Patients with pulmonary arterial hypertension (PAH) who walked >400 meters in the 6-minute walk test (MWT) had a reduced risk for PAH-related death or hospitalization, according to a study published in the journal PLoS One.
Six-MWT data at baseline and at 6 months for patients with PAH in the multicenter, randomized, event-driven Study of Macitentan (ACT-064992) on Morbidity and Mortality in Patients With Symptomatic Pulmonary Arterial Hypertension trial (SERAPHIN; ClinicalTrials.gov Identifier: NCT00660179) were categorized based on distance (> or ≤400 meters). The association between 6MWT results at 6 months and long-term outcome — the risk for PAH-related death or hospitalization — was then compared in both groups.
Of the 742 patients enrolled, 298 had a 6MWT ≤400 meters and 297 had 6-MWT >400 meters at 6 months. A total of 53 deaths occurred in the group of patients who walked ≤400 meters compared with 22 in the group of patients who walked >400 meters. In addition, the risk for hospitalization was higher in patients in the ≤400 meter group compared with patients in the >400 meter group. The poor prognosis for patients walking <400 meters at 6 months was not affected by the distance walked at baseline.
The study investigators wrote, “Although changes in 6-[minute walk distance] were not associated with long-term outcome in patients with PAH, assessing the absolute 6-[minute walk distance] values remains important in the clinical management of patients with PAH.”
They added, “[A]chieving a functional status threshold, not the magnitude of improvement in exercise capacity, should be the target when developing a treatment strategy.”
Disclosures: The study was funded by Actelion Pharmaceuticals, Ltd.
Souza R, Channick R, Delcroix M, et al; Association between six-minute walk distance and long-term outcomes in patients with pulmonary arterial hypertension: data from the randomized SERAPHIN trial [published March 28, 2018]. PLoS One. doi:10.1371/journal.pone.0193226