Distinct features of predictive profiles for poor functional improvement and mortality after TAVR. Incremental value of 6-minute walk test

Abstract Transcatheter aortic valve replacement (TAVR) has become a viable treatment option in severe aortic stenosis (AS). However, since many elderly and multimorbid individuals are referred for TAVR, clinical improvement and survival benefit with this procedure may be uncertain. Despite the existence of evidence on the predictive relevance of multiple factors, prognostic algorithms in patients undergoing TAVR are not well defined. Aim: We sought to explore factors determining the lack of significant improvement in exercise capacity after TAVR despite favourable hemodynamic changes achieved with the intervention, as well as to investigate whether the predictive profile for poor functional response to TAVR could also prove useful in predicting mortality. Methods: We enrolled 220 patients (mean age 78.0±6.4 years) with severe AS who underwent TAVR. Pre- and post-procedural (3 months after the intervention) data were collected, including echocardiographic parameters with LV strain and myocardial work analysis, 6-minute walk test (6MWT) distance, laboratory markers including NT-proBNP, and information on frailty and comorbidities. Poor functional response to TAVR was defined as an increase in 6MWT distance at 3 months 40 m. Results: During a median follow-up of 3.2 years, 39 patients (18%) died, and poor functional response to TAVR at 3 months was found in 111 patients (50%). In multivariable logistic regression analysis, the independent determinants of insufficient improvement in exercise capacity were patient age, atrial fibrillation, diabetes mellitus, global wasted work, and 6MWT distance 80% predicted (Table 1). In multivariable Cox regression analysis, the independent predictors of all-cause death were patient age, frailty, atrial fibrillation, global work index, E/e’ ratio, and 6MWT distance (Table 2). Conclusions: The predictive profiles for mortality and failure to significantly improve functional capacity after TAVR show only limited similarities. Therefore, these two outcomes require separate prognostic evaluations. The 6MWT can be useful in predicting the likelihood of both outcomes, with lower absolute values being associated with mortality, while higher percentage predicted values – with the lack of significant symptomatic benefit. This supports the use of 6MWT in the diagnostic and prognostic work-up in TAVR candidates.