The association of the N-terminal pro-brain-type natriuretic peptide response to exercise with disease severity in therapy-naive pulmonary arterial hypertension: a cohort study

Exercise MR-proANP unmasks latent right heart failure in CTEPH

OBJECTIVE

The present study was designed to investigate the dynamics of right atrial pressure (RAP) and mid-regional pro-atrial natriuretic peptide (MR-proANP) during physical exercise in patients with chronic thromboembolic pulmonary hypertension (CTEPH) and to determine whether these parameters might serve as a tool to measure exercise-dependent atrial stress as an indicator of right heart failure.

METHODS

This prospective observational cohort study included 100 CTEPH patients who underwent right heart catheterization during physical exercise (eRHC). Blood samples for MR-proANP measurement were taken prior, during, and after eRHC. MR-proANP levels were correlated to RAP levels at rest, at peak exercise (eRAP), and during recovery. RAP at rest ≤7 mmHg was defined as normal and eRAP >15 mmHg as suggestive of right heart failure.

RESULTS

During eRHC mean RAP increased from 6 mmHg (standard deviation, SD 4) to 16 mmHg (SD 7; p < 0.001). MR-proANP levels and dynamics correlated with RAP at rest (r_s = 0.61; p < 0.001) and at peak exercise (r_s = 0.66; p < 0.001). Logistic regression analysis revealed the peak MR-proANP level (B = 0.058; p = 0.004) and the right atrial area (B = 0.389; p < 0.001) to be associated with eRAP dynamics. A peak MR-proANP level ≥139 pmol/L (AUC = 0.81) and recovery level ≥159 pmol/L (AUC = 0.82) predicted an eRAP >15 mmHg. Physical exercise unmasked right heart failure in 39% of patients with normal RAP at rest; these patients were also characterized by a more distinct increase in MR-proANP levels (p = 0.005) and higher peak (p < 0.001) and recovery levels (p < 0.001).

CONCLUSIONS

RAP and MR-proANP dynamics unmask manifest and latent right heart failure in CTEPH patients.

Right ventricular expression of NT-proBNP adds predictive value to REVEAL score in patients with pulmonary arterial hypertension

Aims

The Registry to Evaluate Early and Long‐Term PAH Disease Management (REVEAL) risk scores differentiate survivals in patients with pulmonary arterial hypertension (PAH). However, measurements of N‐terminal pro B‐type natriuretic peptide (NT‐proBNP) in the peripheral blood may not adequately reflect early‐stage decompensated heart failure (HF). Given that right heart catheterization (RHC) can facilitate measurements of intracardiac NT‐proBNP, in this study our aim was to evaluate the predictive role of right ventricular (RV) NT‐proBNP measurements in patients with PAH.

Methods and results

We prospectively collected intracardiac blood samples for NT‐proBNP measurements from patients diagnosed with World Health Organization Group I PAH during RHC. Clinical information including the aetiology of PAH (idiopathic, connective tissue disease, or congenital heart disease) and REVEAL scores were recorded. The primary endpoint was hospitalization for decompensated HF; median duration of follow‐up was 28 months. Among the 62 patients evaluated, 12 reached the designated endpoint. REVEAL risk scores were higher among patients hospitalized for HF. We detected no significant differences in plasma NT‐proBNP levels in peripheral circulation, in the right atrium, or in pulmonary arterial blood; however, significantly higher levels of NT‐proBNP were detected in the RV in patients diagnosed with PAH. RV NT‐proBNP was a sensitive predictor (cut‐off value 1500 pg/mL) of subsequent hospitalization for HF. Our findings indicate that RV NT‐proBNP levels add predictive value to REVEAL scores with respect to future hospitalization due to HF.

Conclusions

Right ventricular NT‐proBNP levels combined with REVEAL 2.0 could predict the development of subsequent HF in patients with PAH and may be a potential biomarker.

BNP/NT-proBNP in pulmonary arterial hypertension: time for point-of-care testing?

Despite the advent of new therapies and improved outcomes in patients with pulmonary arterial hypertension (PAH), it remains a life-shortening disease and the time to diagnosis remains unchanged. Strategies to improve outcomes are therefore currently focused on earlier diagnosis and a treatment approach aimed at moving patients with PAH into a category of low-risk of 1-year mortality. B-type natriuretic peptide (BNP; or brain natriuretic peptide) and N-terminal prohormone of BNP (NT-proBNP) are released from cardiac myocytes in response to mechanical load and wall stress. Elevated levels of BNP and NT-proBNP are incorporated into several PAH risk stratification tools and screening algorithms to aid diagnosis of systemic sclerosis. We have undertaken a systematic review of the literature with respect to the use of BNP and NT-proBNP in PAH and the use of these biomarkers in the diagnosis and risk stratification of PAH, their relation to pulmonary haemodynamics and the potential for point-of-care testing to improve diagnosis and prognosis.

Pulmonary arterial remodelling by deficiency of peroxisome proliferator-activated receptor-γ in murine vascular smooth muscle cells occurs independently of obesity-related pulmonary hypertension

Background

Obesity is associated with cardiovascular complications, including pulmonary hypertension (PH). Reports suggest that peroxisome proliferator-activated receptor-γ (PPARγ) has direct action in preventing vascular remodelling in PH. Here we dissected the specific role of high-fat-diet (HFD)-induced obesity and vascular smooth muscle cell (VSMC)-PPARγ for remodelling of small pulmonary arteries.

Methods

Wild-type (WT) and VSMC-specific PPARγ-knockout (SmPparγ^−/−) mice were fed a low-fat-diet (LFD, 10% kcal from fat) or HFD (60% kcal from fat) for 24 weeks. Mice were metabolically phenotyped (e.g. weight development, insulin/glucose tolerance) at the beginning, and after 12 and 24 weeks, respectively. At 24 weeks additionally pulmonary pressure, heart structure, pulmonary vascular muscularization together with gene and protein expression in heart and lung tissues were determined.

Results

HFD increased right ventricular systolic pressure (RVSP) to a similar extent in WT and SmPparγ^−/− mice. HFD decreased glucose tolerance and insulin sensitivity in both WT and SmPparγ^−/− mice. Importantly, the increase in RVSP correlated with the degree of insulin resistance. However, VSMC-PPARγ deficiency increased pulmonary vascular muscularization independently of the diet-induced rise in RVSP. This increase was associated with elevated expression of early growth response protein 1 in heart and osteopontin in lung tissue.

Conclusions

Here we demonstrate a correlation of insulin resistance and pulmonary pressure. Further, deficiency of PPARγ in VSMCs diet-independently leads to increased pulmonary vascular muscularization.