Small, medium but not large arteries are involved in digital ulcers associated with systemic sclerosis

Digital ulcers (DU) are a burden in systemic sclerosis (SSc). Microangiopathy is a cardinal feature of SSc that plays a critical role in the development of DU. However, whether injury of medium or large vessels also contributes to DU in SSc remains controversial.

To measure concomitantly in SSc patients with and without active DU: (i) the Augmentation Index of the reflected wave (Aix_75) by radial applanation tonometry, an index of small and medium arterial function; (II) the aortic pulse wave velocity (PWV), a marker of large vessel injury (aortic stiffness).

Sixty-three consecutive SSc patients were included (49 females, aged 60 [49-65] years, disease duration of 8.5 [5-13] years), including 10 (15.9%) with active DU. Patients with active DU versus those without had increased Aix_75 (35% [28-38] versus 28% [20-34], P=0.041) whereas no difference existed in PWV (7.0m/s [6.7-10.1] versus 7.6m/s [6.8-8.7], P=0.887), in systolic, diastolic, as well as aortic pulse pressure (P=0.126, 0.592, and 0.161, respectively). When compared to patients in the low tertile, patients having Aix_75 in the highest tertile had 10-fold more DU (OR=10.23; 95% CI 1.12 to 93.34, P=0.039).

The presence of DU is associated with increased Aix_75 whereas there is no relation with PWV. These data suggest that small and medium arteries are involved in the occurrence of DU whether large vessel stiffness does not contribute. Whether Aix_75 is predictive of further DU remained to be studied.