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Updated: Jul 26, 2025
Estimating Bilateral Atrial Function by Cardiovascular Magnetic Resonance Feature Tracking in Patients with Paroxysmal Atrial Fibrillation
Published on: July 20, 2022
Left atrial functional measurements' utility in predicting long-term risk of atrial fibrillation after isolated CABG
Mikkel Ravn Dyhr1,2, Flemming Javier Olsen1,2, Søren Lindberg1
1Department of Cardiology, Copenhagen University Hospital-Herlev and Gentofte Hospital, Hellerup, Denmark.
Insights
Atrial fibrillation (AF) after coronary artery bypass grafting (CABG) can be predicted by left atrial (LA) function measures, specifically LA minimum volume index (LAVmin) and LA emptying fraction (LAEF), in patients with normal-sized atria. These findings aid in identifying at-risk individuals post-CABG.
Area of Science:
- Cardiology
- Cardiac Surgery
- Echocardiography
Background:
- Atrial fibrillation (AF) is a common complication after coronary artery bypass grafting (CABG).
- Predicting post-CABG AF is crucial for patient management.
- Left atrial (LA) function may play a role in AF development.
Purpose of the Study:
- To investigate the predictive value of pre-operative left atrial (LA) functional measurements for AF development in patients undergoing CABG.
- To determine if LA volume and emptying fraction can identify patients at higher risk for post-operative AF.
Main Methods:
- A cohort of 611 patients undergoing CABG had pre-operative echocardiograms to assess LA maximum volume index (LAVmax), LA minimum volume index (LAVmin), and LA emptying fraction (LAEF).
- Patients were followed for a median of 3.7 years to identify the occurrence of AF more than 14 days after surgery.
- Statistical analysis, including Cox proportional hazards models, was used to evaluate predictors of AF, adjusting for clinical factors and the CHADS₂ score.
Main Results:
- Overall, no pre-operative LA functional measurements were significant predictors of AF in the entire CABG cohort.
- However, in patients with a normal-sized LA (n=532), both LA minimum volume index (LAVmin) and LA emptying fraction (LAEF) were univariable predictors of AF.
- After adjusting for the CHADS₂ score, LAVmin (HR=1.07) and LAEF (HR=1.02) remained significant independent predictors of AF in the normal-sized LA subgroup.
Conclusions:
- Pre-operative echocardiographic measures of LA function are not universally predictive of AF after CABG.
- In patients with normal LA size, reduced LA minimum volume index and LA emptying fraction are significant predictors of developing AF post-CABG.
- These specific LA functional parameters may help stratify risk for AF in a subset of patients undergoing CABG.
Background:
Atrial fibrillation (AF) is the most common cardiac arrhythmia following coronary artery bypass grafting (CABG). We hypothesized that measures of left atrial (LA) function would be useful in predicting AF in patients undergoing CABG.
Methods And Results:
In the study, 611 patients were included after CABG. All patients had echocardiograms performed preoperatively and LA functional measurements were assessed. These measurements were LA maximum volume index (LAVmax), LA minimum volume index (LAVmin) and LA emptying fraction (LAEF). The endpoint was AF occurring >14 days after surgery. During the follow-up period of a median of 3.7 years, 52 (9%) developed AF. The mean age was 67 years, 84% were male and the average left ventricle ejection fraction was 50%. Patients who developed AF had a lower CCS class and lower LAEF (40 vs. 45%), otherwise no clinical differences were observed between outcome groups. No functional LA measurements were significant predictors of AF in the whole CABG population. However, in patients with normal-sized LA (n = 532, events: 49), both LAEF and LAVmin were univariable predictors of AF. When the functional measurements were adjusted for the CHADS2 score, both LAVmin (HR = 1.07 [1.01-1.13], p = .014) and LAEF (HR: 1.02 [1.00-1.03], p = .023), remained significant predictors.
Conclusion:
No echocardiographic measurements were significant predictors of AF after CABG. In patients with a normal LA size, LAVmin as well as LAEF were significant predictors of AF.
