Exercise tolerance in systemic sclerosis patients without pulmonary impairment: correlation with clinical variables

Area of Science:

• Cardiology
• Pulmonology
• Rheumatology

Background:

• Systemic sclerosis (SSc) frequently involves pulmonary vasculopathy (PV), impacting pulmonary blood flow and exercise capacity.
• Early detection of PV is crucial for managing SSc progression and patient outcomes.

Purpose of the Study:

• To evaluate the utility of cardiopulmonary exercise testing (CPET) in identifying early pulmonary vasculopathy (PV) in SSc patients.
• To assess the relationship between CPET parameters and clinical indicators of disease severity in SSc.

Main Methods:

• 34 SSc patients and 20 healthy controls underwent clinical examination, nailfold videocapillaroscopy (NVC), and symptom-limited CPET.
• CPET measured minute ventilation (VE), workload (WR), peak oxygen uptake (pVO₂), and ventilatory efficiency (VE/VCO₂ slope).

Main Results:

• 45% of SSc patients exhibited reduced exercise tolerance (pVO₂ < 80%).
• Elevated VE/VCO₂ slope, indicating ventilation-perfusion mismatch, was observed in patients with a history of digital ulcers and in those with advanced capillaroscopic findings.
• VE/VCO₂ slope positively correlated with Disease Activity Index and Disease Severity Scale.

Conclusions:

• CPET is a valuable tool for detecting early pulmonary vasculopathy (PV) in SSc patients, even without overt pulmonary or cardiac involvement.
• CPET findings, particularly the VE/VCO₂ slope, correlate with disease severity and clinical manifestations like digital ulcers.