ATRIAL FIBRILLATION RECURRENCE IN PATIENTS WITH TRANSIENT, NEW-ONSET ATRIAL FIBRILLATION DETECTED DURING HOSPITALIZATION FOR MEDICAL ILLNESS OR NON-CARDIAC SURGERY: A PROSPECTIVE, MATCHED COHORT STUDY (VP014)

Friday, October 27, 2023

15:30 – 15:40 EST

Corresponding Author(s)

William F. McIntyre, MD FRCPC

Cardiac electrophysiology
McMaster University
McMaster Unviersity

First Author(s)

William F. McIntyre, MD FRCPC

Cardiac electrophysiology
McMaster University
McMaster Unviersity

Co-Author(s)

MV

Maria E. Vadakken, MBBS

Research Assistant
Hamilton Health Sciences
SC

Stuart J. Connolly, MD MSc

Professor of Medicine
McMaster University
PM

Pablo A. Mendoza

Master's student
McMaster University
AL

Alexandra Lengyel, BHSc

Research student
Hamilton Health Sciences
AR

Anand Rai, BSc
NL

Nicole Latendresse, BSc
AG

Alex Grinvalds, BSc
CR

Chinthanie Ramasundarahettige, M Sc
GA

Gabriel Acosta, MD

Physician
McMaster University
Kevin J. Um, MD FRCPC

Resident
McMaster University
McMaster University
Jason Roberts

Associate Professor
McMaster University and Population Health Research Institute
Population Health Research Institute and McMaster University
David Conen, MD MPH

Associate Professor
McMaster University
McMaster University
Jorge A. Wong, MD MPH FRCPC

Assistant Professor
Population Health Research Institute, McMaster University, Canada
Philip James Devereaux, MD, PhD

Professor
McMaster University
McMaster University
Emilie P. Belley-Cote, MD

EARLY CAREER
CCS, CANCARE
McMaster Unviersity
Richard Whitlock, MD, PhD, FRCSC

Professor
Population Health Research Institute
McMaster Unviersity

Senior Author(s)

JH

Jeffrey S. Healey, MD, MSc, FRCPC, FHRS

Professor
McMaster University
McMaster Unviersity

Background: Atrial fibrillation (AF) is often detected for the first time in patients who are hospitalized for non-cardiac illness or surgery. Many clinicians consider AF in this setting to be temporary and reversible and therefore not requiring long-term oral anticoagulation.
We aimed to estimate the 1-year rate of AF recurrence following hospital discharge among patients with new-onset AF during a hospitalization for non-cardiac surgery or medical illness, compared to a matched population without AF.

METHODS AND RESULTS: We recruited two cohorts of patients, hospitalized for non-cardiac surgery or medical illness, respectively, with transient new-onset AF (cases) from three academic hospitals. For each case, we recruited an age and sex-matched control without any history of AF, from the same hospital ward. All study participants left hospital in sinus rhythm.
Cases and controls wore a 14-day ECG monitor at 1 and 6 months. The primary outcome was AF lasting at least 30 seconds, or captured on a 12 lead ECG, occurring after hospital discharge. Total follow up was 12 months.

We enrolled 139 cases (70 medical and 69 surgical) and identical numbers of matched controls. Participants had a mean age of 71+10 years, a mean CHA2DS2-VASc score of 3.0+1.5 and 59% were male. AF had a median of 15.8 (interquartile range [IQR] 6.4-49.6) hours of AF during the index hospitalization. Upon discharge, 49.6% received oral anticoagulation.
After 1 year, AF was detected in 33.1% (95%CI 31.9-34.2%) of cases and 5.0% (95%CI 4.2-5.3%) of controls (odds ratio [OR] 10.8, 95%CI 3.9-30.0, p < 0.0001). Similar results were seen for both medical (28.6% (95%CI 28.6-30.1%) versus 2.9% (95%CI 1.9-3.3%), OR 19.0 (95%CI 2.4-141.9, p < 0.0001) and surgical illness (37.7% (95%CI 36.0-39.3%) versus 7.2% (95%CI 6.0-7.9%), OR 8.0 95%CI 2.4-26.6, p < 0.0001). The median duration of AF detected in case participants during follow-up was 7.9 (IQR 1.8-45.0) hours.

Conclusion: Among patients who experience transient new-onset AF during a hospitalization for non-cardiac surgery or medical illness, approximately 1 in 3 will have recurrent AF within one year. This high rate of recurrence indicates that AF detected during hospitalization should not automatically be considered as reversible.