Pulmonary Veno-Occlusive Disease in Systemic Sclerosis: A Scoping Review of the Literature

Background: Patients with systemic sclerosis (SSc) may be affected by pulmonary veno-occlusive disease (PVOD), a poorly characterized form of group I pulmonary arterial hypertension (PAH). This scoping review aimed to systematically map the literature regarding SSc-PVOD to identify key clinical features, knowledge gaps, and future research areas. Methods: A systematic literature search was conducted (January 1970 to May 2026) across PubMed, Scopus, and Cochrane databases following the PRISMA-ScR guidelines. We included adult patients with right heart catheterization (RHC)-confirmed SSc-PAH and a concurrent/subsequent diagnosis of PVOD established via pulmonary edema following vasodilators, highly suggestive chest HRCT findings, or histopathology. Results: A total of 20 articles were included, encompassing 63 SSc-PVOD patients (87.2% females). Chest HRCT revealed ≥2 highly suggestive abnormalities (centrilobular ground-glass opacities, interlobular septal thickening, mediastinal lymphadenopathy) in 46/54 patients. Almost all patients had mPAP > 35 mmHg at diagnosis, and 12/25 had DLCO < 30%. Lung tissue was obtained in 13 patients (11 post-mortem); predominant histological findings were venous luminal narrowing (11/13), arteriole fibrosis (9/13), and thickened interalveolar septae (9/13). Notably, 20 out of 24 patients treated with pulmonary vasodilators developed pulmonary edema. Overall, two patients underwent lung transplantation, and 33 (52%) died. Conclusions: SSc-PVOD mimics classic SSc-PAH at RHC but carries a high risk of PAH-treatment-induced pulmonary edema. Early non-invasive recognition is vital to avoid drug-related harm and prompt transplant referral. Novel anti-remodeling therapies should be explored.