To evaluate the association of ulnar artery occlusion (UAO) assessed using Doppler ultrasound (DUS) with the severity markers of systemic sclerosis (SSc).
Two hundred four unselected patients fulfilling the American College of Rheumatology/European League Against Rheumatism 2013 classification criteria for SSc were included in this cross-sectional multicenter study. All patients underwent bilateral hand DUS to evaluate the presence of UAO and clinical/paraclinical visceral evaluation according to current guidelines. Univariable and multivariable ordinal regression models were applied, grading the severity of UAO as "no UAO," "only one UAO," and "UAO on both hands," and assessing its association with clinical features of SSc. Odds ratios (ORs) and 95% confidence intervals (95% CIs) were calculated.
UAO was found in 76 patients (37.3%) and was bilateral in 49 patients (24%). UAO as an ordinal event was significantly associated with disease duration, history of fingertip ulcers, telangiectasia, higher modified Rodnan skin thickness score (MRSS), worse diffusing capacity for carbon monoxide (DLco) values, higher tricuspid jet velocity, late capillaroscopic pattern, and positivity for anticentromere antibodies (ACAs) (univariable analysis). In the adjusted multivariable ordinal model, UAO was less frequent in women (OR 0.35 [95% CI 0.15-0.83], P = 0.017) and in patients receiving steroids (OR 0.24 [95% CI 0.09-0.62], P = 0.0034). In multivariable analyses, significant association with UAO was retained for history of fingertip ulcers (OR 2.55 [95% CI 1.24-5.21], P = 0.011), higher MRSS (OR 1.65 [95% CI 1.06-2.56], P =0.025), lower DLco values (OR 0.85 [95% CI 0.78-0.94], P = 0.0015), and ACA positivity (OR 2.89 [95% CI 1.36-6.11], P = 0.0056).
UAO may represent a relevant severity marker of vasculopathy in SSc. Its predictive value for the onset of severe vascular manifestations such as pulmonary arterial hypertension, and its association with mortality, remain to be determined in longitudinal studies.