NT-proBNP reflects right ventricular structure and function in pulmonary hypertension

Differential biventricular adaption to pulmonary vascular disease in patients with idiopathic/heritable and congenital heart disease: a prospective cardiac magnetic resonance and invasive study

AIMS

Despite shared pathophysiological mechanisms, patients with idiopathic/heritable pulmonary arterial hypertension (IPAH/HPAH) have a poorer prognosis than those with PAH after congenital heart defect repair. Ventricular adaption remains unclear and could provide a basis for explaining differences in clinical outcomes. The aim of this prospective study was to assess clinical status, haemodynamic profile, and biventricular adaptation to PAH in children with various forms of PAH.

METHODS AND RESULTS

Consecutive patients with IPAH/HPAH or post-operative PAH were prospectively recruited (n = 64). All patients underwent a comprehensive, protocolized assessment including functional assessment, measurement of brain natriuretic peptide (BNP) levels, invasive measurements, and a cardiac magnetic resonance (CMR) assessment. A cohort of age- and sex-matched healthy subjects served as controls. Patients with post-operative PAH had a better functional class (61.5 vs. 26.3% in Class I/II, P = 0.02) and a longer 6-min walk distance (320 ± 193 vs. 239 ± 156 m, P = 0.008) than IPAH/HPAH. While haemodynamic parameters were not significantly different between IPAH/HPAH and post-operative patients, post-operative patients with PAH presented with higher left ventricular volumes and better right ventricular function compared with patients with IPAH/HPAH (P < 0.05). On correlation analyses, left ventricular volumetric parameters were highly correlated with BNP and 6-min walk test distance in this population.

CONCLUSION

Despite comparable haemodynamic profiles, patients with post-operative PAH had less functional limitation than their IPAH/HPAH counterparts. This is potentially related to the differential biventricular adaptation pattern evident on CMR with better myocardial contractility and higher left ventricular volumes in post-operative patients with PAH, highlighting the importance of ventriculo-ventricular interaction in the setting of PAH.

An update on utilising brain natriuretic peptide for risk stratification, monitoring and guiding therapy in heart failure

INTRODUCTION

Heart failure (HF) is a dominant health problem with an overall poor prognosis. Natriuretic peptides (NPs) are upregulated in HF as a compensatory mechanism. They have extensively been used for diagnosis and risk stratification.

AREAS COVERED

This review addresses the history and physiology of NPs in order to understand their current role in clinical practice. It further provides a detailed and updated narrative review on the utility of those biomarkers for risk stratification, monitoring, and guiding therapy in HF.

EXPERT OPINION

NPs show excellent predictive ability in heart failure patients, both in acute and chronic settings. Understanding their pathophysiology and their modifications in specific situations is key for an adequate interpretation in specific clinical scenarios in which their prognostic value may be weaker or less well evaluated. To better promote risk stratification in HF, NPs should be integrated with other predictive tools to develop multiparametric risk models. Both inequalities of access to NPs and evidence caveats and limitations will need to be addressed by future research in the coming years.

Prevalence and Correlates of Elevated NT-proBNP in Pregnant Women in the General U.S. Population

BACKGROUND

Physiologic changes in N-terminal pro-B-type natriuretic peptide (NT-proBNP) across trimesters of pregnancy have not been well studied.

OBJECTIVES

The authors aimed to measure NT-proBNP in adult women, by pregnancy status and trimester, in a nationally representative sample from the National Health and Nutrition Examination Survey 1999 to 2004.

METHODS

We conducted a cross-sectional analysis of 2,134 women (546 pregnant) aged 20 to 40 years without a history of cardiovascular disease.

RESULTS

Among pregnant women in the first trimester, the prevalence of elevated NT-proBNP (>125 pg/mL) was 20.0% (SE, 6.6%) compared to 2.4% (SE, 0.8%) among women in the third trimester and 8.0% among nonpregnant women. After adjustment for demographics and cardiovascular risk factors, NT-proBNP was 44% higher (absolute difference 26.4 [95% CI: 11.2-41.6] pg/mL) in the first trimester of pregnancy compared to nonpregnant women. Among pregnant women only, adjusted NT-proBNP was 46% lower (absolute difference -22.2 [95% CI: -36.9 to -7.5] pg/mL) in women in the third trimester compared to women in the first trimester. NT-proBNP was inversely associated with body mass index and with systolic blood pressure.

CONCLUSIONS

Women in the first trimester of pregnancy had significantly higher NT-proBNP than those in the third trimester and compared to similarly aged nonpregnant women. The dynamic nature of NT-proBNP should be taken into consideration when ordering NT-proBNP lab tests in pregnant women.

Doppler Echocardiography Combined with NTproBNP/BNP in the Diagnosis of Pulmonary Artery Hypertension Associated with Congenital Heart Disease

Background

Pulmonary artery hypertension (PAH) is a common complication of congenital heart disease (CHD) and is associated with worse outcomes and increased mortality. The Doppler echocardiography (DE) is a commonly used imaging tool for both diagnosis and follow-up examination of PAH. Here is to evaluate the diagnostic performance of DE combined with NTproBNP/BNP as screening strategy in PAH patients with CHD.

Methods

A retrospective study in 64 patients with CHD has been carried out to compare estimate pulmonary artery systolic pressure (PASP) measured with DE to that measured with right heart catheterization (RHC). The Pearson correlation analyses were used to calculate the correlation coefficients between RHC and DE. The Bland-Altman analyses were carried out to assess the agreement between the two methods. ROC analyses were used to evaluate the diagnostic performance of DE, NTproBNP/BNP, and DE combined with NTproBNP/BNP.

Results

Our data have demonstrated that a mild correlation (r = 0.4401, P < 0.01) was observed between PASP (78.1 ± 29.0 mmHg) measured during RHC and PASP (74.9 ± 19.7 mmHg) as estimated using DE. The Bland-Altman analysis demonstrated that the bias for DE PASP estimates was 3.2 mmHg with 95% limits of agreement ranging from -49.53 to 55.90 mmHg. The results of DE showed an AUC of 0.848 (95% CI = 0.666-1; P < 0.001), the sensitivity of which was 98.3% and the specificity was 77.8%. The AUC of NTproBNP/BNP for the identification of PAH was 0.804 (95% CI = 0.651-0.956; P < 0.001), the sensitivity of which was 81.4% and the specificity was 87.5%. The AUC of DE combined with NTproBNP/BNP was 0.857 (95% CI = 0.676-1; P < 0.001), of which sensitivity was 100% and specificity was 77.8%. The positive predictive value (PPV) and negative predictive value (NPV) were 96.6% and 100%, respectively.

Conclusions

Our study shows that the Doppler echocardiography combined with NTproBNP/BNP has better diagnostic performance in pulmonary artery hypertension associated with congenital heart disease, especially when DE negative screening in PAH patients.

Pregnant outcomes of critically ill pregnant patients with pulmonary hypertension: A multicenter retrospective study

Objective

To identify the pregnancy outcomes and risk factors of critically ill pulmonary hypertension (PH) patients with intensive care unit (ICU) admission.

Methods

The multicenter, retrospective cohort study was performed on 60,306 parturients from January 2013 to December 2018 in China. Diagnosis of PH was based on the estimation of systolic pulmonary arterial pressure (sPAP) via echocardiography. Patients were stratified by sPAP into three groups, mild (30–50 mmHg), moderate (51–70 mmHg), and severe (>70 mmHg). The primary outcome was major adverse cardiovascular events (MACE), defined as a composite of in-hospital death, heart failure, and sustained arrhythmias requiring treatment. The secondary outcome was fetal adverse clinical events (FACE), a composite of fetal/neonatal death, prematurity, small birth weight, and fetal distress.

Results

A total of 181 pregnant patients were enrolled, including 101 patients with mild PH, 31 with moderate PH, and 49 with severe PH. The maternal median age was 32 (27, 35) years and 37% were nulliparous. The MACE occurred in 59 (59/181, 32.6%) women, including in-hospital death in 13 (13/181, 7.2%), heart failure in 53 (53/181, 29.3%), and sustained arrhythmias in 7 (7/181, 3.9%). The incidence of FACE was as high as 66.3% (120/181). Compared with mild and moderate PH patients, patients with severe PH had a significantly higher mortality rate (22.4 vs. 1.51%, P < 0.001) and MACE incidence (51.0 vs. 25.8%, P = 0.001). Although the incidence of FACE in severe PH was slightly higher than that in mild to moderate PH, there was no significant difference (69.4 vs. 65.1%, P = 0.724). PH complicated with left heart disease (OR = 4.365, CI: 1.306–14.591), elevated N-terminal pro-B-type natriuretic peptide (NT-proBNP) level (OR = 1.051, CI:1.015–1.088), and sPAP level estimated by echocardiography (OR = 1.021; CI: 1.003–1.040) were independently associated with MACE in multivariable regression (P < 0.05). Increased risk of FACE was noted for PH patients combined with eclampsia/preeclampsia (OR = 6.713; CI: 1.806–24.959).

Conclusion

The incidence of MACE and FACE remained high in critically ill pregnant patients with PH, particularly moderate and severe PH in China. Further studies are warranted to identify subsets of women with PH at lower pregnant risks and seek more effective therapy to improve pregnancy outcomes.

Veno-Arterial Extracorporeal Membrane Oxygenation Rescue in a Patient With Pulmonary Hypertension Presenting for Revision Total Hip Arthroplasty: A Case Report and Narrative Review

Patients with pulmonary hypertension (PH) are at an increased risk of perioperative morbidity and mortality when undergoing non-cardiac surgery. We present a case of a 57-year-old patient with severe PH, who developed cardiac arrest as the result of right heart failure, undergoing a revision total hip arthroplasty under combined spinal epidural anesthesia. Emergent veno-arterial (VA) extracorporeal membrane oxygenation (ECMO) was undertaken as rescue therapy during the pulmonary hypertensive crisis and a temporizing measure to provide circulatory support in an intensive care unit (ICU). We present a narrative review on perioperative management for patients with PH undergoing non-cardiac surgery. The review goes through the updated hemodynamic definition, clinical classification of PH, perioperative morbidity, and mortality associated with PH in non-cardiac surgery. Pre-operative assessment evaluates the type of surgery, the severity of PH, and comorbidities. General anesthesia (GA) is discussed in detail for patients with PH regarding the benefits of and unsubstantiated arguments against GA in non-cardiac surgery. The literature on risks and benefits of regional anesthesia (RA) in terms of neuraxial, deep plexus, and peripheral nerve block with or without sedation in patients with PH undergoing non-cardiac surgery is reviewed. The choice of anesthesia technique depends on the type of surgery, right ventricle (RV) function, pulmonary artery (PA) pressure, and comorbidities. Given the differences in pathophysiology and mechanical circulatory support (MCS) between the RV and left ventricle (LV), the indications, goals, and contraindications of VA-ECMO as a rescue in cardiopulmonary arrest and pulmonary hypertensive crisis in patients with PH are discussed. Given the significant morbidity and mortality associated with PH, multidisciplinary teams including anesthesiologists, surgeons, cardiologists, pulmonologists, and psychological and social worker support should provide perioperative management.

Prognostic value of brain natriuretic peptides in patients with pulmonary arterial hypertension: A systematic review and meta-analysis

BACKGROUND

Multiple biomarkers have been investigated in the risk stratification of patients with pulmonary arterial hypertension (PAH). This systematic review and meta-analysis is the first to investigate the prognostic value of (NT-pro)BNP in patients with PAH.

METHODS

A systematic literature search was performed using MEDLINE, Embase, Web of Science, the Cochrane Library and Google scholar to identify studies on the prognostic value of baseline (NT-pro)BNP levels in PAH. Studies reporting hazard ratios (HR) for the endpoints mortality or lung transplant were included. A random effects meta-analysis was performed to calculate the pooled HR of (NT-pro)BNP levels at the time of diagnosis. To account for different transformations applied to (NT-pro)BNP, the HR was calculated for a 2-fold difference of the weighted mean (NT-pro)BNP level of 247 pmol/L, for studies reporting a HR based on a continuous (NT-pro)BNP measurement.

RESULTS

Sixteen studies were included, representing 6999 patients (mean age 45.2-65.0 years, 97.3% PAH). Overall, 1460 patients reached the endpoint during a mean follow-up period between 1 and 10 years. Nine studies reported HRs based on cut-off values. The risk of mortality or lung transplant was increased for both elevated NT-proBNP and BNP with a pooled HR based on unadjusted HRs of 2.75 (95%-CI: 1.86-4.07) and 3.87 (95% CI 2.69-5.57) respectively. Six studies reported HRs for (NT-pro)BNP on a continues scale. A 2-fold difference of the weighted mean NT-proBNP resulted in an increased risk of mortality or lung transplant with a pooled HR of 1.17 (95%-CI: 1.03-1.32).

CONCLUSIONS

Increased levels of (NT-pro)BNP are associated with a significantly increased risk of mortality or lung transplant in PAH patients.

Left ventricular dysfunction and intra-ventricular dyssynchrony in idiopathic pulmonary arterial hypertension

BACKGROUND

Left ventricular (LV) filling pressures are normal in idiopathic pulmonary arterial hypertension (IPAH). However, direct and indirect interactions between the RV and LV can affect LV performance. We explored LV strain and LV intra-ventricular dyssynchrony in IPAH using feature tracking CMR (CMR-FT).

METHODS

Seventy IPAH patients and 40 healthy volunteers were included. Patients underwent CMR and right heart catheterisation. The 4-chamber cine was used to calculate LV longitudinal strain (Ell_LV). LV circumferential (Ecc_LV) and radial strain (Err_LV) were derived from a short axis cine. LV longitudinal, circumferential and radial intra-ventricular dyssynchrony indices were calculated.

RESULTS

There were no differences between the IPAH and healthy volunteer group in LV ejection fraction (66.1% vs 64.2% p = 0.6672). Ecc_LV (-29.1 vs -32.1 p = 0.0323) and Ell_LV (-16.6 vs -23.7 p < 0.0001) were lower in IPAH. In patients with more severe disease, there was greater impairment of Err_LV compared to mild disease (50.9 vs 87.5 P < 0.0001). LV synchrony was impaired in all directions in IPAH. Err_LV was associated with RV ejection fraction (r = 0.66), RV end-systolic volume index (r = -0.59), pulmonary vascular resistance (PVR)(r = 0.51) and stroke volume index (SVI)(r = 0.44). In a multivariate model with age, SVI and PVR, Err_LV (HR 0.970 p = 002) and radial dyssynchrony (HR 3.759 p < 0.0001) independently predicted survival.

CONCLUSION

In IPAH, LV is dyssynchronous with impaired function. Measures of LV strain and intraventricular synchrony were associated with known markers of disease severity. These LV variables which are likely to be related to ventricular interaction, may add incremental value to known prognostic variables in IPAH.

ECG in the clinical and prognostic evaluation of patients with pulmonary arterial hypertension: an underestimated value

BACKGROUND

Pulmonary arterial hypertension (PAH) is a rare disease leading to right ventricular (RV) failure and manifests in decreasing exercise tolerance. Our study aimed to assess the usefulness of electrocardiographic parameters reflecting right heart hypertrophy as predictors of clinical status in PAH.

METHODS

The retrospective analysis included 26 patients, mean 49 ± 17 years of age, diagnosed with PAH, and eligible to undergo cardiopulmonary exercise test (CPET). The relations between ECG values and parameters obtained in procedures such as six-minute walk test (6-MWT), echocardiography, right heart catheterization (RHC), and CPET were analyzed.

RESULTS

P-wave amplitude in lead II correlated positively with CPET parameter of respiratory response: minute ventilation to carbon dioxide production slope (VE/VCO₂ slope; r = 0.436, p = 0.029) and echocardiographic estimated RA pressure (RAP; r = 0.504, p = 0.02). RV Sokolow-Lyon index (RVSLI) positively correlated with echocardiographic parameters reflecting RV function, overload, and afterload-tricuspid regurgitation pressure gradient (TRPG; r = 0.788, p < 0.001), RV free wall thickness (r = 0.738, p < 0.001), and mean pulmonary arterial pressure (mPAP_ECHO; r = 0.62, p = 0.0016), respectively, as well as VE/VCO₂ slope (r = 0.593, p = 0.001) and mPAP assessed directly in RHC (mPAP_RHC; r = 0.469, p = 0.0497). R-wave in lead aVR correlated positively with TRPG (r = 0.719, p < 0.001), mPAP_ECHO (r = 0.446, p = 0.033), and several hemodynamic criteria of PAH diagnosis: positively with mPAP_RHC (r = 0.505, p = 0.033) and pulmonary vascular resistance (r = 0.554, p = 0.026) and negatively with pulmonary capillary wedge pressure (r = -0.646, p = 0.004). QRS duration correlated positively with estimated RAP (r = 0.589, p = 0.004), vena cava inferior diameter (r = 0.506, p = 0.016), and RA area (r = 0.679, p = 0.002) and negatively with parameters of exercise capacity: peak VO₂ (r = -0.486, p = 0.012), CPET maximum load (r = - 0.439, p = 0.025), and 6-MWT distance (r = -0.430, p = 0.046). ROC curves to detect intermediate/high 1-year mortality risk (based on ESC criteria) indicate RVSLI (cut-off point: 1.57 mV, AUC: 0.771) and QRS duration (cut-off points: 0.09 s, AUC: 703 and 0.1 s, AUC: 0.759) as relevant predictors.

CONCLUSION

Electrocardiography appears to be an important and underappreciated tool in PAH assessment. ECG corresponds with clinical parameters reflecting PAH severity.

Considerations for Inotrope and Vasopressor Use in Critically Ill Patients With Pulmonary Arterial Hypertension

ABSTRACT

Pulmonary arterial hypertension (PAH) is a rare and progressive cardiopulmonary disease, characterized by pulmonary vasculopathy. The disease can lead to increase pulmonary arterial pressures and eventual right ventricle failure due to elevated afterload. The prevalence of PAH in patients admitted to the intensive care unit (ICU) is unknown, and pulmonary hypertension (PH) in the ICU is more commonly the result of left heart disease or hypoxic lung injury (PH due to left heart disease and PH due to lung diseases and/or hypoxia, respectively), as opposed to PAH. Management of patients with PAH in the ICU is complex as it requires a careful balance to maintain perfusion while optimizing right-sided heart function. A comprehensive understanding of the underlying physiology and underlying hemodynamics is crucial for the management of this population. In this review, we summarized the evidence for use of vasopressors and inotropes in the management of PH and extrapolated the data to patients with PAH. We strongly believe that the understanding of the hemodynamic consequences of inotropes and vasopressors, especially from data in the PH population, can lead to better management of this complex patient population.

Cardiac biomarkers as indicators of right ventricular dysfunction and recovery in chronic thromboembolic pulmonary hypertension patients after balloon pulmonary angioplasty therapy - a cardiac magnetic resonance imaging cohort study

Background

In chronic thromboembolic pulmonary hypertension, right heart failure determines outcome. Balloon pulmonary angioplasty therapy allows right heart recovery, which can be monitored by cardiac magnetic resonance imaging. This study evaluates whether cardiac biomarkers (NT-proBNP, MR-proANP, sST2, and PAPP-A) are associated with cardiac magnetic resonance imaging findings prior to and after balloon pulmonary angioplasty therapy.

Methods

This observational cohort study enrolled 22 chronic thromboembolic pulmonary hypertension patients who underwent balloon pulmonary angioplasty therapy and completed a six-month follow-up including cardiac magnetic resonance imaging. Biomarker levels were compared with findings for right heart morphology and function derived from cardiac magnetic resonance imaging.

Results

Pulmonary hemodynamics improved after balloon pulmonary angioplasty therapy [pulmonary vascular resistance: 7.7 (6.0–9.0) vs. 4.7 (3.5–5.5) wood units, p < 0.001; mean pulmonary artery pressure 41 (38–47) vs. 32 (28–37) mmHg, p < 0.001]. Cardiac magnetic resonance imaging findings indicated right heart maladaptation at baseline and recovery after therapy [right ventricular end-diastolic volume 192 (141–229) ml vs. 143 (128–172) ml, p = 0.002; right ventricular end-systolic volume 131 (73–157) ml vs. 77 (61–99) ml (p < 0.001); right ventricular ejection fraction (RVEF) 34 (28–41) % vs. 52 (41–54) %; p < 0.001]. Biomarker level cut-offs [NT-proBNP 347 ng/L (area under the curve (AUC) 0.91), MR-proANP 230 pg/L (AUC 0.78), PAPP-A 14.5 mU/L (AUC 0.81), and sST2 48.0 ng/ml (AUC 0.88)] indicated a RVEF ≤ 35% at baseline. The dynamics of NT-proBNP (rs = −0.79; p < 0.001), MR-proANP (rs = –0.80; p < 0.001), and sST2 (rs = –0.49; p = 0.02) correlated inversely with the improvement in RVEF after therapy. A relative decrease of NT-proBNP < 53% (AUC 0.86) and MR-proANP < 24% (AUC 0.82) indicated a limited RVEF response.

Conclusions

In chronic thromboembolic pulmonary hypertension patients, cardiac magnetic resonance imaging findings illustrate right heart failure and recovery after balloon pulmonary angioplasty therapy. Cardiac biomarker levels correlate with right heart parameters at baseline and their dynamics after therapy.

Impact of empagliflozin on right ventricular parameters and function among patients with type 2 diabetes

Background

Sodium-glucose cotransporter 2 (SGLT2) inhibition reduces cardiovascular events in type 2 diabetes (T2DM) and is associated with a reduction in left ventricular (LV) mass index. However, the impact on right ventricular (RV) remodeling is unknown. Accordingly, the objective of this study was to assess the impact of SGLT2 inhibition on RV parameters and function in T2DM and coronary artery disease (CAD).

Methods

In EMPA-HEART CardioLink-6, 97 patients with T2DM and CAD were randomly assigned to empagliflozin 10 mg (n = 49) once daily or placebo (n = 48). Cardiac magnetic resonance imaging was performed at baseline and after 6 months. RV mass index (RVMi), RV end-diastolic and end-systolic volume index (RVEDVi, RVESVi) and RV ejection fraction (RVEF) were assessed in blinded fashion.

Results

At baseline, mean RVMi (± SD) (11.8 ± 2.4 g/m²), RVEF (53.5 ± 4.8%), RVEDVi (64.3 ± 13.2 mL/m²) and RVESVi (29.9 ± 6.9 mL/m²) were within normal limits and were similar between the empagliflozin and placebo groups. Over 6 months, there were no significant differences in RVMi (− 0.11 g/m², [95% CI − 0.81 to 0.60], p = 0.76), RVEF (0.54%, [95% CI − 1.4 to 2.4], p = 0.58), RVEDVi (− 1.2 mL/m², [95% CI − 4.1 to 1.7], p = 0.41) and RVESVi (− 0.81 mL/m², [95% CI − 2.5 to 0.90], p = 0.35) in the empaglifozin group as compared with the placebo group. In both groups, there was no significant correlation between RVMi and LVMi changes from baseline to 6 months.

Conclusions

In this post-hoc analysis, SGLT2 inhibition with empagliflozin had no impact on RVMi and RV volumes in patients with T2DM and CAD. The potentially differential effect of empagliflozin on the LV and RV warrants further investigation.

Clinical Trial Registration: URL: https://www.clinicaltrials.gov/ct2/show/NCT02998970?cond=NCT02998970&draw=2&rank=1. Unique identifier: NCT02998970.

Prognostic biomarkers in pediatric pulmonary arterial hypertension

Pulmonary arterial hypertension (PAH) is a progressive life-threatening disease of the pulmonary vasculature. Despite the introduction of targeted therapies, prognosis remains poor. In pediatric PAH, reliable prognostic biomarkers are needed to inform clinicians on disease progression and risk of mortality, in order to be able to assess the need for escalation of medical therapy, consider surgical options such as Pott's shunt and listing for (heart)-lung transplantation. This review provides an overview of prognostic biomarkers that are considered to carry potential for the clinical management of pediatric PAH. These include conventional physiological biomarkers [resting heart rate, heart rate variability (HRV), a child's growth], biomarkers of functional status [World Health Organization functional class, 6-minute walk distance (6MWD), parameters derived from cardiopulmonary exercise testing (CPET), daily physical activity level], electrocardiographic biomarkers, circulating serum biomarkers (natriuretic peptides, uric acid, neurohormones, inflammatory markers, and novel circulating biomarkers), and multiple hemodynamic biomarkers and imaging biomarkers [echocardiography and cardiac magnetic resonance (CMR)]. In recent years, many potential prognostic biomarkers have become available for the management of PAH in children. As the available prognostic biomarkers reflect different aspects of the disease process and functional implications, a multi-marker approach appears the most useful for guiding therapy decisions and improve outcome in pediatric PAH.

What's new in pulmonary hypertension clinical research: lessons from the best abstracts at the 2020 American Thoracic Society International Conference

In this conference paper, we review the 2020 American Thoracic Society International Conference session titled, "What's New in Pulmonary Hypertension Clinical Research: Lessons from the Best Abstracts". This virtual mini-symposium took place on 21 October 2020, in lieu of the annual in-person ATS International Conference which was cancelled due to the COVID-19 pandemic. Seven clinical research abstracts were selected for presentation in the session, which encompassed five major themes: (1) standardizing diagnosis and management of pulmonary hypertension, (2) improving risk assessment in pulmonary arterial hypertension, (3) evaluating biomarkers of disease activity, (4) understanding metabolic dysregulation across the spectrum of pulmonary hypertension, and (5) advancing knowledge in chronic thromboembolic pulmonary hypertension. Focusing on these five thematic contexts, we review the current state of knowledge, summarize presented research abstracts, appraise their significance and limitations, and then discuss relevant future directions in pulmonary hypertension clinical research.

Pulmonary hypertension in interstitial lung disease: screening, diagnosis and treatment

PURPOSE OF REVIEW

Pulmonary vascular disease resulting in pulmonary hypertension in the context of interstitial lung disease (PH-ILD) is a common complication that presents many challenges in clinical practice. Despite recent advances, the pathogenetic interplay between parenchymal and vascular disease in ILD is not fully understood. This review provides an overview of the current knowledge and recent advances in the field.

RECENT FINDINGS

Clinical trials employing the phosphodiesterase-5-inhibitor sildenafil delivered negative results whereas riociguat showed harmful effects in the PH-ILD population. More recently, inhaled treprostinil showed positive effects on the primary endpoint (six-min walk-distance) in the largest prospective randomized placebo-controlled trial to date in this patient population. Additionally, a pilot trial of ambulatory inhaled nitric oxide suggests beneficial effects based on the novel endpoint of actigraphy.

SUMMARY

In view of these novel developments this review provides an overview of the status quo of screening, diagnosis and management of pulmonary vascular disease and PH in patients with ILD.

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.

Role of biomarkers in evaluation, treatment and clinical studies of pulmonary arterial hypertension

Pulmonary arterial hypertension is a complex disease resulting from the interplay of myriad biological and environmental processes that lead to remodeling of the pulmonary vasculature with consequent pulmonary hypertension. Despite currently available therapies, there remains significant morbidity and mortality in this disease. There is great interest in identifying and applying biomarkers to help diagnose patients with pulmonary arterial hypertension, inform prognosis, guide therapy, and serve as surrogate endpoints. An extensive literature on potential biomarker candidates is available, but barriers to the implementation of biomarkers for clinical use in pulmonary arterial hypertension are substantial. Various omic strategies have been undertaken to identify key pathways regulated in pulmonary arterial hypertension that could serve as biomarkers including genomic, transcriptomic, proteomic, and metabolomic approaches. Other biologically relevant components such as circulating cells, microRNAs, exosomes, and cell-free DNA have recently been gaining attention. Because of the size of the datasets generated by these omic approaches and their complexity, artificial intelligence methods are being increasingly applied to decipher their meaning. There is growing interest in imaging the lung with various modalities to understand and visualize processes in the lung that lead to pulmonary vascular remodeling including high resolution computed tomography, Xenon magnetic resonance imaging, and positron emission tomography. Such imaging modalities have the potential to demonstrate disease modification resulting from therapeutic interventions. Because right ventricular function is a major determinant of prognosis, imaging of the right ventricle with echocardiography or cardiac magnetic resonance imaging plays an important role in the evaluation of patients and may also be useful in clinical studies of pulmonary arterial hypertension.

Noninvasive Prediction of Elevated Wedge Pressure in Pulmonary Hypertension Patients Without Clear Signs of Left-Sided Heart Disease: External Validation of the OPTICS Risk Score

Background

Although most newly presenting patients with pulmonary hypertension (PH) have elevated pulmonary artery wedge pressure, identification of so‐called postcapillary PH can be challenging. A noninvasive tool predicting elevated pulmonary artery wedge pressure in patients with incident PH may help avoid unnecessary invasive diagnostic procedures.

Methods and Results

A combination of clinical data, ECG, and echocardiographic parameters was used to refine a previously developed left heart failure risk score in a retrospective cohort of pre‐ and postcapillary PH patients. This updated score (renamed the OPTICS risk score) was externally validated in a prospective cohort of patients from 12 Dutch nonreferral centers the OPTICS network. Using the updated OPTICS risk score, the presence of postcapillary PH could be predicted on the basis of body mass index ≥30, diabetes mellitus, atrial fibrillation, dyslipidemia, history of valvular surgery, sum of SV1 (deflection in V1 in millimeters) and RV6 (deflection in V6 in millimeters) on ECG, and left atrial dilation. The external validation cohort included 81 postcapillary PH patients and 66 precapillary PH patients. Using a predefined cutoff of >104, the OPTICS score had 100% specificity for postcapillary PH (sensitivity, 22%). In addition, we investigated whether a high probability of heart failure with preserved ejection fraction, assessed by the H₂FPEF score (obesity, atrial fibrillation, age >60 yrs, ≥2 antihypertensives, E/e' >9, and pulmonary artery systolic pressure by echo >35 mmHg), similarly predicted the presence of elevated pulmonary artery wedge pressure. High probability of heart failure with preserved ejection fraction (H₂FPEF score ≥6) was less specific for postcapillary PH.

Conclusions

In a community setting, the OPTICS risk score can predict elevated pulmonary artery wedge pressure in PH patients without clear signs of left‐sided heart disease. The OPTICS risk score may be used to tailor the decision to perform invasive diagnostic testing.

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.

CMR-based heart deformation analysis for quantification of hemodynamics and right ventricular dysfunction in patients with CTEPH

INTRODUCTION

Quantification of hemodynamics and right ventricular (RV) function is crucial for pulmonary hypertension (PH). Cardiovascular magnetic resonance-based heart deformation analysis (CMR-HDA) has been used to assess the ventricular strain.

OBJECTIVE

This study was to determine the correlation of right ventricular longitudinal strain (RVLS) assessed with CMR-HDA with RV function as well as hemodynamics in patients with chronic thromboembolic pulmonary hypertension (CTEPH).

METHODS

Thirty-six CTEPH patients were prospectively included in this research. Each patients underwent CMR and right heart catheterization (RHC). RVLS and RV ejection fraction (RVEF) was quantified from cine images acquired with a retrospectively gated turbo FLASH gradient-echo sequence. The late gadolinium enhancement (LGE) images were acquired using a 2D inversion recovery phase-sensitive fast gradient-echo sequence. Hemodynamics were determined with RHC.

RESULTS

Right ventricular longitudinal strain measured with CMR-HDA was -13.99 ± 4.94%. Bland-Altman plots showed statistical agreement with RVLS with low intra- and interobserver variability. RVLS correlated with serum N-terminal-pro-B-type natriuretic peptide (r = 0.615, P < .001). RVLS inversely correlated with RVEF (r = -0.699, P < .001), and it was positively correlated with both RVESV (r = 0.664, P < .001) and myocardial the volume of LGE (r = 0.447, P = .008). Receiver-operating characteristic (ROC) indicated that RVLS values of >-14.20% could be used to predict RVEF <40% with a 100% sensitivity and a 96.7% specificity. Hemodynamically, RVLS was positively correlated with mean pulmonary artery pressure (r = 0.598, P < .001) and pulmonary vascular resistance (r = 0.685, P < .001).

CONCLUSION

Right ventricular longitudinal strain assessed by CMR-HDA is a readily available and reproducible parameters of RV function. RVLS >-14.20% suggests the presence of RV dysfunction.

Two-dimensional speckle tracking echocardiography assessed right ventricular function and exercise capacity in pre-capillary pulmonary hypertension

Resting two-dimensional speckle tracking echocardiography (2D-STE) identified right ventricular (RV) systolic function were reported to predict exercise capacity in pulmonary hypertension (PH) patients, but little attention had been payed to 2D-STE detected RV diastolic function. Therefore, we aim to elucidate and compare the relations between 2D-STE identified RV diastolic/systolic functions and peak oxygen consumption (PVO₂) determined by cardiopulmonary exercise testing (CPET) in pre-capillary PH. 2D-STE was performed in 66 pre-capillary PH patients and 28 healthy controls. Linear correlation and multivariate regression analyses were performed to evaluate and compare the relations between RV 2D-STE parameters and PVO₂. Receiver operating characteristic curves were used to compare the predictive value of 2D-STE parameters in predicting the cut-off-PVO₂ < 11 ml/min/kg. There were significant differences of all the 2D-STE parameters between PH patients and healthy controls. In patients, RV-peak global longitudinal strain (GLS, r_s = - 0.498, P < 0.001), RV- peak systolic strain rate (GSRs, r_s = - 0.537, P < 0.001) and RV- peak early diastolic strain rate (GSRe, r_s = 0.527, P < 0.001) significantly correlated with PVO₂, but no significant correlation was observed between RV- peak late diastolic strain rate (GSRa, r_s = 0.208, P = 0.093) and PVO₂. The first multivariate regression analysis of clinical data without echocardiographic parameters identified WHO functional class, NT-proBNP and BMI as independent predictors of PVO₂ (Model-1, adjusted r² = 0.421, P < 0.001); Then we added conventional echocardiographic parameters and 2D-STE parameters to the clinical data, identified S,(Model-2,adjusted r² = 0.502, P < 0.001), RV-GLS (Model-3, adjusted r² = 0.491, P < 0.001), RV-GSRe (Model-4, adjusted r² = 0.500, P < 0.001) and RV-GSRs (Model-5, adjusted r² = 0.519, P < 0.001) as independent predictors of PVO₂, respectively. The predictive power was increased, and Model-5 including RV-GSRs showed the highest predictive capability. ROC curves found RV-GSRs expressed the strongest predictive value (AUC = 0.88, P < 0.001), and RV-GSRs > - 0.65/s had a 88.2% sensibility and 82.2% specificity to predict PVO₂ < 11 ml/min/kg. 2D-STE assessed RV function improves the prediction of exercise capacity represented by PVO₂ in pre-capillary PH.

High-sensitivity C-reactive protein in heart failure with preserved ejection fraction

Background

Microvascular inflammation may contribute to the pathogenesis of both heart failure with preserved ejection fraction (HFpEF) and pulmonary hypertension (PH). We investigated whether the inflammation biomarker C-reactive protein (CRP) was associated with clinical characteristics, disease severity or PH in HFpEF.

Methods

Patients in the Phosphodiesterase-5 Inhibition to Improve Clinical Status and Exercise Capacity in Diastolic Heart failure (RELAX) trial had baseline high-sensitivity CRP levels measured (n = 214). Clinical characteristics, exercise performance, echocardiographic variables and biomarkers of neurohumoral activation, fibrosis and myocardial necrosis were assessed. Patients with normal (≤3mg/L) versus high (>3mg/L) CRP levels were compared.

Results

The median CRP level was 3.69mg/L. CRP was elevated in 57% of patients. High CRP levels were associated with younger age, higher body mass index (BMI), chronic obstructive pulmonary disease (COPD), lower peak oxygen consumption and higher endothelin-1 and aldosterone levels. CRP increased progressively with the number of comorbidities (0.7mg/L per increment in comorbidity number, P = 0.02). Adjusting for age, BMI and statin use, high CRP levels were additionally associated with atrial fibrillation, right ventricular dysfunction, and higher N-terminal pro-B-type natriuretic peptide levels (P<0.05 for all). CRP was not associated with PH or left ventricular function. CRP did not identify responders to sildenafil(P-value for interaction 0.13).

Conclusions

In HFpEF, high CRP is associated with greater comorbidity burden and some markers of disease severity but CRP was normal in 40% of patients. These findings support the presence of comorbidity-driven systemic inflammation in HFpEF but also the need to study other biomarkers which may better reflect the presence of systemic inflammation.

Macitentan in Pulmonary Arterial Hypertension: A Focus on Combination Therapy in the SERAPHIN Trial

SERAPHIN was a double-blind, placebo-controlled, event-driven phase III trial that evaluated the effects of long-term treatment with macitentan, an oral endothelin receptor antagonist, in patients with pulmonary arterial hypertension (PAH). The majority of patients were receiving PAH therapy at enrollment, providing the opportunity to evaluate the efficacy and safety of macitentan in combination with other PAH therapies (predominantly phosphodiesterase type 5 inhibitors [PDE-5i]). In patients receiving background therapy, macitentan reduced the risk of morbidity/mortality by 38% compared with placebo (hazard ratio [HR] 0.62; 95% confidence level [CL] 0.43-0.89; p = 0.009). Furthermore, patients receiving macitentan and background therapy had a 37% reduction in the risk of being hospitalized for PAH (HR 0.63; 95% CL 0.41-0.96) compared with patients receiving background therapy only (placebo arm). Macitentan treatment in combination with background therapy was also associated with improvements in exercise capacity, functional class, cardiopulmonary hemodynamics, and health-related quality of life compared with background therapy alone. The safety profile of macitentan as part of a combination therapy regimen was consistent with that of macitentan in the overall SERAPHIN population. The SERAPHIN study has provided evidence that combination therapy with macitentan and a PDE-5i is effective and well tolerated in the management of PAH. Based on these data, and those from subsequent long-term trials, combination therapy is increasingly recognized as an important treatment option for improving long-term outcomes in PAH.

CLINICAL TRIAL REGISTRATION NUMBER

NCT00660179.

Right Ventricular Tissue Doppler Myocardial Performance Index in Children with Pulmonary Hypertension: Relation to Invasive Hemodynamics

Right ventricular (RV) failure is a significant cause of morbidity and mortality in patients with pulmonary hypertension (PH). Myocardial performance index measured by tissue Doppler imaging (TDI-MPI) has been useful in assessing RV dysfunction in adults with PH. However, TDI-MPI as a marker for RV dysfunction or disease severity has not been evaluated in pediatric PH. The aim of this study was to investigate TDI-MPI and correlate with invasive hemodynamics in pediatric PH patients. Eighty pediatric PH patients undergoing cardiac catheterization and simultaneous transthoracic echocardiography were analyzed. RV TDI-MPI was averaged over three cardiac cycles and measured under each condition of vasodilatory testing during the catheterization. TDI-MPI was compared between PH patients and age-matched controls and correlated to invasive hemodynamics. RV TDI-MPI was increased in PH patients compared to controls (0.49 vs. 0.35, p < 0.0001). Significant associations (beta ± SE) are seen between RV TDI-MPI and baseline mean pulmonary arterial pressures (0.0002 ± 0.001, p < 0.05), indexed pulmonary vascular resistance (0.007 ± 0.002, p < 0.002), and pulmonary-to-systemic arterial pressure ratio (0.146 ± 0.063, p < 0.05). No statistically significant associations were seen with vasodilatory testing. RV TDI-MPI is elevated in children with PH, suggestive of RV dysfunction. RV TDI-MPI shows correlation with severity of PH at baseline but lacks sensitivity to evaluate the RV response to acute changes in afterload in children with PH. Therefore, while RV TDI-MPI can help identify RV dysfunction in children with PH, its utility as a non-invasive surrogate marker for acute changes in hemodynamics is limited.

SERAPHIN haemodynamic substudy: the effect of the dual endothelin receptor antagonist macitentan on haemodynamic parameters and NT-proBNP levels and their association with disease progression in patients with pulmonary arterial hypertension

Aims

The effect of macitentan on haemodynamic parameters and NT-proBNP levels was evaluated in pulmonary arterial hypertension (PAH) patients in the SERAPHIN study. Association between these parameters and disease progression, assessed by the primary endpoint (time to first morbidity/mortality event), was explored.

Methods and results

Of the 742 randomized patients, 187 with right heart catheterization at baseline and month 6 participated in a haemodynamic sub-study. Prespecified endpoints included change from baseline to month 6 in cardiac index (CI), right atrial pressure (RAP), mean pulmonary arterial pressure (mPAP), pulmonary vascular resistance (PVR), mixed-venous oxygen saturation, and NT-proBNP. Exploratory analyses examined associations between CI, RAP, and NT-proBNP and disease progression using the Kaplan-Meier method and Cox regression models. Macitentan improved CI, RAP, mPAP, PVR and NT-proBNP vs. placebo at month 6. Absolute levels of CI, RAP and NT-proBNP at baseline and month 6, but not their changes, were associated with morbidity/mortality events. Patients with CI > 2.5 L/min/m², RAP < 8 mmHg, or NT-proBNP < 750 fmol/ml at month 6 had a lower risk of morbidity/mortality than those not meeting these thresholds (HR 0.49, 95% CL 0.28–0.86; HR 0.72, 95% CL 0.42–1.22; and HR 0.22, 95% CL 0.15–0.33, respectively).

Conclusions

For all treatment groups, baseline and month 6 values of CI, RAP, and NT-proBNP, but not their changes, were associated with morbidity/mortality events, confirming their relevance in predicting disease progression in patients with PAH. By improving those parameters, macitentan increased the likelihood of reaching threshold values associated with lower risk of morbidity/mortality.

Upfront combination therapy reduces right ventricular volumes in pulmonary arterial hypertension

In pulmonary arterial hypertension (PAH), upfront combination therapy is associated with better clinical outcomes and a greater reduction in N-terminal pro-brain natriuretic peptide (NT-proBNP) than monotherapy. NT-proBNP levels reflect right ventricular (RV) wall stress, which increases when the right ventricle dilates. This study explored the impact of upfront combination therapy on RV volumes compared with monotherapy in PAH patients.This retrospective study involved 80 incident PAH patients (New York Heart Association class II and III) who were treated with upfront combination therapy (n=35) (i.e. endothelin receptor antagonists (ERAs) plus phosphodiesterase-5-inhibitors (PDE5Is)) or monotherapy (n=45) (i.e. either ERAs or PDE5Is). All patients underwent right-sided heart catheterisation and cardiac magnetic resonance imaging at baseline and after 1-year follow-up.Combination therapy resulted in more significant reductions in pulmonary vascular resistance and pulmonary pressures than monotherapy. NT-proBNP was decreased by ∼77% in the combination therapy group compared with a ∼51% reduction after monotherapy (p<0.001). RV volumes and calculated RV wall stress improved after combination therapy (both p<0.001) but remained unchanged after monotherapy (both p=NS). RV ejection fraction improved more in the combination therapy group than in the monotherapy group (p<0.001).In PAH patients, upfront combination therapy was associated with improved RV volumes.

The predictive capabilities of a novel cardiovascular magnetic resonance derived marker of cardiopulmonary reserve on established prognostic surrogate markers in patients with pulmonary vascular disease: results of a longitudinal pilot study

BACKGROUND

No unified method exists to effectively predict and monitor progression of pulmonary arterial hypertension (PAH). We assessed the longitudinal relationship between a novel marker of cardiopulmonary reserve and established prognostic surrogate markers in patients with pulmonary vascular disease.

METHODS AND RESULTS

Twenty participants with confirmed (n = 14) or at high risk (n = 6) for PAH underwent cardiovascular magnetic resonance (CMR) at baseline and after ~6 months of guideline-appropriate management. Ten PAH participants underwent RHC within 48 h of each CMR. RHC (mean pulmonary arterial pressure, mPAP; pulmonary vascular resistance index, PVRI; cardiac index, CI) and phase-contrast CMR (mean pulmonary arterial blood flow velocity, meanPAvel) measurements were taken at rest and during continuous adenosine infusion (70/140/210 mcg/kg/min). Initial meanPAvel's (rest and hyperemic) were correlated with validated surrogate prognostic parameters (CMR: RV ejection fraction, RVEF; RV end systolic volume indexed, RVESVI; RHC: PVRI, CI; biomarker: NT-pro brain natriuretic peptide, NTpBNP; clinical: 6-min walk distance, 6MWD), a measure of pulmonary arterial stiffness (elastic modulus) and volumetric estimation of RV ventriculoarterial (VA) coupling. Changes in meanPAvel's were correlated with changes in comparator parameters over time. At initial assessment, meanPAvel at rest correlated significantly with PVRI (inversely), CI (positively) and elastic modulus (inversely) (R 2 > 0.37,P < 0.05 for all), whereas meanPAvel at peak hyperemia correlated significantly with PVRI, RVEF, RVESVI, 6MWD, elastic modulus and VA coupling (R 2 > 0.30,P < 0.05 for all). Neither resting or hyperemia-derived meanPAvel correlated with NTpBNP levels. Initial meanPAvel at rest correlated significantly with RVEF, RVESVI, CI and VA coupling at follow up assessment (R 2 > 0.2,P < 0.05 for all) and initial meanPAvel at peak hyperemia correlated with RVEF, RVESVI, PVRI and VA coupling (R 2 > 0.37,P < 0.05 for all). Change in meanPAvel at rest over time did not show statistically significant correlation with change in prognostic parameters, while change in meanPAvel at peak hyperemia did show a significant relationship with ΔRVEF, ΔRVESVI, ΔNTpBNP and ΔCI (R 2 > 0.24,P < 0.05 for all).

CONCLUSION

MeanPAvel during peak hyperemia correlated with invasive, non-invasive and clinical prognostic parameters at different time points. Further studies with predefined clinical endpoints are required to evaluated if this novel tool is a marker of disease progression in patients with pulmonary vascular disease.

4,4'-Methylenedianiline Alters Serotonergic Transport in a Novel, Sex-Specific Model of Pulmonary Arterial Hypertension in Rats

Pulmonary arterial hypertension (PAH) is a cardiovascular disorder characterized by elevated pulmonary artery pressure as a result of arterial wall thickening. Patients are 3-4 times more likely to be women than men. This gender discrepancy demonstrates a need for an animal model with similar sex differences. 4,4'-Methylenedianiline (DAPM) is an aromatic amine used industrially in the synthesis of polyurethanes. Chronic, intermittent treatment of male and female rats with DAPM resulted in medial hyperplasia of pulmonary arterioles, exclusively in females, coupled to increases in pulmonary arterial pressures. Significant increases in plasma levels of endothelin-1 (ET-1) and serotonin, but decreases in nitrite [Formula: see text], were observed in females treated with DAPM. A decrease was observed in the serum ratio of the estrogen metabolites 2-hydroxyestradiol (2-OHE1)/16α-hydroxyestrogen (16α-OHE1). In females, ET-1,[Formula: see text] , and 2-OHE1/16α-OHE1 were significantly correlated with peak pressure gradient, an indirect measure of pulmonary arterial pressure. Expression of the serotonin transport protein (SERT) was significantly higher in the arteries of DAPM-treated females. In vitro, DAPM induced human pulmonary vascular smooth muscle cell proliferation and serotonin uptake, both of which were inhibited by treatment with the estrogen receptor antagonist ICI 182,780 or the selective serotonin reuptake inhibitor fluoxetine. DAPM also induced the release of serotonin from human pulmonary endothelial cells in culture, which is blocked by ICI 182,780. Taken together, this suggests that DAPM-mediated dysregulation of serotonin transport is estrogen-receptor dependent. Thus, DAPM-induced PAH pathology may be a new tool to clarify the sex selectivity of PAH disease pathogenesis.

Pulmonary hypertension survival effects and treatment options in cystic fibrosis

PURPOSE OF REVIEW

This review discusses the current impact of pulmonary hypertension on the outcome and treatment of cystic fibrosis (CF).

RECENT FINDINGS

Pulmonary hypertension is commonly encountered in advanced lung diseases such as CF. The prevalence of pulmonary hypertension in CF patients varies based on disease severity and methodology used for diagnosis. Chronic alveolar hypoxia is the most likely cause. The majority of recent studies have shown worse survival in CF patients who develop pulmonary hypertension. The impact of pulmonary hypertension-specific therapies on symptomatology and outcomes in CF patients has not been well studied.

SUMMARY

Pulmonary hypertension is common in patients with CF and it occurs largely because of hypoxemia. The presence of pulmonary hypertension in patients with CF is likely associated with worse outcome; however, it remains unknown whether treatment with pulmonary hypertension-specific therapies would be beneficial.

N-terminal pro-brain natriuretic peptide is a useful prognostic marker in patients with pre-capillary pulmonary hypertension and renal insufficiency

N-terminal pro-brain natriuretic peptide (NT-proBNP) is a routinely used prognostic parameter in patients with pre-capillary pulmonary hypertension (PH). As it accumulates in the presence of impaired renal function, the clinical utility of NT-proBNP in PH patients with concomitant renal insufficiency remains unclear. In a retrospective approach, patients with pre-capillary PH (group I or IV) and concomitant renal insufficiency at time of right heart catheterization (glomerular filtration rate (GFR) ≤60 ml/min/1.73 m²) were identified out of all prevalent pre-capillary PH patients treated at a single center. Forty patients with renal insufficiency (25.8%) were identified and matched regarding hemodynamic parameters with a control group of 56 PH patients with normal renal function (GFR >60 ml/min/1.73 m²). Correlations of NT-proBNP levels with hemodynamic and prognostic parameters (time to clinical worsening and overall survival) were assessed. Overall, GFR correlated inversely with NT-proBNP and had the strongest influence on NT-proBNP levels in a stepwise multiple linear regression model including hemodynamic parameters and age (r² = 0.167). PH patients with renal insufficiency had significant higher levels of NT-proBNP (median: 1935 ng/l vs. 573 ng/l, p = 0.001). Nevertheless, NT-proBNP correlated with invasive hemodynamic parameters in these patients. Using higher cut-off values than in patients with preserved renal function, NT-proBNP levels were significantly associated with time to clinical worsening (>1660 ng/l, p = 0.001) and survival (>2212 ng/l, p = 0.047) in patients with renal insufficiency. Multivariate Cox’s proportional hazards analysis including established prognostic parameters, age and GFR confirmed NT-proBNP as an independent risk factor for clinical worsening in PH patients with renal insufficiency (hazard ratio 4.8, p = 0.007). Thus, in a retrospective analysis we showed that NT-proBNP levels correlated with hemodynamic parameters and outcome regardless of renal function. By using higher cut-off values, NT-proBNP seems to represent a valid clinical marker even in PH patients with renal insufficiency.

Right ventricular diastolic performance in children with pulmonary arterial hypertension associated with congenital heart disease: correlation of echocardiographic parameters with invasive reference standards by high-fidelity micromanometer catheter

BACKGROUND

Right ventricular diastolic dysfunction influences outcomes in pulmonary arterial hypertension (PAH), but echocardiographic parameters have not been investigated in relation to invasive reference standards in pediatric PAH. We investigated echocardiographic parameters of right ventricular diastolic function in children with PAH in relation to simultaneously measured invasive reference measures.

METHODS AND RESULTS

We prospectively recruited children undergoing a clinically indicated cardiac catheterization for evaluation of PAH and pulmonary vasoreactivity testing. Echocardiography was performed simultaneously with invasive reference measurements by high-fidelity micromanometer catheter. For analysis, patients were divided into shunt and nonshunt groups. Sixteen children were studied. In the group as a whole, significant correlations were found among τ and tricuspid deceleration time, E', E/E', TimeE-E', A wave velocity, and global early and late diastolic strain rate. dp/dt minimum correlated significantly with late diastolic tricuspid annular velocity (A'), tissue Doppler imaging-derived systolic:diastolic duration ratio, and global late diastolic strain rate. End-diastolic pressure correlated significantly with tissue Doppler imaging-derived systolic:diastolic duration ratio. On multivariate analysis, tricuspid deceleration time, TimeE-E', and global early diastolic strain rate were independent predictors of τ, whereas tissue Doppler imaging-derived systolic:diastolic duration ratio was an independent predictor of dp/dt minimum. In general, correlations between echocardiographic and invasive parameters were better in the shunt group than in the nonshunt group.

CONCLUSIONS

Echocardiography correlates with invasive reference measures of right ventricular diastolic function in children with PAH, although it does not differentiate between early versus late diastolic abnormalities. Newer echocardiographic techniques may have added value to assess right ventricular diastolic dysfunction in this population.

Changes in Right Ventricular Function Measured by Cardiac Magnetic Resonance Imaging in Patients Receiving Pulmonary Arterial Hypertension–Targeted Therapy

Background—

Most measures that predict survival in pulmonary hypertension (PH) relate directly to, or correlate with, right ventricular (RV) function. Direct assessment of RV function using noninvasive techniques such as cardiac MRI may therefore be an appropriate way of determining response to therapy and monitoring disease progression in PH.

Methods and Results—

In this pan-European study, 91 patients with PH (mean pulmonary arterial pressure 46±15 mm Hg) underwent clinical and cardiac MRI assessments at baseline and after 12 months of disease-targeted therapy (predominantly endothelin receptor antagonists [47.3%] or phosphodiesterase type-5 inhibitors [25.3%]). At month 12, functional class had improved in 21 patients, was unchanged in 63 patients, and had deteriorated in 7 patients. Significant improvements were achieved in RV and left ventricular ejection fraction ( P <0.001 and P =0.0007, respectively), RV stroke volume index ( P <0.0001), and left ventricular end-diastolic volume index ( P =0.0015). Increases in 6-minute walk distance were significant ( P <0.0001) and correlated with change in RV ejection fraction and left ventricular end-diastolic volume, although correlation coefficients were low (r=0.28, P =0.01 and r=0.26, P =0.02, respectively).

Conclusions—

On-treatment changes in cardiac MRI–derived variables from left and right sides of the heart reflected changes in functional class and survival in patients with PH. Direct measurement of RV function using cardiac MRI can fully assess potential benefits of treatment in PH.

Right ventricular diastolic impairment in patients with pulmonary arterial hypertension

BACKGROUND

The role of right ventricular (RV) diastolic stiffness in pulmonary arterial hypertension (PAH) is not well established. Therefore, we investigated the presence and possible underlying mechanisms of RV diastolic stiffness in PAH patients.

METHODS AND RESULTS

Single-beat RV pressure-volume analyses were performed in 21 PAH patients and 7 control subjects to study RV diastolic stiffness. Data are presented as mean ± SEM. RV diastolic stiffness (β) was significantly increased in PAH patients (PAH, 0.050 ± 0.005 versus control, 0.029 ± 0.003; P<0.05) and was closely associated with disease severity. Subsequently, we searched for possible underlying mechanisms using RV tissue of PAH patients undergoing heart/lung transplantation and nonfailing donors. Histological analyses revealed increased cardiomyocyte cross-sectional areas (PAH, 453 ± 31 μm² versus control, 218 ± 21 μm²; P<0.001), indicating RV hypertrophy. In addition, the amount of RV fibrosis was enhanced in PAH tissue (PAH, 9.6 ± 0.7% versus control, 7.2 ± 0.6%; P<0.01). To investigate the contribution of stiffening of the sarcomere (the contractile apparatus of RV cardiomyocytes) to RV diastolic stiffness, we isolated and membrane-permeabilized single RV cardiomyocytes. Passive tension at different sarcomere lengths was significantly higher in PAH patients compared with control subjects (>200%; Pinteraction <0.001), indicating stiffening of RV sarcomeres. An important regulator of sarcomeric stiffening is the sarcomeric protein titin. Therefore, we investigated titin isoform composition and phosphorylation. No alterations were observed in titin isoform composition (N2BA/N2B ratio: PAH, 0.78 ± 0.07 versus control, 0.91 ± 0.08), but titin phosphorylation in RV tissue of PAH patients was significantly reduced (PAH, 0.16 ± 0.01 arbitrary units versus control, 0.20 ± 0.01 arbitrary units; P<0.05).

CONCLUSIONS

RV diastolic stiffness is significantly increased in PAH patients, with important contributions from increased collagen and intrinsic stiffening of the RV cardiomyocyte sarcomeres.

Haemodynamically irrelevant pericardial effusion is associated with increased mortality in patients with chronic heart failure

AIMS

Pericardial effusion (PE) is a common finding in cardiac patients with chronic heart failure. The prognostic relevance of a small, haemodynamically non-compromising PE in such patients, however, remains to be determined.

METHODS AND RESULTS

All patients referred to our heart failure clinic and having a baseline echocardiography and follow-up clinical visits were included. Patients with a haemodynamically relevant PE, acute myo-/pericarditis, systemic sclerosis, rheumatoid arthritis, heart transplantation, heart surgery within the last 6 months or malignancies within the last 3 years were excluded. Patients with or without a haemodynamically irrelevant PE were compared regarding all-cause mortality as the primary and cardiovascular death or need for heart transplantation as secondary outcomes. A total of 897 patients (824 patients in the control vs. 73 patients in the PE group) were included. In the PE group, left ventricular ejection fraction (LVEF) was lower [31%, interquartile range (IQR): 18.0-45.0] than in controls (34%, IQR: 25.0-47.0; P = 0.04), while the end-systolic diameters of the left ventricle and the left atrium were larger (P = 0.01 and P = 0.001, respectively). Similarly, in patients with PE, the right ventricle (RV) systolic function was lower (P < 0.005 for both the fractional area change and the tricuspid annulus movement), the dimensions of RV and right atrium (RA) were larger (P < 0.05 for RV and P < 0.01 for RA), and the degree of tricuspid regurgitation was higher (P < 0.0001). Furthermore, in the PE group, the heart rate was higher (P < 0.001) and the leukocyte count as well as CRP values were increased (P = 0.004 and P < 0.0001, respectively); beta-blocker use was less frequent (P = 0.04), while spironolactone use was more frequent (P = 0.03). The overall survival was reduced in the PE group compared with controls (P = 0.02). Patients with PE were more likely to suffer cardiovascular death (1-year estimated event-free survival: 86 ± 5 vs. 95 ± 1%; P = 0.01) and to require heart transplantation (1-year estimated event-free survival: 88 ± 4 vs. 95 ± 1%; P = 0.009). A multivariate Cox proportional hazard model revealed the following independent predictors of mortality: (a) PE (P = 0.04, hazard ratio (HR): 1.95, 95% confidence interval (CI): 1.0-3.7), (b) age (P = 0.04, HR: 1.02, 95% CI: 1.0-1.04) and (c) LVEF <35% (P = 0.03, HR: 1.7, 95% CI: 1.1-2.8).

CONCLUSION

In chronic heart failure, even minor PEs are associated with an increased risk of all-cause mortality, cardiac death, and need for transplantation.

Circulating biomarkers of interstitial lung disease in systemic sclerosis

Interstitial lung disease (ILD) is a major cause of morbidity and mortality in patients with systemic sclerosis (SSc). Although a large proportion of SSc patients have only limited interstitial involvement with an indolent course, in a significant minority ILD is progressive, requiring prompt treatment and careful monitoring. One of the main challenges for the clinician treating this highly variable disease is the early identification of patients at risk of progressive ILD, while avoiding potentially toxic treatments in those whose disease is inherently stable. Easily available and repeatable biomarkers that allow estimation of the risk of ILD progression and early response to treatment are highly desirable. In this paper, we review the evidence for circulating biomarkers with potential roles in diagnosis, monitoring of disease activity, or determining prognosis. Peripheral blood biomarkers offer the advantages of being readily obtained, non-invasive, and serially monitored. Several possible candidates have emerged from studies performed so far, including SP-D, KL-6, and CCL18. Presently however, there are few prospective studies evaluating the predictive ability of prospective biomarkers after adjustment for disease severity. Future carefully designed, prospective studies of well characterised patients with ILD, with optimal definition of disease severity and outcome measures are needed.

Today's and tomorrow's imaging and circulating biomarkers for pulmonary arterial hypertension

The pathobiology of pulmonary arterial hypertension (PAH) involves a remodeling process in distal pulmonary arteries, as well as vasoconstriction and in situ thrombosis, leading to an increase in pulmonary vascular resistance, right heart failure and death. Its etiology may be idiopathic, but PAH is also frequently associated with underlying conditions such as connective tissue diseases. During the past decade, more than welcome novel therapies have been developed and are in development, including those increasingly targeting the remodeling process. These therapeutic options modestly increase the patients' long-term survival, now approaching 60% at 5 years. However, non-invasive tools for confirming PAH diagnosis, and assessing disease severity and response to therapy, are tragically lacking and would help to select the best treatment. After exclusion of other causes of pulmonary hypertension, a final diagnosis still relies on right heart catheterization, an invasive technique which cannot be repeated as often as an optimal follow-up might require. Similarly, other techniques and biomarkers used for assessing disease severity and response to treatment generally lack specificity and have significant limitations. In this review, imaging as well as current and future circulating biomarkers for diagnosis, prognosis, and follow-up are discussed.

Usefulness of serial N-terminal pro-B-type natriuretic peptide measurements for determining prognosis in patients with pulmonary arterial hypertension

Previous studies have shown the prognostic benefit of N-terminal pro-brain natriuretic peptide (NT-pro-BNP) in pulmonary arterial hypertension (PAH) at time of diagnosis. However, there are only limited data on the clinical utility of serial measurements of the inactive peptide NT-pro-BNP in PAH. This study examined the value of serial NT-pro-BNP measurements in predicting prognosis PAH. We retrospectively analyzed all available NT-pro-BNP plasma samples in 198 patients who were diagnosed with World Health Organization group I PAH from January 2002 through January 2009. At time of diagnosis median NT-pro-BNP levels were significantly different between survivors (610 pg/ml, range 6 to 8,714) and nonsurvivors (2,609 pg/ml, range 28 to 9,828, p <0.001). In addition, NT-pro-BNP was significantly associated (p <0.001) with other parameters of disease severity (6-minute walking distance, functional class). Receiver operating curve analysis identified ≥1,256 pg/ml as the optimal NT-pro-BNP cutoff for predicting mortality at time of diagnosis. Serial measurements allowed calculation of baseline NT-pro-BNP (i.e., intercept obtained by back-extrapolation of concentration-time graph), providing a better discrimination between survivors and nonsurvivors than NT-pro-BNP at time of diagnosis alone (p = 0.010). Furthermore, a decrease of NT-pro-BNP of >15%/year was associated with survival. In conclusion, a serum NT-pro-BNP level ≥1,256 pg/ml at time of diagnosis identifies poor outcome in patients with PAH. In addition, a decrease in NT-pro-BNP of >15%/year is associated with survival in PAH.

Prediction of pulmonary hypertension related to systemic sclerosis by an index based on simple clinical observations

OBJECTIVE

To develop a score to estimate the risk of developing pulmonary hypertension (PH) in patients with systemic sclerosis (SSc).

METHODS

We first examined the prevalence and characteristics of precapillary PH confirmed by right-heart catheterization in a cross-sectional (derivation) sample of 1,165 SSc patients, and we developed a risk prediction score (RPS) based on simple clinical observations associated with PH. We next prospectively tested the 3-year predictive power of the "Cochin RPS" in a separate (validation) sample of 443 patients presenting with PH-free SSc at baseline.

RESULTS

In the derivation sample, age, forced vital capacity, and diffusing capacity for carbon monoxide/alveolar volume were independently associated with the presence of PH and were used to create the Cochin RPS. PH developed during followup in 20 patients in the validation sample. The area under the receiver operating characteristic curve of the Cochin RPS was 0.87 (95% confidence interval 0.79-0.95). With a cutoff value of 2.73, patients at risk of PH during followup could be identified with 89.5% sensitivity and 74.1% specificity. PH occurred in 0.6% of patients in the lowest 2 quintiles of the Cochin RPS, in 1.7% of patients in the third and fourth quintiles, and in 17.1% of patients in the highest quintile (P<0.0001 by log rank test). Patients in the highest quintile incurred a >35-fold higher risk of developing PH compared with patients in the 2 lowest quintiles (P=0.001).

CONCLUSION

Using routine clinical observations, we developed a simple score that accurately predicted the risk of PH in SSc.

NT-proBNP, NT-proANP and cTnI concentrations in dogs with pre-capillary pulmonary hypertension

OBJECTIVES

To compare [NT-proBNP], [NT-proANP] and [cTnI] between control dogs with respiratory disease without pulmonary hypertension (PH) and dogs with pre-capillary PH, and to assess the accuracy of [NT-proBNP], [NT-proANP], [cTnI] to predict Doppler-derived peak tricuspid regurgitation (TR) gradient.

ANIMALS

20 dogs. 8 control dogs with respiratory disease with no PH and 12 with pre-capillary PH.

METHODS

[NT-proBNP], [NT-proANP] and [cTnI] were compared between the 2 groups and simple linear regression analysis was used to predict peak TR gradients from various blood biomarkers.

RESULTS

Median [NT-proBNP] was higher in the dogs with PH (2011 pmol/L, 274-7713 pmol/L) compared to control dogs (744 pmol/L; 531-2710 pmol/L) (p = 0.0339). [NT-proBNP] was associated with peak TR gradient (R(2) = 0.7851, p = 0.0001). Median [NT-proANP] did not differ between dogs with PH (1747 fmol/L; 894-2884 fmol/L) and control dogs (1209 fmol/L; 976-1389 fmol/L (p = 0.058). [NT-proANP] was not associated with peak TR gradient (R(2) = 0.2780, p = 0.0781). Median [cTnI] did not differ between dogs with PH (0.2850 ng/mL; 0.19-1.13 ng/mL) and control dogs (0.2 ng/mL; 0.19-0.82 ng/mL, p = 0.3051). Median [TnI] was not associated with peak TR gradient (R(2) = 0.024, p = 0.6307).

CONCLUSIONS

[NT-proBNP] concentration is significantly higher in dogs with pre-capillary PH when compared to dogs with respiratory disease without PH, and [NT-proBNP] may be useful to predict the severity of estimated PH. Elevations in [NT-proBNP] due to pre-capillary PH may complicate the interpretation of [NT-proBNP] elevations in patients presenting with cardiorespiratory abnormalities. [NT-proANP] and [cTnI] were not elevated in dogs with pre-capillary PH.

Pulmonary arterial size and response to sildenafil in chronic thromboembolic pulmonary hypertension

Background

Relative area change (RAC) of the proximal pulmonary artery is a measurement of pulmonary artery distensibility and has been shown to correlate with vasoreactivity studies in patients with idiopathic pulmonary arterial hypertension. We have previously noted a relationship between invasive hemodynamic vasoreactivity testing and long-term response to sildenafil in patients with inoperable chronic thromboembolic pulmonary hypertension (CTEPH). We therefore set out to determine whether RAC can provide useful correlatory non-invasive data.

Methods

Patients recruited to a randomized, controlled trial (RCT) of sildenafil at 40 mg 3 times daily underwent additional magnetic resonance imaging (MRI) at the baseline of the trial. Eighteen patients had an MRI that led to a diagnosis of inoperable distal CTEPH or significant residual CTEPH post-operatively. The primary end-point was improvement in 6-minute walk test (6MWT) with secondary end-points of right heart catheterization–based hemodynamics, N-terminal pro–brain natriuretic peptide (NT pro-BNP) and functional class. RAC assessed by MRI was correlated with trial end-points.

Results

Fourteen subjects with baseline MRI completed the protocol. RAC was the only baseline variable that correlated at 1 year to the primary end-point of improvement in 6MWT (r = 0.7, p = 0.006), and also to a change in NT pro-BNP (r = 0.59, p = 0.03). Using a cut-off of RAC over 20% there was an 87.5% sensitivity (95% confidence interval [CI]: 45% to 100%) and a 66.7% specificity (95% CI: 22% to 96%) for an improvement in 6MWT of >40 meters.

Conclusions

RAC correlates with functional response to sildenafil, as measured by the 6MWT, and improved heart function, as measured by NT pro-BNP. RAC shows potential in understanding and possibly predicting treatment response.

Evaluation of pimobendan and N-terminal probrain natriuretic peptide in the treatment of pulmonary hypertension secondary to degenerative mitral valve disease in dogs

BACKGROUND

Pimobendan is a positive inotrope and vasodilator that may be useful in the treatment of pulmonary hypertension (PHT) secondary to degenerative mitral valve disease.

HYPOTHESIS

Pimobendan decreases the severity of PHT measured echocardiographically and improves quality-of-life scores. Changes in N-terminal probrain natriuretic peptide (NT-proBNP) concentrations will reflect improvement in severity of PHT.

ANIMALS

Ten client-owned dogs with peak tricuspid regurgitant flow velocity (TRFV) > or =3.5 m/s.

METHODS

Prospective short-term, double-blinded, crossover design, with a long-term, open-label component. Short term, dogs were randomly allocated to receive either placebo or pimobendan (0.18-0.3 mg/kg PO q12 h) for 14 days. After a 1-week washout, they received the alternative treatment for 14 days, followed by pimobendan open-label for 8 weeks.

RESULTS

Short-term comparison: peak TRFV decreased in all dogs on pimobendan compared with placebo from a median of 4.40 (range, 3.2-5.6) to 3.75 (range, 2.4-4.8) m/s (P < .0001). NT-proBNP concentration decreased after treatment with pimobendan from a median of 2,143 (range, 450-3,981) to 1,329 (range, 123-2,411) pmol/L (P= .0009). All dogs improved their quality-of-life score (P= .006). In the long-term comparisons, peak TRFV decreased in all dogs from a median of 4.28 (range, 3.5-5.7) to 3.52 (range, 2.4-5.0) m/s (P < .0001). No significant changes in NT-proBNP or quality-of-life scores were detected.

CONCLUSIONS AND CLINICAL IMPORTANCE

Pimobendan lowered severity of measurable PHT, improved quality-of-life scores, and decreased NT-proBNP concentrations short-term. Long term, only the reduction in TRFV was maintained.

Relation of resting heart rate to prognosis in patients with idiopathic pulmonary arterial hypertension

Heart rate (HR) at rest is an important marker of prognosis in heart failure, but has not been addressed in pulmonary arterial hypertension (PAH). To determine the prognostic value of HR at rest in patients with PAH, we retrospectively analyzed 140 consecutive patients with idiopathic PAH. Electrocardiogram (ECG)-derived HR at rest was evaluated as a potential predictor of adverse prognosis (death or lung transplantation), in addition to World Health Organization functional class, 6-minute walk distance, and hemodynamics before and approximately 1 year and 2 years after initiation of PAH treatment. During follow-up, 49 patients (35%) died, and 5 patients (4%) underwent lung transplantation. Before treatment initiation and after 1 year and 2 years of treatment, respectively, a higher HR at rest was an independent predictor of adverse prognosis (hazard ratios per 10-beats/min increase 1.76, 95% confidence interval 1.42 to 2.18, 2.31, 95% confidence interval 1.58 to 3.38, 2.1, 95% confidence interval 1.39 to 3.19, respectively, p <0.001 for all). Change in HR between the first and last ECG also independently predicted prognosis (hazard ratio per 1-beat/min increase 1.03, 95% confidence interval 1.01 to 1.06). In conclusion, a higher HR at rest and an important increase in HR at rest during follow-up signify a considerable risk of death in patients with PAH. ECG-derived HR at rest is an important marker of prognosis and should be assessed before and at frequent intervals after initiation of treatment for PAH.