Predictive profiles for poor functional improvement and mortality after transcatheter aortic valve replacement. Value of 6-minute walk test and myocardial work analysis

BACKGROUND: Clinical improvement and survival after transcatheter aortic valve replacement (TAVR) remain difficult to predict. Although multiple predictors of both outcomes have been identified, prognostic algorithms for patients undergoing TAVR are not well established. AIMS: This study aimed to identify factors associated with the lack of meaningful improvement in exercise capacity after TAVR and to determine whether the predictive profile for poor functional response (PFR) also relates to mortality. METHODS: We enrolled 220 patients (78.0 [6.4] years) with severe aortic stenosis undergoing TAVR. Pre‑ and post-procedural (3 months) assessments included clinical evaluation, echocardiography with myocardial work analysis, and the 6‑minute walk test (6MWT). PFR was defined as an increase in 6MWT distance <40 m. RESULTS: Only age and atrial fibrillation independently predicted both mortality and PFR. Mortality was associated with lower global work index (HR, 0.99; P <0.001) and shorter 6MWT distance (HR, 0.99; P = 0.008). PFR was associated with higher global wasted work (OR, 1.003; P = 0.04) and less impaired baseline 6MWT relative to predicted values (OR, 0.29; P <0.001 for <80% predicted). Unsupervised machine‑learning analysis (Partition Around Medoids) identified clusters linked to mortality but not to PFR. CONCLUSIONS: Predictive profiles for PFR and mortality after TAVR show limited overlap, indicating that these outcomes require distinct prognostic approaches. The 6MWT may inform both endpoints: lower absolute values predict mortality, whereas higher percentage‑predicted values identify patients less likely to experience significant symptomatic improvement. Myocardial work analysis may further refine prognostic assessment in this population.