Integration of clinical and hemodynamic parameters in the prediction of long-term survival in patients with pulmonary arterial hypertension

Treatment of pulmonary arterial hypertension in patients with connective tissue diseases: a systematic review and meta-analysis

The evidence for the treatment of connective tissue disease-associated pulmonary arterial hypertension (CTD-PAH) mostly depends on subgroup or post hoc analysis of randomized controlled trials (RCTs). Thus, we performed a meta-analysis of RCTs that reported outcomes for CTD-PAH. PubMed and EMBASE were searched for CTD-PAH treatment. The selected outcomes were functional class (FC) change, survival rates, 6-min walk distance (6-MWD), clinical worsening (CW), N-terminal prohormone BNP (NT-proBNP), pulmonary vascular resistance (PVR), mean pulmonary arterial pressure (mPAP), right atrial pressure (RAP), and cardiac index (CI). The meta-analysis was conducted according to the PRISMA guidelines and registered in PROSPERO (CRD42020153560). Twelve RCTs conducted with 1837 patients were included. The diagnoses were systemic sclerosis in 59%, SLE in 20%, and other CTDs in 21%. The pharmacological interventions were epoprostenol, treprostinil, sildenafil, tadalafil, bosentan, macitentan, ambrisentan, riociguat, and selexipag. There was a significant difference between interventions and placebo in FC, 6MWD, CW, PVR, RAP, and CI that favored intervention. Our analysis showed a 39% reduction in the CW risk with PAH treatment. The short-term survival rates and mean serum NT-proBNP changes were similar between the study and control groups. Treatment for CTD-PAH had favorable effects on clinical and hemodynamic outcomes but not on survival and NT-proBNP levels. Different from the previous meta-analyses that focused on 6-MWD, time to clinical worsening, and CW as outcomes, this meta-analysis additionally reports the pooled analysis of change in FC, hemodynamic measurements (RAP, PVR, CI), and NT-proBNP, some of which have prognostic value for PAH.

Real-world evidence to advance knowledge in pulmonary hypertension: Status, challenges, and opportunities. A consensus statement from the Pulmonary Vascular Research Institute's Innovative Drug Development Initiative's Real-world Evidence Working Group

This manuscript on real-world evidence (RWE) in pulmonary hypertension (PH) incorporates the broad experience of members of the Pulmonary Vascular Research Institute's Innovative Drug Development Initiative Real-World Evidence Working Group. We aim to strengthen the research community's understanding of RWE in PH to facilitate clinical research advances and ultimately improve patient care. Herein, we review real-world data (RWD) sources, discuss challenges and opportunities when using RWD sources to study PH populations, and identify resources needed to support the generation of meaningful RWE for the global PH community.

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.

Echo-Doppler and strain assessment of filling pressures in adults with congenitally corrected transposition and systemic right ventricles

AIMS

Systolic dysfunction of the systemic right ventricle (sRV) is common in adults with transposition of the great arteries and sRV. In acquired disease, diastology analysis for assessment of filling pressures (FP) is paramount in patient care.

METHODS AND RESULTS

Retrospective analysis of 47 adults with sRV without prior systemic tricuspid valve surgery undergoing catheterization and echocardiography within 7 days (median -2 [-1, -3]) from January 2000 to February 2021 at our institution. Median age was 48 (31, 55) years, and 16 (34.0%) patients were female. FPs were normal in 21 patients (44.7%). Left atrial size was enlarged in most patients (83.0%) with mean indexed value 58.3 ± 23.4 mL/m2. Tissue Doppler e' was not significantly different between those with high FPs vs. normal (medial 0.07 ± 0.03 vs. 0.08 ± 0.03 m/s, P = 0.63; lateral 0.08 ± 0.04 vs. 0.08 ± 0.04 m/s, P = 0.88). E velocity and subpulmonic mitral regurgitant velocity were higher in those with high FPs (0.9 ± 0.3 vs. 0.6 ± 0.2 m/s, P = 0.005; 3.8 ± 1.1 vs. 2.8 ± 0.9 m/s, P = 0.004). Left atrial reservoir strain, sRV global longitudinal strain, and subpulmonic left ventricular strain were worse in those with high FP (18.0 ± 7.6 vs. 27.9 ± 10.2%, P = 0.0009; -13.0 ± 4.4 vs. -17.9 ± 5.0%, P = 0.002; -16.8 ± 5.7 vs. -23.0 ± 3.8%, P = 0.001).

CONCLUSION

Despite the complex anatomy, FPs can be assessed non-invasively in adults with sRV without prior systemic tricuspid valve surgery. The current guideline algorithm for diastolic dysfunction in acquired heart disease has limited applicability in this population. Given the limitations of Doppler in this heterogeneous population, strain analysis can be a helpful adjunct for estimation of FPs.

Low Pulmonary Artery Pulsatility Index by Echocardiography Is Associated With Increased Mortality in Pulmonary Hypertension

BACKGROUND

Pulmonary hypertension (PH) is a progressive pulmonary vascular disorder with elevated mortality risk. The pulmonary artery (PA) pulsatility index (PAPi) based on invasively acquired parameters has emerged as a hemodynamic risk predictor. Whether noninvasively derived PAPi (PA pulse pressure divided by right atrial pressure) is valuable is unclear.

METHODS

Consecutive patients undergoing transthoracic echocardiography for known or suspected PH were included with conventional echocardiographic measures of PA systolic, PA diastolic, and estimated right atrial pressures. In those patients with PH (mean PA pressure > 20 mm Hg), PAPi was divided into 3 groups: <1.5, 1.5 to 3, and >3. Mortality was assessed over 5 years.

RESULTS

Of 1,045 patients enrolled, 64% had PH. Patients with the lowest PAPi had higher N-terminal-pro hormone B-type natriuretic peptide levels, larger right ventricles (RVs), worse RV systolic function, and greater degrees of tricuspid regurgitation. In patients with PH, PAPi was inversely proportional to the risk of death, with PAPi <3 associated with a 1.96-fold increased risk of death (95% CI, 1.45-2.64, P < .0001). At multivariate analysis, RV longitudinal systolic strain (hazard ratio [HR] = 1.45, 1.24-1.71; P < .0001), PAPi <3 (HR = 1.76, 1.31-2.37; P = .0002), and the presence of a pericardial effusion (HR = 1.64, 1.20-2.26 P = .003) were independently associated with increased mortality. In age- and sex-adjusted models, PAPi was incremental to PA compliance.

CONCLUSIONS

In patients with PH, low PAPi derived noninvasively by transthoracic echocardiography is associated with markers of right heart failure, RV dysfunction, and worse survival. PAPi could be incorporated into the conventional echo parameters reported in patients with PH and may be a useful predictor of outcome.

Right Ventricular Enlargement and Dysfunction Are Associated With Increased All-Cause Mortality in Hypertrophic Cardiomyopathy

OBJECTIVE

To assess whether right ventricular enlargement (RVE) and right ventricular dysfunction (RVD) adversely affect prognosis in hypertrophic cardiomyopathy (HCM).

PATIENTS AND METHODS

Data were retrieved from Mayo Clinic's prospectively collected HCM registry between January 1, 2000, and September 30, 2012. Right ventricle (RV) size and function were semiquantitatively categorized via echocardiography as normal (RV-Norm) versus abnormal (RV-Abn) (RVE or RVD). All-cause mortality was the primary endpoint.

RESULTS

Of 1878 HCM patients studied (mean age 53±15 years; 41.6% female), only 71 (3.8%) had RV-Abn (24 RVE, 28 RVD, 19 combined RVE and RVD). Compared with HCM patients with RV-Norm, RV-Abn patients were older (57±14 vs 53±15 years, P=.02), more symptomatic (New York Heart Association functional class III-IV in 62.0% vs 48.6%, P=.03), had more atrial fibrillation (53.5% vs 17.3%, P<.001), and more prior implantable cardioverter-defibrillator implantation (23.9% vs 11.3%, P=.02). Median follow-up was 9.4 years with 311 deaths. Patients who were RV-Abn had higher all-cause mortality compared with RV-Norm (log-rank P<.001); 24.1% (95% CI, 15.5% to 35.3%) vs 6.1% (95% CI, 5.1% to 7.3%) at 5 years. In multivariable Cox modeling, RV-Abn (hazard ratio, 1.89; 95% CI, 1.18 to 3.03; P=.008) was associated independently with all-cause mortality after adjusting for age, female sex, New York Heart Association functional class, atrial fibrillation, hypertension, coronary artery disease, implantable cardioverter-defibrillator implantation, beta blocker use, prior septal reduction therapy, resting LV outflow tract gradient, maximal LV wall thickness, and moderate or greater tricuspid regurgitation.

CONCLUSION

Although perturbations in RV size and function were observed in fewer than 5% of patients with HCM, they were associated with nearly two-fold higher all-cause mortality at long-term follow-up.

Novel Approaches to Imaging the Pulmonary Vasculature and Right Heart

There is an increased appreciation for the importance of the right heart and pulmonary circulation in several disease states across the spectrum of pulmonary hypertension and left heart failure. However, assessment of the structure and function of the right heart and pulmonary circulation can be challenging, due to the complex geometry of the right ventricle, comorbid pulmonary airways and parenchymal disease, and the overlap of hemodynamic abnormalities with left heart failure. Several new and evolving imaging modalities interrogate the right heart and pulmonary circulation with greater diagnostic precision. Echocardiographic approaches such as speckle-tracking and 3-dimensional imaging provide detailed assessments of regional systolic and diastolic function and volumetric assessments. Magnetic resonance approaches can provide high-resolution views of cardiac structure/function, tissue characterization, and perfusion through the pulmonary vasculature. Molecular imaging with positron emission tomography allows an assessment of specific pathobiologically relevant targets in the right heart and pulmonary circulation. Machine learning analysis of high-resolution computed tomographic lung scans permits quantitative morphometry of the lung circulation without intravenous contrast. Inhaled magnetic resonance imaging probes, such as hyperpolarized 129Xe magnetic resonance imaging, report on pulmonary gas exchange and pulmonary capillary hemodynamics. These approaches provide important information on right ventricular structure and function along with perfusion through the pulmonary circulation. At this time, the majority of these developing technologies have yet to be clinically validated, with few studies demonstrating the utility of these imaging biomarkers for diagnosis or monitoring disease. These technologies hold promise for earlier diagnosis and noninvasive monitoring of right heart failure and pulmonary hypertension that will aid in preclinical studies, enhance patient selection and provide surrogate end points in clinical trials, and ultimately improve bedside care.

Mortality in Pulmonary Arterial Hypertension in the Modern Era: Early Insights From the Pulmonary Hypertension Association Registry

Background Current mortality data for pulmonary arterial hypertension (PAH) in the United States are based on registries that enrolled patients prior to 2010. We sought to determine mortality in PAH in the modern era using the PHAR (Pulmonary Hypertension Association Registry). Methods and Results We identified all adult patients with PAH enrolled in the PHAR between September 2015 and September 2020 (N=935). We used Kaplan-Meier survival analysis and Cox proportional hazards models to assess mortality at 1, 2, and 3 years. Patients were stratified based on disease severity by 3 validated risk scores. In treatment-naïve patients, we compared survival based on initial treatment strategy. The median age was 56 years (44-68 years), and 76% were women. Of the 935 patients, 483 (52%) were ≤6 months from PAH diagnosis. There were 121 deaths (12.9%) during a median follow-up time of 489 days (281-812 days). The 1-, 2-, and 3-year mortality was 8% (95% CI, 6%-10%), 16% (95% CI, 13%-19%), and 21% (95% CI, 17%-25%), respectively. When stratified into low-, intermediate-, and high-risk PAH, the mortality at 1, 2, and 3 years was 1%, 4% to 6%, and 7% to 11% for low risk; 7% to 8%, 11% to 16%, and 18% to 20% for intermediate risk; and 12% to 19%, 22% to 38%, and 28% to 55% for high risk, respectively. In treatment-naïve patients, initial combination therapy was associated with better 1-year survival (adjusted hazard ratio, 0.43 [95% CI, 0.19-0.95]; P=0.037). Conclusions Mortality in the intermediate- and high-risk patients with PAH remains unacceptably high in the PHAR, suggesting the importance for early diagnosis, aggressive use of available therapies, and the need for better therapeutics.

A Clinical Approach to Multimodality Imaging in Pulmonary Hypertension

Pulmonary hypertension (PH) is a clinical condition characterized by progressive elevations in mean pulmonary artery pressures and right ventricular dysfunction, associated with significant morbidity and mortality. For resting PH to develop, ~50-70% of the pulmonary vasculature must be affected, suggesting that even mild hemodynamic abnormalities are representative of advanced pulmonary vascular disease. The definitive diagnosis of PH is based upon hemodynamics measured by right heart catheterization; however this is an invasive and resource intense study. Early identification of pulmonary vascular disease offers the opportunity to improve outcomes by instituting therapies that slow, reverse, or potentially prevent this devastating disease. Multimodality imaging, including non-invasive modalities such as echocardiography, computed tomography, ventilation perfusion scans, and cardiac magnetic resonance imaging, has emerged as an integral tool for screening, classifying, prognosticating, and monitoring response to therapy in PH. Additionally, novel imaging modalities such as echocardiographic strain imaging, 3D echocardiography, dual energy CT, FDG-PET, and 4D flow MRI are actively being investigated to assess the severity of right ventricular dysfunction in PH. In this review, we will describe the utility and clinical application of multimodality imaging techniques across PH subtypes as it pertains to screening and monitoring of PH.

Sex Differences, Estrogen Metabolism and Signaling in the Development of Pulmonary Arterial Hypertension

Pulmonary arterial hypertension (PAH) is a complex and devastating disease with a poor long-term prognosis. While women are at increased risk for developing PAH, they exhibit superior right heart function and higher survival rates than men. Susceptibility to disease risk in PAH has been attributed, in part, to estrogen signaling. In contrast to potential pathological influences of estrogen in patients, studies of animal models reveal estrogen demonstrates protective effects in PAH. Consistent with this latter observation, an ovariectomy in female rats appears to aggravate the condition. This discrepancy between observations from patients and animal models is often called the "estrogen paradox." Further, the tissue-specific interactions between estrogen, its metabolites and receptors in PAH and right heart function remain complex; nonetheless, these relationships are essential to characterize to better understand PAH pathophysiology and to potentially develop novel therapeutic and curative targets. In this review, we explore estrogen-mediated mechanisms that may further explain this paradox by summarizing published literature related to: (1) the synthesis and catabolism of estrogen; (2) activity and functions of the various estrogen receptors; (3) the multiple modalities of estrogen signaling in cells; and (4) the role of estrogen and its diverse metabolites on the susceptibility to, and progression of, PAH as well as their impact on right heart function.

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.

Prediction Models and Scores in Pulmonary Hypertension: A Review

BACKGROUND

Pulmonary arterial hypertension (PAH) is a serious disease with increased morbidity and mortality. The need for an individualized patient treatment approach necessitates the use of risk assessment in PAH patients. That may include a range of hemodynamic, clinical, imaging and biochemical parameters derived from clinical studies and registry data.

OBJECTIVE

In the current systematic review, we summarize the available data on risk prognostic models and scores in PAH and we explore the possible concordance amongst different risk stratification tools in PAH.

METHODS

PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-Analyses) guidelines aided the performance of this systematic review. Eligible studies were identified through a literature search in the electronic databases PubMed, Science Direct, Google Scholar and Cochrane with the use of various combinations of MeSH and non-MeSH terms, with a focus on PAH.

RESULTS

Overall, 25 studies were included in the systematic review; out of them, 9 were studies deriving prognostic equations and risk scores and 16 were validating studies of an existing score. The majority of risk stratification scores use hemodynamic data for the assessment of prognosis, while others also include clinical and demographic variables in their equations. The risk discrimination in the overall PAH population was adequate, especially in differentiating the low versus high-risk patients, but their discrimination ability in the intermediate groups remained lower. Current ESC/ERS proposed risk stratification score utilizes a limited number of parameters with prognostic significance, whose prognostic ability has been validated in European patient populations.

CONCLUSION

Despite improvement in risk estimation of prognostic tools of the disease, PAH morbidity and mortality remain high, necessitating the need for the risk scores to undergo periodic re-evaluation and refinements to incorporate new data into predictors of disease progression and mortality and, thereby, maintain their clinical utility.

Validation of the REVEAL Prognostic Models in Systemic Lupus Erythematosus-Associated Pulmonary Arterial Hypertension

No previous studies have investigated the predictive performance of the Registry to Evaluate Early and Long-term Pulmonary Arterial Hypertension Disease Management (REVEAL) prognostic equation and simplified risk score calculator in patients with systemic lupus erythematosus-associated pulmonary arterial hypertension (SLE-PAH). We aimed to validate these prediction tools in an external cohort of patients with SLE-PAH. In this study, the validation cohort consisted of patients with SLE-PAH registered in a prospective, multicenter, nationwide database between November 2006 and May2016. The follow-up of patients was censored at 1 year. Discrimination, calibration, model fit, and risk stratification of the REVEAL prognostic equation and simplified risk score calculator were validated. As a result, a total of 306 patients with SLE-PAH were included. The 1-year overall survival rate was 91.5%. The C-index of the prognostic equation was 0.736, demonstrating reasonably good discrimination, and it was greater than that for the simplified risk score calculator (0.710). The overall calibration slope was 0.83, and the Brier score was 0.079. The risk of renal insufficiency and World Health Organization Functional Class III (WHO FC III) were underestimated, and the risk assigned to a heart rate >92 bpm in the REVEAL prognostic models was not observed in our validation cohort. Both model discrimination and calibration were poor in the very high-risk group. In conclusion, the REVEAL models exhibit good discriminatory ability when predicting 1-year overall survival in patients with SLE-PAH. Findings from both models should be interpreted with caution in cases of renal insufficiency, WHO FC III, and heart rate >92 bpm.

Reducing rates of readmission and development of an outpatient management plan in pulmonary hypertension: lessons from congestive heart failure management

Pulmonary hypertension currently has minimal guidelines for outpatient disease management. Congestive heart failure studies, however, have shown effectiveness of disease management plans in reducing all-cause mortality and all-cause and congestive heart failure-related hospital readmissions. Heart failure exacerbation is a common reason for readmission in both pulmonary hypertension and congestive heart failure. Our aim was to review individual studies and comprehensive meta-analyses to identify effective congestive heart failure interventions that can be used to develop similar disease management plans for pulmonary hypertension. A comprehensive literature review from 1993 to 2019 included original articles, systematic reviews, and meta-analyses. We reviewed topics of outpatient congestive heart failure interventions to decrease congestive heart failure mortality and readmission and patient management strategies in congestive heart failure. The most studied interventions included case management, multidisciplinary intervention, structured telephone strategy, and tele-monitoring. Case management showed decreased all-cause mortality at 12 months, all-cause readmission at 12 months, and congestive heart failure readmission at 6 and 12 months. Multidisciplinary intervention resulted in decreased all-cause readmission and congestive heart failure readmission. There was some discrepancy on effectiveness of tele-monitoring programs in individual studies; however, meta-analyses suggest tele-monitoring provided reduced all-cause mortality and risk of congestive heart failure hospitalization. Structured telephone strategy had similar results to tele-monitoring including decreased risk of congestive heart failure hospitalization, without effect on mortality. Extrapolating from congestive heart failure data, it seems strategies to improve the health of pulmonary hypertension patients and development of comprehensive care programs should include structured telephone strategy and/or tele-monitoring, case management strategies, and multidisciplinary interventions.

Development and validation of a web-based calculator to predict individualized conditional risk of site-specific recurrence in nasopharyngeal carcinoma: Analysis of 10,058 endemic cases

Background

Conditional survival (CS) provides dynamic prognostic estimates by considering the patients existing survival time. Since CS for endemic nasopharyngeal carcinoma (NPC) is lacking, we aimed to assess the CS of endemic NPC and establish a web‐based calculator to predict individualized, conditional site‐specific recurrence risk.

Methods

Using an NPC‐specific database with a big‐data intelligence platform, 10,058 endemic patients with non‐metastatic stage I–IVA NPC receiving intensity‐modulated radiotherapy with or without chemotherapy between April 2009 and December 2015 were investigated. Crude CS estimates of conditional overall survival (COS), conditional disease‐free survival (CDFS), conditional locoregional relapse‐free survival (CLRRFS), conditional distant metastasis‐free survival (CDMFS), and conditional NPC‐specific survival (CNPC‐SS) were calculated. Covariate‐adjusted CS estimates were generated using inverse probability weighting. A prediction model was established using competing risk models and was externally validated with an independent, non‐metastatic stage I–IVA NPC cohort undergoing intensity‐modulated radiotherapy with or without chemotherapy (n = 601) at another institution.

Results

The median follow‐up of the primary cohort was 67.2 months. The 5‐year COS, CDFS, CLRRFS, CDMFS, and CNPC‐SS increased from 86.2%, 78.1%, 89.8%, 87.3%, and 87.6% at diagnosis to 87.3%, 87.7%, 94.4%, 96.0%, and 90.1%, respectively, for an existing survival time of 3 years since diagnosis. Differences in CS estimates between prognostic factor subgroups of each endpoint were noticeable at diagnosis but diminished with time, whereas an ever‐increasing disparity in CS between different age subgroups was observed over time. Notably, the prognoses of patients that were poor at diagnosis improved greatly as patients survived longer. For individualized CS predictions, we developed a web‐based model to estimate the conditional risk of local (C‐index, 0.656), regional (0.667), bone (0.742), lung (0.681), and liver (0.711) recurrence, which significantly outperformed the current staging system (P < 0.001). The performance of this web‐based model was further validated using an external validation cohort (median follow‐up, 61.3 months), with C‐indices of 0.672, 0.736, 0.754, 0.663, and 0.721, respectively.

Conclusions

We characterized the CS of endemic NPC in the largest cohort to date. Moreover, we established a web‐based calculator to predict the CS of site‐specific recurrence, which may help to tailor individualized, risk‐based, time‐adapted follow‐up strategies.

Long-term outcomes in pulmonary arterial hypertension by functional class: a meta-analysis of randomized controlled trials and observational registries

Limited data about the long-term prognosis and response to therapy in pulmonary arterial hypertension patients with World Health Organization functional class I/II symptoms are available. PubMed and Embase were searched for publications of observational registries and randomized, controlled trials in pulmonary arterial hypertension patients published between January 2001 and January 2018. Eligible registries enrolled pulmonary arterial hypertension patients ≥18 years, N > 30, and reported survival by functional class. Randomized, controlled trial inclusion criteria were pulmonary arterial hypertension patients ≥18 years, ≥6 months of treatment, and morbidity, mortality, or time to worsening as end points reported by functional class. The primary outcomes were survival for registries and clinical event rates for randomized, controlled trials. Separate random effects models were calculated for registries and randomized, controlled trials. Four randomized, controlled trials (n = 2482) and 10 registries (n = 6580) were included. Registries enrolled 9%–47% functional class I/II patients (the vast majority being functional class II) with various pulmonary arterial hypertension etiologies. Survival rates for functional class I/II patients at one, two, and three years were 93% (95% confidence interval (CI): 91%–95%), 86% (95% CI: 82%–89%), and 78% (95% CI: 73%–83%), respectively. The hazard ratio for the treatment effect in randomized, controlled trials overall was 0.61 (95% CI: 0.51–0.74) and 0.60 (95% CI: 0.44–0.82) for functional class I/II patients and 0.62 (95% CI: 0.49–0.78) for functional class III/IV. The calculated risk of death of 22% within three years for functional class I/II patients underlines the need for careful assessment and optimal treatment of patients with functional class I/II disease. The randomized, controlled trial analysis demonstrates that current medical therapies have a beneficial treatment effect in this population.

Tetramethylpyrazine: A promising drug for the treatment of pulmonary hypertension

BACKGROUND AND PURPOSE

Tetramethylpyrazine (TMP) was originally isolated from the traditional Chinese herb ligusticum and the fermented Japanese food natto and has since been synthesized. TMP has a long history of beneficial effects in the treatment of many cardiovascular diseases. Here we have evaluated the therapeutic effects of TMP on pulmonary hypertension (PH) in animal models and in patients with pulmonary arterial hypertension (PAH) or chronic thromboembolic pulmonary hypertension (CTEPH).

EXPERIMENTAL APPROACH

Three well-defined models of PH -chronic hypoxia (10% O₂ )-induced PH (HPH), monocrotaline-induced PH (MCT-PH) and Sugen 5416/hypoxia-induced PH (SuHx-PH) - were used in Sprague-Dawley rats, and assessed by echocardiography, along with haemodynamic and histological techniques. Primary cultures of rat distal pulmonary arterial smooth muscle cells (PASMCs) were used to study intracellular calcium levels. Western blots and RT-qPCR assays were also used. In the clinical cohort, patients with PAH or CTEPH were recruited. The effects of TMP were evaluated in all systems.

KEY RESULTS

TMP (100 mg·kg^-1 ·day^-1 ) prevented rats from developing experimental PH and ameliorated three models of established PH: HPH, MCT-PH and SuHx-PH. The therapeutic effects of TMP were accompanied by inhibition of intracellular calcium homeostasis in PASMCs. In a small cohort of patients with PAH or CTEPH, oral administration of TMP (100 mg, t.i.d. for 16 weeks) increased the 6-min walk distance and improved the 1-min heart rate recovery.

CONCLUSION AND IMPLICATIONS

Our results suggest that TMP is a novel and inexpensive medication for treatment of PH. Clinical trial is registered with www.chictr.org.cn (ChiCTR-IPR-14005379).

Sex, Gender, and Sex Hormones in Pulmonary Hypertension and Right Ventricular Failure

Pulmonary hypertension (PH) encompasses a syndrome of diseases that are characterized by elevated pulmonary artery pressure and pulmonary vascular remodeling and that frequently lead to right ventricular (RV) failure and death. Several types of PH exhibit sexually dimorphic features in disease penetrance, presentation, and progression. Most sexually dimorphic features in PH have been described in pulmonary arterial hypertension (PAH), a devastating and progressive pulmonary vasculopathy with a 3-year survival rate <60%. While patient registries show that women are more susceptible to development of PAH, female PAH patients display better RV function and increased survival compared to their male counterparts, a phenomenon referred to as the "estrogen paradox" or "estrogen puzzle" of PAH. Recent advances in the field have demonstrated that multiple sex hormones, receptors, and metabolites play a role in the estrogen puzzle and that the effects of hormone signaling may be time and compartment specific. While the underlying physiological mechanisms are complex, unraveling the estrogen puzzle may reveal novel therapeutic strategies to treat and reverse the effects of PAH/PH. In this article, we (i) review PH classification and pathophysiology; (ii) discuss sex/gender differences observed in patients and animal models; (iii) review sex hormone synthesis and metabolism; (iv) review in detail the scientific literature of sex hormone signaling in PAH/PH, particularly estrogen-, testosterone-, progesterone-, and dehydroepiandrosterone (DHEA)-mediated effects in the pulmonary vasculature and RV; (v) discuss hormone-independent variables contributing to sexually dimorphic disease presentation; and (vi) identify knowledge gaps and pathways forward. © 2020 American Physiological Society. Compr Physiol 10:125-170, 2020.

The Role of Noninvasive Endpoints in Predicting Long-Term Outcomes in Pulmonary Arterial Hypertension

Background

Until recently, many clinical trials in patients with pulmonary arterial hypertension (PAH) evaluated exercise capacity with 6-minute walk distance (6MWD) as the primary endpoint. Common secondary endpoints include PAH functional class (FC), which assesses symptoms, and either brain natriuretic peptide (BNP) or the inactive N-terminal cleavage product of its prohormone (NT-proBNP), which assesses cardiac function.

Objective

Examine the relationships among 6MWD, FC, and BNP/NT-proBNP measured at baseline or follow-up with long-term outcomes in PAH studies.

Methods

Relevant literature from January 1990 to April 2018 were obtained by searching PubMed, Embase, and Cochrane. Articles in English reporting on associations between 6MWD, FC, or BNP/NT-proBNP and outcomes in PAH were identified. Each endpoint was evaluated individually. Prespecified inclusion and exclusion criteria were applied at level 1 (titles/abstracts) and level 2 (full-text review).

Results

The database search yielded 836 unique records; 65 full-text articles were reviewed. Twenty-five studies were eligible for inclusion. Findings supported the importance of measuring PAH noninvasive endpoints in predicting long-term outcomes. Patients with shorter or decreased 6MWD, poor (III/IV) or declining FC (e.g., from II to III), or elevated or increasing BNP/NT-proBNP had a higher risk of death and costly events (e.g., hospitalization, lung transplant). FC also predicted health care resource utilization and costs. Collectively, these endpoints establish risk groups that predict likelihood of complications from PAH or death.

Conclusion

Assessment of 6MWD, FC, and BNP/NT-proBNP provides low-cost, efficient, and noninvasive means of predicting long-term health and economic outcomes in patients with PAH.

Effects of 6-mercaptopurine in pressure overload induced right heart failure

Background

Several antineoplastic drugs have been proposed as new compounds for pulmonary arterial hypertension treatment but many have cardiotoxic side effects. The chemotherapeutic agent 6-mercaptopurine may have an effect in treatment of pulmonary arterial hypertension but at the same time, its effects on the afterload adaption of the right ventricle is unpredictable due to interaction with multiple downstream signalling pathways in the cardiomyocytes. We investigated the direct cardiac effects of 6-mercaptopurine in rats with isolated right heart failure caused by pulmonary trunk banding (PTB).

Methods

Male Wistar rat weanlings (112±2 g) were randomized to sham operation (sham, n = 10) or PTB. The PTB animals were randomized to placebo (PTB-control, n = 10) and 6-mercaptopurine (7.5 mg/kg/day) groups with treatment start before the PTB procedure (PTB-prevention, n = 10) or two weeks after (PTB-reversal, n = 10). Right ventricular effects were evaluated by echocardiography, cardiac MRI, invasive pressure-volume measurements, and histological and molecular analyses.

Results

PTB increased right ventricular afterload and caused right ventricular hypertrophy and failure. 6-mercaptopurine did not improve right ventricular function nor reduce right ventricular remodelling in both prevention and reversal studies compared with placebo-treated rats.

Conclusion

Treatment with 6-mercaptopurine did not have any beneficial or detrimental effects on right ventricular function or remodelling. Our data suggest that treatment of pulmonary arterial hypertension with 6-mercaptopurine is not harmful to the failing right ventricle.

Prognostic Importance and Predictors of Survival in Isolated Tricuspid Regurgitation: A Growing Problem

OBJECTIVE

To define mortality associated with isolated tricuspid regurgitation (TR) and identify risk factors associated with decreased survival.

PATIENTS AND METHODS

We conducted a retrospective cohort study of residents of southeastern Minnesota with moderate-severe or more severe isolated TR diagnosed between January 1, 2005, and April 15, 2015. Isolated TR was defined as TR in the absence of left-sided heart disease or pulmonary hypertension. Patients with an ejection fraction of less than 50%, right ventricular systolic pressure greater than 45 mm Hg, moderate or more severe left-sided valve disease, congenital cardiac anomalies, previous valve operation, tricuspid stenosis, flail leaflet, carcinoid, and rheumatic disease were excluded. Five-year survival was compared with age- and sex-matched Minnesota census bureau data. Multivariate regression was used to identify variables associated with mortality.

RESULTS

Over a 10-year period, 289 patients with isolated TR were identified. The mean ± SD age was 79.2±10.6 years, 70.6% (204) were women, atrial fibrillation was present in 74.0% (214), and 24.6% (71) had an intracardiac device. By 5 years after diagnosis, 51.5% had been hospitalized for heart failure. Observed 5-year mortality was 47.8% compared with 36.3% in the census data (P=.005). After adjusting for age and other comorbidities, multivariate regression identified a dilated inferior vena cava (≥2.1 cm) without respiratory variation on echocardiography (hazard ratio, 1.93; 95% CI, 1.13-3.31; P=.02) and creatinine level greater than 1.6 mg/dL (hazard ratio, 1.8; 95% CI, 1.16-2.8; P=.009) as associated with increased mortality.

CONCLUSION

Patients with isolated TR are frequently hospitalized for heart failure and experience excess mortality. Elevated right atrial pressure and renal dysfunction are associated with mortality. This poor outcome may have implications for timing of intervention.

Retrospective Validation of the REVEAL 2.0 Risk Score With the Australian and New Zealand Pulmonary Hypertension Registry Cohort

BACKGROUND

Pulmonary arterial hypertension (PAH) prognosis has improved with targeted therapies; however, the long-term outlook remains poor. Objective multiparametric risk assessment is recommended to identify patients at risk of early morbidity and mortality, and for optimization of treatment. The US Registry to Evaluate Early and Long-Term PAH Disease Management (REVEAL) 2.0 risk score is a new model proposed for the follow-up of patients with PAH but has not been externally validated.

METHODS

The REVEAL 2.0 risk score was applied to a mixed prevalent and incident cohort of patients with PAH (n = 1,011) from the Pulmonary Hypertension Society of Australia and New Zealand (PHSANZ) Registry. Kaplan-Meier survival was estimated for each REVEAL 2.0 risk score strata and for a simplified three-category (low, intermediate, and high risk) model. Sensitivity analysis was performed on an incident-only cohort.

RESULTS

The REVEAL 2.0 model effectively discriminated risk in the large external PHSANZ Registry cohort, with a C statistic of 0.74 (both for full eight-tier and three-category models). When applied to incident cases only, the C statistic was 0.73. The three-category REVEAL 2.0 model demonstrated robust separation of 12- and 60-month survival estimates (all risk category comparisons P < .001). Although the full eight-tier REVEAL 2.0 model separated patients at low, intermediate, and high risk, survival estimates overlapped within some of the intermediate- and high-risk strata.

CONCLUSIONS

The REVEAL 2.0 risk score was validated in a large external cohort from the PHSANZ Registry. The REVEAL 2.0 model can be applied for risk assessment of patients with PAH at follow-up. The simplified three-category model may be preferred for clinical use and for future comparison with other prognostic models.

[Risk stratification methods and their significance in pulmonary arterial hypertension]

Despite significant advances in therapy, pulmonary arterial hypertension (PAH) remains a progressive disease with a poor prognosis. Immediately after establishing the diagnosis of PAH, urgent treatment with PAH-specific therapy is required. Due to the progressive nature of the disease, all patients should be closely monitored and their treatment regimen should be promptly changed according to clinical need. Risk stratification is an important method for informing the clinician and the patient about the prognosis of disease and the choice of therapy methods. The REVEAL scale and the ESC/ERS 2015 risk assessment table are important multifactorial tools for making decisions about the prescription and correction of PAH therapy, as well as for assessment of patients' response to therapy. Current guidelines for PAH indicate that the most important task of treatment of PAH is to achieve the low - risk status.

Increasing Incidence and Prevalence of World Health Organization Groups 1 to 4 Pulmonary Hypertension: A Population-Based Cohort Study in Ontario, Canada

BACKGROUND

The World Health Organization recognizes 5 groups of pulmonary hypertension (PH), categorized by pathogenesis or comorbidity: 1-pulmonary arterial hypertension 2-left-heart disease, 3-lung disease and hypoxia 4-chronic thromboembolic disease, and 5-miscellaneous. The epidemiology of PH, apart from group 1, is largely unknown.

METHODS AND RESULTS

We describe incidence, prevalence, comorbidities, mortality and prescribing patterns for groups 1 to 4 PH from 1993 to 2012. Case definitions are based on hospitalizations and emergency department visits, using the Institute for Clinical Evaluative Sciences data, which comprises linked databases of universal coverage health service records for Ontario residents. This cohort included 50 529 patients with PH. The annual incidence of adult PH increased from 2003 to 2012 from 24.1 to 28.7 cases/100 000 population and the annual prevalence from 1993 to 2012 from 99.8 to 127.3 cases/100 000 population, respectively. The most common form of adult PH was group 2, alone (34.2%) or combined with group 3 PH (29.3%). A diagnosis of PH increased the 1-year standardized mortality ratio 7.2-fold. Mortality in adults with PH was 13.0%, 36.4%, and 62.4%, at 30 days, 1 year, and 5 years, respectively. Mortality was highest in groups 2 and 3 and lowest in group 1. PH was present in only 3.6% of people with left heart disease, 0.7% with lung disease, and 1.4% with thromboembolic disease, suggesting that PH is a relatively rare complication of these common diseases. Children (age<16 years) accounted for 3.6% of the cohort. In children group 1 PH was most common (65.2%), and 5-year mortality was lower (21.4%) than in adults. Group 1-specific PH therapies were increasingly prescribed over time and paradoxically were often used in patients who seemed to have group 2, PH based on diagnostic codes indicating left heart disease.

CONCLUSIONS

The incidence and prevalence of adult PH are increasing. Groups 2 and 3 are the most common and lethal forms of PH. This study identifies an emerging epidemic of PH that likely has substantial adverse health and economic implications.

Pulmonary arterial hypertension in Russia: six-year observation analysis of the National Registry

AIM

Assess the prevalence, clinical course, current therapy, and mortality in patients with pulmonary arterial hypertension (PAH) in the National Registry.

MATERIALS AND METHODS

In the prospective study we included patients over 18 years of age with diagnosed PAH [idiopathic PAH (IPAH); Drug- and Toxin-Induced Pulmonary Hypertension; inherited PAH; PAH associated with congenital heart disease (PAH-CHD); PAH associated with systemic connective tissue disease (PAH-CTD); PAH associated with HIV infection (PAH-HIV); with portal pulmonary hypertension (portoPAH)]. The observation was carried out in 15 expert centers of Russia from 01.01.2012 to 31.12.2017.

RESULTS

Our registry included 470 patients with PAH: IPAH - 41.5%, PAH-CHD - 36%, PAH-CTD - 19.5%, inherited PAH - 0.4%, portoPAH - 1.9%, PAH-HIV - 0.4%, Drug- and Toxin-Induced PAH - 0.4%. The prevalence among women was 84%. The mean age at the time of patient enrollment in the registry for the overall group of PAH was 42.7±15.3 years. The distance in the 6-minute walking test was 361.3±129.3 m. Among all patients with PAH, 65% had functional class (FC) III/IV at the time of diagnosis, among IPAH - 62%. 69.9% received PAH-specific therapy, of which 62.1% - monotherapy, 32.7% - dual combination therapy, and 5.2% triple therapy. Sildenafil is the most commonly prescribed drug in the regimen of monotherapy. 31.6% of patients were treated with bosentan, 6.4% - riociguat, 3.4% - ambrisentan, 2.1% - macitentan and 2.0% iloprost. Survival of patients with PAH was 98.9% at 1 year of follow-up, 94.1% at 3 years and 86.0% at 5 years.

CONCLUSION

The registry data indirectly indicates the need to increase efforts aimed at improving the diagnosis of systemic connective tissue diseases in adults, as well as congenital heart defects in children for timely surgical treatment. In recent years, PAH-specific drugs of the new generation have been introduced into clinical practice, but currently in Russia there are no parenteral prostanoids, which are recommended for the most severe patients.

The Use of Risk Assessment Tools and Prognostic Scores in Managing Patients with Pulmonary Arterial Hypertension

PURPOSE OF REVIEW

Pulmonary arterial hypertension (PAH) is a chronic, progressive, and incurable disease with significant morbidity and mortality. Despite increasingly available treatment options, PAH patients continue to experience disease progression and increased rates of hospitalizations due to right heart failure. Physician's ability to comprehensively assess PAH patients, determine prognosis, and monitor disease progression and response to treatment remains critical in optimizing outcomes.

RECENT FINDINGS

Risk assessment in PAH should include a range of clinical, hemodynamic, and exercise parameters, performed in a serial fashion over the course of treatment. Approaches to risk assessment in PAH patients include the use of risk variables, scores, and equations that stratify the impact of both modifiable (e.g., 6-min walk distance, functional class, brain natriuretic peptide), and non-modifiable (e.g., age, gender, PAH etiology) risk factors. Such tools allow physicians to better determine prognosis, allocate treatment resources, and enhance the consistency of treatment approaches across providers. Comprehensive and accurate risk prediction is essential to make individualized treatment decisions and optimizing outcomes in PAH.

Expert Council resolution on pulmonary arterial hypertension (PAH) "Changing the paradigm of treating patients with pulmonary arterial hypertension"

On behalf of the team of co-authors

EXPRESS: Statement on imaging and pulmonary hypertension from the Pulmonary Vascular Research Institute (PVRI)

Pulmonary hypertension (PH) is highly heterogeneous and despite treatment advances it remains a life-shortening condition. There have been significant advances in imaging technologies, but despite evidence of their potential clinical utility, practice remains variable, dependent in part on imaging availability and expertise. This statement summarizes current and emerging imaging modalities and their potential role in the diagnosis and assessment of suspected PH. It also includes a review of commonly encountered clinical and radiological scenarios, and imaging and modeling-based biomarkers. An expert panel was formed including clinicians, radiologists, imaging scientists, and computational modelers. Section editors generated a series of summary statements based on a review of the literature and professional experience and, following consensus review, a diagnostic algorithm and 55 statements were agreed. The diagnostic algorithm and summary statements emphasize the key role and added value of imaging in the diagnosis and assessment of PH and highlight areas requiring further research.

Relevance of the TAPSE/PASP ratio in pulmonary arterial hypertension

BACKGROUND

The ratio of echocardiography-derived tricuspid annular plane systolic excursion (TAPSE) and pulmonary arterial systolic pressure (PASP) has recently been reported as an independent prognostic parameter in heart failure. The TAPSE/PASP ratio has not been evaluated in detail in patients with pulmonary arterial hypertension (PAH).

METHODS

We analyzed TAPSE/PASP in 290 patients with PAH entered into the Giessen Pulmonary Hypertension Registry between November 2003 and July 2014. The prognostic relevance of TAPSE/PASP was assessed with multivariate Cox regression models, adjusting for clinical covariates, echocardiographic parameters, or hemodynamics, and was confirmed by Kaplan-Meier analyses.

RESULTS

When stratified by tertile of TAPSE/PASP (low: <0.19 mm/mmHg; middle: 0.19-0.32 mm/mmHg; high: >0.32 mm/mmHg), patients in the low tertile showed significantly compromised hemodynamic, functional, and echocardiographic status compared with patients in the middle and high tertiles. In all multivariate models, TAPSE/PASP remained independently associated with overall mortality: the hazard ratio (95% confidence interval) was 1.87 (1.35-2.59) when adjusting for clinical covariates (p < .001), 5.21 (2.17-12.5) when adjusting for echocardiographic parameters (p < .001), 1.92 (1.30-2.83) when adjusting for hemodynamics (p = .001), and 4.13 (2.02-8.48) when adjusting for a selection of previously identified independent echocardiographic and hemodynamic prognostic indicators (p < .001). Kaplan-Meier analyses showed better overall survival in the middle and high tertiles versus the low tertile (log-rank p < .001).

CONCLUSIONS

The TAPSE/PASP ratio is a meaningful prognostic parameter in patients with PAH and is associated with hemodynamics and functional class.

Risk stratification and medical therapy of pulmonary arterial hypertension

Pulmonary arterial hypertension (PAH) remains a severe clinical condition despite the availability over the past 15 years of multiple drugs interfering with the endothelin, nitric oxide and prostacyclin pathways. The recent progress observed in medical therapy of PAH is not, therefore, related to the discovery of new pathways, but to the development of new strategies for combination therapy and on escalation of treatments based on systematic assessment of clinical response. The current treatment strategy is based on the severity of the newly diagnosed PAH patient as assessed by a multiparametric risk stratification approach. Clinical, exercise, right ventricular function and haemodynamic parameters are combined to define a low-, intermediate- or high-risk status according to the expected 1-year mortality. The current treatment algorithm provides the most appropriate initial strategy, including monotherapy, or double or triple combination therapy. Further treatment escalation is required in case low-risk status is not achieved in planned follow-up assessments. Lung transplantation may be required in most advanced cases on maximal medical therapy.

State of the art and research perspectives on medical therapy of pulmonary arterial hypertension, including treatment algorithmhttp://ow.ly/4UkJ30md5GS

Bendopnea and Its Clinical Importance in Outpatient Patients with Pulmonary Arterial Hypertension

Purpose

Bendopnea is a recently reported novel symptom in patients with heart failure (HF) defined as shortness of breath when bending forward. It has been demonstrated that bendopnea is associated with advanced symptoms and worse outcomes. The aim of this study was to assess the presence of bendopnea and its clinical importance with regards to functional status, hemodynamic and echocardiographic characteristics in outpatient pulmonary arterial hypertension (PAH) patients.

Methods

We conducted this prospective observational study of 53 patients who were admitted to our PAH clinic for routine control visits. We determined the presence of bendopnea and analyzed hemodynamic parameters, World Heart Organization (WHO) functional class, transcutaneous oxygen saturation, 6-minute walking distance (6-MWD), N-terminal pro-brain natriuretic peptide (NT-proBNP) and right ventricular (RV) function indicators in patients with and without bendopnea.

Results

Bendopnea was present 33.9% of the PAH patients. The mean age was higher in the patients with bendopnea than in those without bendopnea, but the difference was not significant (p = 0.201). The patients with bendopnea had a lower 6-MWD and higher NT-proBNP level (p < 0.001), and worse WHO functional class symptoms (p = 0.010). Mean right atrial pressure, pulmonary artery pressure, and pulmonary vascular resistance were higher in the patients with bendopnea. The patients with bendopnea had a more dilated RV end-diastolic diameter and lower tricuspid annular plane systolic excursion value (p < 0.001 and p = 0.001, respectively).

Conclusions

Bendopnea was associated with worse functional capacity status, hemodynamic characteristics and RV function in our outpatient PAH patients.

Tolerability and clinical efficacy of inhaled treprostinil in patients with group 1 pulmonary arterial hypertension

Background

Treprostinil is a prostacyclin analogue that directly vasodilates pulmonary and systemic arterial vascular beds. The United States Food and Drug Administration approved inhaled treprostinil in July 2009 for the treatment of group 1 pulmonary arterial hypertension. Inhaled treprostinil avoids issues with continuous infusion prostanoids. This study describes a single institutional experience with inhaled treprostinil.

Methods

This was a retrospective review of group 1 pulmonary arterial hypertension patients receiving inhaled treprostinil from July 2009 through September 2015. Patient demographics, vital signs, prognostic indicators, pulmonary arterial hypertension assessments, treprostinil dosing, pulmonary arterial hypertension medications, and physician assessment were collected. Prognostic indicators and the physician assessment were used to assess treatment response. A modified Registry to Evaluate Early and Long-term Pulmonary Arterial Hypertension Disease Management (REVEAL) risk score was calculated prior to and after initiation of inhaled treprostinil.

Results

The mean time on inhaled treprostinil for the 16 patients was 21 ± 17 months. A total of 31% discontinued treatment. The New York Heart Association Functional Class, right ventricular size, and right ventricular function improved after inhaled treprostinil. Directional improvement in B-type natriuretic peptide, 6-minute walk distance, right arterial pressure and mean pulmonary artery pressure were also observed. The mean modified REVEAL risk score (RRS) was 7 ± 3 at baseline. The RRS decreased in 7 of the 11 patients that improved and remained stable in 2 patients.

Conclusion

The majority of patients in this consecutive series receiving inhaled treprostinil tolerated treatment. Most patients remained on therapy for over 12 months. Clinical assessments of disease severity all changed directionally toward improvement and the overall risk assessment was improved or stable in 56% by the RRS.

Pulmonary arterial hypertension: pathogenesis and clinical management

Pulmonary hypertension is defined as a resting mean pulmonary artery pressure of 25 mm Hg or above. This review deals with pulmonary arterial hypertension (PAH), a type of pulmonary hypertension that primarily affects the pulmonary vasculature. In PAH, the pulmonary vasculature is dynamically obstructed by vasoconstriction, structurally obstructed by adverse vascular remodeling, and pathologically non-compliant as a result of vascular fibrosis and stiffening. Many cell types are abnormal in PAH, including vascular cells (endothelial cells, smooth muscle cells, and fibroblasts) and inflammatory cells. Progress has been made in identifying the causes of PAH and approving new drug therapies. A cancer-like increase in cell proliferation and resistance to apoptosis reflects acquired abnormalities of mitochondrial metabolism and dynamics. Mutations in the type II bone morphogenetic protein receptor (BMPR2) gene dramatically increase the risk of developing heritable PAH. Epigenetic dysregulation of DNA methylation, histone acetylation, and microRNAs also contributes to disease pathogenesis. Aberrant bone morphogenetic protein signaling and epigenetic dysregulation in PAH promote cell proliferation in part through induction of a Warburg mitochondrial-metabolic state of uncoupled glycolysis. Complex changes in cytokines (interleukins and tumor necrosis factor), cellular immunity (T lymphocytes, natural killer cells, macrophages), and autoantibodies suggest that PAH is, in part, an autoimmune, inflammatory disease. Obstructive pulmonary vascular remodeling in PAH increases right ventricular afterload causing right ventricular hypertrophy. In some patients, maladaptive changes in the right ventricle, including ischemia and fibrosis, reduce right ventricular function and cause right ventricular failure. Patients with PAH have dyspnea, reduced exercise capacity, exertional syncope, and premature death from right ventricular failure. PAH targeted therapies (prostaglandins, phosphodiesterase-5 inhibitors, endothelin receptor antagonists, and soluble guanylate cyclase stimulators), used alone or in combination, improve functional capacity and hemodynamics and reduce hospital admissions. However, these vasodilators do not target key features of PAH pathogenesis and have not been shown to reduce mortality, which remains about 50% at five years. This review summarizes the epidemiology, pathogenesis, diagnosis, and treatment of PAH.

Prognostic value of three-dimensional echocardiographic right ventricular ejection fraction in patients with pulmonary arterial hypertension

Background

Right ventricular (RV) function is an independent predictor of clinical outcomes in patients with pulmonary arterial hypertension (PAH). However, it remains controversial which RV parameter should be measured as an appropriate index for the treatment of PAH. The aim of this study was to identify the most useful parameter that correlates with hemodynamics and predicts clinical outcomes in PAH.

Results

Most of the clinical and echocardiographic RV parameters were significantly correlated with pulmonary vascular resistance (PVR) as well as mean pulmonary arterial pressure (mPAP). Among these, three dimensional right ventricular ejection fraction (3DRVEF) showed the strongest hemodynamic correlation, followed by 6-minute walk distance. Receiver operating characteristic analysis of association with cardiac events including death, hospitalization, and intervention revealed a greater area under the curve for 3DRVEF than for mPAP (0.78 vs. 0.74). Kaplan-Meier analysis showed that patients with 3DRVEF less than 38% had significantly shorter event-free survival than those with greater than 38% (P = 0.0007). Finally, the Cox proportional hazards analysis revealed that 3DRVEF, but not mPAP, was an independent predictor of clinical events in PAH.

Materials and Methods

Eighty-six consecutive patients were enrolled in this study. RV hemodynamic parameters were measured by right heart catheterization (RHC). RV function was assessed using two-dimensional speckle-tracking echocardiography and three-dimensional transthoracic echocardiography (3DTTE) to evaluate RV free wall global strain (RVFS) and RVEF.

Conclusions

RVEF measured by 3DTTE could be a useful parameter for noninvasively assessing RV hemodynamics and predicting the clinical outcomes in PAH patients.

Pulmonary Arterial Hypertension and the Sex Hormone Paradox

PURPOSE OF REVIEW

Prevalence and outcome differences between women and men with pulmonary arterial hypertension (PAH) raise questions about the role of sex hormones in disease pathobiology. This review will summarize the current understanding of sex and sex hormone pathways and their influence on heart-lung function in health and in disease.

RECENT FINDINGS

Female sex has been shown to be a risk factor for the development of PAH, but women have improved survival compared to men with PAH. These paradoxical observations are likely driven in part by complex sex hormone signaling and processing pathways and their interaction with the pulmonary vasculature and the right ventricle. These relationships may vary depending on an individual's underlying sex, age, and/or genetic substrate. The study of the connections between sex, sex hormones, the pulmonary circulation, and the right ventricle may improve our understanding of disease epidemiology and outcomes and lead to new treatment strategies for PAH.

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.

Development of prognostic tools in pulmonary arterial hypertension: Lessons from modern day registries

Pulmonary arterial hypertension (PAH) is characterised by increased pressure in the pulmonary arteries leading to right-sided ventricular failure, and death. Identification of factors that affect patient survival is important to improve patient management and outcomes. The first registry to evaluate survival and develop a prognostic model was the National Institutes of Health (NIH) registry in 1981. Importantly this prognostic model is based on data collected prior to availability of PAH-targeted therapies and does not reflect survival rates for treated patients. Since the 1980s, however, four modern registries of PAH now exist which compensate for the NIH equations shortcomings and include the French National registry, Pulmonary Hypertension Connection registry, the Mayo registry, and the Registry to Evaluate Early and Long-Term PAH Disease Management (REVEAL). The similarities and difference in these registries are highlighted in this review and although similar in many respects, the four registries vary in patient population, including the numbers of newly and previously diagnosed patients, as well as the era of observation, period of survival, and timing of assessment of potential predictive factors. Despite this, the predictive factors identified in each registry and described in detail within the body of this manuscript share surprising homology in that disease aetiology, patient gender and factors reflective of right heart failure are integral in depicting survival. Future modifications of modern prognostic equations should be an ongoing goal of the PAH community in order to provide increased accuracy with identification of novel risk factors and prediction of disease course.

The prognostic significance of tricuspid valve regurgitation in pulmonary arterial hypertension

INTRODUCTION

Tricuspid valve regurgitation (TR) is a frequent finding in patients with pulmonary arterial hypertension (PAH). However, its prognostic significance and relation to PAH, while suspected, are poorly understood. We assessed 727 consecutive patients with newly diagnosed PAH who underwent transthoracic echocardiographic evaluation of tricuspid valve function.

OBJECTIVES

The study objective was to determine the association of TR presence and severity with patient characteristics, pulmonary artery hemodynamics and outcome.

METHODS

Consecutive patients with newly diagnosed PAH (N = 727 with group 1 pulmonary hypertension) underwent transthoracic echocardiographic evaluation of tricuspid valve function at diagnosis. The primary study end point was all-cause mortality or lung transplantation.

RESULTS

In this population, 702 patients (96.5%) had TR; in 165 patients (23%), TR was severe. Compared with those with no or mild TR by echocardiography criteria, patients with severe TR had shorter mean (SD) 6-minute walk distances (285 [125] m vs 360 [121] m; P = .02) and higher levels of B-type natriuretic peptide (695 [672] pg/dL vs 328 [300] pg/dL; P < .05). Severe TR was associated with greater right atrial dilatation (91% vs 47%; P = .004) and right ventricular (RV) dilatation (92% vs 51%; P = .008), greater right atrial pressure (mean [SD] 15 [7] mm Hg vs 10 [6] mm Hg; P < .001) and lower cardiac index (mean [SD], 2.2 [0.7] L/min/m2 vs 2.8 [0.9] L/min/m2; P < .001). Severe TR was strongly predictive of greater 5-year mortality risk after adjustment for age, sex, functional class, 6-minute walk distance, diffusing capacity, RV size and pulmonary vascular resistance index (adjusted hazard ratio, 1.83; 95% CI, 1.38-2.41; P < .001).

CONCLUSIONS

Severe TR was a significant predictor of long-term mortality rate in PAH, and TR severity correlated with PAH severity.

New paradigm for pulmonary arterial hypertension treatment

PURPOSE OF REVIEW

Pulmonary arterial hypertension (PAH) was previously considered a uniformly fatal disease, with patients succumbing to right heart failure and death at an average of 3 years after diagnosis. The past 20 years, however, have seen the development of numerous targeted therapies that have changed the natural history of PAH. As more pharmacologic agents have been approved and utilized, further advances in the design of and endpoints for clinical trials. This study will review some of these notable developments.

RECENT FINDINGS

The successful design and completion of long-term, event-driven trials is exemplified in three recent studies: SERAPHIN, GRIPHON, and AMBITION. SERAPHIN and GRIPHON evaluated the newer agents, macitentan, an endothelin receptor antagonist, and selexipag, a prostacyclin receptor agonist, respectively. Both trials were large-scale studies that, in addition to showing marked effect on the primary endpoint of morbidity/mortality, clearly demonstrated that assessment of long-term effects of PAH therapies is feasible for new compounds. The AMBITION study evaluated a treatment strategy, namely up-front combination therapy with tadalafil and ambrisentan compared with monotherapy and showed the combination approach to be superior at decreasing the likelihood of clinical failure.

SUMMARY

The evolution of clinical trials in PAH has direct implications for care of these patients. The short and long-term benefits of combination regimens suggest that the multidrug approach to PAH should, in fact, be standard of care for this disease.

Regulation of Pulmonary Vascular Smooth Muscle Contractility in Pulmonary Arterial Hypertension: Implications for Therapy

There are two primary components that produce pulmonary arterial hypertension (PAH); aberrant structural changes (smooth muscle cell proliferation, smooth muscle cell hypertrophy, and the deposition of matrix proteins within the media of pulmonary arterial vessels), and excess vasoconstriction. However, in PAH, the target and aim of all current therapeutic agents is to reduce the contractility of the pulmonary vasculature; prostaglandins, phosphodiesterase inhibitors, guanylate cyclase stimulators, endothelin antagonists, NO inhalation and Rho kinase inhibitors all influence signaling pathways in the pulmonary vascular smooth muscle to decrease vasoconstriction, and hence, pulmonary vascular resistance (PVR). This review will therefore primarily focus on discussing the signaling pathways regulating contractility in pulmonary vascular smooth muscle, the mechanism for current treatments, as well as highlighting potential targets for the development of novel therapies.

Trends in Pulmonary Hypertension Over a Period of 30 Years: Experience From a Single Referral Centre

INTRODUCTION AND OBJECTIVES

Pulmonary arterial hypertension (PAH) is characterized by increased pulmonary vascular resistance, right ventricular dysfunction and death. Despite scientific advances, is still associated with high morbidity and mortality. The aim is to describe the clinical approach and determine the prognostic factors of patients with PAH treated in a national reference center over 30 years.

METHODS

Three hundred and seventy nine consecutive patients with PAH (January 1984 to December 2014) were studied. Were divided into 3 periods of time: before 2004, 2004-2009 and 2010-2014. Prognostic factors (multivariate analysis) were analyzed for clinical deterioration.

RESULTS

Median age was 44 years (68.6% women), functional class III-IV: 72%. An increase was observed in more complex etiologies in the last period of time: Pulmonary venooclusive disease and portopulmonary hypertension. Upfront combination therapy significantly increased (5% before 2004 vs 27% after 2010; P < .05). Multivariate analysis showed prognostic significance in age, sex, etiology and combined clinical variables as they are independent predictors of clinical deterioration (P < .05). Survival free from death or transplantation for the 1st, 3rd and 5th year was 92.2%, 80.6% and 68.5% respectively. The median survival was 9 years (95% confidence interval, 7.532-11.959) CONCLUSIONS: The PAH is a heterogeneous and complex disease, the median survival free from death or transplantation in our series is 9 years after diagnosis. The structure of a multidisciplinary unit PAH must adapt quickly to changes that occur over time incorporating new diagnostic and therapeutic techniques.

Risk assessment in pulmonary arterial hypertension

Regular patient assessment is essential for the management of chronic diseases, such as pulmonary arterial hypertension (PAH). Comprehensive patient assessment and risk stratification in PAH are important to guide treatment decisions and to monitor disease progression as well as patients' response to treatment. Approaches for assessing risk in PAH patients include the use of risk variables, as recommended in the 2015 European Society of Cardiology (ESC)/European Respiratory Society (ERS) pulmonary hypertension (PH) guidelines, and the application of risk equations and scores, such as the French registry risk equation and the REVEAL registry risk score. Risk stratification and risk scores are both useful predictors of survival on a population basis, and provide an estimate for individual patients' risk. The 2015 ESC/ERS PH guidelines recommend regular assessment of multiple variables at an expert centre. The respective merits and limitations of different risk assessment methods in PAH are discussed in this article, as well as some considerations that can be taken into account in the future development of risk assessment tools.

Regular risk assessment with multiple parameters evaluates PAH disease progression and treatment responsehttp://ow.ly/Nq0I305kgpU

Surgical Treatment of Double Outlet Right Ventricle Complicated by Pulmonary Hypertension

Background:

Double outlet right ventricle (DORV) is a group of complex congenital heart abnormalities. Preoperative pulmonary hypertension (PH) is considered an important risk factor for early death during the surgical treatment of DORV. The aim of this study was to report our experience on surgical treatment of DORV complicated by PH.

Methods:

From June 2004 to November 2016, 61 patients (36 males and 25 females) aged 2 weeks to 26 years (median: 0.67 years and interquartile range: 0.42–1.67 years) with DORV (two great arteries overriding at least 50%) complicated by PH underwent surgical treatment in our center. All patients were categorized according to surgical age and lesion type, respectively. Pulmonary artery systolic pressure (PASP), pulmonary artery diastolic pressure (PADP), and mean pulmonary artery pressure (mPAP) were measured directly before cardiopulmonary bypass (CPB) was established and after CPB was removed. An intracardiac channel procedure was performed in 37 patients, arterial switch procedure in 19 patients, Rastelli procedure in three patient, Senning procedure in one patients, and Mustard procedure in one patient. The Student's t-test and Chi-squared test were performed to evaluate clinical outcomes of the surgical timing and operation choice.

Results:

Fifty-five patients had uneventful recovery. PASP fell from 55.3 ± 11.2 mmHg to 34.7 ± 11.6 mmHg (t = 14.05, P < 0.001), PADP fell from 29.7 ± 12.5 mmHg to 18.6 ± 7.9 mmHg (t = 7.39, P < 0.001), and mPAP fell from 40.3 ± 10.6 mmHg to 25.7 ± 8.3 mmHg (t = 11.85, P < 0.001). Six (9.8%) patients died owing to complications including low cardiac output syndrome in two patients, respiratory failure in two, pulmonary hemorrhage in one, and sudden death in one patient. Pulmonary artery pressure (PAP) dropped significantly in infant and child patients. Mortality of both infants (13.9%) and adults (33.3%) was high.

Conclusions:

PAP of patients with DORV complicated by PH can be expected to fall significantly after surgery. An arterial switch procedure can achieve excellent results in patients with transposition of the great arteries type. Higher incidence of complications may occur in patients with ventricular septal defect (VSD) type before 1 year of age. For those with remote VSD type, VSD enlargement and right ventricle outflow tract reconstruction are usually required with acceptable results. The degree of aortic overriding does not influence surgical outcome.