Prevalence of albuminuria and its association with left atrial remodelling in patients with atrial fibrillation.

Aims: Although recent epidemiological studies identified albuminuria as an independent risk for atrial fibrillation (AF), even in individuals with a preserved or mildly reduced estimated glomerular filtration rate (eGFR), the prevalence of albuminuria and its association with left atrial (LA) remodelling in patients with AF remains unknown. This study aimed to investigate the association of albuminuria with LA structure and mechanics before and after catheter ablation (CA) in AF patients.

Methods and results: We examined 133 AF patients with an eGFR ≥60 mL/min/1.73 m² who underwent first CA. Conventional and speckle-tracking echocardiography was performed before and 6 months after CA to assess the LA volume index, LA reservoir strain, and LA stiffness. The median eGFR was 70 mL/min/1.73m², and 21 (15.8%) patients had albuminuria. The difference between the eGFR values of patients with and without albuminuria was not significant (P  = 0.709). Patients with albuminuria had a larger LA volume index, reduced LA reservoir strain and increased LA stiffness compared with patients without albuminuria (all P < 0.001). The presence of albuminuria was associated with reduced LA reservoir strain and increased LA stiffness, independent of age, AF type, and AF risk factors. After CA, there was significant improvement in LA size and function in both groups, while albuminuria group still had a larger LA volume index and increased LA stiffness (both P < 0.05).

Conclusion: Approximately 16% of AF patients with preserved or mildly reduced eGFR had albuminuria. The presence of albuminuria was related to unfavourable LA remodelling and its persistence even after restoration of sinus rhythm.