Significant Nailfold Capillary Loss and Late Capillaroscopic Pattern Are Associated with Pulmonary Arterial Hypertension in Systemic Sclerosis

Objective: To evaluate differences in nailfold videocapillaroscopy (NVC) findings between SSc patients with and without a diagnosis of pulmonary arterial hypertension (PAH).Methods: One hundred and ten SSc patients were enrolled in this cross-sectional, case-control, multicentre study. Patients were divided into cases (SSc-PAH confirmed by right heart catheterization) and controls (SSc-nonPAH with low probability of PAH). NVC patterns (early, active and late) and morphological parameters (microvascular density, non-specific abnormalities, giant capillaries, micro-haemorrhages, avascular areas) were considered using a semiquantitative scoring system.Results: SSc-PAH patients showed higher frequencies of late pattern (P < 0.01), non-specific abnormalities (P < 0.01), lower capillary density (P < 0.01), higher avascular areas (P < 0.01) and a higher mean NVC score (P < 0.01). Contrarily, the early/active pattern (P < 0.01) and a higher rate of micro-haemorrhages (P = 0.04) were more frequent in non-PAH patients. By a multivariate analysis, SSc-PAH patients, compared with non-PAH, had more non-specific abnormalities [27/55, 49.1% vs 10/55, 18.2%; adjusted odd ratio (OR) 16.89; 95% CI: 3.06, 93.16], a lower capillary density (grade 3, 20/55, 36.4% vs 5/55, 9.1%; adjusted OR 38.33; 95% CI: 2.34, 367.80) and avascular areas (18/55, 32.7% vs 10/55, 18.2%; adjusted OR 16.90; 95% CI: 2.64, 44.35). A correlation was found between the mean pulmonary arterial pressure and avascular areas (P < 0.01), capillary density (P < 0.01) and non-specific abnormalities (P < 0.01). A clinical model including the NVC variables may be able to predict a diagnosis of PAH.Conclusion: Our results indicate that the distinctive peripheral microcirculatory injury of SSc, i.e. capillary loss and morphological abnormalities, appear more severe and pronounced in patients with SSc-PAH.