Author + information
- Marco Guazzi, MD, PhD⁎ and
- Francesco Bandera, MD
- ↵⁎Heart Failure Unit, University of Milan, IRCCS Policlinico San Donato, P.za Malan, 2, 20097 San Donato Milanese, Milan, Italy
The study by Forman et al. (1) increases the perspectives on how the distance of the 6-min walk test (6MWT) and the measured oxygen uptake (VO2) and ventilatory efficiency (VE/VCO2 slope) may add to the prognostic workup of heart failure (HF) patients.
By examining these variables in a mild-to-moderate risk HF population, a similar prediction for hospitalization and mortality was observed at univariate analysis, whereas no prognostic discrimination emerged when variables were tested against main demographic and clinical characteristics.
Findings are relevant because they definitively strengthen the 6MWT as a simple test that quantitatively mirrors the severity of HF syndrome. The question is whether this further evidence may restrain clinicians from performing a cardiopulmonary exercise test (CPET) that would not add to the prognostic indications provided by a 6MWT, obviously opting for cost-effectiveness and avoiding some complexity related to a CPET.
We believe that a few considerations may help to critically reconsider this conceivable but perhaps simplistic conclusion, anticipating future directions in pre-specified trials.
Over the past 10 years, survival studies of CPET in HF and statements (2) have defined how an approach that includes multiple variables would better define prognosis based on the assumption that exercise limitation is multifactorial and any single variable may only partially reflect the complex pathophysiology.
Peak VO2 and VE/VCO2 slope are strong predictive variables, but it seems important to question how the present findings would have been changed if, for example, the presence of the exercise oscillatory ventilation (EOV) pattern, which has been consistently proven prognostically superior to both peak VO2 and VE/VCO2 slope, or the oxygen efficiency slope, had been included in the statistical model. EOV clearly outperformed the 6MWT distance in a previous report (3).
Addressing the role of different exercise modalities by using a multiparametric approach that may truly reflect the whole potentiality of each test will probably provide a balanced view on how 6MWT distance and CPET are equal or when each test may provide better value in the risk stratification among HF populations.
- American College of Cardiology Foundation
- Forman D.E.,
- Fleg J.L.,
- Kitzman D.W.,
- et al.
- Guazzi M.,
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- Conraads V.,
- et al.
- Guazzi M.,
- Dickstein K.,
- Vicenzi M.,
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