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Updated: Oct 3, 2026
Estimating Bilateral Atrial Function by Cardiovascular Magnetic Resonance Feature Tracking in Patients with Paroxysmal Atrial Fibrillation
Published on: July 20, 2022
The relative importance of left atrial function versus dimension in predicting atrial fibrillation after coronary
Toshiko Nakai1, Randall J Lee, Nelson B Schiller
1Department of Medicine, Section of Cardiac Electrophysiology, and Cardiovascular Research Institute, University of California, San Francisco 94143, USA. nakai@medicine.ucsf.edu
Insights
Age and larger atrial size, not atrial function, predict atrial fibrillation (AF) after coronary artery bypass graft (CABG) surgery. These findings aid in identifying patients at higher risk for AF post-CABG.
Area of Science:
- Cardiology
- Cardiac Surgery
- Echocardiography
Background:
- Atrial fibrillation (AF) is a frequent complication following coronary artery bypass graft (CABG) surgery.
- Identifying predictors of postoperative AF is crucial for patient management.
Purpose of the Study:
- To investigate whether pre-existing left atrial dysfunction predicts postoperative AF after CABG.
- To compare the predictive value of left atrial function against other clinical factors.
Main Methods:
- Prospective study of 93 patients undergoing CABG.
- Intraoperative transesophageal echocardiography to assess left atrial size and function.
- Atrial index calculated using transmitral flow velocity and left atrial ejection fraction.
- Statistical analysis including logistic regression to identify predictors of postoperative AF.
Main Results:
- Postoperative AF occurred in 30.1% of patients.
- Patients with AF were older and had larger left atrial dimensions.
- Multivariate analysis identified age (OR 1.11) and atrial dimension (OR 1.75) as independent predictors.
- Body surface area also showed a significant association with increased AF risk.
Conclusions:
- Age and left atrial enlargement are significant independent predictors of postoperative AF after CABG.
- Left atrial function, as assessed by the atrial index, was not a significant predictor.
- These findings highlight the importance of age and atrial size in risk stratification for AF post-CABG.
Background:
Atrial fibrillation (AF) is a common complication after coronary artery bypass graft (CABG) surgery. The purpose of this study was to determine whether pre-existing left atrial dysfunction is a predictor of postoperative AF compared with other clinical predictors.
Methods:
Ninety-three patients undergoing CABG were prospectively studied. Intraoperatively, transesophageal echocardiography was performed to measure left atrial size, transmitral flow velocity, and other routine parameters. Left atrial function was estimated by the following formula: Atrial index = Transmitral VTI total x LAEF/Left atrial maximal area (where VTI = velocity time integral of E and A waves, LAEF = left atrial ejection fraction). The association of potential clinical predictors with the occurrence of postoperative AF was evaluated by chi2 or Fisher exact tests, followed by stepwise multivariate logistic regression model. P values and odds ratios (OR) with 95% CIs were reported. Significance was set at P <.05.
Results:
Postoperative AF occurred in 28 of 93 patients (30.1%). Patients with postoperative AF were older (67.0 +/- 8.3 vs 61.5 +/- 9.6 years, P =.0075), had larger left atrial maximal area (14.3 +/- 4.6 cm(2) vs 10.9 +/- 4.3 cm2, P <.001), lower atrial index (0.54 +/- 0.56 vs 0.82 +/- 0.64, P =.008), larger body surface area (BSA) (OR 57, 95% CI 3.97-827), longer aortic cross-clamp time (OR 1.03, 95% CI 1.00-1.05), and more likely to have a postoperative myocardial infarction (OR 3.28, 95% CI 0.99-10.87) compared with those without AF. By multivariate analysis, only age (OR 1.11, 95% CI 1.04-1.19, P =.002) and atrial dimension (OR 1.75, 95% CI 1.03-2.96, P =.038) were significant independent predictors of postoperative AF. Body surface area also increased the odds of postoperative AF, but the CI was wide (OR 114, 95% CI 4.65-2810, P =.004).
Conclusions:
Our results demonstrate that age and atrial enlargement, rather than atrial function, were independent predictors of postoperative AF.
