SAT0265 DETERMINANTS OF RENAL RESISTIVE INDEX (RRI) AT RENAL ARTERY DOPPLER ULTRASOUND IN SYSTEMIC SCLEROSIS (SSC): MORE THAN GENERAL POPULATION FACTORS

Abstract

Background: RRI can be measured on renal artery Doppler ultrasound, showing the difficulty blood flow encounters distally from where it is measured. RRI can be determined by vascular and interstitial renal features: Studies on the general population showed arterial hypertension, arteriosclerosis, low-grade inflammation, diabetes mellitus, hyperuricaemia as possible causes of renal vasculopathy or tubular-interstitial nephrop-athy, thus determining altered RRI values. Studies on SSc have shown increased RRI values, associated with nailfold-videocapillaroscopy pattern and history of digital ulcers. Objective(s): To identify determinants of RRI in SSc patients. Method(s): SSc patients fulfilling the 2013 ACR/EULAR criteria were enrolled from two SSc-care units. Data regarding SSc clinical manifestations, instrumental and laboratory evaluation for renal, cardiac and cardiovascular involvement were collected. RRI was measured at least once in each patient. Linear regression analysis was carried out to determine predictors for baseline RRI and change in RRI in time (DRRI). Result(s): 380 patients [aged 57 (46-68) years, 12% males] were enrolled in the study. On univariate analysis, both general population determinants (age, arterial hypertension, diabetes mellitus, hyper-lipidaemia and hyper-uricaemia) and SSc specific features [time from Raynaud's phenomenon onset, ACA positivity, scleroderma renal crisis history, estimates systolic pulmonary arterial pressure on Echo (sPAP), presence of dyspnea, %DLCO and presence of lower intestinal symptoms] predicted RRI values, with only age and sPAP being significant independent predictors at baseline. Follow-up RRI, available for 230 patients, showed that none of the general population determinants was predictive for DRRI, while presence of telangectasias, baseline FVC, use of Sildenafil, change in sPAP and new diagnosis of PAH were predictive at univari-ate regression. Among them, only presence of baseline telangectasias was an independent predictor of DRRI at multivariate regression analysis. Conclusion(s): Data show that among general population determinants, age is the only predictive factor for RRI in SSc patients. However, also sPAP (for RRI) and telangectasias could be predicitive for DRRI. Therefore, the use of specific age-adjusted cut-offs (table 1) are recommended when assessing SSc patients. Data show that among general population determinants, age is the only predictive factor for RRI in SSc patients. However, also sPAP (for RRI) and telangectasias could be predicitive for DRRI. Therefore, the use of specific age-adjusted cut-offs (table 1) are recommended when assessing SSc patients. [TABLE PRESENTED].