Prognosis of Pulmonary Arterial Hypertension*

Gender-based research underscores sex differences in biological processes, clinical disorders and pharmacological interventions

Earlier research has presumed that the male and female biology is similar in most organs except the reproductive system, leading to major misconceptions in research interpretations and clinical implications, with serious disorders being overlooked or misdiagnosed. Careful research has now identified sex differences in the cardiovascular, renal, endocrine, gastrointestinal, immune, nervous, and musculoskeletal systems. Also, several cardiovascular, immunological, and neurological disorders have shown differences in prevalence and severity between males and females. Genetic variations in the sex chromosomes have been implicated in several disorders at young age and before puberty. The levels of the gonadal hormones estrogen, progesterone and testosterone and their receptors play a role in the sex differences between adult males and premenopausal women. Hormonal deficiencies and cell senescence have been implicated in differences between postmenopausal and premenopausal women. Specifically, cardiovascular disorders are more common in adult men vs premenopausal women, but the trend is reversed with age with the incidence being greater in postmenopausal women than age-matched men. Gender-specific disorders in females such as polycystic ovary syndrome, hypertension-in-pregnancy and gestational diabetes have attained further research recognition. Other gender-related research areas include menopausal hormone therapy, the "Estrogen Paradox" in pulmonary arterial hypertension being more predominant but less severe in young females, and how testosterone may cause deleterious effects in the kidney while having vasodilator effects in the coronary circulation. This has prompted the National Institutes of Health (NIH) initiative to consider sex as a biological variable in research. The NIH and other funding agencies have provided resources to establish state-of-the-art centers for women health and sex differences in biology and disease in several academic institutions. Scientific societies and journals have taken similar steps to organize specialized conferences and publish special issues on gender-based research. These combined efforts should promote research to enhance our understanding of the sex differences in biological systems beyond just the reproductive system, and provide better guidance and pharmacological tools for the management of various clinical disorders in a gender-specific manner.

Right ventricular systolic strain in patients with pulmonary hypertension: clinical feasibility, reproducibility, and correlation with ejection fraction

BACKGROUND

Right ventricular (RV) systolic function is the major determinant of prognosis in patients with pulmonary hypertension (PH) with quantitative assessment by speckle-tracking strain echocardiography emerging as a viable candidate measure.

METHOD

We evaluated a prospective cohort of 231 patients with known or suspected PH referred for clinical echocardiography. All underwent measurement of RV free-wall systolic strain by sonographer staff. Digital images were recorded for blinded offline assessment by an expert echocardiographer. Reproducibility was assessed using the analysis methods of Bland-Altman and the Cohen's-Kappa coefficient.

RESULTS

RV strain was feasible in 213 (92%). The average RV systolic pressure was 59 ± 22 mmHg. RV systolic strain correlated with functional class, NT-proBNP, and the degree of RV enlargement. The average free-wall systolic strain was - 20 ± 7% (range  - 2 to  - 37%). The RV strain measures (clinical practice versus blinded expert) had an excellent correlation with a normal distribution (R2 0.87, p < 0.0001). By Bland-Altman analysis, the mean difference in measurement was - 1.7% (95% CI - 1.4 to - 2.1) with a correlation of 0.93, p value of < 0.0001. The reproducibility of RV strain for clinically relevant thresholds was also excellent (Kappa coefficients 0.68-0.83). There was no effect on the variability of strain measures across body mass, pulmonary pressures, or rhythm. RV strain correlated with RV diastolic volumes and ejection fraction with RV free wall strain being the best echo predictor for a reduction in ejection fraction.

CONCLUSION

Here RV systolic strain was found to be highly feasible and reproducible in clinical practice with excellent levels of agreement for clinically relevant thresholds.

Comprehensive ultrasound imaging of right ventricular remodeling under surgically induced pressure overload in mice

This study reports a new methodology for right heart imaging by ultrasound in mice under right ventricular (RV) pressure overload. Pulmonary artery constriction (PAC) or sham surgeries were performed on C57BL/6 male mice at 8 wk of age. Ultrasound imaging was conducted at 2, 4, and 8 wk postsurgery using both classical and advanced ultrasound imaging modalities including electrocardiogram (ECG)-based kilohertz visualization, anatomical M-mode, and strain imaging. Based on pulsed Doppler, the PAC group demonstrated dramatically enhanced pressure gradient in the main pulmonary artery (MPA) as compared with the sham group. By the application of advanced imaging modalities in novel short-axis views of the ventricles, the PAC group demonstrated increased thickness of RV free wall, enlarged RV chamber, and reduced RV fractional shortening compared with the sham group. The PAC group also showed prolonged RV contraction, asynchronous interplay between RV and left ventricle (LV), and passive leftward motion of the interventricular septum (IVS) at early diastole. Consequently, the PAC group exhibited prolongation of LV isovolumic relaxation time, without change in LV wall thickness or systolic function. Significant correlations were found between the maximal pressure gradient in MPA measured by Doppler and the RV systolic pressure by catheterization, as well as the morphological and functional parameters of RV by ultrasound.NEW & NOTEWORTHY The established protocol overcomes the challenges in right heart imaging in mice, thoroughly elucidating the changes of RV, the dynamics of IVS, and the impact on LV and provides new insights into the pathophysiological mechanism of RV remodeling.

Muscle strength is reduced in children with pulmonary arterial hypertension

Muscle strength is decreased in adults with pulmonary arterial hypertension (PAH). We aim to investigate muscle strength in children with PAH in relation to a cohort of healthy children, and investigate correlations with disease severity markers. This prospective study included children with PAH aged 4-18 years, who visited the Dutch National Referral Center for Pulmonary Hypertension in Childhood between October 2015 and March 2016. Muscle strength was assessed using handgrip strength and maximum voluntary isometric contractility (MVIC) of four peripheral muscles. Dynamic muscle function was evaluated with the Bruininks-Oseretsky test of motor proficiency (BOT-2). These measurements were compared with those in two cohorts of healthy children and correlated with 6-minute walk distance (6MWD), World Health Organization functional class (WHO-FC), N-terminal pro-brain natriuretic peptide (NT-proBNP), and time since diagnosis. Eighteen children with PAH aged 14.0 [interquartile range: 9.9-16.0] years showed reduced muscle strength. Handgrip strength z-score -2.4 ± 1.2, p < 0.001, total MVIC z-score -2.9 ± 1.2, p < 0.001, and BOT-2 z-score -1.0 ± 0.9, p < 0.001. 6MWD (67 ± 11% predicted) correlated with most muscle measurements (r = 0.49-0.71, p = 0.001). Dynamic muscle function (BOT-2) differed between WHO-FC, whereas handgrip strength and MVIC did not. NT-proBNP and time since diagnosis did not show significant correlations with muscle strength measurements. Muscle strength was significantly reduced in children with PAH and correlated with 6MWD, but not with disease severity markers WHO-FC and NT-pro-BNP. The nature of this reduced muscle strength is yet unclear, but its occurrence in children with seemingly mild or well-controlled PAH supports the concept of PAH being a systemic syndrome involving peripheral skeletal muscles.

Apply pressure-strain loop to quantify myocardial work in pulmonary hypertension: A prospective cohort study

Objectives

Pressure-strain loop (PSL) is a novel method to quantify myocardial work in many cardiovascular diseases. To investigate the value of myocardial work parameters derived from PSL for evaluating cardiac function and clinical prognosis in patients with pulmonary hypertension (PH).

Methods

A total of 52 patients with PH and 27 healthy controls were enrolled in this prospective study. PSLs determined by echocardiography were used to calculate global work index (GWI) of left ventricle (LV) and right ventricle (RV). Global constructive work (GCW) comprised the sum of myocardial work performed during shortening in systole and during lengthening in isovolumic relaxation. Global wasted work (GWW) comprised the sum of myocardial work performed during lengthening in systole and during shortening in isovolumic relaxation. Global work efficiency (GWE) was defined as GCW/(GCW + GWW).

Results

LVGWW, RVGWI, RVGCW and RVGWW were significantly higher in patients than controls (all P < 0.001). LVGWE, LVGWI, LVGCW, and RVGWE were lower in patients than controls (all P < 0.01). Myocardial work parameters correlated well with clinical and other conventional echocardiographic assessments (all P < 0.05). In binary logistic regression analysis, the combination of RVGWE and estimation of pulmonary arterial systolic pressure (ePASP) was the best model to predict clinical outcomes (OR = 0.803, P = 0.002 and OR = 1.052, P = 0.015, respectively). Receiver operating characteristic curv demonstrated the combination of RVGWE and ePASP was the best predictor of adverse events with 100% sensitivity and 76.3% specificity (AUC = 0.910, P < 0.001).

Conclusion

Myocardial work parameters derived from PSL are emerging markers of cardiac function. And the combination of RVGWE and ePASP is a useful predictor of clinical outcome in PH patients.

Correlation Between Right Ventricular Echocardiography Measurements and Functional Capacity in Patients With Pulmonary Arterial Hypertension

BACKGROUND

Accelerometry is an emerging option for real-time evaluation of functional capacity in patients with pulmonary arterial hypertension (PAH). This prospective pilot study assesses the relationship between functional capacity by accelerometry and right ventricular measurements on echocardiography for this high-risk cohort.

METHODS

Patients with PAH were prospectively enrolled and underwent 6-Minute Walk Test and cardiopulmonary exercise testing. They were given a Fitbit, which collected steps and sedentary time per day. Echocardiographic data included right ventricular global longitudinal, free wall, and septal strain; tricuspid regurgitant peak velocity; tricuspid annular plane systolic excursion; tricuspid annular plane systolic velocity; right ventricular myocardial performance index; and pulmonary artery acceleration time. Pairwise correlations were performed.

RESULTS

The final analysis included 22 patients aged 13 to 59 years. Tricuspid regurgitant peak velocity had a negative correlation with 6-Minute Walk Test (r = -0.58, P = .02), peak oxygen consumption on exercise testing (r = -0.56, P = .03), and average daily steps on accelerometry (r = -0.59, P = .03), but a positive correlation with median sedentary time on accelerometry (r = 0.64, P = .02). Pulmonary artery acceleration time positively correlated with peak oxygen consumption on exercise testing (r = 0.64, P = .002). There was no correlation between right ventricular strain measurements and functional capacity testing.

CONCLUSION

In this pilot study, tricuspid regurgitant jet and pulmonary artery acceleration time were the echocardiographic variables that correlated most with accelerometry data. With further echocardiographic validation, accelerometry can be a useful, noninvasive, and cost-effective tool to monitor disease progression in patients with PAH.

Non-Invasive Assessment of Right Ventricle to Arterial Coupling for Prognosis Stratification of Fibrotic Interstitial Lung Diseases

Background: The coupling of the right ventricle (RV) to the pulmonary circulation is an indicator of RV performance that can be non-invasively estimated by echocardiography. There are no data about its use in patients affected by fibrotic interstitial lung diseases (f-ILD). Methods: Fifty f-ILD patients, including 27 cases with idiopathic pulmonary fibrosis (IPF) (M = 37; mean age 67 ± 7 years), were studied with standard and speckle-tracking echocardiography and compared with 30 age-matched healthy volunteers. The mean patient follow-up was 70 ± 4 months. Results: Fibrotic ILD patients had a larger right ventricle (RV) and worse diastolic function because the RV global longitudinal strain (GLS) was significantly lower and the systolic pulmonary artery pressure (sPAP) estimates were higher in comparison with those of controls. Conversely, tricuspid annular systolic excursion (TAPSE) did not differ between controls and patients. Median values of TAPSE/sPAP and RV GLS/sPAP were significantly reduced in f-ILD patients (p < 0.0001). Patients with an RV GLS/sPAP below the median value had a shorter survival time (61 vs. 74 months, p = 0.01); this parameter was an independent predictor of a worse outcome. Conclusion: Low estimates of RV GLS/sPAP are predictive of worse outcomes in f-ILD patients. RV coupling seems to be a promising surrogate biomarker of RV performance to discriminate the patient phenotype with significant management and prognosis implications.

Exercise Rehabilitation Training in Patients with Pulmonary Hypertension: A Review

Pulmonary hypertension (PH) has a high morbidity and mortality. Despite the existing disease-targeted therapy, most patients with PH continue to suffer from difficulty in breathing, exercise intolerance, and reduced quality of life. Recently, a large body of research results has suggested that exercise rehabilitation training (ERT) seems to be a beneficial, safe, and cost-effective treatment for patients with PH. However, knowledge gaps still exist for a uniformly accepted ERT protocol, the modality, duration, intensity, and frequency of ERT in PH. The purpose of this review is to summarise the existing research evidence and knowledge, aiming to strengthen clinicians' awareness of the application of ERT in patients with PH. PubMed databases were systematically searched for eligible studies. Twelve (12) randomised controlled trials and other important studies documenting effectiveness, safety, and adverse events of ERT are summarised. Additionally, the modality, duration, intensity, and frequency of various types of ERT and future research directions are discussed. In summary, ERT is generally effective and safe for PH patients as an adjuvant treatment to disease-specific therapy. It can improve the exercise capacity and tolerance, skeletal and respiratory muscle performance, cardiopulmonary function, and quality of life of PH patients. In view of the occurrence of a small number of adverse events, we currently recommend a combination of in-hospital and home-based ERT under close supervision. In the future, more multi-centre randomised controlled studies are needed to evaluate the effectiveness and feasibility of long-term, community, or home-based ERT, as well as to explore the molecular mechanism behind it.

Long-term mortality after pulmonary artery denervation stratified by baseline functional class in patients with pulmonary arterial hypertension: Long-term mortality after PADN stratified by functional class

AIMS

This study aimed to assess the long-term effects of pulmonary artery denervation (PADN) on mortality in patients with pulmonary arterial hypertension (PAH).

METHODS AND RESULTS

Between March 2012 and March 2018, a total of 120 patients with PAH, who underwent PADN treatment and were prospectively followed up, were analysed. Patients were classified into World Health Organization (WHO) Functional Class I and II (FC 1-2; n=46) and Functional Class III and IV (FC 3-4; n=74) according to their FC prior to PADN. The primary endpoint was lung transplantation-free mortality until March 2021. The secondary endpoint was a change in the six-minute walk distance (6MWD). During the median of 4.8 years of follow-up, 23 (19.2%) patients died, predominantly from the FC 3-4 group (25.7%), compared to 8.7% in the FC 1-2 group (p=0.034). The mortality rate at one year (2.2% vs 12.2%, p=0.087) and three years (6.5% vs 17.6%, p=0.102) was numerically low in the FC 1-2 group versus the FC 3-4 group, respectively. The median net increase of 6MWD was +29 m in the FC 1-2 group, compared to +60.5 m in the FC 3-4 group (p=0.037).

CONCLUSIONS

PADN results in significant improvements in survival at long-term follow-up, especially in patients with PAH in FC 3-4. This study was the continuation of the PADN-1 study which was registered at URL: http://www.chictr.trc.com.cn. Unique identifier: chiCTR-ONC-12002085.

The Role of Multimodality Imaging in HIV-Associated Cardiomyopathy

Despite marked advances in therapeutics, HIV infection remains a leading cause of morbidity and mortality worldwide. HIV infection is associated with cardiovascular complications including myocardial dysfunction. The description of HIV-associated cardiomyopathy (HIVAC) has evolved over time from a predominantly dilated cardiomyopathy with systolic dysfunction to one of subclinical diastolic dysfunction. Multimodality cardiovascular imaging plays an integral role in our understanding of the etiology and pathogenesis of HIVAC. Such imaging is also essential in the evaluation of individuals with chronic HIV disease who present with cardiac symptoms, especially of heart failure. In the present review, we will highlight current evidence for the role of multimodality imaging in establishing the diagnosis, etiology and pathophysiology of HIVAC as well as guiding treatment and assessing prognosis.

Long-Term Outcomes in Adult Patients With Pulmonary Hypertension After Percutaneous Closure of Atrial Septal Defects

BACKGROUND

Pulmonary hypertension (PH), recently redefined as mean pulmonary arterial pressure >20 mm Hg (PH₂₀), may be observed in patients with atrial septal defects (ASD). We aimed to determine the effect of preprocedural PH₂₀ status on outcomes among patients undergoing ASD closure.

METHODS

Study population was selected from a retrospective registry of adult patients who underwent percutaneous ASD closure from 1998 to 2016 from a single center and had right heart catheterizations during the procedure. The clinical registry was linked to administrative databases to capture short- and long-term outcomes.

RESULTS

We included a total of 632 ASD closure patients of whom 359 (56.8%) had PH₂₀. The mean follow-up length was 7.6±4.6 years. Patients with PH₂₀ were older (mean age 56.5 versus 43.1 years, P<0.001) and a higher prevalence of comorbidities including hypertension (54.3% versus 21.6%, P<0.001) and diabetes (18.1% versus 5.9%, P<0.001) than those without PH. In a Cox proportional hazards model after covariate adjustment, patients with PH had a significantly higher risk of developing major adverse cardiac and cerebrovascular events (heart failure, stroke, myocardial infarction, or cardiovascular mortality), with hazards ratio 2.45 (95% CI, 1.4-4.4). When applying the prior, mean pulmonary arterial pressure ≥25 mm Hg (PH₂₅) cutoff, a significantly higher hazard of developing major adverse cardiac and cerebrovascular events was observed in PH versus non-PH patients.

CONCLUSIONS

ASD patients with PH undergoing closure suffer from more comorbidities and worse long-term major adverse cardiac and cerebrovascular events outcomes, compared with patients without PH. The use of the new PH₂₀ definition potentially dilutes the effect of this serious condition on outcomes in this population.

Differential serum lipid distribution in IPAH and CHD-PAH patients

Lipid homeostasis is dysregulated in pulmonary arterial hypertension (PAH). A decrease in serum high- and low-density lipoprotein cholesterol (HDL-C and LDL-C) is significantly associated with the worse prognosis of PAH. However, no study has investigated the differential distribution of lipids in various PAH subtypes. We enrolled 190 patients in this retrospective study, which includes 20 patients with congenital heart disease without PAH (CHD-nonPAH), 101 patients with PAH associated with congenital heart disease (CHD-PAH), 69 patients with idiopathic PAH (IPAH) and 81 healthy controls. Laboratory parameters such as liver and renal function, serum lipids, C-reactive protein, N-terminal pro-brain natriuretic peptide (NT-proBNP), echocardiography, right heart catheterization and 6-min walk distance (6MWD) were performed. All types of cholesterol including HDL-C, LDL-C and total cholesterol (CHOL) were significantly lower in IPAH patients in association with right heart function. Although LDL-C and CHOL were lower in CHD-PAH, they were not associated with disease severity or heart failure. Thus, we conclude that IPAH and CHD-PAH patients exhibited a differential distribution pattern of serum lipids.

Diagnostic test accuracy of artificial intelligence analysis of cross-sectional imaging in pulmonary hypertension: a systematic literature review

OBJECTIVES

To undertake the first systematic review examining the performance of artificial intelligence (AI) applied to cross-sectional imaging for the diagnosis of acquired pulmonary arterial hypertension (PAH).

METHODS

Searches of Medline, Embase and Web of Science were undertaken on 1 July 2020. Original publications studying AI applied to cross-sectional imaging for the diagnosis of acquired PAH in adults were identified through two-staged double-blinded review. Study quality was assessed using the Quality Assessment of Diagnostic Accuracy Studies and Checklist for Artificial Intelligence in Medicine frameworks. Narrative synthesis was undertaken following Synthesis Without Meta-Analysis guidelines. This review received no funding and was registered in the International Prospective Register of Systematic Reviews (ID:CRD42020196295).

RESULTS

Searches returned 476 citations. Three retrospective observational studies, published between 2016 and 2020, were selected for data-extraction. Two methods applied to cardiac-MRI demonstrated high diagnostic accuracy, with the best model achieving AUC=0.90 (95% CI: 0.85-0.93), 89% sensitivity and 81% specificity. Stronger results were achieved using cardiac-MRI for classification of idiopathic PAH, achieving AUC=0.97 (95% CI: 0.89-1.0), 96% sensitivity and 87% specificity. One study reporting CT-based AI demonstrated lower accuracy, with 64.6% sensitivity and 97.0% specificity.

CONCLUSIONS

Automated methods for identifying PAH on cardiac-MRI are emerging with high diagnostic accuracy. AI applied to cross-sectional imaging may provide non-invasive support to reduce diagnostic delay in PAH. This would be helped by stronger solutions in other modalities.

ADVANCES IN KNOWLEDGE

There is a significant shortage of research in this important area. Early detection of PAH would be supported by further research advances on the promising emerging technologies identified.

Measures of excess [Formula: see text]CO2 and recovery [Formula: see text]CO2 as indices of performance fatigability during exercise: a pilot study

BACKGROUND

The severity of performance fatigability and the capacity to recover from activity are profoundly influenced by skeletal muscle energetics, specifically the ability to buffer fatigue-inducing ions produced from anaerobic metabolism. Mechanisms responsible for buffering these ions result in the production of excess carbon dioxide (CO2) that can be measured as expired CO2 ([Formula: see text]CO2) during cardiopulmonary exercise testing (CPET). The primary objective of this study was to assess the feasibility of select assessment procedures for use in planning and carrying out interventional studies, which are larger interventional studies investigating the relationships between CO2 expiration, measured during and after both CPET and submaximal exercise testing, and performance fatigability.

METHODS

Cross-sectional, pilot study design. Seven healthy subjects (30.7±5.1 years; 5 females) completed a peak CPET and constant work-rate test (CWRT) on separate days, each followed by a 10-min recovery then 10-min walk test. Oxygen consumption ([Formula: see text]O2) and [Formula: see text]CO2 on- and off-kinetics (transition constant and oxidative response index), excess-[Formula: see text]CO2, and performance fatigability severity scores (PFSS) were measured. Data were analyzed using regression analyses.

RESULTS

All subjects that met the inclusion/exclusion criteria and consented to participate in the study completed all exercise testing sessions with no adverse events. All testing procedures were carried out successfully and outcome measures were obtained, as intended, without adverse events. Excess-[Formula: see text]CO2 accounted for 61% of the variability in performance fatigability as measured by [Formula: see text]O2 on-kinetic ORI (ml/s) (R2=0.614; y = 8.474x - 4.379, 95% CI [0.748, 16.200]) and 62% of the variability as measured by PFSS (R2=0.619; y =  - 0.096x + 1.267, 95% CI [-0.183, -0.009]). During CPET, [Formula: see text]CO2 -off ORI accounted for 70% (R2=0.695; y = 1.390x - 11.984, 95% CI [0.331, 2.449]) and [Formula: see text]CO2 -off Kt for 73% of the variability in performance fatigability measured by [Formula: see text]O2 on-kinetic ORI (ml/s) (R2=0.730; y = 1.818x - 13.639, 95% CI [0.548, 3.087]).

CONCLUSION

The findings of this study suggest that utilizing [Formula: see text]CO2 measures may be a viable and useful addition or alternative to [Formula: see text]O2 measures, warranting further study. While the current protocol appeared to be satisfactory, for obtaining select cardiopulmonary and performance fatigability measures as intended, modifications to the current protocol to consider in subsequent, larger studies may include use of an alternate mode or measure to enable control of work rate constancy during performance fatigability testing following initial CPET.

Correlation of Computed Tomography Test Bolus Dynamics and Conventional Computed Tomography Parameters With Pulmonary Vascular Resistance in Patients With Pulmonary Arterial Hypertension

Objective: Pulmonary vascular resistance (PVR) is a measurement obtained with invasive right heart catheterization (RHC) that is commonly used for management of patients with pulmonary arterial hypertension (PAH). Computed tomography pulmonary angiography (CTPA) is also done as part of the workup for PAH in some cases. The aim of our study was to assess the correlation of contrast dynamic changes in the main pulmonary artery (MPA) on CTPA with PVR obtained with RHC.

Methods: This is an IRB-approved retrospective study performed in two separate institutions (Medical College of Wisconsin and University of Alabama) between January 2010 and December 2013. During CTPA done as test bolus, serial images are acquired at the level of MPA after intravenous injection of contrast to determine timing of the CT acquisition. Since the PVR changes with the degree of PAH, we hypothesize that will be reflected in the contrast kinetics in MPA. A correlation of standard CT metrics (MPA diameter, right pulmonary artery [PA] diameter, left PA diameter, MPA/aorta ratio, and right ventricle/left ventricle [RV/LV] ratio) and dynamic (full width at half maximum) CTPA parameters in patients with known PAH was performed with PVR obtained from RHC done within 30 days. Statistical analysis was performed by Pearson correlation coefficient.

Results: Among 221 patients in our database, 37 patients fulfilled the selection criteria. There was a strong correlation between full width half maximum (FWHM) and mean pulmonary artery pressure (mPAP) (r=0.69, p value<0.00001), PVR (r=0.8, p value<0.00001) and indexed PVR (PVRI) (r=0.75, p value<0.00001).

Conclusion: FWHM obtained from CTPA strongly correlates with RHC parameters and is potentially more helpful than static measurements for follow-up of patients with known PAH to assess response to treatment or progression.

Prevalence and outcomes of pulmonary hypertension after percutaneous closure of atrial septal defect: a systematic review and meta-analysis

BACKGROUND

Atrial septal defect (ASD) is a common form of congenital heart disease. Significant shunts may increase the risk of developing pulmonary hypertension (PH). We aimed to describe current PH definitions, evaluate PH prevalence and the effect of PH on outcomes in patients undergoing percutaneous ASD closure.

METHODS

EMBASE, MEDLINE and Cochrane databases were systematically searched. Studies reporting PH prevalence or mean systolic pulmonary arterial pressure (sPAP) before and after percutaneous ASD closure in adults were included. We conducted meta-analyses to obtain summary estimates for PH prevalence and mean sPAP.

RESULTS

15 articles with a total of 1073 patients met the eligibility criteria. Studies applied variable PH definitions. PH prevalence and mean sPAP levels decreased in all studies after closure. The pooled PH prevalence decreased from 44% (95% CI 29-60%) to 18% (95% CI 8-27%). The overall standardised mean difference in sPAP was 1.12 (95% CI 0.81-1.44) and 1.62 (95% CI 1.00-2.23) in cohort and case-series studies respectively indicating a large decrease. The pooled standard mean difference among the younger and older patients were different, 1.25 (95% CI 0.78-1.71) and 0.91 (95% CI 0.56-1.27), respectively. A high degree of between-study heterogeneity was noted.

CONCLUSIONS

Both PH prevalence and mean sPAP decrease after ASD closure. Larger, prospective studies with consistent PH definitions using the recommended measurement modality are warranted.

Myocardial deformation assessment in patients with precapillary pulmonary hypertension: A cardiac magnetic resonance study

PURPOSE

The purpose of this study was to investigate right atrial and ventricular strain parameters on cardiac magnetic resonance (CMR) in patients with precapillary pulmonary hypertension (PPH) and whether they can aid in the assessment of PPH prognosis.

MATERIALS AND METHODS

Adult patients with groups 1 and 4 PPH were invited to participate in the study. Age- and sex-matched healthy volunteers were also recruited as controls. At baseline, patients underwent clinical examination, N-terminal pro-B-type natriuretic peptide measurement and CMR with feature tracking post-processing (CMR-FT). Healthy controls underwent only CMR-FT. The study's primary endpoint was clinical failure, defined as death, hospitalization or demonstrable clinical deterioration during follow-up. Patients who were unable to perform 6-minute walking test due to musculoskeletal disorders were excluded from the study.

RESULTS

Thirty-six patients (8 men, 28 women; mean age, 50.6±13.8 [SD] years [range: 18.6-78.5years]) and 12 healthy control subjects (5 mean, 7 women; mean age, 40.6±13.5 [SD] years [range: 23.1-64.4years]) were recruited. Right ventricular global longitudinal strain (GLS) was significantly impaired in PPH patients (-20.2±5.3 [SD] % [range: -28.8 to -9.1%] vs. -28.4±3.1% [-33.7 to -22.7%] respectively, P<0.001). The right atrial GLS was significantly impaired in PPH compared to healthy controls (-19.9±4.5% [range: -28.6 to -3.6%] vs. -26.5±4.2% [range: -32.8 to -15.8%] respectively) (P<0.001). Clinical failure occurred in 19 (19/36, 53%) of patients. Right ventricular GLS predicted clinical failure most reliably among CMR parameters (-22.6±3.8 [SD] % [range: -27.6 to -12.7%] for patients without clinical failure vs. -18±5.6 [SD] % [range: -28.8 to -9.1%] for patients with clinical failure; hazard ratio [HR]=1.85; P=0.007; area under the AUC curve=0.75). Lower absolute right atrial GLS was significantly associated with clinical failure (-22.7±3.0 [SD] % [range: -28.6 to -17.7%] for patients without clinical failure vs. -16.9±5.8 [SD] % [range: -24.2 to -3.6%] for patients with clinical failure) (HR=1.53; P=0.035).

CONCLUSION

CMR feature tracking-derived myocardial strain parameters of both the right atrium and ventricle can assist clinicians in the prognosis of PPH.

Tsantan Sumtang attenuated chronic hypoxia-induced right ventricular structure remodeling and fibrosis by equilibrating local ACE-AngII-AT1R/ACE2-Ang1-7-Mas axis in rat

ETHNOPHARMACOLOGICAL RELEVANCE

Tsantan Sumtang, which consists of Choerospondias axillaris (Roxb.) Burtt et Hill, Myristica fragrans Houtt and Santalum album L, is a traditional and common prescription of Tibetan medicine. Tsantan Sumtang originates from Four Tantra with properties of nourishing heart and has been used as a folk medicine for cardiovascular diseases and heart failure in Qinghai, Tibet and Inner Mongolia. Our previous studies found that Tsantan Sumtang showed beneficial effects on right ventricular structure in hypoxia rats, while the underling mechanism remains unclear.

AIM OF THE STUDY

To elucidate the underlying mechanisms of Tsantan Sumtang attenuated right ventricular (RV) remodeling and fibrosis of chronic hypoxia-induced pulmonary arterial hypertension (HPAH) rats.

MATERIALS AND METHODS

Fifty male Sprague Dawley (SD) rats (170 ± 20 g) were randomly divided into control group, hypoxia group, and hypoxia + Tsantan Sumtang groups (1.0 g· kg^-1·day^-1, 1.25 g· kg^-1·day^-1, 1.5 g ·kg^-1·day^-1). Rats in the hypoxia group and hypoxia + Tsantan Sumtang groups were maintained in a hypobaric chamber by adjusting the inner pressure and oxygen content to simulate an altitude of 4500 m for 28 days. The mean pulmonary arterial pressure (mPAP), right ventricle hypertrophy index (RVHI), the ratio of RV weight to tibia length (TL) (RV/TL), heart rate (HR) and RV systolic pressure (RVSP) was determined. Histomorphological assay of RV structure was evaluated by hematoxylin and eosin (HE) staining. RV tissue fibrosis was assessed by collagen proportion area (CPA), collagen I, collagen III and hydroxyproline content. CPA was obtained by picro-sirius red staining (PSR). The expression of collagen I and collagen III were detected by immunohistochemistry and western blotting. The hydroxyproline content was detected by alkaline hydrolysis. In addition, the level of angiotensin II (AngII) and angiotensin 1-7 (Ang1-7) in RV tissue was tested by enzyme-linked immune sorbent assay (ELISA). Protein expression of angiotensin-converting enzyme (ACE), AngII, AngII type 1 receptor (AT1R), angiotensin-converting enzyme 2 (ACE2), Mas receptor (Mas) were determined by immunohistochemistry and western blotting. mRNA level of ACE, AT1R, ACE2, Mas were tested by qPCR. The chemical profile of Tsantan Sumtang was revealed by UHPLC-Q-Exactive hybrid quadrupole-orbitrap mass analysis.

RESULTS

Our results showed that RVHI, RV/TL and RVSP were significantly increased in HPAH rat. Furthermore, levels of collagen I, collagen III and hydroxyproline were up-regulated in RV tissue under hypoxia. We found that RV hypertrophy and fibrosis were associated with increased expression of ACE, AngII, AT1R as well as decreased expression of ACE2, Ang1-7 and Mas. RV remodeling and fibrosis were attenuated after Tsantan Sumtang administration by up-regulating ACE2 and Mas level as well as down-regulating ACE, AngII and AT1R levels in RV tissue. 35 constituents in Tsantan Sumtang were identified.

CONCLUSION

Tsantan Sumtang attenuated RV remodeling and fibrosis in rat exposed to chronic hypoxia. The pharmacological effect of Tsantan Sumtang was based on equilibrating ACE-AngII-AT1R and ACE2-Ang1-7-Mas axis of RV tissue in HPAH rat.

Novel imaging techniques in pulmonary hypertension

PURPOSE OF REVIEW

Pulmonary hypertension is a life-shortening condition, which may be idiopathic but is more frequently seen in association with other conditions. Current guidelines recommend cardiac catheterization to confirm the diagnosis of pulmonary hypertension. Evidence suggests an increasing role for noninvasive imaging modalities in the initial diagnostic and prognostic assessment and evaluation of treatment response.

RECENT FINDINGS

In this review we examine the evidence for current noninvasive imaging methodologies: echocardiography computed tomography and MRI in the diagnostic and prognostic assessment of suspected pulmonary hypertension and explore the potential utility of modeling and machine-learning approaches.

SUMMARY

Noninvasive imaging allows a comprehensive assessment of patients with suspected pulmonary hypertension. It plays a key part in the initial diagnostic and prognostic assessment and machine-learning approaches show promise in the diagnosis of pulmonary hypertension.

Right Ventricular Involution: Big Changes in Small Hearts

BACKGROUND

Before birth, the fetal right ventricle (RV) is the pump for the systemic circulation and is about as thick as the left ventricle (LV). After birth, the RV becomes the pump for the lower pressure pulmonary circulation, and the RV chamber elongates without change in its wall thickness. We hypothesize that the fetal RV may be a model of compensated RV hypertrophy, and understanding this process may aid in discovering therapeutic strategies for RV failure.

METHODS

We performed a literature review and identified pertinent articles from 1980 to present.

RESULTS

The following topics were identified to be most pertinent in right ventricular involution: morphologic and histologic changes of the RV, cellular proliferation and terminal differentiation, the effect of stress on RV development, excitation contraction coupling and inotropic response change over time, and the amount of apoptosis through RV development.

CONCLUSIONS

The RV changes on multiple levels after its transition from systemic to pulmonary circulation. Although published literature has variable results due partly from differences between animal models, the literature shows a clear need for more research in the field.

Risk Factors for Pulmonary Hypertension in Adults After Atrial Septal Defect Closure

Atrial septal defect (ASD) closure is performed to prevent pulmonary hypertension (PH), which is associated with poor outcome. This study investigated the prevalence of PH in adults before and after ASD closure and explored associations between patient characteristics and PH after ASD closure. Consecutive adult patients who underwent surgical or percutaneous ASD closure in the Erasmus MC, the Netherlands, were included (2000 to 2014). Echocardiograms before and after ASD closure were retrospectively assessed. Patients were categorized into 3 groups (no PH, possible PH, and PH) based on tricuspid regurgitation velocity (<2.9, 2.9 to 3.4, and ≥3.4 m/s) or mean pulmonary arterial pressure (<20, 20 to 24, and ≥25 mm Hg). Cox regression was performed to identify associations between patient characteristics and PH after ASD closure. Of the 244 eligible patients who underwent ASD closure, 198 (81%) had echocardiograms both before and median 15 (interquartile range 12 to 35) months after ASD closure (median age at closure 45 [interquartile range 30 to 57] years, 75% woman). The prevalence of PH was 13.1% (n = 26) before ASD closure and 5.0% (n = 10) after closure. New York Heart Association III to IV (hazard ratio [HR] 11.07, 95% confidence interval [CI] 3.12 to 39.29, p <0.001), pulmonary disease (HR 10.43, 95% CI 2.12 to 51.21, p = 0.004), cardiac medication use (HR 3.96, 95% CI 1.02 to 15.34, p = 0.047), right ventricular fractional area change (HR 0.87, 95% CI 0.81 to 0.93, p <0.001), and tricuspid annular plane systolic excursion (HR 0.75, 95% CI 0.59 to 0.95, p = 0.018) were significantly associated with PH. In conclusion, adult patients with low pulmonary pressures before ASD closure are not at risk of PH after closure. Nevertheless, PH remained prevalent in approximately 5% of patients. Especially those patients with high New York Heart Association functional class, presence of pulmonary disease, cardiac medication use and impaired RV function at baseline are at risk.

Percutaneous Mechanical Circulation Support Combined with Extracorporeal Membrane Oxygenation (oxyRVAD) in Secondary Right Heart Failure

Right heart failure (RHF) because of pulmonary hypertension (PH) is a frequently encountered clinical problem with high mortality. The last resort, if pharmacological therapy fails, is mechanical circulatory support. There is a lack of percutaneous systems to support the right ventricle (RV). Venoarterial extracorporeal membrane oxygenation is widely used as a bailout in acute RHF in non-left ventricular assist device patients. Venoarterial extracorporeal membrane oxygenation does not unload the left ventricle and may cause failure of the left ventricle if used for a longer period of time. We report the long-term use of an ECMO-based percutaneous right ventricular assist system (oxyRVAD) capable to deliver up to 6 L/min of blood flow with a returning cannula placed in the main pulmonary artery used in RHF originating from PH with poor oxygenation. We present a series of four patients on oxyRVAD (mean treatment duration 15 ± 7.6 days). Patients benefited from the system clinically; however, two patients eventually died while on oxyRVAD. Nevertheless, we provide a proof-of-concept of this system in PH patients, which is feasible and might provide a useful "bridge-to-recovery" or "bridge-to-transplant" option in the management of patients with severe RHF because of PH.

Analysis of Biphasic Right Ventricular Outflow Doppler Waveform in Patients with Pulmonary Hypertension

Pulmonary hypertension (PH) with pulmonary vascular disease (PVD) is a progressive and debilitating disease associated with increased pulmonary vascular resistance (PVR). Biphasic right ventricular outflow tract (RVOT) Doppler flow is frequently seen in severe PH patients with PVD. In association with hemodynamics, the precise analysis of biphasic RVOT Doppler flow (RVDF) has not been fully elucidated. Therefore, the purpose of the present study is to analyze the relation between the hemodynamics and indices of biphasic RVDF in PH patients with PVD.Seventy PH patients with biphasic RVDF were analyzed. All patients underwent transthoracic echocardiography and right heart catheterization. For the analysis of biphasic RVDF, the early waveform was determined as P₁ while the late waveform was determined as P₂. For each P₁ and P₂, the duration (D, seconds) and peak flow velocity (PFV, in m/second) were measured.P₁D and P₂PFV were significantly correlated with PVR (P₁D: r = -0.542, P < 0.0001, P₂PFV: r = -0.513, P < 0.0001). Therefore, we propose a novel RVDF formula for estimation of PVR, as follows. PVR = 26 - 77 × P₁D - 14 × P₂PFV. The PVR could be estimated by this proposed formula (r = 0.649, P < 0.0001), which is derived from one Doppler image only unlike previously used PVR prediction formula.P₁D and P₂PFV were associated with PVR. Moreover, this simple RVDF formula proposed herein can estimate PVR in PH patients with PVD.

CT-measured pulmonary artery diameter as an independent predictor of pulmonary hypertension in cystic fibrosis

Purpose

The role of computed tomography (CT) scan, as a promising prognostic imaging modality in cystic fibrosis (CF), has been widely investigated, focusing on parenchymal abnormalities. The aim of the present study was to evaluate the diagnostic performance of thoracic vascular parameters on CT to detect pulmonary hypertension (PH).

Material and methods

CF patients who contemporaneously underwent CT and echocardiography were retrospectively enrolled. Baseline characteristics in addition to pulmonary artery diameter (PAD) and pulmonary to aortic (PA/A) ratio were compared between cohorts with and without PH, based on the results of echocardiography separately in paediatric patients (< 18) and adults (≥ 18).

Results

Of a total 119 CF patients, 39 (32.8%) had PH (paediatric: 23/78, 29.5%, adult: 16/41, 39%). In paediatric CF patients, mean age, HCo₃, PCo₂, and pulmonary artery diameter (PAD) were significantly higher in the PH group compared to the non-PH group. Mean pulmo however, only PAD remained as the independent predictor of PH based on multivariate analysis (overall: 22.86 mm [±3.86] vs. 18.43 mm [±4.72], p = 0.005, paediatric patients: 22.63 mm [±4.4] vs. 17.10 mm [±4.64], p = 0.03). Using a cut off of 19.25 mm, the diagnostic performance of PAD to detect PH was found to be as follows: sensitivity = 82%, specificity = 70%, and accuracy = 73.1%. No significant difference was demonstrated in PAD between PH and non-PH groups in adults with CF (23.19 [±3.60] vs. 21.34 [±3.49], p = 0.7).

Conclusions

In CF patients, PAD revealed an age-dependent performance to detect PH. PAD can be applied to predict pulmonary hypertension in paediatric CF patients and may be recommended to be routinely measured on follow-up chest CT scan in childhood CF.

Current and emerging imaging techniques in the diagnosis and assessment of pulmonary hypertension

INTRODUCTION

Pulmonary hypertension (PH) is a challenging condition to diagnose and treat. Over the last two decades, there have been significant advances in therapeutic approaches and imaging technologies. Current guidelines emphasize the importance of cardiac catheterization; however, the increasing availability of non-invasive imaging has the potential to improve diagnostic rates, whilst providing additional information on patient phenotypes. Areas covered: This review discusses the role of imaging in the diagnosis, prognostic assessment and follow-up of patients with PH. Imaging methods, ranging from established investigations (chest radiography, echocardiography, nuclear medicine and computerized tomography (CT)), to emerging modalities (dual energy CT, magnetic resonance imaging (MRI), optical coherence tomography and positron emission tomography (PET)) are reviewed. The value and limitations of the clinical utility of these imaging modalities and their potential clinical application are reviewed. Expert commentary: Imaging plays a key role in the diagnosis and classification of pulmonary hypertension. It also provides valuable prognostic information and emerging evidence supports a role for serial assessments. The authors anticipate an increasing role for imaging in the pulmonary hypertension clinic. This will reduce the need for invasive investigations, whilst providing valuable insights that will improve our understanding of disease facilitate a more targeted approach to treatment.

Demographics, treatment trends, and survival rate in incident pulmonary artery hypertension in Korea: A nationwide study based on the health insurance review and assessment service database

Epidemiologic data regarding pulmonary arterial hypertension (PAH) have relied on registries from Western countries. We assessed the current status of PAH in the Korean population. The Health Insurance Review and Assessment Service (HIRA) claim database, which comprises nationwide medical insurance data of Koreans from 2008–2016, was assessed to determine the current status of PAH. Overall, 1,307 patients were newly diagnosed with PAH from 2008–2016 (0.0005%, annual incidence: 4.84 patients/1 million people/year). The mean age at diagnosis was 44±13 years (range 18–65) and patients were mostly women (n = 906, 69.3%). Cases of idiopathic PAH (51.6%) accounted for the largest proportion, followed by acquired PAH (APAH) associated with congenital heart disease (25.8%) and APAH with connective tissue disease (17.2%). Overall, 807 (61.7%) patients received a single PAH-specific treatment based on their last prescription, of which bosentan (50.6%) was the most frequently used. Only 240 (18.4%) patients received combination therapy, with the bosentan-beraprost combination (32.9%) being the most common. During the mean follow-up of 1.9 years, the 1-, 2-, 3-, and 5-year estimated survival rates were 85%, 62%, 54%, and 46%, respectively. The prevalence and incidence of PAH in the Korean population is currently comparable with that in previous registries. The 5-year survival rate was slightly higher in the Korean population than previously reported.

The Role of G Protein-Coupled Receptors in the Right Ventricle in Pulmonary Hypertension

Pressure overload of the right ventricle (RV) in pulmonary arterial hypertension (PAH) leads to RV remodeling and failure, an important determinant of outcome in patients with PAH. Several G protein-coupled receptors (GPCRs) are differentially regulated in the RV myocardium, contributing to the pathogenesis of RV adverse remodeling and dysfunction. Many pharmacological agents that target GPCRs have been demonstrated to result in beneficial effects on left ventricular (LV) failure, such as beta-adrenergic receptor and angiotensin receptor antagonists. However, the role of such drugs on RV remodeling and performance is not known at this time. Moreover, many of these same receptors are also expressed in the pulmonary vasculature, which could result in complex effects in PAH. This manuscript reviews the role of GPCRs in the RV remodeling and dysfunction and discusses activating and blocking GPCR signaling to potentially attenuate remodeling while promoting improvements of RV function in PAH.

Pulmonary hypertension in Spanish patients with systemic sclerosis. Data from the RESCLE registry

INTRODUCTION

Our objective was to evaluate the pulmonary hypertension (PH) data for Spanish patients with systemic sclerosis (SSc), define the PH types and determine the associated factors.

METHOD

Descriptive study of PH-related data from the multicentre RESCLE registry. Estimated systolic pulmonary artery pressure (esPAP), measured via echocardiogram was considered elevated if ≥ 35 mmHg. Left heart disease (LHD) and interstitial lung disease (ILD) were identified. When performed, data from right heart catheterisation (RHC) were collected.

RESULTS

esPAP was elevated in 350 of 808 patients (43.3%). One hundred and forty-four patients (17.8%) were considered to have PH (88 via RHC and the rest due to elevated esPAP along with evidence of significant LHD or ILD): PAH 3.7%, secondary to ILD 8.3%, secondary to LHD 2.8% and unclassified 3%. Prevalence of elevated esPAP was greater in diffuse SSc (dSSc) than in limited scleroderma (lSSc) (50.5 vs. 42.2%, p 0.046). In the group with elevated esPAP, a lower prevalence of anti-centromere antibodies (41.9% vs. 52.3%, p 0.006) and a greater prevalence of anti-topoisomerase-1 antibodies (ATA) (25.1% vs. 18.6%, p 0.04) were observed compared to the group with normal esPAP. Patients with elevated esPAP had a lower rate of digital ulcers (50.6% vs. 60.2%, p 0.007) and esophageal involvement (83.6% vs. 88.7%, p 0.07) and higher rate of renal crisis (4.6% vs. 1.8%, p 0.066).

CONCLUSIONS

Prevalence of PAH was lower than expected (3.7%). Probability of having elevated esPAP was higher among patients with dSSc and among those with ATA.

Right Ventricular Function is Associated With Quality of Life in Patients With Systemic Lupus Erythematosus Associated Pulmonary Arterial Hypertension

BACKGROUND

Right ventricular (RV) function has been identified as an important determinant of outcome in patients with pulmonary hypertension. We aimed to investigate the relationship between echocardiographic-derived RV function and health-related quality of life (HRQOL) in patients with systemic lupus erythematosus associated pulmonary arterial hypertension (SLE-APAH), and to identify the best echocardiographic parameter for evaluating RV function in these patients.

METHODS

Sixty (60) consecutive patients with SLE-APAH (all female, mean age 33.6±8.2years) were recruited from May 2013 to November 2014. Echocardiograph, right heart catheterisation, SLE disease activity index (SLEDAI), and functional status and SF-36 generic questionnaire were assessed.

RESULTS

Echocardiograph-derived RV systolic function was significantly correlated with haemodynamics (p<0.05), with tricuspid annular plane systolic excursion (TAPSE) showing the strongest correlation with pulmonary vascular resistance (R²=0.278, p<0.001) and cardiac index (R²=0.215, p<0.001). Patients with a TAPSE<17mm had a shorter 6-minute-walk-distance (6MWD), lower mixed venous oxygen saturation, and higher plasma N-terminal pro-brain natriuretic peptide (p<0.05). Patients with TAPSE <17mm had lower physical component summary (PCS) and mental component summary (MCS) scores than those with TAPSE ≥17mm (35.5±13.2 vs. 55.0±15.5; 46.3±15.3 vs. 64.8±18.8, respectively, all p<0.05). On multiple regression analysis, a TAPSE <17mm was independently related to lower PCS (β -15.797, 95% confidence interval [CI] -24.746 to -6.848, p=0.001) and lower MCS (β -12.887, 95% CI -24.018 to -1.755, p=0.024).

CONCLUSIONS

TAPSE is a useful index for RV function assessment, and is associated with HRQOL in patients with SLE-APAH.

The prevalence of pulmonary arterial hypertension before and after atrial septal defect closure at adult age: A systematic review

BACKGROUND

The development or persistence of pulmonary arterial hypertension (PAH) after atrial septal defect (ASD) closure at adult age is associated with a poor prognosis. The objective of this review was to investigate the prevalence of PAH before and after ASD closure and to identify factors that are associated with PAH.

METHODS

EMBASE and MEDLINE databases were searched for publications until March 2017. All studies reporting the prevalence of PAH or data on pulmonary artery pressures both before and after surgical or percutaneous ASD closure in an adult population (≥16 years of age) were included. Papers were methodologically checked and data was visualized in tables, bar charts and plots.

RESULTS

A total of 30 papers were included. The prevalence of PAH ranged from 29% to 73% before ASD closure and from 5% to 50% after closure; being highest in older studies, small study cohorts, and studies with high rates of loss to follow-up. The pooled systolic pulmonary artery pressure (PAP) was 43±13 before ASD closure and 32±10 after closure. The overall mean PAP was 34±10 before closure and 28±8 after closure. Studies with a higher mean PAP before closure and a higher mean age of the study cohort reported greater PAP reductions.

CONCLUSIONS

The prevalence of PAH and mean pulmonary pressures decreased in all studies, regardless of the mean age or pulmonary pressures of the cohort. The reported prevalence of PAH after ASD closure is substantial, although widely varying (5%-50%), which is likely affected by selection of the study cohort.

Atrial arrhythmias are associated with increased mortality in pulmonary arterial hypertension

Pulmonary arterial hypertension (PAH) is a deadly vascular disease, characterized by increased pulmonary arterial pressures and right heart failure. Considering prior non-US studies of atrial arrhythmias in PAH, this retrospective, regional multi-center US study sought to define more completely the risk factors and impact of paroxysmal and non-paroxysmal forms of atrial fibrillation and flutter (AF/AFL) on mortality in this disease. We identified patients seen between 2010 and 2014 at UPMC (Pittsburgh) hospitals with hemodynamic and clinical criteria for PAH or chronic thromboembolic pulmonary hypertension (CTEPH) and determined those meeting electrocardiographic criteria for AF/AFL. We used Cox proportional hazards regression with time-varying covariates to analyze the association between AF/AFL occurrence and survival with adjustments for potential cofounders and hemodynamic severity. Of 297 patients with PAH/CTEPH, 79 (26.5%) suffered from AF/AFL at some point. AF/AFL was first identified after PAH diagnosis in 42 (53.2%), identified prior to PAH diagnosis in 27 (34.2%), and had unclear timing in the remainder. AF/AFL patients were older, more often male, had lower left ventricular ejection fractions, and greater left atrial volume indices and right atrial areas than patients without AF/AFL. AF/AFL (whether diagnosed before or after PAH) was associated with a 3.81-fold increase in the hazard of death (95% CI 2.64-5.52, p < 0.001). This finding was consistent with multivariable adjustment of hemodynamic, cardiac structural, and heart rate indices as well as in sensitivity analyses of patients with paroxysmal versus non-paroxysmal arrhythmias. In these PAH/CTEPH patients, presence of AF/AFL significantly increased mortality risk. Mortality remained elevated in the absence of a high burden of uncontrolled or persistent arrhythmias, thus suggesting additional etiologies beyond rapid heart rate as an explanation. Future studies are warranted to confirm this observation and interrogate whether other therapies beyond rate and rhythm control are necessary to mitigate this risk.

Design of the exercise MRI evaluation of HIV-pulmonary arterial hypertension longitudinal determinants (EXALTED) trial

BACKGROUND

Pulmonary arterial hypertension (PAH) is a potentially serious cause of dyspnea and exercise limitation in patients with HIV infection. In this trial, we propose using exercise MRI in conjunction with cardiopulmonary testing to delineate PAH from other causes of cardiovascular dysfunction, identify individuals with exercise-induced PAH who are at high risk of developing resting PAH, and provide longitudinal estimates of progression of PAH and right ventricular function.

METHODS

In this prospective observational study, HIV patients with dyspnea and exercise limitation in the absence of identifiable causes and those who meet the inclusion criteria will be enrolled based on resting pulmonary artery pressure (≤ or >40 mmHg) on a screening echocardiogram and exercise limitation on the Modified Medical Research Council dyspnea scale. Patients without evidence of resting PAH will be enrolled into both rest and exercise MRI and cardiopulmonary testing protocol, whereas patients with evidence of PAH on resting echocardiograms will undergo only resting cardiac MRI studies to evaluate right ventricular function and fibrosis. Both patient subgroups will be followed for 24 months to obtain longitudinal progression of the disease. In a sub-study, we will further analyze inflammatory variables that may predict these changes, thus allowing early identification of these patients.

IMPLICATIONS AND CONCLUSIONS

This trial will be the first study to provide an understanding of the mechanisms underpinning the functional deterioration of the right ventricle in patients with HIV and will impart insight into the immune mediators of PAH progression and right ventricular functional deterioration in patients with HIV-PAH.

Diagnosing and managing scleroderma-related pulmonary arterial hypertension

Scleroderma is an uncommon autoimmune disease of unknown cause that may affect any organ system in the body. Patients with scleroderma are prone to developing pulmonary complications, including pulmonary arterial hypertension (PAH), that are the leading cause of death in this population. This article describes scleroderma-related PAH and its diagnosis and management.

Health-Related Quality of Life in Pulmonary Hypertension and Its Clinical Correlates: A Cross-Sectional Study

BACKGROUND

Health-related quality of life (HRQoL) impairment is common in pulmonary hypertension (PH), but its clinical predictors are not well established. This study aims to characterize the HRQoL of patients with pulmonary arterial hypertension (PAH) and other precapillary forms of PH (pcPH) and to explore its clinical correlates.

MATERIALS AND METHODS

A cross-sectional, observational study of patients with documented PAH and other forms of pcPH. Patients completed two patient-reported outcome measures (PROM): Cambridge Pulmonary Hypertension Outcome Review (CAMPHOR) and Nottingham Health Profile (NHP). Clinical characteristics were retrieved from electronic medical records.

RESULTS

Mean CAMPHOR and NHP scores for the study population were indicative of a moderate HRQoL impairment. Patients in World Health Organisation Functional Classes (WHO FC) III/IV showed significantly worse HRQoL. The main clinical correlates of HRQoL were WHO FC, 6-minute walking distance (6MWD), and Borg dyspnoea index. Overall quality of life (QoL), assessed through CAMPHOR's QoL domain, showed patterns comparable to HRQoL measured by both instruments.

CONCLUSIONS

HRQoL, measured by two different PROMs, is impaired in Portuguese patients with PAH and other forms of pcPH, particularly in patients with increased disease severity. WHO FC, 6MWD, and Borg dyspnoea index are highly correlated with HRQoL and QoL.

Lung Function, Inflammation, and Endothelin-1 in Congenital Heart Disease-Associated Pulmonary Arterial Hypertension

Background

Breathlessness is the most common symptom in people with pulmonary arterial hypertension and congenital heart disease (CHD‐APAH), previously thought to be caused by worsening PAH, but perhaps also by inflammation and abnormalities of lung function. We studied lung function and airway inflammation in patients with CHD‐APAH and compared the results with controls.

Methods and Results

Sixty people were recruited into the study: 20 CHD‐APAH, 20 CHD controls, and 20 healthy controls. Spirometry, gas transfer, whole body plethysmography and lung clearance index, 6‐minute walk distance, and medical research council dyspnea scoring were performed. Inflammatory markers and endothelin‐1 levels were determined in blood and induced sputum. The CHD‐APAH group had abnormal lung function with lung restriction, airway obstruction, and ventilation heterogeneity. Inverse correlations were shown for CHD‐APAH between medical research council dyspnea score and percent predicted peak expiratory flow (r=−0.5383, P=0.0174), percent predicted forced expiratory flow rate at 50% of forced vital capacity (r=−0.5316, P=0.0192), as well as for percent predicted forced expiratory volume in 1 s (r=−0.6662, P=0.0018) and percent predicted forced vital capacity (r=−0.5536, P=0.0186). The CHD‐APAH patients were more breathless with lower 6‐minute walk distance (360 m versus 558 m versus 622 m, P=0.00001). Endothelin‐1, interleukin (IL)‐β, IL‐6, IL‐8, tumor necrosis factor α, and vascular endothelial growth factor were significantly higher in CHD‐APAH than controls. Serum endothelin‐1 for CHD‐APAH correlated with airflow obstruction with significant negative correlations with percent predicted forced expiratory flow rate at 75% of forced vital capacity (r=−0.5858, P=0.0135).

Conclusions

Raised biomarkers for inflammation were found in CHD‐APAH. Significant abnormalities in airway physiology may contribute to the dyspnea but are not driven by inflammation as assessed by circulating and sputum cytokines. A relationship between increased serum endothelin‐1 and airway dysfunction may relate to its bronchoconstrictive properties.

Comparison of thermodilution and indirect Fick cardiac outputs in pulmonary hypertension

BACKGROUND

The accurate measurement of cardiac output (CO) is required in patients with pulmonary hypertension (PH).While both the thermodilution (TDCO) and indirect Fick (IFCO) methods are commonly used, there is little data comparing them in patients with PH.

METHODS

We performed a retrospective analysis of patients evaluated at our center. All patients who had right heart catheterization (RHC) within 3 months of an echocardiogram, and CO assessment by both TDCO and IFCO methods were included. Bland-Altman analysis was used to assess agreement between the two methods. We further evaluated their agreement in each sex, and within tertiles of age, BMI and TR severity. We investigated the correlation between each method of CO and objective parameters of right ventricular function on echocardiography.

RESULTS

In a cohort of 168 patients, the correlation between IFCO and TDCO was modest at (r = 0.61). On average, values for CO were lower with IFCO than with TDCO, by 0.62 L/min (95% CI -0.82, -0.40). This difference was greater for females: 0.86 L/min (95% CI -1.08, -0.63) and in the highest tertile of BMI: 0.97 L/min (95% CI -1.4, -0.55). Moderate and severe TR did not in general result in lower TDCO values. Echocardiographic parameters of right ventricular function were correlated more strongly with TDCO than with IFCO.

CONCLUSION

In PH patients, IFCO was substantially lower than TDCO on average, suggesting that these two techniques cannot be used interchangeably. TDCO correlated more strongly with echocardiographic measures of RV function, suggesting that it may be preferred over IFCO.

Risk Assessment in Pulmonary Arterial Hypertension Patients: The Long and Short of it

Pulmonary arterial hypertension (PAH) is a chronic and rapidly progressive disease that is characterized by extensive narrowing of the pulmonary vasculature, leading to increases in pulmonary vascular resistance, subsequent right ventricular dysfunction, and eventual death. There are currently multiple approved drugs—developed as single or combination therapies in the last few years—that have improved outcome and functionality in PAH. However, despite improvement in short-term survival with these new effective therapies, PAH remains an incurable disease with a median survival of 7 years (Figure 1).1 This chronic disease state may be characterized by morbid events such as hospitalizations that herald rapid disease progression and account for a significant disease burden (Figure 2).23 Physician ability to predict PAH disease progression is critical for determining optimal care of patients. Accurate risk assessment allows clinicians to determine the patient's prognosis, identify treatment goals, and monitor disease progression and the patient's response to treatment. Risk assessment for PAH patients should include a range of clinical, hemodynamic, and exercise parameters, performed in a serial fashion over the treatment course. Patient risk stratification can also help physicians better allocate treatment resources in settings where they are scarce. If widely adopted, risk prediction can enhance the consistency of treatment approaches across PAH practitioners and improve the timeliness of referral for lung transplantation. Hence, along with advancing PAH treatment options, comprehensive risk prediction is essential to make individualized treatment decisions in the current treatment era.

Several tools are currently available for assessing risk in PAH (Figure 3). These include the 2015 European Society of Cardiology/European Respiratory Society pulmonary hypertension guidelines' risk variables,4 the French registry equation,5 the National Institutes of Health risk equation,6 or a risk score such as the one derived from the Registry to Evaluate Early And Long-term PAH Disease Management.1 These registries and evaluations of clinical trial sets have provided important insights into the importance of both modifiable (eg, 6-minute walk distance, functional class, brain natriuretic peptide, and nonmodifiable (eg, age, gender, PAH etiology) risk factors that predict survival. The following review explores commonly cited risk factors, both modifiable and nonmodifiable, and their implications for patient outcomes.

Right ventricular involution: What can we learn from nature's model of compensated hypertrophy?

BACKGROUND

Right ventricular (RV) failure (RVF) is a vexing problem facing patients with various disease processes and carries a high mortality. RVF is a poorly understood phenomenon with limited treatment options. In mammalian fetal circulation, the right ventricle is the systemic ventricle. In neonates, however, the left ventricle assumes that role and gradually thickens compared with the right ventricle. This process, known as right ventricular involution (RVI), is poorly understood. We sought to define the time course and identify mechanisms involved in RVI.

METHODS

Wild-type mice were bred and sacrificed on day of life (DOL) 1, 4, 8, 16, and 30 to evaluate left ventricular (LV) and RV wall thickness and apoptosis. A terminal deoxynucleotidyl transferase nick-end labeling assay and RNA sequencing were performed to measure changes during RVI.

RESULTS

Morphometric analysis demonstrated the changes in RV and LV wall thickness occurring between DOL 1 and DOL 16 (RV:LV, 0.53:0.44; P = .03). In addition, apoptosis was most active early, with the highest percentage of apoptotic cells on DOL 1 (1.0%) and a significant decrease by DOL 30 (0.23%) (P = .02). Similarly, expression of the proapoptotic genes BCL2l11 and Pawr were increased at DOL 1, and the antiapoptotic genes Nol3 and Naip2 were significantly increased at DOL 30.

CONCLUSIONS

RVI is a misnomer, but significant changes occur early (by DOL 16) in neonatal mouse hearts. Apoptosis plays a role in RVI, but whether manipulation of apoptotic pathways can prevent or reverse RVI is unknown and warrants further investigation.

Hyperactive TGF-β Signaling in Smooth Muscle Cells Exposed to HIV-protein(s) and Cocaine: Role in Pulmonary Vasculopathy

We earlier demonstrated synergistic increase in the proliferation of pulmonary smooth muscle cells on exposure to HIV-proteins and/or cocaine due to severe down-modulation of bone morphogenetic protein receptor (BMPR) axis: the anti-proliferative arm of TGF-β super family of receptors. Here, now we demonstrate the effect of HIV-Tat and cocaine on the proliferative TGF-β signaling cascade. We observed a significant increase in the secretion of TGF-β1 ligand along with enhanced protein expression of TGFβ Receptor (TGFβR)-1, TGFβR-2 and phosphorylated SMAD2/3 in human pulmonary arterial smooth muscle cells on treatment with cocaine and Tat. Further, we noticed an increase in the levels of p-TAK1 complexed with TGFβR-2. Concomitant to this a significant increase in the activation of TAK1-mediated, SMAD-independent downstream signaling molecules: p-MKK4 and p-JNK was observed. However, activation of MKK3/6-p38MAPK, another axis downstream of TAK1 was found to be reduced due to attenuation in the protein levels of BMPR2. Both SMAD and non-SMAD dependent TGFβR cascades were found to contribute to hyper-proliferation. Finally the increase in the levels of phosphorylated TGFβR1 and TGFβR2 on exposure to HIV-proteins and cocaine was confirmed in pulmonary smooth muscle cells from cocaine injected HIV-transgenic rats and in total lung extracts from HIV infected cocaine and/or opioid users.

Effect of Body Position, Exercise, and Sedation on Estimation of Pulmonary Artery Pressure in Dogs with Degenerative Atrioventricular Valve Disease

Background

Severity of pulmonary hypertension (PH) in dogs is related to clinical signs and prognosis.

Hypothesis/Objectives

We hypothesized that Doppler echocardiographic (DE) indices of pulmonary artery pressure (PAP) and pulmonary vascular resistance (PVR) are influenced by independent factors that create clinically important variability of DE‐based estimates of PH in dogs.

Animals

Thirty‐eight client owned dogs with naturally acquired degenerative atrioventricular valve disease and tricuspid regurgitation (TR).

Methods

Dogs were prospectively enrolled, and target variables were acquired during 4 echocardiographic study periods (lateral recumbency, standing, lateral recumbency after a 6‐minute walk test [6MWT], and lateral recumbency after sedation with butorphanol 0.25 mg/kg IM). Statistical methods included repeated measures ANOVA, mixed model analysis, and Chi‐squared test of association.

Results

There was a significant increase in peak TR flow velocity (TRFV; P < 0.01) after sedation in 78% of dogs, with TRFV increasing by >0.4 m/s in 42% of dogs, independent of stroke volume. A significant effect of study period on DE‐estimated PVR was not found (P = 0.15). There were negligible effects of sonographer, body position, and 6MWT on echocardiographic variables of PH. Clinically relevant cyclic variation of TRFV was found. There was an association between estimation of right atrial pressure based on subjective assessment and estimation based on cranial vena cava collapsibility (P = 0.03).

Conclusions and Clinical Importance

The increase in TRFV observed with sedation could change assessment of PH severity and impact prognostication and interpretation of treatment response. Further studies with invasive validation are needed.

Replacing a phosphodiesterase-5 inhibitor with riociguat in patients with connective tissue disease-associated pulmonary arterial hypertension: a case series

Patients with pulmonary arterial hypertension associated with connective tissue disease (PAH-PAH-CTD) such as systemic sclerosis (SSc) have a poorer response to treatment and increased mortality compared with patients with idiopathic PAH. Current treatment options for PAH-CTD include prostanoids, phosphodiesterase type-5 inhibitors (PDE-5i), endothelin receptor antagonists, and the soluble guanylate cyclase stimulator riociguat. In this case series, we describe three patients with PAH-CTD related to limited scleroderma who were switched from a PDE-5i to riociguat due to insufficient clinical response. The switch to riociguat was associated with an improvement in respiratory and hemodynamic parameters and a favorable tolerability profile. These cases demonstrate that switching to riociguat is a therapeutic option in patients with PAH-CTD who have not achieved a satisfactory clinical response to a PDE-5i.