Use of platelet inhibitors for digital ulcers related to systemic sclerosis: EUSTAR study on derivation and validation of the DU-VASC model

Abstract

Objective To develop and validate the prognostic prediction model DU-VASC to assist the clinicians in decision-making regarding the use of platelet inhibitors (PIs) for the management of digital ulcers in patients with systemic sclerosis. Secondly, to assess the incremental value of PIs as predictor. Methods We analysed patient data from the European Scleroderma Trials and Research group registry (one time point assessed). Three sets of derivation/validation cohorts were obtained from the original cohort. Using logistic regression, we developed a model for prediction of DUs. C-statistics and calibration plots were calculated to evaluate the prediction performance. Variable importance plots and the decrease in C-statistics were used to address the importance of the predictors. Results Of 3710 patients in the original cohort, 487 had DUs and 90 were exposed to PIs. For the DU-VASC model, which includes 27 predictors, we observed good calibration and discrimination in all cohorts (C-statistics = 81.1% [95%CI: 78.9%-83.4%] for the derivation and 82.3% [95%CI: 779.3%-85.3%] for the independent temporal validation cohort). Exposure to PIs was associated with absence of DUs and was the most important therapeutic predictor. Further important factors associated with absence of DUs were: lower mRSS, anti-Scl-70 negativity and normal CRP. Conversely, the exposure to PDE-5i, prostacyclin analogues or ERAs seemed to be associated with the occurrence of DUs. Nonetheless, previous DUs remains the most impactful predictor of DUs. Conclusion The DU-VASC model, with good calibration and discrimination ability, revealed that PIs treatment was the most important therapy-related predictor associated with reduced DUs occurrence.

Peripheral Macrovascular Involvement in Systemic Sclerosis: A Cohort Study by Color and Spectral Doppler Ultrasonography

“…This could represent a limitation because it is not possible to know the real prevalence of UAO without these drugs or even the real prevalence of pulmonary artery hypertension; we could speculate that the vasodilator effect of the treatment could protect patients from UAO, but we did not demonstrate this result neither could we say that vasodilators are protective against UAO. However, a recent paper from the EUSTAR group was published underling how a low dose of ASA could be protective against DUs [ 30 ].…”