Eye signs as a novel risk predictor in pulmonary arterial hypertension associated with systemic lupus erythematosus.

Objective: To investigate the role of eye signs in predicting poor outcomes in systemic lupus erythematosus (SLE) patients with pulmonary arterial hypertension (PAH).

Methods: This prospective observational study recruited patients diagnosed with SLE-PAH from Jan. 2021 to Dec. 2021 at the First Affiliated Hospital of Nanchang University; those with other potential causes of PAH were excluded. The evaluation of various parameters, such as N-terminal prohormone of brain natriuretic peptide (NT-proBNP), 6-minute walking distance (6MWD), World Health Organization functional class (WHO-FC), echocardiography, and risk stratification based on the 2015 European Society of Cardiology (ESC)/European Respiratory Society (ERS) Guidelines, was conducted at intervals of every 1-3 months, and a 6-month follow-up period was observed. The primary outcome measure considered improvement if there was a decline in the risk stratification grade at the end point and unimproved if there was no decline. Conjunctival microvascular images were observed and recorded.

Results: A total of 29 SLE-PAH patients were enrolled, comprising 12 in the improved group and 17 in the nonimproved group. All SLE-PAH patients showed various manifestations of eye signs, including vessel twisting, dilation, ischaemic areas, haemorrhages, reticulum deformity, and wound spots. The nonimproved group exhibited significantly lower vessel density (VD) and microvascular flow index (MFI) of conjunctival microvascular images than the improved group. Correlation analysis revealed that VD displayed a negative correlation with the WHO-FC (r = -0.413, p = 0.026) and NT-proBNP (r = -0.472, p = 0.010), as well as a positive correlation with the 6MWD (r = 0.561, p = 0.002). Similarly, MFI exhibited a negative correlation with WHO-FC (r = -0.408, p = 0.028) and NT-proBNP (r = -0.472, p = 0.010) and a positive correlation with 6MWD (r = 0.157, p = 0.004). Multivariate logistic regression analysis indicated that VD (OR 10.11, 95% CI 1.95-52.36), MFI (OR 7.85, 95% CI 1.73-35.67), NT-proBNP, and 6MWD were influential factors in predicting the prognostic improvement of SLE-PAH patients. ROC curve analysis demonstrated that VD, MFI, 6MWD, and NT-proBNP (with respective AUC values of 0.83, 0.83, 0.76, and 0.90, respectively) possessed a sensitivity and specificity of 75 and 100%, as well as 83 and 100%, respectively. Regarding prognostic prediction, VD and MFI exhibited higher sensitivity than 6MWD, whereas MFI displayed higher sensitivity and specificity than NT-proBNP.

Conclusion: SLE-PAH can lead to various conjunctival microvascular manifestations in which vascular density and microvascular flow index can be used to assess cardiopulmonary function and predict therapeutic efficacy and prognosis in SLE-PAH patients.