Six-minute walk test reflects neurohormonal activation and right ventricular function in systemic sclerosis patients.

CER5703
2013 Vol.31, N°2 ,Suppl.76
PI 0018, PF 0023
Clinical aspects

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PMID: 23406664 [PubMed]

Received: 17/05/2012
Accepted : 26/09/2012
In Press: 13/02/2013
Published: 22/07/2013

Abstract

OBJECTIVES:
Heart and pulmonary involvement is a leading cause of systemic sclerosis (SSc)-related deaths. The six-minute walk test (6MWT) is a simple and reproducible test commonly used to evaluate exercise capacity. We tried to assess a potential relationship between exercise capacity assessed by 6MWT, echocardiographic parameters of right ventricular function and serum levels of endothelin-1 and NTproBNP.
METHODS:
We prospectively studied 111 consecutive patients (101F, 10M, age 54.2±13.8 years) with diagnosed SSc (mean disease duration 9±12.4 years) and a group of 21 age-matched subjects (18F, 3M, age 49.3±10.5 years). In addition to routine evaluation, 6MWT and transthoracic echocardiography (Phillips iE 33) were performed. We also measured serum endothelin-1 (Human Endothelin-1 immunoassay R & D Systems) and NT-proBNP levels (Elecsys pro-BNP immunoassay; Roche Diagnostics).
RESULTS:
The mean 6MWT distance was significantly shorter in the SSc group than in the controls (562.8±60.3 vs. 514.7±102.5 m, p=0.03). In the SSc group 6MWT distance correlated with ET-1 (r=-0.5, p<0.0001), NTproBNP (r=-0.4, p=0.0008) levels, and echocardiographic indices AcT (r=0.4, p=0.0002) and TRPG (r=-0.4, p=0.0011). Moreover, in patients with 6MWT distance <450 m NTproBNP and endotothelin-1 levels were significantly higher than in patients with distance >450 m (311.2, 31.1–17237 vs. 105.3, 5–17670 pg/ml, p=0.0138 and 2.9±2.2 vs. 1.4±0.7 pg/ml, p=0.0032).
CONCLUSIONS:
Decreased exercise capacity significantly correlates with biochemical and echocardiographic parameters of right ventricular dysfunction and neurohormonal activation providing a potential link for neuroendocrine derangement in patients with SSc.