Circulating Aldosterone Levels and Disease Severity in Pulmonary Arterial Hypertension.

Abstract

OBJECTIVES It is not known whether aldosterone levels are associated with increased mortality in patients with pulmonary arterial hypertension (PAH). The primary goal of this study was to determine whether circulating aldosterone levels predict severity of PAH in terms of hemodynamic characteristics and mortality. METHODS Patients with stable PAH were enrolled at the Baylor PH program. The plasma levels of aldosterone and BNP were measured. Clinical, hemodynamic, and outcome data was collected by chart review. Mean follow up time from study enrollment was 39 ± 102 months. Cox proportional hazards model was used to assess time to death. RESULTS There were 125 PAH patients with plasma aldosterone levels. Median aldosterone level was 9.9 pg/ml (25th-75th percentile: 4.1 pg/ml, 27.1 pg/ml) and median brain natriuretic peptide (BNP) level was 67.5 pg/ml (25th-75th percentile: 31 pg/ml, 225 pg/ml). Aldosterone levels were not significantly associated with BNP levels, six-minute walk distance, Borg dyspnea score, right ventricular systolic pressure, cardiac output and cardiac index. However, the association between aldosterone and right atrial pressure was dependent on mineralocorticoid receptor blocker treatment (Coef. =2.88, 95CI: 1.19, 4.56, p=0.001). By log-rank statistic there was no statistical difference between the survival of patients divided by median aldosterone level (p=0.914). However, there was a significant difference in patient survival between the BNP categories (p<0.001) such that those with high BNP level (>180 pg/mL) had a shorter survival time. CONCLUSIONS The aldosterone level was not associated with increased mortality in PAH but was a marker of disease severity.