Phenotyping Exercise Limitation in Systemic Sclerosis: The Use of Cardiopulmonary Exercise Testing

Boutou, Afroditi K.; Pitsiou,
Georgia G.; Siakka, Panagiota; Dimitroulas, Theodoros; Paspala,
Asimina; Sourla, Evdokia; Chavouzis, Nikolaos; Garyfallos, Alexandros;
Argyropoulou, Paraskevi; Stanopoulos, Ioannis.

Respiration, February  2016, Vol. 91 Issue: Number 2 p115-123, 9p;

AbstractBackground:Exercise impairment is a common symptom of systemic
sclerosis (SSc), a disorder which is frequently complicated by
cardiopulmonary involvement.

Objectives:This study’s aims were: (a) to
define the prevalence and the potential causes of limited exercise
capacity and (b) to study potential differences in clinical,
radiological and functional characteristics and blood serology among
SSc patients with exercise limitation of different etiology.
Methods:Prospectively collected data on SSc patients who had conducted
full lung function testing, blood serology, thorax high-resolution
computed tomography, Doppler echocardiogram and a maximal
cardiopulmonary exercise testing (CPET) were retrospectively analyzed.
Using a CPET algorithm, patients were characterized as having normal or
subnormal exercise capacity (N), respiratory limitation (RL), left
ventricular dysfunction (LVD) or pulmonary vasculopathy (PV). Group
comparisons were conducted using either one-way ANOVA or the
Kruskal-Wallis test. A p value <0.05 was considered significant.
Results:The study population consisted of 78 patients (53.7 ± 13.7
years old; 10.3 male). PV was present in 32.1, LVD in 25.6 and RL in
10.2, while 32.1 of the patients constituted the N group. The presence
of antisclero-70 antibodies, low anaerobic threshold and low peak
exercise capacity measures could discriminate LVD from the other
groups. Low end-tidal carbon dioxide pressure and its change from rest
to anaerobic threshold could discriminate between the PV, LVD and N
groups, while respiratory restriction along with ventilatory
inefficiency indices could differentiate the RL group from the rest.

Conclusions:The combined evaluation of CPET gas exchange patterns with
baseline measurements could discriminate the causes of exercise
limitation among SSc patients.