Impact of declining renal function on outcomes in pulmonary arterial hypertension: A REVEAL registry analysis

Background: Renal dysfunction is associated with abnormal cardiopulmonary hemodynamics, in-hospital death and poor survival in patients with pulmonary arterial hypertension (PAH), and thus it may be a prognostic biomarker. In our analysis we assess the relationship between change in estimated glomerular filtration rate (eGFR) and outcomes in PAH patients in the Registry to Evaluate Early and Long-term PAH Disease Management (REVEAL). Methods: Overall 2,368 patients were classified into chronic kidney disease (CKD) stages based on baseline eGFR: normal or Stages 1 or 2 (n = 1,699); Stage 3a (n = 399); Stage 3b (n = 196); and Stages 4 or 5 (n = 74). We evaluated the relationship between baseline CKD stage and survival, as well as the composite end-point of survival and freedom from all-cause hospitalization. The relationships between change in eGFR at ≥1 year and these clinical end-points were also evaluated. Results: Patients with a ≥10% decline in eGFR from baseline over ≥1 year had a significantly increased risk of death (hazard ratio 1.66; p < 0.0001) and the composite of all-cause hospitalization and death (hazard ratio 1.33; p = 0.002). This decline predicted survival independently of changes in 6-minute walk distance and functional class. However, a ≥10% increase in eGFR was not significantly associated with either end-point. Conclusion: In REVEAL, a ≥10% decline in eGFR over ≥1 year independently predicted poorer survival. Thus, eGFR may be a simple and economical biomarker in PAH.