Presence of Kidney Disease as an Outcome Predictor in Patients with Pulmonary Arterial Hypertension.

BACKGROUND: Pulmonary arterial hypertension (PAH) may lead to right heart failure and subsequently alter glomerular filtration rates (GFR). Chronic kidney disease (CKD, GFR <60 mL/min/1.73 m2) may also adversely affect PAH prognosis. This study aimed to assess how right heart hemodynamics was associated with reduced estimated GFR (eGFR) and the association of CKD with survival in PAH patients.

METHODS: In a prospective PAH cohort (2003-2012), invasive hemodynamics and eGFR were collected at diagnosis (179 patients) and during follow-up (159 patients). The prevalence of CKD was assessed at PAH diagnosis. Variables, including hemodynamics, associated with reduced eGFR at diagnosis and during follow-up were tested in multivariate analysis. The association of CKD with survival was evaluated using a multivariate Cox regression model.

RESULTS: At diagnosis, mean age was 60.4 ± 16.5 years, mean pulmonary arterial pressure was 43 ± 12 mm Hg, and eGFR was 74.4 ± 26.4 mL/min/1.73 m2. CKD was observed in 52 incident patients (29%). Independent determinants of reduced eGFR at diagnosis were age, systemic hypertension, and decreased cardiac index. Independent determinants of reduced eGFR during follow-up were age, female gender, PAH etiology, systemic hypertension, decreased cardiac index, and increased right atrial pressure. Age ≥60 years, female gender, NYHA 4, and CKD at diagnosis were independently associated with decreased survival. The adjusted hazards ratio for death associated with CKD was 1.81 (95% confidence interval [1.01-3.25]).

CONCLUSION: CKD is frequent at PAH diagnosis and is independently associated with increased mortality. Right heart failure may induce renal hypoperfusion and congestion, and is associated with eGFR decrease.