Association between six-minute walk distance and long-term outcomes in patients with pulmonary arterial hypertension: Data from the randomized SERAPHIN trial

作者：Souza Rogerio^*; Channick Richard N; Delcroix Marion; Galie Nazzareno; Ghofrani Hossein Ardeschir; Jansa Pavel; Le Brun Franck Olivier; Mehta Sanjay; Perchenet Loic; Pulido Tomas; Sastry B K S; Sitbon Olivier; Torbicki Adam; Rubin Lewis J; Simonneau Gerald

来源：PLos One, 2018, 13(3): e0193226.

DOI：10.1371/journal.pone.0193226

Background
Patients with pulmonary arterial hypertension who achieve a six-minute walk distance of 380-440 m may have improved prognosis. Using the randomized controlled trial of macitentan in pulmonary arterial hypertension (SERAPHIN), the association between six-minute walk distance and long-term outcomes was explored.
Methods
Patients with six-minute walk distance data at Month 6 were dichotomized as above or below the median six-minute walk distance (400 m) and assessed for future risk of pulmonary arterial hypertension-related death or hospitalization and all-cause death. Additionally, six-minute walk distance values at baseline, Month 6 and the change from baseline to Month 6 were categorized by quartiles. All associations were analyzed by the Kaplan Meier method using a log-rank test and Cox regression models.
Results
Patients with a six-minute walk distance >400 m vs. <= 400 m at Month 6 have a reduced risk of pulmonary arterial hypertension-related death or hospitalization (hazard ratio 0.48; 95% confidence interval 0.33-0.69). The risk was also lower for patients with higher quartiles of six-minute walk distance at baseline or Month 6 (baseline: hazard ratio [Q4 (>430 m) vs. Q1 (<= 300 m)] 0.23; 95% confidence interval 0.15-0.36; Month 6: hazard ratio [Q4 (>455 m) vs. Q1 (<= 348 m)] 0.33; 95% confidence interval 0.19-0.55). In contrast, six-minute walk distance changes at Month 6 were not associated with the risk of pulmonary arterial hypertension-related death or hospitalization (p = 0.477). These findings were consistent when adjusted for known confounders. Similar results were observed for the risk of all-cause death up to end of study.
Conclusions
Patients with pulmonary arterial hypertension walking >400 m had better long-term prognosis. Although changes in six-minute walk distance were not associated with long-term outcomes, assessing absolute six-minute walk distance values remains important in the clinical management of patients with pulmonary arterial hypertension.

• 出版日期2018-3-28