The Role of NT-proBNP as a Prognostic Marker in Pulmonary Hypertension

Associations of circulating natriuretic peptides with haemodynamics in precapillary pulmonary hypertension

BACKGROUND

While N-terminal B-type natriuretic peptide (NT-proBNP) has been examined extensively in pulmonary hypertension (PH), limited data exists on the subtype A, C and D. The aim of this prospective pilot study was a head-to-head comparison of NPs in respect to haemodynamic parameters and the influence of renal function.

METHODS

Plasma samples were drawn during routine right heart catheterization in 62 patients with precapillary PH and 20 control patients. MR-proANP measurements were performed on the automated Kryptor platform, NT-proBNP by CLIA, NT-proCNP and DNP levels by ELISA. Results are expressed as median [range] and tested non-parametrically. Non-parametric locally linear multiple regression was performed to determine the influence of renal function on NP levels. P-values <0.05 were considered significant.

RESULTS

Patients with PH had significantly higher MR-proANP and NT-proBNP levels. NT-proCNP showed a trend to higher levels, while DNP did not differ from control subjects. Both MR-proANP and NT-proBNP were associated with cardiac index (CI), right atrial pressure (RAP), mean pulmonary artery pressure (PAPm) and pulmonary vascular resistance index (PVRI). NT-proCNP was associated with RAP, while DNP showed no associations with haemodynamic variables. Associations of haemodynamic parameters with NPs were weakened in patients with in elevated serum creatinine and showed increased regression slopes.

CONCLUSION

MR-proANP demonstrated equivalent associations with haemodynamics compared to NT-proBNP, but both markers depend on intact renal function. NT-proCNP was correlated with RAP and renal function, while DNP showed no associations. Larger studies should evaluate MR-proANP as candidate prognostic biomarker in PH.

Quality of life as a prognostic marker in pulmonary arterial hypertension

Background

Improvement in quality of life together with better survival are the ultimate goals in the treatment of pulmonary arterial hypertension (PAH) patients. The objective of this study was to evaluate the health-related quality of life (HRQL) of pulmonary arterial hypertension (PAH) patients with the SF-36 generic questionnaire and to identify the prognostic implication of this assessment.

Methods

Fifty-four consecutive newly diagnosed PAH patients (WHO classification group I) in a single PAH reference center were included. Patients were evaluated at baseline for clinical and hemodynamic parameters, and they subsequently received first-line therapy with either an endothelin receptor antagonist or a phosphodiesterase-5 inhibitor. After 16 weeks of specific PAH therapy, all patients were re-evaluated using a 6MWT and a SF 36 questionnaire, and then they were followed up for at least 36 months.

Results

After treatment, the patients demonstrated an improved 6MWT (414 ± 124 m vs. 440 ± 113 m, p = 0.001). Specific PAH therapy also improved the HRQL scores.

Patients with a baseline Physical Component Score (PCS) higher than 32 had a better survival rate than those who had a score under 32 (p = 0.04). Similarly, patients with a PCS of at least a 38 after the 16 week therapy period had a better survival rate when compared with those who did not achieve this value (p = 0.016). Unlike the absolute PCS values, the post-treatment PCS variability was unable to predict better survival rates (p = 0.58).

Conclusions

Our findings suggest that HRQL is associated with prognosis in PAH. Furthermore, achieving pre-determined PCS scores might represent a specific goal to be reached in treatment-to-target strategies.

Diagnosis and treatment of pulmonary hypertension: an update

Over the last five years, knowledge in the field of pulmonary hypertension has grown consistently and significantly. On the basis of various clinical studies showing the usefulness of new diagnostic tools, as well as the efficacy of new medications and drug combinations, new diagnostic and treatment algorithms have been developed. Likewise, in order to simplify the clinical management of patients, the classification of pulmonary hypertension has been changed in an attempt to group the various forms of pulmonary hypertension in which the diagnostic and therapeutic approaches are similar. The objective of this review was to discuss these modifications, based on the 2005 Brazilian guidelines for the management of pulmonary hypertension, emphasizing what has been added to the international guidelines.

Analytical and clinical performance of the Ortho-Clinical Diagnostics VITROS® amino-terminal pro-B type natriuretic peptide assay

BACKGROUND

Measurement of amino-terminal pro-B-type natriuretic peptide (NT-proBNP) is useful for evaluating patients with heart failure (HF).

METHODS

We evaluated the performance of a new automated NT-proBNP assay.

RESULTS

The VITROS NT-proBNP assay had mean within-run and total imprecision of 1.0% and 3.4% at NT-proBNP concentrations from 67-27,500 ng/l. Acceptable linearity, functional/analytical sensitivity were demonstrated. Anticoagulant/tube types had no effect on results. Excellent sample stability and no high-dose hook were observed. High correlation between the VITROS and Elecsys methods was demonstrated (r=0.995; P<.001), with 98.3% clinical concordance. VITROS NT-proBNP concentrations were significantly higher in HF subjects than those without (1210 versus 68 ng/l; P<.001) and associated with HF symptom severity (P<.001). The VITROS assay had AUC for HF of 0.95 (P<.001), and had excellent NPV for excluding HF.

CONCLUSIONS

The automated VITROS NT-proBNP assay demonstrates excellent analytical and clinical performance for evaluating the presence and severity of HF.