Distance covered during a six-minute walk test predicts long-term cardiovascular mortality and hospitalisation rates in men with systolic heart failure: an observational study

Question: Does the distance covered during a 6-minute walk test predict risk of death or hospitalisation for cardiovascular reasons in men with stable heart failure over three years of follow-up? Design: Prospective observational study. Participants: 243 men with stable systolic heart failure, with a mean age of 60 yr (SD 11) and left ventricular ejection fraction of 29% (SD 8). According to the New York Heart Association (NYHA) classification, 15% of the participants were in Class I, 44% in Class II, 37% in Class III, and 4% in class IV. Outcome measures: The exercise capacity of participants was measured using the 6-minute walk test. The participants were followed up for at least three years in the case of survivors. The primary end-points of the survival analyses included cardiovascular death or urgent cardiovascular hospitalisation. Results: During the 3-year follow-up, 44% of the participants died, and 69% died or required hospitalisation for cardiovascular reasons. A multivariate analysis showed that the shorter the distance covered in the 6-minute walk test, the greater the 1-year and 3-year mortality risk. Participants with a 6-minute walk test 468 m had a mortality hazard ratio of 3.22 (95% CI 1.17 to 8.86) at one year and 2.18 (95% CI 1.18 to 4.03) at three years. Multivariate analysis also showed that higher risk mortality or hospitalisation for cardiovascular reasons was predicted by a 6-minute walk distance 468 m, with a hazard ratio of 2.77 (95% CI 1.30 to 5.88) at one year and 1.71 (95% CI 1.08 to 2.72) at three years. Conclusion: The 6-minute walk test distance constitutes an independent predictor of mortality and mortality or hospitalisation for cardiovascular reasons in men with stable systolic heart failure.