Euvolemia-Based Assessment of Pulmonary Hypertension in Stable Hemodialysis Patients

Pulmonary hypertension (PH), defined as mean pulmonary arterial pressure (mPAP) \>20 mmHg, is increasingly recognized in patients with chronic kidney disease and is particularly prevalent in those with ESKD on maintenance HD. Despite its prognostic importance, PH remains under-recognized and insufficiently characterized in HD patients. A major limitation of prior studies is the lack of standardized assessment of volume status, which significantly influences pulmonary pressures. This prospective, multicenter cohort study aims to address this gap by evaluating PH after rigorous volume optimization. The study includes: * A pretrial volume assessment phase (3 consecutive HD sessions) * A structured volume correction phase (if needed) * A main study cohort including only euvolemic patients * An exploratory subgroup of patients with persistent hypervolemia Euvolemia is defined using a multimodal approach including clinical examination, bioimpedance spectroscopy, inferior vena cava (IVC) diameter, interdialytic weight gain, blood pressure stability, and lung ultrasound criteria. The primary objective is to determine the prevalence of PH in euvolemic HD patients. Secondary objectives include characterization of PH phenotypes and identification of clinical, dialysis-related, and echocardiographic predictors. Right heart catheterization (RHC) is not mandated for all participants. In patients with echocardiographic findings suggestive of PHafter confirmation of euvolemia, RHC may be performed when clinically indicated and separately consented. When available, invasive hemodynamic data will be used to confirm PH and refine phenotype classification.