Renal function and outcomes in pulmonary arterial hypertension: a French Pulmonary Hypertension Registry study

Background Renal impairment is frequent in pulmonary arterial hypertension (PAH), yet renal function is not currently accounted for in the European Society of Cardiology (ESC)/European Respiratory Society (ERS) risk stratification tools. We investigated whether renal function provides independent prognostic information in PAH after adjustment for ESC/ERS risk score. Methods We conducted a retrospective analysis of the French Pulmonary Hypertension (PH) Network registry. Estimated glomerular filtration rate (eGFR) was calculated using the 2021 CKD-EPI equation. Renal dysfunction prevalence (eGFR <60 mL·min −1 ·1.73 m −2 ) was assessed in patients with PAH (n=3383). Time-to-event analyses for transplant-free survival were performed using Cox models adjusted for age, sex and ESC/ERS risk scores at baseline and at 3–12 months of follow-up. Results Renal dysfunction (eGFR <60 mL·min −1 ·1.73 m −2 ) was present in 28% of patients with PAH. Baseline eGFR <45 mL·min −1 ·1.73 m −2 was independently associated with reduced transplant-free survival in multivariable analysis. At 3–12 months of follow-up, eGFR <60 mL·min −1 ·1.73 m −2 predicted adverse outcomes in multivariable models (HR 1.25; 95% CI 1.04–1.50; p=0.018). Among patients with preserved baseline renal function, a relative decline in eGFR of ≥10% was independently associated with a higher risk of death or lung transplantation. Conclusions Baseline renal impairment and subsequent deterioration in renal function are independently associated with poorer transplant-free survival in PAH, beyond ESC/ERS risk stratification. These findings support consideration of renal function in prognostic assessment of patients with PAH.