Electrophysiology
Toronto General Hospital
Toronto, Ontario, Canada

Supervisor(s)

AH

Andrew C.T. C. Ha

Cardiac Electrophysiology
Toronto General Hospital
Toronto, Ontario, Canada

Background: Patients undergoing valve surgery have a higher risk of developing post-operative atrial fibrillation (POAF) relative to those undergoing isolated coronary artery bypass grafting (CABG). Whether this risk extends beyond hospital discharge is unknown.

METHODS AND RESULTS: We examined the association between surgery type (isolated CABG vs. valve repair or replacement) on the incidence of POAF from a sub-analysis of the Post-Surgical Enhanced Monitoring for Cardiac Arrhythmias and Atrial Fibrillation (SEARCH-AF) CardioLink-1 randomized trial. It randomized 336 patients with risk factors for stroke (CHA2DS2-VASc score ≥2) and no history of preoperative AF were randomized to usual care or continuous cardiac rhythm monitoring for 30 days after discharge from cardiac surgery with a wearable, patched-based device. The primary outcome was occurrence of cumulative atrial fibrillation/flutter (AF/AFL) lasting for ≥6 minutes detected by continuous monitoring or AF/AFL documented by a 12-lead electrocardiogram within 30 days of randomization. The trial excluded patients who underwent mechanical valve replacement or left atrial appendage ligation. We compared the risk of POAF between patients who underwent CABG vs. valve repair or replacement. Patients who experienced post-operative AF during hospitalization were excluded from this analysis.

The overall cohort consisted of 255, 39, and 42 patients who underwent isolated CABG, isolated valve replacement/repair, and CABG + valve repair/replacement, respectively. Baseline characteristics were similar among the groups except for younger age (p=0.0014), higher prevalence of preoperative myocardial infarction (p=0.002) and lower ejection fraction (p=0.025) in the isolated CABG group. Eighteen patients experienced post-operative AF during hospitalization. Among 3 surgery subgroups, patients who underwent CABG + valve surgery or isolated valve surgery were more likely to experience post-operative AF compared with those who underwent isolated CABG (Log-Rank ptrend=0.0096). Among patients who were randomized to continuous cardiac rhythm monitoring, the probability of post-operative AF among patients who underwent isolated CABG, valve surgery, and CABG + valve surgery was 15.8%, 29.4%, and 35.0%, respectively (Log-Rank ptrend=0.017). After multivariable adjustment, the risk of developing post-operative AF within 30 days after discharge remained higher among patients who underwent valve surgery compared with those who underwent isolated CABG (hazard ratio (HR) 2.22, 95% CI 1.01-4.87. Patients who underwent CABG + repair/replacement had the highest risk of experiencing post-operative AF relative to patients who underwent isolated CABG (HR 2.78, 95% CI 1.12-6.86).

Conclusion: An aggressive cardiac rhythm monitoring strategy for AF detection should be considered for patients who are discharged after valvular surgery in light of their elevated stroke risk.