# More Questions Than Answers: A Narrative Review of the Epidemiology, Risk Factors, and Outcomes of Postoperative Atrial Fibrillation

## TL;DR

This paper reviews the current understanding of postoperative atrial fibrillation, highlighting inconsistencies in its definition and outcomes across different patient groups.

## Contribution

The paper identifies gaps in consensus definitions and monitoring practices for postoperative atrial fibrillation.

## Key findings

- Postoperative atrial fibrillation lacks a unified definition and is under-monitored in noncardiac surgeries.
- Black and female patients show paradoxical trends in POAF risk and outcomes.
- Cancer surgeries, especially lung and colorectal, are associated with high POAF rates.

## Abstract

Postoperative atrial fibrillation (POAF) lacks a consensus definition but is generally considered to be atrial fibrillation (AF) that develops following surgery. There is disagreement as to whether POAF must be de novo or whether a patient with a history of AF episodes can have true POAF. POAF has been more studied after cardiac versus noncardiac surgery, but this may be the result of less postoperative cardiac monitoring after noncardiac surgery. POAF can be clinically silent, paroxysmal, and self-terminating, or it may persist and have the potential to evolve into more chronic forms of AF. The pathogenesis of POAF has yet to be fully elucidated. A recent study indicates that postoperative atrial flutter may occur more often than previously thought and may be underestimated as a postoperative risk. Cancer surgeries have high rates of POAF, particularly following surgeries for lung, colorectal, gastrointestinal, and hematologic cancers. Among the best-known POAF risk factors are older age, male sex, White race, duration of surgery, comorbidities, and history of cardiac disease. The Black paradox of POAF finds that Black patients have more risk factors and more severe risk factors than White patients for POAF, yet Black patients are less likely to develop POAF than White patients. However, a Black patient with POAF is more likely to have a worse outcome than a White patient. A female paradox has also come to light, because women often have more risk factors for POAF than men but develop POAF less often; however, when POAF occurs in females, they can have severe outcomes. Urgently needed is a consensus definition of POAF to support epidemiologic and clinical work, and more widely used monitoring and surveillance tools to detect POAF when it does occur.