External Validation of Two Different Cardiac Damage Staging Systems for Aortic Stenosis in Patients Treated with Surgical Aortic Valve Replacement

<b>Background</b>: Several cardiac damage staging systems for aortic stenosis (AS) have been proposed, but their usefulness in patients undergoing surgical aortic valve replacement (SAVR) remains unknown. <b>Objectives</b>: We aim to externally validate two staging systems in patients who underwent SAVR. <b>Methods</b>: Single-centre prospective cohort of patients treated with SAVR (2017-2022). Based on baseline echocardiographic parameters, patients were classified into the different stages of two published staging systems (Généreux et al. and Gutiérrez et al.), and the discriminatory yield of these systems for 1-year mortality was evaluated. <b>Results</b>: In total, 350 patients were analysed (mean age 69 (9.4) years, 37.8% were female). The median EuroSCORE II was 1.7 (1.1-3.1), and 1-year mortality occurred in 17 (4.8%) patients. The staging system developed by Gutiérrez et al. had an area under the ROC curve (AUC) of 0.687 (95% CI: 0.571-0.803) and was superior to Généreux et al.'s system (AUC of 0.554; 95% CI: 0.439-0.669; <i>p</i> = 0.008). Applying Gutiérrez et al.'s system, 1-year mortality rates progressively increased with higher damage staging: 1.9% (2/103) for Stage 0; 5.1% (5/175) for Stage 1; 12.5% (5/40) for Stage 2; and 15.6% (5/32) for Stage 3 (which represents right-sided damage measured by right ventricular-arterial coupling (RVAc); <i>p</i>= 0.038). No significant differences in outcomes between stages were found when using the staging proposed by Généreux et al. (<i>p</i> = 0.218). <b>Conclusions</b>: In a surgical cohort of patients with AS, a cardiac staging system that included RVAc showed greater discriminatory power for 1-year mortality. Assessing the interrelation between right ventricular function and afterload could help in better risk stratification in this context.