Background

In patients with atrial fibrillation (AF) the atrial substrate plays an essential role in the maintenance of this arrhythmia. As a surrogate parameter of atrial fibrosis, low-voltage-areas (LVA) can be reliably identified using modern 3D mapping systems. While in the development of ventricular LVA the pathomechanism is often based on coronary artery disease (CAD) or history of myocardial infarction (MI), the mechanisms contributing to atrial fibrosis have not yet been adequately characterised. Therefore, the aim of this study was to investigate predictors for the presence of atrial LVA in AF-patients with and without CAD.

Methods and results

Between 2015 and 2020, 169 AF-patients (mean age: 69 ±9 years, female sex: 45.0%, persistent AF: 49.7%, CAD: 36.7%) with invasively diagnosed or excluded CAD, in whom 3D mapping of the left atrium was performed during AF-ablation, were included (ATRIUM DRKS-ID: DRKS00013013 ). Areas in which the measured bipolar voltage in 3D mapping was less than 0.5mV were counted as LVA.

In a multivariate logistic regression, female sex (Odd's ratio: 7.9, p<0.001), CAD (Odd's ratio: 2.7, p=0.04), left atrial diameter (Odd's ratio: 1.1, p<0.01), body-mass-index (Odd's ratio: 0.9, p=0.01) and chronic renal failure (Odd's ratio: 3.2, p=0.04) emerged as independent predictors of severe LVA burden. A gender-specific regression revealed the presence of CAD as the only independent predictor in men (Odd's ratio: 13.1, p=0.02), while in women an enlarged left atrial diameter statistically independently predicted the presence of LVA (Odd’s ratio: 1.1, p=0.01).

Conclusion

Gender-specific differences in the prediction of LVA as a surrogate parameter for left atrial fibrosis in AF-patients indicates different pathomechanisms in men compared to women. In men, the presence of CAD is associated with a more than 10-fold increased risk for LVA, suggesting that an impaired coronary supply plays a crucial role in the development of atrial cardiomyopathy in male AF-patients.