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2024 Australian Society of Anaesthetists’ National Scientific Conference

New perioperative atrial fibrillation after major non-cardiac surgery: incidence and risk factors at Westmead Hospital

Prize

Prize

4:15 pm

07 September 2024

Waterfront Room 3

Trainee Member Group (TMG) Best Poster Prize

Themes

Prize

Talk Description

Introduction: 
Perioperative atrial fibrillation (POAF) is one of the most common cardiovascular complications in the perioperative period [1-2]. Previously thought to be a transient self-limiting condition, recently we have come to understand that the development of new POAF demonstrates vulnerability towards progressing to persisting AF, thereby increasing a patient’s long-term stroke risk and mortality [1-2]. Westmead Hospital is participating in the ASPIRE-AF international multicentre clinical trial which aims to address the paucity of evidence guiding the commencement of therapeutic anticoagulation for patients who develop new POAF. The study at Westmead Hospital thus far has been hampered by difficulties identifying patients for recruitment. The aim of our study was therefore to determine the incidence of new POAF in the Westmead Hospital non-cardiac surgical cohort, in addition to determining the optimal method for identifying these patients for subsequent recruitment to the ASPIRE-AF study. The secondary aim of our study was to identify risk factors for the development of new POAF in our cohort.

Methods: 
We conducted a retrospective observational study to determine the incidence of new POAF in the Westmead Hospital non-cardiac surgical cohort over the year of 2022. We obtained a list of all procedures performed in 2022 at Westmead Hospital operating suite and filtered using the exclusion criteria for the ASPIRE-AF study. A random sample of 15% of procedures were selected for data extraction. We reviewed pre- and post-operative documentation for evidence of pre-existing AF and new POAF respectively to subsequently determine the incidence of new POAF in our cohort. We additionally collected relevant demographic and comorbidity data to perform multivariate logistic regression analysis to identify risk factors for the development of new POAF. Ethics approval was obtained through the Western Sydney Local Health District Human Research Ethics Committee (WSLHD HREC 2310-05-QA, 25/10/23).

Results: 
Of 10,812 procedures performed in 2022, 7,479 were eligible for data extraction on initial screening. 15% (1,125) of procedures underwent data extraction, with an additional 28.4% excluded. 12 cases of new POAF were identified in the remaining 806 procedures, giving an incidence rate of 1.5%. It is therefore estimated that approximately 80 patients are eligible for recruitment into the ASPIRE-AF study each year from our cohort. 5-year increase in age (OR 1.25 (95% C.I. 1.00-1.52), p 0.05) and history of congestive cardiac failure (CCF) (OR 11.16 (95% C.I. 3.15-39.54), p < 0.001) were independent predictors of new POAF in our cohort.

Discussion: 
We identified an incidence rate of 1.5% of new POAF in our cohort, compared with a pooled incidence rate of 2.3-6.2% published in a recent systematic review [1]. Our lower-than-expected incidence rate compared with studies actively screening for new POAF [1] likely reflects the silent and transient nature of the majority of POAF cases [2]. Referrals to Cardiology were identified to be the most robust source for recruitment to the ASPIRE-AF study. Identified risk factors, such as age and history of CCF, may be used to focus an active-screening program for screening higher-risk patients for the development of new POAF.

Conflicts of Interest: 
nil

References:
[1] Subramani, Y., El Tohamy, O., Jalali, D., Nagappa, M., Yang, H., & Fayad, A. (2021). Incidence, Risk Factors, and Outcomes of Perioperative Atrial Fibrillation following Noncardiothoracic Surgery: A Systematic Review and Meta-Regression Analysis of Observational Studies. Anesthesiology research and practice, 2021, 5527199. https://doi.org/10.1155/2021/5527199
[2] Lin, M.-H., Kamel, H., Singer, D. E., Wu, Y.-L., Lee, M., & Ovbiagele, B. (2019). Perioperative/Postoperative Atrial Fibrillation and Risk of Subsequent Stroke and/or Mortality. Stroke, 50(6), 1364-1371. https://doi.org/doi:10.1161/STROKEAHA.118.023921

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