Hirji S, McGurk S, Kiehm S, et al. - Whether 30-day vs 90-day mortality following transcatheter aortic valve replacement (TAVR) and surgical aortic valve replacement (SAVR) holds utility as a mortality quality metric, was investigated in this nationally representative, multicenter, cohort study. Researchers utilized data from Medicare beneficiaries receiving TAVR and SAVR procedures from January 1, 2012, to December 31, 2015. They ranked hospitals depending on their 4-year mean 30-day mortality into top- (10%), middle- (80%), and bottom-performing (10%) groups. They assessed alterations in hospital performance rankings at 90 days and 1 year as well as the correlation of 30- and 90-day mortality with 1-year mortality as main outcomes. This analysis included 30,329 TAVR admissions at 184 hospitals and 26,021 SAVR admissions at 191 hospitals. At 90 days, performance rankings were changed by 40 hospitals (21.7%) for TAVR. At 1 year, 56 hospitals (30.4%) changed rankings. For SAVR, similar results were obtained, with an overall 90-day conversion rate of 17.3% and a 1-year rate of 30.3%. According to the findings, assessment of hospital performance on the basis of 30-day mortality, vs 90-day mortality, may lead to underestimation of outcomes and thereby substantial misinterpretation of institutional performance following TAVR and SAVR, even following risk adjustment. Despite the validation gained by 30-day mortality, greater reliability may be achieved with the use of 90-day mortality as an outcome metric for assessing hospital performance and capturing procedure-associated mortality.