Abstract
Natriuretic peptides (NP) are recognized as the most powerful predictors of adverse outcomes in heart failure (HF). We hypothesized that a measure of functional limitation, as assessed by 6-min walking test (6MWT), would improve the accuracy of a prognostic model incorporating a NP. This was a multicenter observational retrospective study. We studied the prognostic value of severe functional impairment (SFI), defined as the inability to perform a 6MWT or a distance walked during a 6MWT < 300 m, in 1696 patients with HF admitted to cardiac rehabilitation. The primary outcome was 1-year all-cause mortality. After adjusting for the baseline multivariable risk model-including age, sex, systolic blood pressure, anemia, renal dysfunction, sodium level, and NT-proBNP-or for the MAGGIC score, SFI had an odds ratio of 2.58 (95% CI 1.72-3.88; p < 0.001) and 3.12 (95% CI 2.16-4.52; p < 0.001), respectively. Adding SFI to the baseline risk model or the MAGGIC score yielded a significant improvement in discrimination and risk classification. Our data suggest that a simple, 6MWT-derived measure of SFI is a strong predictor of death and provide incremental prognostic information over well-established risk markers in HF, including NP, and the MAGGIC score.