Can the six-minute walk test predict peak oxygen uptake in men with heart transplant?
OBJECTIVE
To determine whether the six-minute walk test (6MWT) might predict peak oxygen consumption (VO2peak) after heart transplantation.


METHODS
Case-control prospective study.


METHODS
Public hospital.


METHODS
Patients with heart transplant (n=22) and age-matched sedentary male subjects (n=13).


METHODS
Not applicable.


METHODS
Exercise performance using a maximal exercise test, distance walked using the 6MWT, heart rate, and VO2peak.


RESULTS
Compared with controls, exercise performance was decreased in patients with heart transplant with less distance ambulated (516+/-13m vs 592+/-13m; P<.001) and a decrease in mean VO2peak (23.3+/-1.3 vs 29.6+/-1mL x min(-1) x kg(-1); P<.001). Patients with heart transplant showed an increased resting heart rate, a response delayed both at the onset of exercise and during recovery. However, the patient's heart rate at the end of the 6MWT was similar to that obtained at the ventilatory threshold. The formula did not predict measured VO2, with a weak correlation observed between the six-minute walk distance and both VO2peak (r=.53; P<.01) and ventilatory threshold (r=.53; P<.01) after heart transplantation. Interestingly, when body weight was considered, correlations coefficient increased to .74 and .77, respectively (P<.001).


CONCLUSIONS
In heart transplant recipients, the 6MWT is a safe, practical, and submaximal functional test. The distance-weight product can be used as an alternative method for assessing the functional capacity after heart transplantation but cannot totally replace maximal VO2 determination.
Doutreleau
Stéphane
S
Physiology Institute, Medicine Faculty and Hospital, University Hospital of Strasbourg, Strasbourg, France. stephane.doutreleau@chru-strasbourg.fr
Di Marco
Paola
P
Talha
Samy
S
Charloux
Anne
A
Piquard
François
F
Geny
Bernard
B
D016022:Case-Control Studies; D005080:Exercise Test / Q000379:methods*; D016027:Heart Transplantation / Q000502:physiology*; D006439:Hemodynamics; D006801:Humans; D008297:Male; D008875:Middle Aged; D010101:Oxygen Consumption; D016138:Walking