Severe myocardial degeneration and DNA damage were associated with delayed recovery of left ventricular systolic function in AF-CM patients undergoing catheter ablation (r=0.42 to 0.49).
Observational (n=23)
No
Are histological features of myocardial degeneration and DNA damage associated with delayed recovery of left ventricular function in patients with atrial fibrillation-induced cardiomyopathy undergoing catheter ablation?
In patients with AF-induced cardiomyopathy, histological evidence of severe myocardial degeneration and DNA damage from right ventricular biopsies correlates with delayed recovery of left ventricular systolic function after catheter ablation.
Effect estimate: r=0.43, 0.42, 0.49, and 0.47
Background: Atrial fibrillation-induced cardiomyopathy (AF-CM) is a secondary cardiomyopathy characterized by recovery of left ventricular (LV) dysfunction after restoration of sinus rhythm from atrial fibrillation (AF); however, the pathological evidence of AF-CM remains limited. Methods and Results: We retrospectively analyzed AF-CM patients who underwent both endomyocardial biopsy (EMB) from the right ventricle and catheter ablation (CA) for AF at Kyushu University Hospital between 2014 and 2023. We investigated the relationships between histological features and the recovery process of LV function in AF-CM after CA for AF. Recovery of LV ejection fraction (EF) was defined as an improvement ≥15%. EMB specimens were evaluated for myocardial fibrosis, cytoplasmic vacuolization, and nuclear expression of phosphorylated histone H2A variant X (γ-H2A.X) and poly(ADP-ribose) (PAR). Among 23 patients, the median time from CA to LVEF recovery was 145 days 90–220, and 83% achieved an LVEF ≥50%. Greater myocardial fibrosis, cytoplasmic vacuolization, and higher nuclear expression of γ-H2A.X and PAR were associated with delayed LVEF recovery (r=0.43, 0.42, 0.49, and 0.47, respectively). AF-CM severity scores derived from these histological features demonstrated associations with LVEF recovery time (R 2 =0.33 for the “structural damage score” and R 2 =0.29 for the “DNA damage score”). Conclusions: In AF-CM patients undergoing CA, severe myocardial degeneration and DNA damage were associated with delayed recovery of LV systolic function.
Yokoyama et al. (2026) conducted an observational in Atrial fibrillation-induced cardiomyopathy (n=23). Myocardial degeneration and DNA damage was evaluated on Delayed recovery of left ventricular ejection fraction (improvement ≥15%) (r=0.43, 0.42, 0.49, and 0.47). Severe myocardial degeneration and DNA damage were associated with delayed recovery of left ventricular systolic function in AF-CM patients undergoing catheter ablation (r=0.42 to 0.49).