Femoral venous stasis index improves risk classification in patients with pulmonary hypertension: a post-hoc analysis of the CODOVEIN study

BACKGROUND: Pulmonary hypertension (PH) requires accurate risk stratification to guide management. Although current ESC/ERS three-strata model is widely used, most patients remain classified at intermediate risk, limiting clinical decision-making. The femoral venous stasis index (FVSI), a Doppler-derived marker of venous congestion, has been associated with elevated right atrial pressure. We evaluated whether FVSI improves 1-year prognostic classification beyond the ESC/ERS 2022 model. METHODS: This post hoc analysis used data from the CODOVEIN study, including patients with confirmed PH. The primary composite endpoint was 1-year morbidity-mortality: escalation of PH-specific therapy, hospitalization for right-heart failure, or PH-related death. Patients were classified using ESC/ERS 2022 criteria. FVSI was categorized using predefined thresholds (<0.18, 0.18-0.45, >0.45). Risk improvement was assessed using the Net Reclassification Index (NRI). Survival was analyzed with log-rank tests. RESULTS: Ninety-one patients were included (62.2% precapillary PH). The global NRI was 0.736, with event and non-event components of 0.333 and 0.403, respectively. Among intermediate-risk patients, 1-year event rates increased across FVSI categories (16.7%, 43.5%, 66.7%; p = 0.027). Survival differed significantly across FVSI-based subgroups (p < 0.001). CONCLUSIONS: FVSI significantly improves 1-year risk classification in PH patients, particularly within the intermediate-risk category. As a simple, non-invasive marker of venous congestion, FVSI may refine prognostication and deserve evaluation in prospective multicenter studies.