Pulmonary arterial hypertension (PAH) represents one of the most devastating complications in connective tissue diseases (CTDs). The aim of this study was to investigate the presence of peripheral microangiopathy in patients with PAH associated with CTDs (CTD-PAH) by exploring nailfold videocapillaroscopic (NVC) changes and identify possible associations of NVC characteristics with markers of disease severity. Α cross-sectional study was performed in 18 CTD-PAH patients [13 PAH due to systemic sclerosis (SSc-PAH) and 5 with other types of CTD-PAH], 14 patients with SSc without PAH (SSc-non-PAH) and 20 healthy controls. NVC quantitative and qualitative parameters were evaluated using Optilia Digital Capillaroscope. To ensure inter-observer repeatability, capillaroscopic images were reviewed by two independent investigators. When compared to healthy controls, patients with CTD-PAH (77.8% women, mean age 65.9 years) presented reduced capillary density (6.5 ± 1.6 loops/mm vs. 9.7 ± 0.7 loops/mm, p < 0.001) and increased capillary loop width (23.3 ± 10.1 μm vs. 11.2 ± 2.5 μm, p < 0.001). SSc-PAH patients presented lower capillary density in comparison with other CTD-PAH patients and SSc-non-PAH subjects and abnormal and disorganized capillaries compared to controls. Patients with other CTD-PAH had also reduced capillary density and increased loop diameter compared to controls. A significant linear correlation was identified between capillary density and estimated glomerular filtration rate in the total CTD-PAH population (r = 0.63, p = 0.007). In SSc-PAH group, capillary loop diameter was positively correlated to cardiac index (r = 0.61, p = 0.02). Significant NVC microvascular changes were detected in patients with various types of CTD-PAH, suggesting an impaired peripheral microcirculation parallel to pulmonary vasculopathy.
Keywords: Connective tissue disease; Nailfold videocapillaroscopy; Peripheral microangiopathy; Pulmonary arterial hypertension; Systemic lupus erythematosus; Systemic sclerosis.