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Updated: Jul 10, 2025
Estimating Bilateral Atrial Function by Cardiovascular Magnetic Resonance Feature Tracking in Patients with Paroxysmal Atrial Fibrillation
Published on: July 20, 2022
Heart Failure, Female Sex, and Atrial Fibrillation Are the Main Drivers of Human Atrial Cardiomyopathy: Results From
Joris Winters1, Aaron Isaacs1,2, Stef Zeemering1
1Department of Physiology, Cardiovascular Research Institute Maastricht University Maastricht Maastricht The Netherlands.
Insights
Atrial cardiomyopathy (atCM) shows distinct fibrotic and hypertrophic subtypes. Fibrotic atCM is linked to female sex, persistent atrial fibrillation (AF), and heart failure, while hypertrophy is more common in men.
Area of Science:
- Cardiology
- Pathology
- Histology
Background:
- Atrial cardiomyopathy (atCM) is an increasingly recognized prognostic factor in cardiovascular disease.
- Key features of atCM include fibrotic remodeling, cardiomyocyte hypertrophy, and altered capillary density.
- The specific contributions of etiological factors and atrial fibrillation (AF) to diverse atCM phenotypes remain unclear.
Purpose of the Study:
- To investigate the association between histological characteristics of atCM and clinical phenotypes.
- To quantify the influence of etiological factors, such as AF and heart failure, on atCM histological features.
Main Methods:
- Histological analysis of left and right atrial appendages from 171 patients using specialized staining techniques.
- Multiple linear regression models to assess the impact of AF, heart failure, sex, and age on histological features.
- Fuzzy k-means clustering to identify distinct atCM subtypes based on histological findings.
Main Results:
- Persistent AF correlated with increased endomysial fibrosis in both atria.
- Men exhibited larger cardiomyocytes, while women showed greater endomysial fibrosis.
- Heart failure patients presented with more fibrosis, extracellular matrix content, and increased capillary density and size.
- Two atCM subtypes were identified: one with enhanced fibrosis and extracellular matrix, and another with cardiomyocyte hypertrophy.
- Fibrotic atCM was associated with female sex, persistent AF, and heart failure; hypertrophic features were more prevalent in men.
Conclusions:
- Atrial cardiomyopathy exhibits distinct histological subtypes, primarily fibrotic and hypertrophic.
- Fibrotic atCM is significantly associated with female sex, persistent atrial fibrillation, and heart failure.
- Hypertrophic features of atCM are more commonly observed in men.
Background:
Atrial cardiomyopathy (atCM) is an emerging prognostic factor in cardiovascular disease. Fibrotic remodeling, cardiomyocyte hypertrophy, and capillary density are hallmarks of atCM. The contribution of etiological factors and atrial fibrillation (AF) to the development of differential atCM phenotypes has not been quantified. This study aimed to evaluate the association between histological features of atCM and the clinical phenotype.
Methods And Results:
We examined left atrial (LA, n=95) and right atrial (RA, n=76) appendages from a European cohort of patients undergoing cardiac surgery. Quantification of histological atCM features was performed following wheat germ agglutinin/CD31/vimentin staining. The contributions of AF, heart failure, sex, and age to histological characteristics were determined with multiple linear regression models. Persistent AF was associated with increased endomysial fibrosis (LA: +1.13±0.47 microm, P=0.038; RA: +0.94±0.38 microm, P=0.041), whereas total extracellular matrix content was not. Men had larger cardiomyocytes (LA: +1.92±0.72 microm, P<0.001), while women had more endomysial fibrosis (LA: +0.99±0.56 microm, P=0.003). Patients with heart failure showed more endomysial fibrosis (LA: +1.85±0.48 microm, P<0.001) and extracellular matrix content (LA: +3.07±1.29%, P=0.016), and a higher capillary density (LA: +0.13±0.06, P=0.007) and size (LA: +0.46±0.22 microm, P=0.044). Fuzzy k-means clustering of histological features identified 2 subtypes of atCM: 1 characterized by enhanced endomysial fibrosis (LA: +3.17 microm, P<0.001; RA: +2.86 microm, P<0.001), extracellular matrix content (LA: +3.53%, P<0.001; RA: +6.40%, P<0.001) and fibroblast density (LA: +4.38%, P<0.001), and 1 characterized by cardiomyocyte hypertrophy (LA: +1.16 microm, P=0.008; RA: +2.58 microm, P<0.001). Patients with fibrotic atCM were more frequently female (LA: odds ratio [OR], 1.33, P=0.002; RA: OR, 1.54, P=0.004), with persistent AF (LA: OR, 1.22, P=0.036) or heart failure (LA: OR, 1.62, P<0.001). Hypertrophic features were more common in men (LA: OR=1.33, P=0.002; RA: OR, 1.54, P=0.004).
Conclusions:
Fibrotic atCM is associated with female sex, persistent AF, and heart failure, while hypertrophic features are more common in men.
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