Taking a walk on the heart failure side: comparison of metabolic variables during walking and maximal exertion

Although cardiopulmonary exercise testing (CPET) is the gold standard to assess exercise capacity, simpler tests (i.e., 6-min walk test, 6MWT) are also commonly used. The aim of this study was to evaluate the relationship between cardiorespiratory parameters during CPET and 6MWT in a large, multicentre, heterogeneous population.

The investigation included athletes, healthy subjects, and heart failure (HF) patients of different severity, including left ventricular assist device (LVAD) carriers, who underwent both CPET and 6MWT with oxygen consumption measurement. HF patients (including LVAD carriers), healthy subjects, and athletes were recruited at Heart Failure Units of Centro Cardiologico Monzino IRCCS, Istituti Clinici Scientifici Maugeri IRCCS, and Department of Cardiology, University of Copenhagen, Rigshospitalet.

The study demonstrated for the first time in a broad population, that V̇O2 values obtained during a standard 6MWT are significantly related to the peakV̇O2 measured with a maximal CPET, generally considered the gold standard method to assess functional capacity.

In conclusion, these data confirm that 6MWT can be a maximal effort especially in most severe HF patients and suggest that, in absence of prognostic studies related to 6MWT metabolic values, CPET should remain the first method of choice in the functional assessment of patients with HF as well as in sport medicine.