Prognostic value of preprocedural 6-min walk test in patients undergoing transcatheter mitral valve repair-insights from the German transcatheter mitral valve interventions registry

AIMS: The 6-min walk test (6 MWT) has been established as an important tool for functional assessment in heart failure patients. However, its prognostic impact on the outcome in subjects with mitral regurgitation undergoing transcatheter mitral valve repair is unknown.

METHODS: This present work represents a sub-analysis of the German, prospective, multicenter, Transcatheter Mitral Valve Interventions (TRAMI) registry. Of the main study cohort (n = 828) 326 patients underwent 6 MWT prior to the procedure. Patients were assigned to two groups depending on the preprocedural 6 MWT distance using the median (< 200 m [group 1] vs. ≥ 200 m [group 2]).

RESULTS: No differences regarding procedural success (97 vs. 96%; p = 0.71) and 30-day mortality (3 vs. 4%; p = 0.96) were observed between the groups. With regards to 1-year outcome, patients with a walking distance < 200 m had higher all-cause mortality (26 vs. 14%; p = 0.013) as compared to those with a 6 MWT distance 200 m. After adjustment of baseline risk factors, 6 MWT distance < 200 m still showed a strong trend towards increased 1-year all-cause mortality (HR 1.63, 95% confidence interval 0.96-2.76; p = 0.071).

CONCLUSIONS: In the present study preprocedural 6 MWT distance < 200 m showed a strong trend towards increased 1-year mortality in patients undergoing MitraClip implantation.