Ulnar artery occlusion is predictive of digital ulcers in SSc: a duplex sonography study

Abstract

To assess the prevalence and risk factors of ulnar artery occlusion (UAO) in an unselected SSc patient cohort and to determine whether UAO is associated with digital ulcers (DUs). A total of 79 SSc patients and 40 'healthy' controls underwent colour duplex sonography of the radial and ulnar artery to compare blood flow velocity, resistive indices (RIs) and presence of occlusion and were followed for a mean of 53 months. In both, radial and ulnar arteries, peak systolic velocity (PSV) and end-diastolic velocity (EDV) were significantly lower and RI higher in SSc patients compared with controls (PSVrad: 40.1 vs 48.6 cm/s; PSVuln 38.2 vs 56.6 cm/s; EDVrad 3.8 vs 10.4 cm/s; EDVuln 3.0 vs 13.0 cm/s; RIrad 0.91 vs 0.82; RIuln 0.92 vs 0.80; all P < 0.01). Seventeen (21.5%) SSc patients had UAO (11 patients bilateral) compared with none in the control subjects. Patients with UAO had a significantly longer disease duration (170 vs 66 months, P < 0.001). At baseline, the prevalence of DU was not different in upper extremities with UAO [8/28 (28.6%)] compared with upper extremities without UAO [36/129 (27.9%)]. However, during follow-up new or recurrent DU occurred more often in upper extremities with UAO than in those without UAO [14/28 (50%) vs 24/113 (21.2%); relative risk (RR) = 2.4; 95% CI 1.4, 3.7; P = 0.002]. Blood flow is significantly decreased in radial and ulnar arteries in SSc. UAO is frequent and an important risk factor for the development of DUs in patients with SSc.