Serum albumin concentration as an independent prognostic indicator in patients with pulmonary arterial hypertension

Abstract

Background: Serum albumin is a strong prognostic indicator for many disease processes, yet limited data exist regarding its prognostic relationship in pulmonary arterial hypertension (PAH). Our study aims to assess the relationship of hypoalbuminemia with disease severity and mortality in this population. Hypothesis: Serum albumin concentrations are a predictor of outcomes in PAH. Methods: A retrospective review of all patients with World Health Organization group 1 PAH evaluated between March 2001 and August 2008 was performed. Patients were stratified into groups based on serum albumin concentration ≤3.3 g/dL (hypoalbuminemia) vs >3.3 g/dL. Clinical, hemodynamic, and survival comparisons were compared between groups using Student t test and χ2 test, followed by univariate analysis and multivariate logistic regression. Results: A total of 163/273 (59.7%) patients had a documented serum albumin concentration. Hypoalbuminemia was present in 41 (25.2%) patients and serum albumin ≤3.3 g/dL represented the lowest quartile of serum albumin. Patients with hypoalbuminemia had higher rates of renal dysfunction (26.8% vs 9.8%, P =0.0069) and hepatic dysfunction (29.3% vs 6.6%, P <0.001), and lower hemoglobin levels (11.6 vs 13.4 g/dL, P < 0.001). Hemodynamic and functional capacity assessments were comparable between groups. Independent predictors of mortality included low albumin levels (hazard ratio [HR]: 0.485, P = 0.008), high right atrial systolic area (HR: 1.062, P = 0.003), low Fick-derived cardiac index (HR: 1.465, P = 0.016), and high New York Heart Association functional class (HR: 1.767, P = 0.042). Patients with hypoalbuminemia demonstrated a significantly lower survival rate at latest follow-up (P = 0.01). Conclusions: Lower serum albumin concentrations in patients with PAH are associated with higher mortality and can serve as a marker of disease severity in this patient population.