NPPB and hydrops fetalis: In this prospective cohort of propensity score-matched MR patients (38% functional, 62% degenerative MR) who underwent either TMVR or SMV, we report three main findings: (1) both techniques showed equivalent event-free survival at two years; (2) patients who did not meet the composite endpoint (HF hospitalization/death), labeled as “Super Responders”, were characterized by lower baseline NT-proBNP serum levels and less residual MR; and finally, (3) only EuroSCORE-II and residual MR were independently associated with outcome.