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Updated: May 29, 2026

Estimating Bilateral Atrial Function by Cardiovascular Magnetic Resonance Feature Tracking in Patients with Paroxysmal Atrial Fibrillation
Published on: July 20, 2022
Atrial Function by Long Axis Shortening Enhances Risk Stratification Beyond Traditional CMR Markers in Possible
Nicola Ciocca1, Delia Brändle2, Lars Riederer1
1Department of Cardiology, Inselspital, Bern University Hospital, University of Bern, Bern, Switzerland.
Insights
Atrial dysfunction, measured by atrial long axis shortening (LAS) via cardiac magnetic resonance (CMR), independently predicts adverse cardiovascular events in patients with possible myocarditis. This finding enhances risk stratification beyond traditional markers like ejection fraction and late gadolinium enhancement.
Area of Science:
- Cardiology
- Cardiovascular Imaging
- Myocardial Diseases
Background:
- Left ventricular ejection fraction (LVEF) and cardiac magnetic resonance (CMR) late gadolinium enhancement (LGE) are established risk markers in myocarditis.
- The prognostic value of atrial functional impairment in myocarditis is currently unknown.
Purpose of the Study:
- To evaluate the association of left atrial (LA) and right atrial (RA) long axis shortening (LAS) assessed by CMR with major cardiovascular adverse events (MACE) in patients with possible myocarditis.
Main Methods:
- Included 787 patients meeting 2025 European Society of Cardiology criteria for 'possible myocarditis' without coronary artery disease.
- Assessed LA and RA long axis shortening (LAS) using CMR.
- Associated LAS with a composite of first MACE, including heart failure hospitalization, sustained ventricular tachycardia, recurrent myocarditis, and all-cause mortality.
Main Results:
- After a median follow-up of 3.5 years, 17.5% of patients experienced MACE.
- Both LA-LAS and RA-LAS were independently associated with MACE in multivariable models.
- Adding atrial LAS to a baseline model significantly improved risk stratification for MACE (C-index from 0.72 to 0.75).
Conclusions:
- Atrial dysfunction, indicated by atrial LAS, is present in possible myocarditis.
- Atrial LAS independently and incrementally predicts outcomes, offering added value beyond traditional CMR markers.
- Atrial LAS may refine future risk stratification for patients with possible myocarditis.
Background:
Left ventricular ejection fraction (LVEF) and cardiac magnetic resonance (CMR) late gadolinium enhancement (LGE) are established risk markers for patients with myocarditis. Whether atrial functional impairment may occur in this clinical setting, and whether this finding offers incremental prognostic value, remains unknown.
Objectives:
The authors sought to evaluate the association of left atrial (LA) and right atrial (RA) long axis shortening (LAS) assessed by CMR with major cardiovascular adverse events (MACE) in patients with possible myocarditis.
Methods:
Patients meeting 2025 European Society of Cardiology criteria for "possible myocarditis" undergoing CMR at 2 tertiary centers, without coronary artery disease or alternative diagnosis, were included. LAS was associated with a composite of first MACE (heart failure hospitalization, sustained ventricular tachycardia, recurrent myocarditis, and all-cause mortality).
Results:
A total of 787 patients (age 48 ± 16 years, 36% female) were included. LA-LAS was 21.5% ± 10.1%, and RA-LAS 29.5% ± 12.1%. After a median follow-up of 3.5 years (Q1-Q3: 1.8-6.5 years), 17.5% experienced a MACE. In the univariate analysis, both LA-LAS (per 5% decrease) (HR: 1.37; 95% CI: 1.23-1.52; P < 0.001) and RA-LAS (HR: 1.27; 95% CI: 1.19-1.37; P < 0.001), were associated with MACE. In multivariable models, LA-LAS below the median (22%) (HR: 2.17; 95% CI: 1.33-3.57; P = 0.002) and RA-LAS below the median (29%) (HR: 1.75; 95% CI: 1.12-2.70; P = 0.012) both independently predicted MACE. Adding LA-LAS and RA-LAS to the baseline model (clinical variables, left ventricular end-diastolic volume, LVEF, and LGE) resulted in improved risk stratification for MACE (chi-square increase by 11.3; P < 0.001; C-index from 0.72 to 0.75).
Conclusions:
Atrial dysfunction can be present in possible myocarditis and atrial LAS was independently and incrementally associated with outcomes beyond traditional CMR markers and may refine future risk stratification in this clinical setting. (CMR Features in Patients With Suspected Myocarditis [CMRMyo]; NCT03470571; Inflammatory Cardiomyopathy Bern Registry [FlamBER]; NCT04774549).
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