Relation between six-minute walk test performance and outcomes after transcatheter aortic valve implantation (from the PARTNER trial)

Abstract

Functional capacity as assessed by 6-minute walk test distance (6MWTD) has been shown to predict outcomes in selected cohorts with cardiovascular disease. To evaluate the association between 6MWTD and outcomes after transcatheter aortic valve implantation (TAVI) among participants in the Placement of AoRTic TraNscathetER valve (PARTNER) trial, TAVI recipients (n = 484) were stratified into 3 groups according to baseline 6MWTD: unable to walk (n = 218), slow walkers (n = 133), in whom 6MWTD was below the median (128.5 meters), and fast walkers (n = 133) with 6MWTD >128.5 meters. After TAVI, among fast walkers, follow-up 6MWTD decreased by 44 ± 148 meters at 12 months (p <0.02 compared with baseline). In contrast, among slow walkers, 6MWTD improved after TAVI by 58 ± 126 meters (p <0.001 compared with baseline). Similarly, among those unable to walk, 6MWTD distance increased by 66 ± 109 meters (p <0.001 compared with baseline). There were no differences in 30-day outcomes among 6MWTD groups. At 2 years, the rate of death from any cause was 42.5% in those unable to walk, 31.2% in slow walkers, and 28.8% in fast walkers (p = 0.02), driven primarily by differences in noncardiac death. In conclusion, among high-risk older adults undergoing TAVI, baseline 6MWTD does not predict procedural outcomes but does predict long-term mortality. Nonetheless, patients with poor baseline functional status exhibit the greatest improvement in 6MWTD. Additional work is required to identify those with poor functional status who stand to benefit the most from TAVI.

Trial registration: ClinicalTrials.gov NCT00530894.