Significant nailfold capillary loss and late capillaroscopic pattern are associated with pulmonary arterial hypertension in systemic sclerosis

Objectives: To evaluate differences in nailfold videocapillaroscopy (NVC) findings between systemic sclerosis-SSc patients with and without a diagnosis of pulmonary arterial hypertension (PAH). Methods: 110 SSc patients were enrolled in this cross-sectional, case-control, multi-centre study. Patients were divided into cases (SSc-PAH confirmed by right hearth catheterization-RHC) 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 the multivariate analysis, SSc-PAH patients, compared to non-PAH, had more non-specific abnormalities (27/55, 49.1% vs 10/55, 18.2%, adjusted 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-mPAP 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 the diagnosis of PAH. Conclusions: 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.