Macrovascular Involvement in Systemic Sclerosis: Association Between Carotid Ultrasound Hemodynamics Parameters and Digital Ulcers

<b>Background:</b> Digital ulcers (DUs) are among the most debilitating vascular complications in SSc and are commonly attributed to microvascular damage. However, recent evidence suggests a potential involvement of macrovascular abnormalities, including subclinical atherosclerosis and altered hemodynamic parameters. <b>Objectives:</b> This study aimed to investigate the association between a history of DUs and macrovascular involvement in SSc patients through carotid and vertebral Doppler ultrasonography, with a focus on hemodynamic indices such as Peak Systolic Velocity (PSV), End-Diastolic Velocity (EDV), Resistive Index (RI), and Intima-Media Thickness (IMT). <b>Methods:</b> A cross-sectional study was conducted on 107 SSc patients. Clinical, serological, cardiovascular, and metabolic data were collected, and carotid-vertebral ultrasound was performed. Patients were stratified based on DU history. Statistical analyses assessed associations between DU status and carotid-vertebral US findings. <b>Results:</b> Patients with DUs showed a significantly higher PSV in both right (86.9 ± 67.9 vs. 64.2 ± 20.5 cm/s, <i>p</i> = 0.010) and left ICA (78.9 ± 29.6 vs. 63.4 ± 18.2 cm/s, <i>p</i> = 0.002). Right ICA RI vas elevated in the DU group (<i>p</i> = 0.021). PSV in the external carotid arteries was also bilaterally increased in DU patients (<i>p</i> < 0.005). DU-positive patients had a higher prevalence of left carotid plaques (<i>p</i> = 0.012) and right-sided ICA RI > 0.75 (<i>p</i> = 0.01). Logistic regression identified DU history as an independent predictor of PSV at ICA (β = 31.89, <i>p</i> = 0.043) and carotid plaque presence at any side (OR 14.34, <i>p</i> = 0.012). <b>Conclusions:</b> A history of digital ulcers in SSc patients is associated with altered carotid hemodynamics and an increased subclinical atherosclerotic burden. These findings suggest that DUs may reflect not only microvascular damage, but also macrovascular dysfunction, supporting the need for integrated vascular assessment in SSc clinical practice.