Composite biatrial cardiomyopathy severity score and its clinical associations in patients with left-sided valvular heart disease

Background Atrial cardiomyopathy (ACM) is increasingly recognized as a structural and functional substrate associated with atrial fibrillation (AF) and increased thromboembolic risk [1]. Echocardiographic volumetric and strain parameters enable detailed characterization of atrial structure and function. However, integrated approaches to assess biatrial remodeling severity remain limited [2]. To address this gap, we performed a comprehensive biatrial evaluation and developed a composite severity score reflecting structural and functional impairment. Purpose To develop a composite biatrial ACM severity score reflecting the extent of atrial remodeling and to investigate its clinical associations in patients with left-sided valvular heart disease. Methods We conducted a prospective data analysis of 90 patients with left-sided valvular heart disease (aortic stenosis, aortic regurgitation, mitral stenosis and mitral regurgitation). The median age was 70.5 [58.8–80.0] years. The cohort included 25.6% men and 74.4% women. AF was present in 36.7% of patients. Six patients were excluded from strain analysis due to inadequate image quality. Baseline characteristics did not differ significantly between included and excluded patients. The composite biatrial ACM score was constructed in 84 patients using 12 echocardiographic parameters: left and right atrial volumes and indexed volumes, emptying fractions, and strain parameters (reservoir, conduit, and contractile phases). Each parameter was categorized into tertiles within the study population and assigned a score from 1 to 3, with 1 denoting the lowest degree of impairment and 3 the highest. The summed score, ranging form 12 to 36, was calculated for each patient, and patients were stratified into mild, moderate, and severe ACM groups according to score tertiles. Comparisons between severity groups were performed using ANOVA/Kruskal–Wallis and Chi-square tests. Trend analysis across ACM categories was conducted. Results Increasing ACM severity was significantly associated with higher BNP levels (p = 0.005), a more advanced AF phenotype (p = 0.015; trend p = 0.002), and higher CHA2DS2-VASc score (p = 0.002). Greater severity was also associated with electrocardiographic (ECG) markers of atrial remodeling, including biphasic P-wave morphology (p = 0.017), as well as the presence of a family history of conduction disorders (p = 0.027), diastolic function assessed by E/A ratio (p = 0.029), and functional capacity measured by 6-minute walk test distance (p = 0.027). Conclusion A composite biatrial atrial cardiomyopathy severity score based on volumetric and strain parameters is associated with higher BNP levels, a more advanced AF phenotype, increased thromboembolic risk profile, and ECG evidence of atrial remodeling. This integrated score may serve as a practical tool for atrial disease phenotyping and risk stratification in patients with left-sided valvular heart disease.