B-type natriuretic peptide predicts all-cause mortality in Eisenmenger syndrome
MedWire News: B-type natriuretic peptide (BNP) concentration can be used to predict all-cause mortality in patients with Eisenmenger syndrome, an analysis suggests.
Eisenmenger syndrome, the extreme manifestation of pulmonary arterial hypertension in adults with congenital heart disease, is associated with high mortality. As risk stratification is increasingly needed in this population of patients due to the availability of oral disease-targeting therapies, say Gerhard-Paul Diller (Royal Brompton Hospital, London, UK) and colleagues, they investigated the prognostic significance of BNP in the current study.
Diller et al assessed BNP concentration as part of routine clinical care in 181 patients with Eisenmenger syndrome (mean age 36.9 years; 31% with Down syndrome) between 2003 and 2010, and followed them up over a median of 3.3 years for all-cause mortality.
During this period, 20 patients died, of whom seven had Down syndrome. Univariate analysis revealed that baseline BNP concentration was significantly associated with all-cause mortality.
Kaplan-Meir analysis showed that the risk for mortality increased with increasing plasma BNP concentration both in the non-Down and Down syndrome populations. Patients with a BNP concentration above 30 pmol/L had a 4.6-fold overall increased risk for mortality, while those in the Down syndrome population had a 7.8-fold increased risk.
Multivariate analysis showed that baseline BNP concentration was a significant predictor for all-cause mortality in patients with Eisenmenger syndrome. Indeed, the hazard ratio for mortality increased 1.71-fold with each 100 pg/mL increase in BNP concentration, compared with 0.70 for each 10 µm/L increase in creatinine level, and 0.93 for each 10 m increase in 6-minute walk test (p=0.02).
Furthermore, time-dependent receiver-operating curve analysis showed that increases in BNP concentration over 1, 2, and 3 years of follow up were of prognostic significance.
In addition, among patients with a baseline BNP concentration above 104.2 pg/mL, corresponding to the highest quartile of BNP, a significant reduction in BNP concentration was seen during the first year of treatment with disease-targeting therapies such as bosentan, ambrisentan, and sildenafil compared with treatment-naïve patients (300 vs 184 pg/mL).
This "supports the notion that disease-targeting therapies are associated with reductions in plasma BNP concentrations," say the authors.
"BNP measurements may thus be useful in predicting mortality and guiding disease targeting therapies in patients with Eisenmenger syndrome," they conclude.
By Piriya Mahendra