Nailfold capillaroscopy improves cardiovascular risk stratification in SSc: an adjustment of the SCORE2 algorithm

SSc is characterized by micro- and macrovascular damage, increasing cardiovascular (CV) risk. The SCORE2 algorithm underestimates CV risk in systemic autoimmune diseases. Nailfold capillaroscopy (NFC) is used to assess SSc-related microvascular damage. We aimed to evaluate whether incorporating NFC findings into SCORE2/SCORE2-OP improves CV risk stratification in SSc.

Retrospective multicentre study including 276 patients with SSc. Baseline 10-year CV risk was estimated using SCORE2 or SCORE2-OP. NFC at diagnosis was assessed. Cox regression identified NFC variables associated with major CV events (MCEs). Their adjusted hazard ratios (HRs) were applied to derive NFC-modified SCORE2 models. Discrimination, calibration and reclassification of original vs modified models were compared, with bootstrap internal validation.

Over a median follow-up of 9.5 years, 45 (16.3%) patients experienced an MCE. In multivariable models, late NFC pattern (HR 4.056, P = 0.002) and avascular areas (HR 2.631, P = 0.039) were independently associated with MCEs, whereas microhaemorrhages were associated with reduced risk (HR 0.345, P = 0.017). Original SCORE2 showed modest discrimination for incident MCEs (AUC 0.687, 95% CI 0.574-0.801). NFC-modified models improved discrimination (AUC 0.784, 95% CI 0.674-0.894 for the NFC-findings model and 0.764, 95% CI 0.654-0.875 for the NFC-pattern model; both P < 0.05 vs SCORE2), with consistent gains in Harrell's C-index. Risk reclassification analyses showed classification of patients with MCEs, with categorical net reclassification indices of 0.31 and 0.36, respectively.

Incorporating baseline NFC into SCORE2 improves CV stratification in patients with SSc, and may support more individualized CV prevention strategies in SSc.