Towards understanding atrial cardiomyopathy in atrial fibrillation

Atrial fibrillation (AF) is a condition characterized by irregular heartbeat, affecting millions of people worldwide. Although AF itself is not directly fatal, it is linked to various risk factors and other health issues like poor quality of life, stroke, heart failure, and worse cardiovascular outcomes.

Atrial fibrillation is considered a progressive disease, meaning it worsens over time, particularly as more risk factors and comorbidities accumulate. The progression of AF involves changes in the structure and function of the atria (the upper chambers of the heart), known as atrial cardiomyopathy (ACM). Atrial cardiomyopathy encompasses a range of changes in the atria that can contribute to clinical manifestations of atrial fibrillation.

The general aim of this thesis of Vincente Artola Arita was to provide insights on how risk factors, comorbidities and sex differences are associated to AF and its progression. This association was investigated by exploring underlying mechanisms using clinical, echocardiographic and blood biomarkers. In addition, this thesis aimed to explore the role of atrial cardiomyopathy in atrial fibrillation and its progression.

Atrial cardiomyopathy can be challenging to measure directly, as it often requires invasive procedures to examine atrial tissue. Instead, alternative non-invasive techniques can provide insights into atrial cardiomyopathy. These methods include imaging techniques, like echocardiography, and blood biomarkers associated with atrial cardiomyopathy.

The results of this thesis suggest that atrial cardiomyopathy starts early in the presence of atrial fibrillation and comorbidities, and in patients with multiple comorbidities, atrial cardiomyopathy is already well established. These results may indicate that controlling comorbidities and managing atrial fibrillation early may be crucial in stopping or delaying atrial cardiomyopathy. Additionally, results from this thesis found differences between men and women with atrial fibrillation. Biomarker levels suggest that the underlying pathophysiological mechanisms of atrial fibrillation may vary between men and women, with more inflammatory responses in women and more prominent vascular remodeling in men. Understanding these differences could help tailor interventions for atrial fibrillation based on sex-specific considerations.