Characterizing Right Atrial Phenotypic Shifts and Tissue Scarring in Persistent Atrial Fibrillation

Article Impact Level: HIGH
Data Quality: STRONG
Summary of  Cardiovascular Research  https://doi.org/10.1093/cvr/cvag076
Dr. Aiste Liutkute et al.

Points

Investigators utilized high-resolution mass spectrometry to analyze thousands of proteins in tissue samples from patients with persistent atrial fibrillation to map disease-related changes in heart tissue.
The study established a comprehensive human heart proteome reference library to compare diseased atrial tissues against healthy tissues from non-transplanted donor hearts without arrhythmias.
Results demonstrated that long-standing persistent atrial fibrillation causes the right atrium to undergo profound pathological remodeling that closely mirrors the damage found in the left atrium.
Proteomic profiling revealed a distinct loss of chamber-specific markers in the right atrium which increasingly adopted left atrial features associated with altered energy metabolism and structural tissue scarring.
These findings suggest that focusing therapies exclusively on the left atrium may explain long-term treatment failures and that future clinical procedures must evaluate both heart chambers.

Summary

This study evaluated the extent of pathological structural and functional remodeling in the right atrium relative to the left atrium during persistent atrial fibrillation (persAF). Traditionally, clinical research and targeted ablation therapies have focused on the left atrium and its converging pulmonary veins as the primary drivers of arrhythmogenesis. The investigators sought to determine if long-standing persAF induces independent, systemic changes across the right atrial chamber, potentially accounting for the long-term failure rates observed with localized left atrial interventions.

Using high-resolution mass spectrometry, the research team performed extensive proteomic profiling on human tissue specimens harvested from the right and left atria of patients undergoing cardiac surgery. Samples from non-transplanted donor hearts without a history of cardiac arrhythmias served as the control cohort. To facilitate precise quantification, the investigators first established a deep human heart spectral library, allowing for the simultaneous identification of thousands of proteins. The proteomic datasets were further validated through microscopic evaluation of tissue fibrosis, biochemical assays, and circulating biomarkers of myocardial stress.

The analyses demonstrated that persAF triggers profound, symmetrical remodeling that effectively homogenizes the distinct molecular profiles of both chambers. In the right atrium, the condition induced severe tissue scarring, degradation of crucial contractile myofilament structures, altered energy metabolism, and cellular stress responses that mirrored left atrial pathology. Notably, the right atrium lost its chamber-specific protein markers, increasingly adopting a left atrial phenotype. These findings suggest that persistent atrial fibrillation is a bi-atrial pathology, indicating that future therapeutic interventions may require a comprehensive bi-atrial approach to improve long-term clinical efficacy.

Link to the article: https://academic.oup.com/cardiovascres/advance-article/doi/10.1093/cvr/cvag076/8578687?login=false

References 

Liutkute, A., Berrandou, T.-E., Kestel, S., Schnelle, M., Dschun, O., Amedei, H. A., Neuenroth, L., Rytkin, E., Kyshynska, O., Kensah, G., El-Essawi, A., Jebran, A. F., Danner, B. C., Baraki, H., Kutschka, I., Bremmer, F., Urlaub, H., Schmidt, C., Bouatia-Naji, N., … Voigt, N. (2026). Mass spectrometric proteome profiling using a deep spectral library reveals homogenization of right and left atrial proteomes in persistent atrial fibrillation patients. Cardiovascular Research, cvag076. https://doi.org/10.1093/cvr/cvag076