Finger Systolic Blood Pressure Index Measurement: A Useful Tool for the Evaluation of Arterial Disease in Patients With Systemic Sclerosis

Objective To evaluate the prevalence and clinical correlates of peripheral arterial disease of the upper limbs in patients with systemic sclerosis (SSc), as detected with finger brachial pressure index (FBPI) measurements. Methods This work is based on the baseline data of the SCLEROCAP multicenter cohort of SSc patients. Finger systolic blood pressure was measured with laser Doppler flowmetry, and the FBPI was obtained as its ratio over the ipsilateral brachial systolic blood pressure. An FBPI of <0.70 was used as the diagnostic criterion for occlusive arterial disease of the upper limbs. Thus, the prevalence of defined arterial disease as well as its clinical, biologic, and capillaroscopic correlates were evaluated. Results Among 326 enrolled patients, 177 (54.3%) met the criterion for arterial disease (FBPI <0.70). No association was found with the type of SSc nor with the type of associated antinuclear antibodies, but a significant association was found with the duration of the disease (P < 0.001), the capillaroscopic pattern (P < 0.001), and most strikingly with the presence of digital ulcers (42.9% versus 13.4%; P < 0.001). A quantitative relationship was found between the FBPI and the prevalence of digital ulcers and was shown to be independent from the capillaroscopic pattern. Conclusion This cross-sectional study shows a high prevalence of arterial disease of the upper limbs in patients with SSc. FBPI appears to be a strong and independent predictor of digital ulcers. This study suggests that both macro- and microangiopathy are contributing to the ischemic damage of the fingertips.