Abstract
Objective Early diagnosis of systemic sclerosis (SSc) is imperative and Raynaud’s phenomenon (RP) is an important component of progressive vasculopathy. Nailfold videocapillaroscopy (NVC) is a wellestablished tool that can quantify structural vascular abnormalities. Digital thermal monitoring (DTM) assesses microvascular functional dysfunction related to thermoregulation. In this study, we investigated the correlation of NVC patterns and DTM variables in SSc patients.
Methods Patients with SSc by 2013 ACR/EULAR criteria that were consented into the clinical care registry had NVC and DTM performed. For NVC, the number of capillaries (density), measurement of apical diameter (dimension), presence or absence of hemorrhages and number of abnormal shapes were assessed to categorize three different qualitative patterns: ‘early’, ‘active’ and ‘late’. For DTM, Doppler ultrasound hyperemic, low frequency, blood velocity of radial artery and fingertip vascular function was assessed and a vascular reactive index (VRI) measurement was automated. Statistical evaluation was performed by non-parametric tests to assess the correlation of NVC and VRI.
Results Thirty-one SSc subjects with interpretable NVC and DTM performed on the same day were included in the study. VRI was progressively higher in SSc patients with the ‘early’, ‘active’ and ‘late’ NVC patterns of microangiopathy (p< 0.0001). There was a significant negative correlation between VRI and microhemorrhages score (r=-0.363, p=0.044).
Conclusion Our study suggests that more advanced vasculopathy correlates to reduced microvascular function as detected by DTM and more advanced structural abnormalities detected by NVC. NVC and DTM may provide different aspects of vasculopathy quantification and complement each other as investigative tools.
