Color doppler ultrasonography of digital arteries and digital ulcers development in systemic sclerosis

Background: The aim of this study was to evaluate the role of Color Doppler Ultrasonography (CDUS) of proper palmar digital arteries (PPDA) as predictive marker of new digital ulcers (DUs) in systemic sclerosis (SSc) patients during 5 years follow-up. Methods: 36 SSc patients were examined using nailfold videocapillaroscopy (NVC) and CDUS of PPDA. Results: Fourteen (38.9%) patients had chronic or acute occlusions (C and D pattern) on CDUS evaluation. Using a cut-off of 0.70, 21 (58.3%) patients had a Resistive Index (RI) ≥0.70. Nineteen (52.8%) patients developed new DUs during the follow-up. The median value of RI was higher in SSc patients with DUs than in SSc patients without DUs [0.73 (IQR 0.70-0.81) vs 0.67 (IQR 0.57-0.70), p < 0.0001]. The Kaplan-Meier analysis showed a free survival from new DUs higher (p < 0.01) in SSc patients with Pattern A and B than SSc patients with Pattern C and D. The Kaplan-Meier curves showed that free survival from new DUs is lower (p < 0.001) in SSc patients with increased RI (≥0.70) than in SSc patients with normal RI. In multivariate analysis with two co-variates, RI ≥ 0.70 [HR 5.197 (1.471-18.359), p < 0.01] and NVC late scleroderma pattern [HR 7.087 (1.989-25.246), p < 0.01] were predictive markers of new DUs. Conclusions: RI of PPDA in association with NVC could be used to evaluate SSc patients with increased risk of new DUs development.