THU0341 DIGITAL ARTERY VOLUME INDEX (DAVIX©) PREDICTS THE ONSET OF FUTURE DIGITAL ULCERS IN PATIENTS WITH SYSTEMIC SCLEROSIS
Authors: K. Gjeloshi, F. Danzo, G. Lettieri, G. Abignano, M. Hinton, A. M. Dean, G. Cuomo, O. Kubassova, F. Del Galdo
Journal: Annals of the Rheumatic Diseases (2020)

Background: Neointima proliferation is a key pathologic feature of Systemic Sclerosis (SSc), causing arterial vessel narrowing and being the recognised culprit pathological lesion in Digital Ulcers (DUs), pulmonary artery hypertension and renal crisis. Nevertheless, there are no validated imaging techniques to assess the severity of vascular involvement in SSc. Digital Artery Volume index (DAVIX ©) is an MRI Time of flight angiography based quantitative score of digital arteries flow, without the need to administer contrast. Objectives: To determine the value of DAVIX in predicting the onset of digital ulcers (DUs), the worsening of patient reported outcomes (PROs) and clinical parameters in SSc patients. Methods: We enrolled 91 consecutive patients affected by Raynaud’s phenomenon, 63 of which fulfilled the 2013 ACR/EULAR classification criteria for SSc and 28 had a score &lt;9. The data collected included: pulmonary function tests (PFTs), nailfold capillaroscopy, modified Rodnan Skin Score (mRSS), and Scleroderma Health Assessment Questionnaire Disability Index (sHAQ-DI). DAVIX of the dominant hand was calculated as % mean of the 4 fingers, employing IAG proprietary algorithm. The distribution was analysed with D’Agostino-Pearson normality test. Medians were compared by Mann-Whitney-Wilcoxon test, correlation with clinical parameters was performed using Spearman’s or Pearson test, as appropriate (Prism 7). Results: 78/91 patients were females and median disease duration was 4 years (IQR1.91-9). Complete historical and prospective follow-up data were available for 68 patients. DAVIX© correlated with mRSS (r=-0.258, p=0.017), DLCO% (r=0.338, p=0.008) and capillaroscopy pattern (r=-0.388, p=0.001). In patients with DUs, DAVIX© showed a stronger correlation with DLCO% (r=0.786, p=0.048). DAVIX© predicted the worsening of HAQ-DI (r=-0.295, p=0.029), sHAQ (r =-0.333, p=0.029) and VAS pain (r=-0.269, p=0.038) independently of the presence of DUs. In the context of DU, 7 patients had DUs at baseline (5 with a positive history for DUs). 12 patients developed DUs within 12 months, 3 of them had DUs at baseline. 38 patients did not have either previous or current DUs, neither did they develop new DUs within 12 months. DAVIX of patients with current DUs was 3-fold lower than DAVIX of patients without DUs (0.18 vs 0.63 p=0.0093). Further, DAVIX of patients with positive history of DUs was 50% lower than in patient with a negative history (median 0.34 vs 0.64, p=0.0052). In patients without current DUs, DAVIX of patients who developed new DUs within 12 months of follow-up was 3-fold lower than in patients who didn’t develop DU (0.21 vs 0.65, p=0.0156). ROC curve analysis indicated that DAVIX threshold &lt;0.49 conferred a 4 times higher risk of developing new DUs (67%) compared to overall risk of our population 17.6%. Conclusion: Outcome measures of vascular involvement in SSc are scanty. We demonstrated that DAVIX© is a promising and feasible surrogate outcome measure of neointima proliferation in SSc and a useful imaging biomarker of vascular disease activity. The predictive value of DAVIX for the future onset of DU could be employed as a useful stratification tool in clinical trials. The value of DAVIX in predicting the worsening of PROs and clinical parameters in overall patients, may offer insights on the role of vascular disease activity in the overall progression of SSc. References: [1]Lettieri G, Abignano G , et al Digital artery volume index: the first objective, automated, non-invasive imaging diagnostic of macrovascular involvement in ssc. Annals Rheum Dis 2018 Disclosure of Interests: Klodian Gjeloshi: None declared, Fiammetta Danzo: None declared, Giovanni Lettieri: None declared, Giuseppina Abignano: None declared, Mark Hinton: None declared, Anne-Maree Dean: None declared, Giovanna CUOMO: None declared, Olga Kubassova Shareholder of: IAG, Image Analysis Group, Consultant of: Novartis, Takeda, Lilly, Employee of: IAG, Image Analysis Group, Francesco Del Galdo: None declared