Validation of a treadmill six-minute walk test protocol for the evaluation of patients with pulmonary arterial hypertension.
OBJECTIVE
To develop and validate a protocol for the treadmill six-minute walk test (tread6MWT) to evaluate patients with pulmonary arterial hypertension (PAH).


METHODS
The study population comprised 73 patients with PAH, diagnosed by means of right heart catheterization, with or without NO inhalation. All patients performed a hallway 6MWT and three tread6MWTs based on a pre-determined incremental speed protocol and interposed by a rest period. The patients who had been submitted to hemodynamic testing using NO performed the third tread6MWT while inhaling the same dose of NO that had been used during the catheterization.


RESULTS
We found that the treadmill six-minute walk distance (tread6MWD) correlated with hemodynamic data, functional class and the hallway six-minute walk distance (6MWD). In addition, the tread6MWD correlated significantly with survival, thereby confirming the correlation with disease severity. Inhalation of NO during the tread6MWT led to variations that were consistent with the hemodynamic changes induced by the same dose of inhaled NO, suggesting that the protocol developed can reflect the effect of therapeutic interventions.


CONCLUSIONS
We conclude that the tread6MWD is a useful prognostic and functional marker for the routine evaluation of PAH patients.
Camargo
Viviane Moreira de
VM
Grupo de Circulação Pulmonar, Instituto do Coração, Hospital das Clínicas, Faculdade de Medicina Universidade de São Paulo, São Paulo, SP, Brasil.
Martins
Barbara do Carmo Dos Santos
Bdo C
Jardim
Carlos
C
Fernandes
Caio Julio Cesar
CJ
Hovnanian
Andre
A
Souza
Rogério
R
D000328:Adult; D000704:Analysis of Variance; D006328:Cardiac Catheterization; D005080:Exercise Test / Q000295:instrumentation / Q000379:methods / Q000592:standards*; D005260:Female; D006439:Hemodynamics / Q000502:physiology; D006801:Humans; D006976:Hypertension, Pulmonary / Q000175:diagnosis / Q000401:mortality / Q000503:physiopathology*; D001239:Inhalation / Q000502:physiology; D053208:Kaplan-Meier Estimate; D008297:Male; D009569:Nitric Oxide / Q000008:administration & dosage; D016138:Walking / Q000502:physiology*
D009569:Nitric Oxide