Survival in primary pulmonary hypertension. Validation of a prognostic equation

Prognostic Value of Serial Risk Stratification in Adult and Pediatric Pulmonary Arterial Hypertension: A Systematic Review

BACKGROUND

In pulmonary arterial hypertension, it is recommended to base therapeutic decisions on risk stratification. This systematic review aims to report the prognostic value of serial risk stratification in adult and pediatric pulmonary arterial hypertension and to explore the usability of serial risk stratification as treatment target.

METHODS AND RESULTS

Electronic databases PubMed, Embase, and Web of Science were searched up to January 30, 2023, using terms associated with pulmonary arterial hypertension, pediatric pulmonary hypertension, and risk stratification. Observational studies and clinical trials describing risk stratification at both baseline and follow-up were included. Sixty five studies were eligible for inclusion, including only 2 studies in a pediatric population. C-statistic range at baseline was 0.31 to 0.77 and improved to 0.30 to 0.91 at follow-up. In 53% of patients, risk status changed (42% improved, 12% worsened) over 168 days (interquartile range, 137-327 days; n=22 studies). The average proportion of low-risk patients increased from 18% at baseline to 36% at a median follow-up of 244 days (interquartile range, 140-365 days; n=40 studies). In placebo-controlled drug studies, risk statuses of the intervention groups improved more and worsened less compared with the placebo groups. Furthermore, a low-risk status, but also an improved risk status, at follow-up was associated with a better outcome. Similar results were found in the 2 pediatric studies.

CONCLUSIONS

Follow-up risk stratification has improved prognostic value compared with baseline risk stratification, and change in risk status between baseline and follow-up corresponded to a change in survival. These data support the use of serial risk stratification as treatment target in pulmonary arterial hypertension.

Mild elevation of pulmonary vascular resistance predicts mortality regardless of mean pulmonary artery pressure in mild interstitial lung disease

BACKGROUND

Pulmonary hypertension (PH) is defined by elevated mean pulmonary arterial pressure (MPAP), and elevated pulmonary vascular resistance (PVR) reflects pulmonary vascular abnormalities. The clinical significance of non-severe PH in patients with various interstitial lung diseases (ILDs) has not been fully elucidated. We aimed to investigate the clinical significance of MPAP and PVR for mortality in patients with newly diagnosed ILD.

METHODS

We retrospectively analysed consecutive patients with ILD at initial evaluations that included right heart catheterisation from 2007 to 2018. These patients were classified by MPAP and PVR using the 2022 the European Society of Cardiology (ESC)/the European Respiratory Society (ERS) guidelines for PH. The clinical significance of MPAP and PVR for mortality was analysed.

RESULTS

Among 854 patients, 167 (19.6%) had MPAP>20 mm Hg. The proportion of patients with PVR>2 Wood units (WU) among those with MPAP≤20 mm Hg, 202 WU was associated with a higher mortality rate (HR 1.61, 95% CI 1.28 to 2.02, p<0.0001) even in a group with MPAP≤20 mm Hg.

CONCLUSIONS

Mild elevation of PVR was associated with a higher mortality rate in patients with newly diagnosed ILD, even in those with MPAP≤20 mm Hg.

Demographic, hemodynamic characteristics, and therapeutic trends of pulmonary hypertension patients: The Pulmonary Hypertension Mexican registry (REMEHIP)

Data on demographic characteristics and therapeutic approaches in Latin American pulmonary arterial hypertension (PAH) patients are scarce. Pulmonary Hypertension Mexican registry (REMEHIP) is a multicenter Mexican registry of adult and pediatric patients, including prevalent and incident cases. Objective: assess clinical characteristics, treatment trends, and in-hospital outcomes. Inclusion: age >2 years, diagnosis of pulmonary hypertension (PH) (groups 1 and 4), right heart catheterization with mPAP ≥25 mmHg, PWP ≤ 15 mmHg, and PVR > 3 Wood unit (WU). We included 875 PH patients, 619 adults, 133 pediatric idiopathic PAH (IPAH), and 123 chronic thromboembolic pulmonary hypertension (CTEPH) patients. We enrolled 48.4% of the incident and 51.6% of the prevalent adult and pediatric patients. PAH adults: age 43 ± 15, females 81.9%, functional class (FC) (I/II) 66.5%, 6-min walk distance (6MWD) 378 ± 112 m, mPAP 57.3 ± 19.0 mmHg, confidence interval (CI) 3.3 ± 1.5 L/min/m2, PVR 12.0 ± 8.1 WU. PAH pediatrics: age 9 ± 5, females 51.1%, FC (I/II) 85.5%, 6MWD 376 ± 103 m, mPAP 49.7 ± 13.4 mmHg, CI 2.6 ± 0.9 L/min/m2, PVR 16.4 ± 13.5 WU. CTEPH: age 44 ± 17, females 56.1%, FC (I/II) 65.5%, 6MWD 369 ± 126 m, mPAP 49.7 ± 13.4 mmHg, CI 2.6 ± 0.9 L/min/m2, PVR 10.5 + 6.5 WU. When we analyzed the IPAH group separately, it sustained a high functional class I/II incidence. REMEHIP shows better functional class in young females with severe PAH than in American and European patients. Also, PAH pediatric patients had a better functional class than other registries. However, our registry also shows that our population's access to specific pharmacologic treatments is still far from optimal.

Natural history of chronic thromboembolic pulmonary disease with no or mild pulmonary hypertension

BACKGROUND

We describe baseline characteristics, disease progression and mortality in chronic thromboembolic pulmonary disease patients as a function of mean pulmonary artery pressure (mPAP) according to new and previous definitions of pulmonary hypertension.

METHODS

All patients diagnosed with chronic thromboembolic pulmonary disease between January, 2015 and December, 2019 were dichotomized according to initial mPAP: ≤ 20 mmHg ('normal') vs 21-24 mmHg ('mildly-elevated'). Baseline features were compared between the groups, and pairwise analysis performed to determine changes in clinical endpoints at 1-year, excluding those who underwent pulmonary endarterectomy or did not attend follow-up. Mortality was assessed for the whole cohort over the entire study period.

RESULTS

One hundred thirteen patients were included; 57 had mPAP ≤ 20 mmHg and 56 had mPAP 21-24 mmHg. Normal mPAP patients had lower pulmonary vascular resistance (1.6 vs 2.5WU, p < 0.01) and right ventricular end-diastolic pressure (5.9 vs 7.8 mmHg, p < 0.01) at presentation. At 3 years, no major deterioration was seen in either group. No patients were treated with pulmonary artery vasodilators. Eight had undergone pulmonary endarterectomy. Over 37 months median follow-up, mortality was 7.0% in the normal mPAP group and 8.9% in the mildly-elevated mPAP group. Cause of death was malignancy in 62.5% of cases.

CONCLUSIONS

Chronic thromboembolic pulmonary disease patients with mild pulmonary hypertension have statistically higher right ventricular end-diastolic pressure and pulmonary vascular resistance than those with mPAP ≤ 20 mmHg. Baseline characteristics were otherwise similar. Neither group displayed disease progression on non-invasive tests up to 3 years. Mortality over 37 months follow-up is 8%, and mainly attributable to malignancy. Further prospective study is required to validate these findings.

QSM Throughout the Body

Magnetic materials in tissue, such as iron, calcium, or collagen, can be studied using quantitative susceptibility mapping (QSM). To date, QSM has been overwhelmingly applied in the brain, but is increasingly utilized outside the brain. QSM relies on the effect of tissue magnetic susceptibility sources on the MR signal phase obtained with gradient echo sequence. However, in the body, the chemical shift of fat present within the region of interest contributes to the MR signal phase as well. Therefore, correcting for the chemical shift effect by means of water-fat separation is essential for body QSM. By employing techniques to compensate for cardiac and respiratory motion artifacts, body QSM has been applied to study liver iron and fibrosis, heart chamber blood and placenta oxygenation, myocardial hemorrhage, atherosclerotic plaque, cartilage, bone, prostate, breast calcification, and kidney stone.

Potential Prognostic Value of Native T1 in Pulmonary Hypertension Patients

Native T1, extracellular volume fraction (ECV), and late gadolinium enhancement (LGE) characterize myocardial tissue and relate to patient prognosis in a variety of diseases, including pulmonary hypertension. The purpose of this study was to evaluate if left ventricle (LV) fibrosis measurements have prognostic value for cardiac outcomes in pulmonary hypertension subgroups. 54 patients with suspected pulmonary hypertension underwent right-heart catheterization and were classified into pulmonary hypertension subgroups: pre-capillary component (PreCompPH) and isolated post-capillary (IpcPH). Cardiac magnetic resonance imaging (MRI) scans were performed with the acquisition of balanced cine steady-state free precession, native T1, and LGE pulse sequences to measure cardiac volumes and myocardial fibrosis. Associations between cardiac events and cardiac MRI measurements were analyzed within PreCompPH and IpcPH patients. IpcPH: LV native T1 was higher in patients who experienced a cardiac event within two years vs. those who did not. In patients with LV native T1 > 1050 ms, the rate of cardiac events was higher. ECV and quantitative LGE did not differ between groups. PreCompPH: native T1, ECV, and quantitative/qualitative LGE did not differ between patients who experienced a cardiac event within two years vs. those who did not. LV native T1 may have potential value for forecasting cardiac events in IpcPH, but not in PreCompPH, patients.

Right ventricular strain and volume analyses through deep learning-based fully automatic segmentation based on radial long-axis reconstruction of short-axis cine magnetic resonance images

OBJECTIVE

We propose a deep learning-based fully automatic right ventricle (RV) segmentation technique that targets radially reconstructed long-axis (RLA) images of the center of the RV region in routine short axis (SA) cardiovascular magnetic resonance (CMR) images. Accordingly, the purpose of this study is to compare the accuracy of deep learning-based fully automatic segmentation of RLA images with the accuracy of conventional deep learning-based segmentation in SA orientation in terms of the measurements of RV strain parameters.

MATERIALS AND METHODS

We compared the accuracies of the above-mentioned methods in RV segmentations and in measuring RV strain parameters by Dice similarity coefficients (DSCs) and correlation coefficients.

RESULTS

DSC of RV segmentation of the RLA method exhibited a higher value than those of the conventional SA methods (0.84 vs. 0.61). Correlation coefficient with respect to manual RV strain measurements in the fully automatic RLA were superior to those in SA measurements (0.5-0.7 vs. 0.1-0.2).

DISCUSSION

Our proposed RLA realizes accurate fully automatic extraction of the entire RV region from an available CMR cine image without any additional imaging. Our findings overcome the complexity of image analysis in CMR without the limitations of the RV visualization in echocardiography.

Quantitative susceptibility mapping (QSM) of the cardiovascular system: challenges and perspectives

Quantitative susceptibility mapping (QSM) is a powerful, non-invasive, magnetic resonance imaging (MRI) technique that relies on measurement of magnetic susceptibility. So far, QSM has been employed mostly to study neurological disorders characterized by iron accumulation, such as Parkinson's and Alzheimer's diseases. Nonetheless, QSM allows mapping key indicators of cardiac disease such as blood oxygenation and myocardial iron content. For this reason, the application of QSM offers an unprecedented opportunity to gain a better understanding of the pathophysiological changes associated with cardiovascular disease and to monitor their evolution and response to treatment. Recent studies on cardiovascular QSM have shown the feasibility of a non-invasive assessment of blood oxygenation, myocardial iron content and myocardial fibre orientation, as well as carotid plaque composition. Significant technical challenges remain, the most evident of which are related to cardiac and respiratory motion, blood flow, chemical shift effects and susceptibility artefacts. Significant work is ongoing to overcome these challenges and integrate the QSM technique into clinical practice in the cardiovascular field.

Time-Velocity Integral of Left Ventricular Outflow Tract Predicts Worse Long-Term Survival in Pulmonary Arterial Hypertension

BACKGROUND

The time-velocity integral of the left ventricular outflow tract (TVI_LVOT) has been demonstrated to correlate with heart failure hospitalization and mortality, but the association of TVI_LVOT with the severity and prognosis of pulmonary arterial hypertension (PAH) has not been evaluated.

OBJECTIVES

The aim of this study was to investigate the predictive value of baseline TVI_LVOT in PAH.

METHODS

A total of 225 consecutive patients with a diagnosis of incident PAH were prospectively studied and echocardiology-derived TVI_LVOT was measured at enrollment followed by right heart catheterization examination within 48 hours. Cox proportional hazards analysis was performed to assess the association between baseline variables and mortality.

RESULTS

During a median follow-up period of 33.8 months, 44 patients died of cardiovascular events. Baseline TVI_LVOT was significantly lower in the nonsurvivors compared with the survivors (P < 0.001). Baseline TVI_LVOT was positively correlated with stroke volume obtained by right heart catheterization (r = 0.709; P < 0.001), and inversely correlated with N-terminal pro-B-type natriuretic peptide (r = -0.533; P < 0.001), pulmonary vascular resistance (r = -0.423; P < 0.001). Multivariate analysis showed that baseline TVI_LVOT (hazard ratio: 0.856; 95% CI: 0.780-0.941; P = 0.001) was an independent predictor of cardiovascular mortality in PAH. Patients with a baseline TVI_LVOT <17.1 cm (median value) had a significantly worse survival than those with a baseline TVI_LVOT ≥17.1 cm (P < 0.001).

CONCLUSIONS

The findings of this study suggest that noninvasive TVI_LVOT provides a practical method to assess the severity and predict long-term outcome of PAH.

Prevalence, incidence, and survival of pulmonary arterial hypertension: A systematic review for the global burden of disease 2020 study

Pulmonary arterial hypertension (PAH) is characterized by increased resistance in the pulmonary arterioles as a result of remodeled blood vessels. We sought all available epidemiologic data on population‐based prevalence, incidence, and 1‐year survival of PAH as part of the Global Burden of Disease Study. We performed a systematic review searching Global Index Medicus (GIM) for keywords related to PAH between 1980 and 2021 and identified population‐representative sources of prevalence, incidence, and mortality for clinically diagnosed PAH. Of 6772 articles identified we found 65 with population‐level data: 17 for prevalence, 17 for incidence, and 58 reporting case fatality. Reported prevalence ranged from 0.37 cases/100,000 persons in a referral center of French children to 15 cases/100,000 persons in an Australian study. Reported incidence ranged from 0.008 cases/100,000 person‐years in Finland, to 1.4 cases/100,000 person‐years in a retrospective chart review at a clinic in Utah, United States. Reported 1‐year survival ranged from 67% to 99%. All studies with sex‐specific estimates of prevalence or incidence reported higher levels in females than males. Studies varied in their size, study design, diagnostic criteria, and sampling procedures. Reported PAH prevalence, incidence, and mortality varied by location and study. Prevalence ranged from 0.4 to 1.4 per 100,000 persons. Harmonization of methods for PAH registries would improve efforts at disease surveillance. Results of this search contribute to ongoing efforts to quantify the global burden of PAH.

A Feasibility Study on Using Single-Photon Emission Computed Tomography Pulmonary Perfusion/Ventilation Imaging for the Diagnosis of Chronic Thromboembolic Pulmonary Hypertension and Patient Risk Assessment

Objective

The study is designed to evaluate the diagnostic ability of single-photon emission computed tomography (SPECT) pulmonary ventilation/perfusion (V/Q) imaging in patients with chronic thromboembolic pulmonary hypertension (CTEPH) and investigate its feasibility in assessing patient risk.

Methods

A total of 83 patients suspected of having CTEPH who received V/Q tomography were retrospectively analyzed. The consistency between SPECT V/Q imaging and pulmonary angiography was compared to investigate the correlation between the percentage of pulmonary perfusion defect score (PPDs%) and the hemodynamic indices. Patients were grouped according to the pulmonary arterial hypertension risk stratification, and the V/Q imaging results were compared between different groups.

Results

For the 1494 pulmonary segments of the 83 patients, the sensitivity, specificity, and accuracy of identifying pulmonary segments with defects using V/Q imaging was 87.05%, 82.78% (668/807), and 84.74% (1266/1494), respectively. The average PPDs% (58.8 ± 12.6%) was positively correlated with the mean pulmonary arterial pressure (mPAP), pulmonary vascular resistance (PVR), and right ventricular pressure (RVP; r =0.316, 0.318, and 0.432, respectively; P < 0.05) and negatively correlated with the six-minute walk distance (6MWD; r = −0.309; P < 0.05). There were 37 patients in the low-risk group and 46 in the medium-high-risk group. The number of pulmonary segments with perfusion defects (NPSPDs) and PPDs% were higher in the medium-high risk than in the low-risk group (t = −6.721, −5.032; P < 0.05). In the low- and medium-high-risk groups, the cut-off values for the NPSPDs (7.2 ± 2.1 and 10.2 ± 2.0) and PPDs% (51.9 ± 11.1% and 64.3 ± 11.1%,) were 8.5 and 61.25%, respectively.

Conclusion

SPECT V/Q imaging achieved an accurate diagnosis of CTEPH. The semi-quantitative analysis index (PPDs%) was correlated with the hemodynamic indices and 6MWD. SPECT V/Q could be used for the preoperative risk assessment of patients with CTEPH.

The prognostic significance of the alterations of pulmonary hemodynamics in patients with pulmonary arterial hypertension: a meta-regression analysis of randomized controlled trials

BACKGROUND

Hemodynamic assessment in patients with pulmonary arterial hypertension (PAH) is essential for risk stratification and pharmacological management. However, the prognostic value of the hemodynamic changes after treatment is less well established.

OBJECTIVES

We investigated the prognostic impacts of the changes in hemodynamic indices, including mean pulmonary artery pressure (mPAP), pulmonary vascular resistance (PVR), right atrial pressure (RAP), and cardiac output index (CI). We conducted this systematic review with meta-regression analysis on existing clinical trials.

METHODS

We searched and identified all relevant randomized controlled trials from multiple databases. An analogous R² index was used to quantify the proportion of variance explained by each predictor in the association with PAH patients' prognosis. A total of 21 trials and 3306 individuals were enrolled.

RESULTS

The changes in mPAP, PVR, RAP, and CI were all significantly associated with the change in 6MWD (∆6MWD). The change in mPAP was with the highest explanatory power for ∆6MWD (R² analog = 0.740). Additionally, the changes in mPAP, PVR, and CI were independently predictive of adverse clinical events. The change in mPAP had the highest explanatory power for the clinical events (R² analog = 0.911). Furthermore, the change in PVR was with the highest explanatory power for total mortality of PAH patients (R² analog = 0.612).

CONCLUSION

Hemodynamic changes after treatment, including mPAP, PVR, CI, and RAP, were significantly associated with adverse clinical events or mortality in treated PAH patients. It is recommended that further studies be conducted to evaluate the changes in hemodynamic indices to guide drug titration.

SYSTEMATIC REVIEW REGISTRATION

PROSPERO CRD42019125157.

The Impact of Septoplasty on Cardiopulmonary Functions in Patients With Nasal Septal Deviation: A Prospective Comprehensive Analysis of Echocardiographic Outcome and Serum N-Terminal Pro BNP Levels

ABSTRACT

This study was designed to evaluate the impact of septoplasty on cardiopulmonary functions in patients with nasal septal deviation (NSD). A total of 30 consecutive adult patients (mean [standard deviation] age: 33.7 [10.9] years, 56.7% were males) who underwent septoplasty due NSD were included. Visual analog scale scores, nose obstruction symptom evaluation scale scores, serum N-terminal Pro BNP levels, and cardiologic examination findings on electrocardiogram, transthoracic echocardiography, and exercise treadmill testing were evaluated both 7 days before and 3-months after septoplasty operation. A significant decrease was noted in mean (standard deviation) visual analog scale scores (8.27 [0.83] versus 1.87 [0.73], P < 0.001), and nose obstruction symptom evaluation scores (83.7 [4.9] versus 12.7 [(5.4], P < 0.001) from preoperative to postoperative period, while maximum effort capacity was improved significantly (11.8 [1.9] versus 13.1 [2.1], P = 0.010) after septoplasty. Echocardiography findings at 3rd postoperative month revealed significant decrease in pulmonary artery systolic pressure (22.2 [3.2] versus 19.0 [3.6], P = 0.001), whereas significant increase in trans-mitral early diastolic rapid filling (E wave, 0.82 [0.14] versus 0.87 [0.13], P = 0.011), peak systolic velocity (S, 0.11 [0.02] versus 0.12 [0.02], P = 0.002), tricuspid annular plane systolic excursion (22.6 [3.2] versus 24.9 [2.9], P = 0.002), and right ventricle stroke volume (0.14 [(0.02] versus 0.15 [0.02], P = 0.013). In conclusion, our findings indicate favorable outcome of septoplasty in NSD patients not only in terms of improved nasal airflow but also cardiopulmonary functions, particularly the exercise capacity, pulmonary artery pressure, and right ventricular systolic functions. In this regard, our findings emphasize the important role of treating NSD patients without delay, given the likelihood of septoplasty to reverse the changes in the pulmonary artery system and to prevent onset of permanent cardiopulmonary dysfunction via amelioration of chronic obstruction of the upper respiratory tract.

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.

Serial T1 mapping of right ventricle in pulmonary hypertension: comparison with histology in an animal study

BACKGROUND

Right ventricular (RV) free wall fibrosis is an important component of adverse remodeling with RV dysfunction in pulmonary hypertension (PH). However, no previous reports have compared cardiovascular magnetic resonance (CMR) findings and histological analysis for RV free wall fibrosis in PH. We aimed to assess the feasibility of CMR T1 mapping with extracellular volume fraction (ECV) for evaluating the progression of RV free wall fibrosis in PH, and compared imaging findings to histological collagen density through an animal study.

METHODS

Among 42 6-week-old Wistar male rats, 30 were classified according to disease duration (baseline before monocrotaline injection, and 2, 4, 6 and 8 weeks after injection) and 12 were used to control for aging (4 and 8 weeks after the baseline). We obtained pre and post-contrast T1 maps for native T1 and ECV of RV and left ventricular (LV) free wall for six animals in each disease-duration group. Collagen density of RV free wall was calculated with Masson's trichrome staining. The Kruskall-Wallis test was performed to compare the groups. Native T1 and ECV to collagen density were analyzed with Spearman's correlation.

RESULTS

The mean values of native T1, ECV and collagen density of the RV free wall at baseline were 1541 ± 33 ms, 17.2 ± 1.3%, and 4.7 ± 0.5%, respectively. The values of RV free wall did not differ according to aging (P = 0.244, 0.504 and 0.331, respectively). However, the values significantly increased according to disease duration (P < 0.001 for all). Significant correlations were observed between native T1 and collagen density (r = 0.770, P < 0.001), and between ECV and collagen density for the RV free wall (r = 0.815, P < 0.001) in PH. However, there was no significant difference in native T1 and ECV values for the LV free wall according to the disease duration from the baseline (P = 0.349 and 0.240, respectively).

CONCLUSIONS

We observed significantly increased values for native T1 and ECV of the RV free wall without significant increase of the LV free wall according to the disease duration of PH, and findings were well correlated with histological collagen density.

Resistin-Like Molecule α Dysregulates Cardiac Bioenergetics in Neonatal Rat Cardiomyocytes

Heart (right) failure is the most frequent cause of death in patients with pulmonary arterial hypertension. Although historically, increased right ventricular afterload has been considered the main contributor to right heart failure in such patients, recent evidence has suggested a potential role of load-independent factors. Here, we tested the hypothesis that resistin-like molecule α (RELMα), which has been implicated in the pathogenesis of vascular remodeling in pulmonary artery hypertension, also contributes to cardiac metabolic remodeling, leading to heart failure. Recombinant RELMα (rRELMα) was generated via a Tet-On expression system in the T-REx 293 cell line. Cultured neonatal rat cardiomyocytes were treated with purified rRELMα for 24 h at a dose of 50 nM. Treated cardiomyocytes exhibited decreased mRNA and protein expression of peroxisome proliferator-activated receptor gamma coactivator 1α (PGC-1α) and transcription factors PPARα and ERRα, which regulate mitochondrial fatty acid metabolism, whereas genes that encode for glycolysis-related proteins were significantly upregulated. Cardiomyocytes treated with rRELMα also exhibited a decreased basal respiration, maximal respiration, spare respiratory capacity, ATP-linked OCR, and increased glycolysis, as assessed with a microplate-based cellular respirometry apparatus. Transmission electron microscopy revealed abnormal mitochondrial ultrastructure in cardiomyocytes treated with rRELMα. Our data indicate that RELMα affects cardiac energy metabolism and mitochondrial structure, biogenesis, and function by downregulating the expression of the PGC-1α/PPARα/ERRα axis.

Better Outcomes in Pulmonary Arterial Hypertension After Repair of Congenital Heart Disease, Compared With Idiopathic Pulmonary Arterial Hypertension

Background

Pulmonary vascular changes in postoperative pulmonary artery hypertension (PAH) are similar to those seen in idiopathic PAH. Data are sparse on direct comparative midterm outcomes for these 2 high-risk populations.

Methods

Patients with idiopathic or postoperative PAH referred to a large tertiary hospital between June 2005 and July 2019 were retrospectively evaluated.

Results

A total of 364 consecutive patients were studied, including 201 postoperative PAH patients and 163 patients with idiopathic PAH, with a median age of 18.7 (interquartile range 10.0, 31.5) and 7.3 (IQR: 2.9, 18.3) years, respectively. PAH-specific drugs were used in 77.7% of patients; 31.4% received combination therapy. Patients with idiopathic PAH had a shorter 6-mintue walk distance, lower percutaneous oxygen saturation, and higher B-type natriuretic peptide levels than those with postoperative PAH at diagnosis (all P < 0.001), During a median follow-up time of 3.4 (interquartile range: 2.1, 5.8) years, 56 patients (15.4%) died, and one underwent bilateral lung transplantation. Patients with postoperative PAH had better survival than those with idiopathic PAH, according to age (hazard ratio [HR] 0.128, 95% confidence interval [CI]: 0.07-0.22, P < 0.0001); Kaplan–Meier survival estimates at 5 years for idiopathic and postoperative PAH patients were 74.3% and 92.6%, respectively. Patients in New York Heart Association functional class III–IV had an over 4-fold increased risk of death (HR 4.85, 95% CI: 2.61-9.00, P < 0.0001). Patients < 18 years of age at idiopathic PAH diagnosis had a worse survival compared to adult patients (HR 6.90, 95% CI: 4.19-15.56, P = 0.040).

Conclusions

Postoperative-PAH patients had better midterm survival compared to patients with idiopathic PAH. Mortality was significant in both PAH groups, reinforcing the need for early diagnosis and optimal individualized management to improve outcomes.

Correlation Between Perfusion Abnormalities Extent in Ventilation/Perfusion SPECT/CT with Hemodynamic Parameters in Patients with Chronic Thromboembolic Pulmonary Hypertension

Objectives

Chronic thromboembolic pulmonary hypertension (CTEPH) is a type of pulmonary hypertension with persistent pulmonary vascular obstruction and exercise intolerance, which may benefit from pulmonary endarterectomy (PEA). Ventilation/perfusion (V/Q) scan is the preferred screening test of CTEPH, which can be used to assess the anatomical extent of the disease. This study aimed to analyze the correlation between the extent of mismatched Q defects in V/Q single photon emission computed tomography/computed tomography (SPECT/CT) with preoperative clinical and hemodynamic parameters in patients with CTEPH.

Methods

A total of 102 patients with CTEPH prior to PEA having V/Q SPECT/CT scans were retrospectively reviewed. Age, gender, New York Heart Association classification, intraoperative right-sided heart catheterization (mPAP and PVR), and 6-minute walk test (6MWT) findings were obtained from clinical records of patients.

Results

Linear regression analysis showed a significant but weak correlation between the preoperative mPAP and PVR with the extent of mismatched Q defects in V/Q SPECT/CT (rs=0.09474 with p=0.0016 and rs=0.045 with p=0.045, respectively). No significant correlation was found between 6MWT and extent of mismatched Q defects in V/Q SPECT/CT (p>0.05).

Conclusion

A quantitative assessment of Q defects on V/Q SPECT/CT might provide information about hemodynamic parameters in patients with CTEPH.

Parasympathetic modulation withdrawal improves functional capacity in pulmonary arterial hypertension

In 15 pulmonary arterial hypertension patients, the relation of functional capacity to their peripheral endothelial function and sympathaovagal modulation was studied by carrying out brachial artery ultrasound and electrocardiogram spectral analysis, respectively. The functional capacity was assessed by cardiopulmonary exercise testing and six-minute walking test. The sympathovagal modulation was correlated with the predicted peak oxygen consumption (peak VO₂ %; r = 0.692, P < 0.05), peak O₂ pulse (mL/beat; r = 0.661, P < 0.05), VE, minute ventilation, VCO₂ carbon dioxide production (VE/VCO₂ slope; r=-0.806, P < 0.01) and distance walked predicted (%6MWT; r = 0.694, P < 0.05). Moreover, there were negative correlations between parasympathetic modulation with peak VO₂ (r = 0.755, P < 0.01), peak VO₂% (r=-0.727, P < 0.01) and peak O₂ pulse (r = 0.615, P < 0.05), %6MWT (r=-0.834, P < 0.01). Collectively these correlations indicate that parasympathetic withdrawal is crucial for improving functional capacity. This conclusion is supported by both positive and negative correlations of parasympathetic modulation with the functional capacity parameters. The sympathetic modulation predominance, although increases the cardiovascular risk, is probably crucial to facilitate the bronchodilation and the oxygen uptake.

Patient-Specific Computational Analysis of Hemodynamics and Wall Mechanics and Their Interactions in Pulmonary Arterial Hypertension

Vascular wall stiffness and hemodynamic parameters are potential biomechanical markers for detecting pulmonary arterial hypertension (PAH). Previous computational analyses, however, have not considered the interaction between blood flow and wall deformation. Here, we applied an established computational framework that utilizes patient-specific measurements of hemodynamics and wall deformation to analyze the coupled fluid-vessel wall interaction in the proximal pulmonary arteries (PA) of six PAH patients and five control subjects. Specifically, we quantified the linearized stiffness (E), relative area change (RAC), diastolic diameter (D), regurgitant flow, and time-averaged wall shear stress (TAWSS) of the proximal PA, as well as the total arterial resistance (R t ) and compliance (C t ) at the distal pulmonary vasculature. Results found that the average proximal PA was stiffer [median: 297 kPa, interquartile range (IQR): 202 kPa vs. median: 75 kPa, IQR: 5 kPa; P = 0.007] with a larger diameter (median: 32 mm, IQR: 5.25 mm vs. median: 25 mm, IQR: 2 mm; P = 0.015) and a reduced RAC (median: 0.22, IQR: 0.10 vs. median: 0.42, IQR: 0.04; P = 0.004) in PAH compared to our control group. Also, higher total resistance (R t ; median: 6.89 mmHg × min/l, IQR: 2.16 mmHg × min/l vs. median: 3.99 mmHg × min/l, IQR: 1.15 mmHg × min/l; P = 0.002) and lower total compliance (C t ; median: 0.13 ml/mmHg, IQR: 0.15 ml/mmHg vs. median: 0.85 ml/mmHg, IQR: 0.51 ml/mmHg; P = 0.041) were observed in the PAH group. Furthermore, lower TAWSS values were seen at the main PA arteries (MPAs) of PAH patients (median: 0.81 Pa, IQR: 0.47 Pa vs. median: 1.56 Pa, IQR: 0.89 Pa; P = 0.026) compared to controls. Correlation analysis within the PAH group found that E was directly correlated to the PA regurgitant flow (r = 0.84, P = 0.018) and inversely related to TAWSS (r = -0.72, P = 0.051). Results suggest that the estimated elastic modulus E may be closely related to PAH hemodynamic changes in pulmonary arteries.

The systolic pulmonary artery pressure and the E/e' ratio decrease after septoplasty in patients with grade 2 and 3 pure nasal septal deviation

INTRODUCTION

Nasal septal deviation may contribute to a wide range of symptoms including nasal obstruction, headache, increased secretion, crusting, mucosal damage, and loss of taste and smell. Excessive increase in the respiratory resistance, as seen in nasal septal deviation, results in reduced lung ventilation, thereby potentially leading to hypoxia, hypercapnia, pulmonary vasoconstriction. The deformities in the nasal cavity can be associated with major respiratory and circulatory system diseases.

OBJECTIVE

To investigate cardiovascular effects of septoplasty by comparing pre- and postoperative transthoracic echocardiography findings in nasal septal deviation patients undergoing septoplasty.

METHODS

The prospective study included 35 patients with moderate and severe nasal septal deviation (mean age, 23.91±7.01) who underwent septoplasty. The Turkish version of the nasal obstruction symptom evaluation, NOSE questionnaire, was administered to each participant both pre- and postoperatively in order to assess their views on the severity of nasal septal deviation, the effect of nasal obstruction, and the effectiveness of surgical outcomes. A comprehensive transthoracic echocardiography examination was performed both preoperatively and at three months postoperatively for each patient and the findings were compared among patients.

RESULTS

Mean preoperative NOSE score was 17.34±1.62 and the mean postoperative score was 2.62±1.68 (p=0.00). Mean preoperative systolic pulmonary artery pressure value was 22.34±4.31mmHg and postoperative value was 18.90±3.77mmHg (p=0.00). Mean E/e' ratio was 5.33±1.00 preoperatively and was 5.01±0.90 postoperatively (p=0.01). The NOSE scores, systolic pulmonary artery pressure values, and the E/e' ratios decreased significantly after septoplasty (p<0.05 for all), whereas no significant difference was found in other transthoracic echocardiography parameters (p>0.05).

CONCLUSION

The decrease in NOSE scores following septoplasty indicated that the satisfaction levels of the patients were increased. Upper airway obstruction secondary to nasal septal deviation may be a cardiovascular risk factor and may affect transthoracic echocardiography measurements. Moreover, the significant decrease in the systolic pulmonary artery pressure value and E/e's ratio following septoplasty indicated that negative echocardiographic findings may be prevented by this surgery.

Prognostic Impact of the Pulmonary Artery Pulsatility Index in Patients with Chronic Heart Failure and Severe Mitral Regurgitation Undergoing Percutaneous Edge-to-Edge Repair

BACKGROUND

Pulmonary artery (PA) pulsatility index (PAPi), calculated as (PA systolic pressure - PA diastolic pressure)/right atrial pressure, emerged as a novel predictor of right ventricular failure in patients with acute inferior myocardial infarction, advanced heart failure, and severe pulmonary hypertension. However, the prognostic utility of PAPi in transcatheter mitral valve repair (TMVR) using the MitraClip® system has never been tested.

OBJECTIVE

To assess the prognostic impact of PAPi in patients with severe functional mitral regurgitation (MR) and chronic heart failure (CHF) undergoing TMVR.

METHODS

Consecutive patients with severe functional MR (grade 3+ or 4+) and CHF who underwent successful TMVR (MR ≤2+ at discharge) were enrolled and divided into 3 groups according to PAPi (A: low PAPi ≤2.2; B: intermediate PAPi 2.21-3.99; C: high PAPi ≥4.0). The primary endpoint was a composite of all-cause mortality and rehospitalization due to CHF during a mean follow-up period of 16 ± 4 months. The impact of PAPi on prognosis was assessed by a receiver-operating characteristic (ROC) analysis and a multivariable Cox proportional hazard regression analysis investigating independent predictors for outcome.

RESULTS

78 patients (A: n = 27, B: n = 28, C: n = 23) at high operative risk (logistic EuroSCORE [European System for Cardiac Operative Risk Evaluation] 18.8 vs. 21.5 vs. 20.6%; nonsignificant) were enrolled. Mean PAPi was 1.6 ± 0.41 vs. 2.9 ± 0.53 vs. 6.8 ± 3.5; p < 0.001). Patients with low PAPi showed significantly higher rates of early rehospitalization for heart failure at the 30-day follow-up (14.9 vs. 7.1 vs. 4.3%; p = 0.04). In the long term, a significantly lower event-free survival for the combined primary endpoint was observed in the low PAPi group (44.4 vs. 25.0 vs. 20.3%; log-rank p = 0.016). ROC curve analysis revealed that optimal sensitivity and specificity were achieved using a PAPi cutoff of 2.46 (sensitivity 83%, specificity 78.3%, area under the curve 0.82 [0.64-0.99]; p = 0.01). In Cox regression analysis, PAPi ≤2.46 was an independent predictor for the combined primary endpoint (hazard ratio 2.85; 95% confidence interval 1.15-7.04; p = 0.023).

CONCLUSIONS

PAPi is strongly associated with clinical outcome among patients with CHF and functional MR undergoing TMVR. A PAPi value ≤2.46 predicts a worse prognosis independent of other important clinical, echocardiographic, and hemodynamic factors. Therefore, PAPi may serve as a new parameter to improve patient selection for TMVR.

Long-term changes of exercise hemodynamics and physical capacity in chronic thromboembolic pulmonary hypertension after pulmonary thromboendarterectomy

BACKGROUND

A substantial number of chronic thromboembolic pulmonary hypertension (CTEPH) patients experience dyspnea on exertion and limited exercise capacity despite surgically successful pulmonary endarterectomy (PEA). We sought to prospectively evaluate resting and peak exercise hemodynamics before, 3 and 12 months after PEA in consecutive CTEPH-patients and correlate it to physical functional capacity.

METHODS AND RESULTS

Twenty consecutive CTEPH-patients were examined. Twelve months after PEA, 75% of patients with severely increased pre-PEA mean pulmonary arterial pressure (mPAP) at rest had normal or mildly increased mPAP. However, mPAP reduction was less pronounced during exercise where only 45% had normal or mildly increased mPAP at 12 months. Hemodynamic changes during exercise were tested using the pressure-flow relationship (i.e. mPAP/cardiac output (CO) slope). The average mPAP/CO slope was 7.5 ± 4.2 mm Hg/L/min preoperatively and 3.9 ± 3.0 mm Hg/L/min at 12 months (p < .005). CO reserve (CO increase from rest to peak exercise) was increased (5.7 ± 2.9 L/min) 12 months after PEA compared with pre-PEA (2.5 ± 1.8 L/min), p < .0001. However, 12 months after PEA, the CO reserve was only 49% of that of healthy controls, p < .0001. Changes in cardiac output (∆CO), calculated as the difference between CO before PEA and 12 months later, were significantly correlated with six-minute-walk-test and peak oxygen uptake (VO2), both at rest and peak exercise.

CONCLUSION

Invasive exercise hemodynamic examination in CTEPH-patients demonstrates that after otherwise successful PEA surgery, >50% of patients have a significant increase in exercise mPAP, and the CO reserve remains compromised 12 months after PEA. Improvement in physical capacity is correlated with ∆CO.

Nocturnal hypoxia in patients with idiopathic pulmonary arterial hypertension

Background

Sleep-disordered breathing causes a variety of cardiovascular complications and increases the risk of a poor prognosis in patients. There is still some controversy regarding the clinical diagnosis and treatment of sleep-disordered breathing in patients with pulmonary hypertension. The aim of this study was to determine the incidence of desaturation in idiopathic pulmonary arterial hypertension (IPAH) patients, evaluate the effect of desaturation on the clinical status of patients with IPAH, and identify possible influencing factors.

Methods

Patients with IPAH diagnosed by right heart catheterization who underwent overnight cardiorespiratory monitoring from January 2018 to July 2019 were enrolled. Nocturnal hypoxic time was defined as the time that oxygen saturation remained below 90%. Desaturation was defined as a nocturnal oxygen saturation level less than 90% for more than 10% of the total recording time. Baseline clinical characteristics and parameters were collected to compare IPAH patients with and without desaturation. In addition, logistic regression was performed to identify possible factors associated with desaturation in IPAH patients.

Results

Fifty patients with IPAH were included. Among them, 17 patients presented desaturation. Patients with desaturation were older, had a shorter six-min walking distance (6MWD), had a higher mean right atrial pressure, and had a lower daytime arterial oxygen partial pressure than patients without desaturation, and there were significant differences in the VE/VCO₂ and VE/VCO₂ slope (P < 0.05). The multivariate logistic regression analysis indicated that the 6 MWD (OR = 0.971, 95% CI: 0.948-0.994, P = 0.013) and; VE/VCO₂ slope (OR = 1.095, 95% CI: 1.010-1.307, P = 0.032) were independently associated with desaturation after adjusting for age, sex, and body mass index.

Conclusion

Nocturnal hypoxia is common in IPAH patients. Desaturation may aggravate the clinical situation of patients with IPAH. In IPAH patients, a poor exercise capacity (6 MWD) and the VE/VCO₂ slope can predict desaturation after adjusting for age, sex, and body mass index.

Supra-coronary aortic banding improves right ventricular function in experimental pulmonary arterial hypertension in rats by increasing systolic right coronary artery perfusion

AIM

Pulmonary arterial hypertension (PAH) results in right ventricular (RV) dysfunction owing, in part, to RV ischemia. The relative contribution of RV microvascular rarefaction vs reduced right coronary artery perfusion pressure (RCA-PP) to RV ischemia remains unknown. We hypothesize that increasing RCA-PP improves RV function in PAH by increasing RV systolic perfusion.

METHODS

Supra-coronary aortic banding (SAB) or sham surgery was performed on male Sprague-Dawley rats. Seven to ten days later, rats received either monocrotaline (MCT; 60 mg/kg) or saline. After 1 month, echocardiography, cardiac catheterization, ^99m Tc-sestamibi single-photon emission computed tomography (SPECT) and microsphere infusion studies were performed. The RV was harvested for measurement of hypertrophy (RVH), fibrosis and immunoblotting, and the lung was harvested for pulmonary artery (PA) histology.

RESULTS

Supra-coronary aortic banding increased systolic pressures in proximal aorta and systolic RCA-PP in SAB + MCT vs MCT rats (114 ± 12 vs 5 ± 9 mm Hg), without altering diastolic RCA-PP. SAB + MCT rats had improved RV function vs MCT rats, evident from their significantly increased cardiac output (CO), RV free wall (RVFW) thickening, tricuspid annular plane systolic excursion (TAPSE) and RV-PA coupling indices. RV-PA coupling indices and CO correlated directly with systolic RCA-PP. RV perfusion was increased in SAB + MCT vs MCT rats and correlated well with CO; whereas microvascular rarefaction was unaltered. SAB + MCT rats had less RVH and fibrosis and lower PA pressures vs MCT rats. SAB + MCT rats had significantly lower RV pyruvate kinase muscle isoform 2/1 ratios than MCT rats, consistent with restoration of oxidative metabolism.

CONCLUSION

A SAB-induced increase in systolic RCA-PP improves RV perfusion and function in MCT rats. Maintaining systolic RCA perfusion can preserve RV function in PAH.

Mixed Venous Oxygen Saturation Is a Better Prognosticator Than Cardiac Index in Pulmonary Arterial Hypertension

BACKGROUND

European Society of Cardiology (ESC) and European Respiratory Society (ERS) guidelines include thermodilution cardiac index (TDCI) and mixed venous oxygen saturation (SvO₂) as two of the three hemodynamic determinations used in risk assessment of patients with pulmonary arterial hypertension (PAH). SvO₂ may be a better measurement than TDCI to assess prognosis in patients with either idiopathic or heritable PAH.

RESEARCH QUESTION

What is the concordance between TDCI and SvO₂ ESC/ERS risk group allocation and their prognostic value in patients with PAH?

STUDY DESIGN AND METHODS

In this retrospective study, we assessed the correlation between SvO₂ and TDCI in patients with idiopathic and heritable PAH. We determined concordance in the ESC/ERS risk group allocation and association with survival, both at baseline and follow-up.

RESULTS

A total of 158 patients (mean age, 58 ± 17 years; 72% women) with idiopathic (91%) and heritable (9%) PAH were included. There was moderate association between TDCI and SvO₂ (r = 0.50; 95% CI, 0.37-0.62). Weighted kappa revealed a fair agreement between TDCI and SvO₂ (κ = 0.30; 95% CI, 0.18-0.42), with concordance in risk group allocation in 49% of patients. During a median follow-up of 45 months (interquartile range, 23-105), 62 patients (39%) died. Using Kaplan-Meier analysis, survival was impacted by the SvO₂ (log rank = 0.002) but not by the TDCI risk group allocation (log-rank = 0.51). Using the Cox proportional hazard model, adjusted for age and sex, SvO₂ (but not TDCI) was associated with mortality (hazard ratio per 1% change, 0.94; 95% CI, 0.91-0.97; P < .001).

INTERPRETATION

When using the cutoffs proposed by the ESC/ERS guidelines, we noted poor concordance in risk score allocation between TDCI and SvO₂. In patients with idiopathic or heritable PAH, SvO₂ measurements are superior to TDCI in predicting long-term mortality.

MnTBAP Reverses Pulmonary Vascular Remodeling and Improves Cardiac Function in Experimentally Induced Pulmonary Arterial Hypertension

Pulmonary arterial hypertension (PAH) is a life-threatening disease characterized by obstructed pulmonary vasculatures. Current therapies for PAH are limited and only alleviate symptoms. Reduced levels of BMPR2 are associated with PAH pathophysiology. Moreover, reactive oxygen species, inflammation and autophagy have been shown to be hallmarks in PAH. We previously demonstrated that MnTBAP, a synthetic metalloporphyrin with antioxidant and anti-inflammatory activity, inhibits the turn-over of BMPR2 in human umbilical vein endothelial cells. Therefore, we hypothesized that MnTBAP might be used to treat PAH. Human pulmonary artery endothelial cells (PAECs), as well as pulmonary microvascular endothelial (MVECs) and smooth muscle cells (MVSMCs) from PAH patients, were treated with MnTBAP. In vivo, either saline or MnTBAP was given to PAH rats induced by Sugen 5416 and hypoxia (SuHx). On PAECs, MnTBAP was found to increase BMPR2 protein levels by blocking autophagy. Moreover, MnTBAP increased BMPR2 levels in pulmonary MVECs and MVSMCs isolated from PAH patients. In SuHx rats, MnTBAP reduced right ventricular (RV) afterload by reversing pulmonary vascular remodeling, including both intima and media layers. Furthermore, MnTBAP improved RV function and reversed RV dilation in SuHx rats. Taken together, these data highlight the importance of MnTBAP as a potential therapeutic treatment for PAH.

Epigenetic Metabolic Reprogramming of Right Ventricular Fibroblasts in Pulmonary Arterial Hypertension: A Pyruvate Dehydrogenase Kinase-Dependent Shift in Mitochondrial Metabolism Promotes Right Ventricular Fibrosis

RATIONALE

Right ventricular (RV) fibrosis in pulmonary arterial hypertension contributes to RV failure. While RV fibrosis reflects changes in the function of resident RV fibroblasts (RVfib), these cells are understudied.

OBJECTIVE

Examine the role of mitochondrial metabolism of RVfib in RV fibrosis in human and experimental pulmonary arterial hypertension.

METHODS AND RESULTS

Male Sprague-Dawley rats received monocrotaline (MCT; 60 mg/kg) or saline. Drinking water containing no supplement or the PDK (pyruvate dehydrogenase kinase) inhibitor dichloroacetate was started 7 days post-MCT. At week 4, treadmill testing, echocardiography, and right heart catheterization were performed. The effects of PDK activation on mitochondrial dynamics and metabolism, RVfib proliferation, and collagen production were studied in RVfib in cell culture. Epigenetic mechanisms for persistence of the profibrotic RVfib phenotype in culture were evaluated. PDK expression was also studied in the RVfib of patients with decompensated RV failure (n=11) versus control (n=7). MCT rats developed pulmonary arterial hypertension, RV fibrosis, and RV failure. MCT-RVfib (but not left ventricular fibroblasts) displayed excess mitochondrial fission and had increased expression of PDK isoforms 1 and 3 that persisted for >5 passages in culture. PDK-mediated decreases in pyruvate dehydrogenase activity and oxygen consumption rate were reversed by dichloroacetate (in RVfib and in vivo) or siRNA targeting PDK 1 and 3 (in RVfib). These interventions restored mitochondrial superoxide and hydrogen peroxide production and inactivated HIF (hypoxia-inducible factor)-1α, which was pathologically activated in normoxic MCT-RVfib. Redox-mediated HIF-1α inactivation also decreased the expression of TGF-β1 (transforming growth factor-beta-1) and CTGF (connective tissue growth factor), reduced fibroblast proliferation, and decreased collagen production. HIF-1α activation in MCT-RVfib reflected increased DNMT (DNA methyltransferase) 1 expression, which was associated with a decrease in its regulatory microRNA, miR-148b-3p. In MCT rats, dichloroacetate, at therapeutic levels in the RV, reduced phospho-pyruvate dehydrogenase expression, RV fibrosis, and hypertrophy and improved RV function. In patients with pulmonary arterial hypertension and RV failure, RVfib had increased PDK1 expression.

CONCLUSIONS

MCT-RVfib manifest a DNMT1-HIF-1α-PDK-mediated, chamber-specific, metabolic memory that promotes collagen production and RV fibrosis. This epigenetic mitochondrial-metabolic pathway is a potential antifibrotic therapeutic target.

FHL-1 is not involved in pressure overload-induced maladaptive right ventricular remodeling and dysfunction

AIMS

The cytoskeletal signaling protein four and-a-half LIM domains 1 (FHL-1) has recently been identified as a novel key player in pulmonary hypertension as well as in left heart diseases. In this regard, FHL-1 has been implicated in dysregulated hypertrophic signaling in pulmonary arterial smooth muscle cells leading to pulmonary hypertension. In mice, FHL-1-deficiency (FHL-1^-/-) led to an attenuated hypertrophic signaling associated with a blunted hypertrophic response of the pressure-overloaded left ventricle (LV). However, the role of FHL-1 in right heart hypertrophy has not yet been addressed.

METHODS AND RESULTS

We investigated FHL-1 expression in C57Bl/6 mice subjected to chronic biomechanical stress and found it to be enhanced in the right ventricle (RV). Next, we subjected FHL-1^-/- and corresponding wild-type mice to pressure overload of the RV by pulmonary arterial banding for various time points. However, in contrast to the previously published study in LV-pressure overload, which was confirmed here, RV hypertrophy and hypertrophic signaling was not diminished in FHL-1^-/- mice. In detail, right ventricular pressure overload led to hypertrophy, dilatation and fibrosis of the RV from both FHL-1^-/- and wild-type mice. RV remodeling was associated with impaired RV function as evidenced by reduced tricuspid annular plane systolic excursion. Additionally, PAB induced upregulation of natriuretic peptides and slight downregulation of phospholamban and ryanodine receptor 2 in the RV. However, there was no difference between genotypes in the degree of expression change.

CONCLUSION

FHL-1 pathway is not involved in the control of adverse remodeling in the pressure overloaded RV.

Free breathing three-dimensional cardiac quantitative susceptibility mapping for differential cardiac chamber blood oxygenation - initial validation in patients with cardiovascular disease inclusive of direct comparison to invasive catheterization

BACKGROUND

Differential blood oxygenation between left (LV) and right ventricles (RV; ΔSaO2) is a key index of cardiac performance; LV dysfunction yields increased RV blood pool deoxygenation. Deoxyhemoglobin increases blood magnetic susceptibility, which can be measured using an emerging cardiovascular magnetic resonance (CMR) technique, Quantitative Susceptibility Mapping (QSM) - a concept previously demonstrated in healthy subjects using a breath-hold 2D imaging approach (2DBHQSM). This study tested utility of a novel 3D free-breathing QSM approach (3DNAVQSM) in normative controls, and validated 3DNAVQSM for non-invasive ΔSaO2 quantification in patients undergoing invasive cardiac catheterization (cath).

METHODS

Initial control (n = 10) testing compared 2DBHQSM (ECG-triggered 2D gradient echo acquired at end-expiration) and 3DNAVQSM (ECG-triggered navigator gated gradient echo acquired in free breathing using a phase-ordered automatic window selection algorithm to partition data based on diaphragm position). Clinical testing was subsequently performed in patients being considered for cath, including 3DNAVQSM comparison to cine-CMR quantified LV function (n = 39), and invasive-cath quantified ΔSaO2 (n = 15). QSM was acquired using 3 T scanners; analysis was blinded to comparator tests (cine-CMR, cath).

RESULTS

3DNAVQSM generated interpretable QSM in all controls; 2DBHQSM was successful in 6/10. Among controls in whom both pulse sequences were successful, RV/LV susceptibility difference (and ΔSaO2) were not significantly different between 3DNAVQSM and 2DBHQSM (252 ± 39 ppb [17.5 ± 3.1%] vs. 211 ± 29 ppb [14.7 ± 2.0%]; p = 0.39). Acquisition times were 30% lower with 3DNAVQSM (4.7 ± 0.9 vs. 6.7 ± 0.5 min, p = 0.002), paralleling a trend towards lower LV mis-registration on 3DNAVQSM (p = 0.14). Among cardiac patients (63 ± 10y, 56% CAD) 3DNAVQSM was successful in 87% (34/39) and yielded higher ΔSaO2 (24.9 ± 6.1%) than in controls (p < 0.001). QSM-calculated ΔSaO2 was higher among patients with LV dysfunction as measured on cine-CMR based on left ventricular ejection fraction (29.4 ± 5.9% vs. 20.9 ± 5.7%, p < 0.001) or stroke volume (27.9 ± 7.5% vs. 22.4 ± 5.5%, p = 0.013). Cath measurements (n = 15) obtained within a mean interval of 4 ± 3 days from CMR demonstrated 3DNAVQSM to yield high correlation (r = 0.87, p < 0.001), small bias (- 0.1%), and good limits of agreement (±8.6%) with invasively measured ΔSaO2.

CONCLUSION

3DNAVQSM provides a novel means of assessing cardiac performance. Differential susceptibility between the LV and RV is increased in patients with cine-CMR evidence of LV systolic dysfunction; QSM-quantified ΔSaO2 yields high correlation and good agreement with the reference of invasively-quantified ΔSaO2.

Assessment of Right Ventricular Function in the Research Setting: Knowledge Gaps and Pathways Forward. An Official American Thoracic Society Research Statement

BACKGROUND

Right ventricular (RV) adaptation to acute and chronic pulmonary hypertensive syndromes is a significant determinant of short- and long-term outcomes. Although remarkable progress has been made in the understanding of RV function and failure since the meeting of the NIH Working Group on Cellular and Molecular Mechanisms of Right Heart Failure in 2005, significant gaps remain at many levels in the understanding of cellular and molecular mechanisms of RV responses to pressure and volume overload, in the validation of diagnostic modalities, and in the development of evidence-based therapies.

METHODS

A multidisciplinary working group of 20 international experts from the American Thoracic Society Assemblies on Pulmonary Circulation and Critical Care, as well as external content experts, reviewed the literature, identified important knowledge gaps, and provided recommendations.

RESULTS

This document reviews the knowledge in the field of RV failure, identifies and prioritizes the most pertinent research gaps, and provides a prioritized pathway for addressing these preclinical and clinical questions. The group identified knowledge gaps and research opportunities in three major topic areas: 1) optimizing the methodology to assess RV function in acute and chronic conditions in preclinical models, human studies, and clinical trials; 2) analyzing advanced RV hemodynamic parameters at rest and in response to exercise; and 3) deciphering the underlying molecular and pathogenic mechanisms of RV function and failure in diverse pulmonary hypertension syndromes.

CONCLUSIONS

This statement provides a roadmap to further advance the state of knowledge, with the ultimate goal of developing RV-targeted therapies for patients with RV failure of any etiology.

Goal-Oriented Sequential Combination Therapy Evaluated Using Cardiopulmonary Exercise Parameters for the Treatment of Newly Diagnosed Pulmonary Arterial Hypertension - Goal-Oriented Therapy Evaluated by Cardiopulmonary Exercise Testing for Pulmonary Arterial Hypertension (GOOD EYE)

Background: Many treatment options are available for pulmonary arterial hypertension (PAH), but specific recommendations for long-term treatment are unavailable. We compared prognosis in PAH patients receiving goal-oriented, sequential combination therapy evaluated using cardiopulmonary exercise testing (CPX) parameters or conventional empiric therapy.

Methods and Results: The Goal-Oriented Therapy Evaluated by Cardiopulmonary Exercise Testing for Pulmonary Arterial Hypertension (GOOD EYE) study was a multicenter, retrospective/prospective study in which a total of 129 patients with newly diagnosed PAH were enrolled (goal-oriented sequential combination therapy, n=42; conventional empiric therapy, n=87). Patients in the goal-oriented therapy group received sequential combination therapy, the efficacy of which was regularly evaluated using CPX parameters. Patients in the conventional empiric therapy group received conventional empiric therapy. The primary endpoint was cardiovascular death. In the goal-oriented therapy group, plasma brain natriuretic peptide, mean pulmonary arterial pressure, pulmonary vascular resistance, and 6-min walk test were significantly improved at 12 months compared with baseline. Survival in the goal-oriented therapy group at 1, 2, and 3 years (97.6%, 95.2%, and 86.0%, respectively) tended to be higher than that in the conventional empiric therapy group (P=0.082).

Conclusions: Goal-oriented sequential combination therapy evaluated using CPX parameters may be associated with a favorable prognosis compared with conventional empiric therapy in patients with newly diagnosed PAH.

Analysis of pulmonary hypertension patient survival after treatment in referral center (data of first Ukrainian register)

The aims of the study were: (1) to evaluate the Ukrainian reality of survival in patients with pulmonary arterial hypertension (PAH) and chronic thromboembolic pulmonary hypertension (CTEPH); and (2) to determine predictors of death. A total of 281 patients were enrolled (52 [18.5%] with CTEPH, 229 [81.5%] with PAH). Long-term survival (Kaplan–Meier) and its predictors (Stepwise binary logistic regression and Cox's proportional hazards analyses) were evaluated in adult patients with PH (diagnosed by right heart catheterization [RHC]) within a prospective registry at a single referral center in Kyiv, Ukraine. Follow-up period was up to 51 months. The Kaplan–Meier survival rate for the total cohort was 93.3%, 86.8%, and 81.5% at one, two, and three years, respectively. Survival was better in patients with congenital heart diseases (CHD) in comparison with idiopathic PAH (long rank P = 0.002), connective tissue diseases (CTD; long rank P = 0.001) and CTEPH (long rank P = 0.04). Univariate Cox's predictors of death were: functional class IV (odds ratio [OR] = 4.94; 95% confidence interval [CI] = 2.12–11.48), presence of ascites (OR = 4.52; 95% CI = 2.21–9.24), PAH-CTD (OR = 3.07; 95% CI = 1.07–8.87), PAH-CHD (OR = 0.28; 95% CI = 0.11–0.68), HR on treatment > 105 beats per min (OR = 7.85; 95% CI = 1.83–33.69), office systolic BP < 100 mmHg (OR = 2.78; 95% CI = 1.26–6.1), 6MWT on treatment < 340 m (OR = 3.47; 95% CI = 1.01–12.35), NT-proBNP > 300 pg/mL (OR = 4.98; 95% CI = 1.49–16.6), right atrium square > 22 cm² (OR = 14.2; 95% CI = 1.92–104.89), right ventricular square in diastole (OR = 1.08; 95% CI = 1.03–1.14), right ventricular square in systole (OR = 1.08; 95% CI = 1.02–1.11), mean pressure in right atrium per each 1-mmHg increase (OR = 1.02; 95% CI = 1.02–1.19). In multivariate Cox regression analyses only presence of ascites, office systolic BP < 100 mmHg, CHD etiology of PH, and NT-proBNP > 300 pg/mL were associated with survival.

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.

"Treat-to-close": Non-repairable ASD-PAH in the adult: Results from the North American ASD-PAH (NAAP) Multicenter Registry

BACKGROUND

Adults presenting with an unrepaired atrial septal defect and pulmonary arterial hypertension (ASD-PAH) are typically classified as "correctable" or "non-correctable". The use of directed PAH medical therapy in non-correctable ASD-PAH leading to favorable closure candidacy, repair status and long-term follow-up is not well studied. We therefore sought to characterize response to PAH targeted therapy in 'non-correctable' ASD-PAH.

METHODS AND RESULTS

Nine North American tertiary care centers submitted retrospective data from adults with unrepaired ASD-PAH that did not meet recommendations for repair at initial presentation (1996-2017). Sixty-nine patients (women 51(74%), 40 ± 15 years, mean pulmonary artery pressure (mPA) 51 ± 13 mm Hg, pulmonary vascular resistance (PVR) 8.7 ± 4.9 Wood units, Qp:Qs 1.6 ± 0.4) were enrolled. All patients were prescribed PAH targeted therapy and late shunt repair occurred in 19(28%) (Women 15(29%) vs. Men 4(22%), p = 0.6). At late follow-up (4.4 ± 2.9 years) 6-minute walk test distance (6MWTD) was significantly better in the group that underwent repair (486 ± 89 m vs. 375 ± 139 m, p < 0.05). Transthoracic echo showed significant improvement in right ventricular (RV) function (severe dysfunction in repaired 8(40%) vs. unrepaired groups 35(69%), p < 0.05). Divergent survival curves suggest that with larger studies and more follow-up, differences in survival between repaired and unrepaired groups may be important. (repaired: 17(94%) vs. unrepaired: 32(81%), p = 0.18).

CONCLUSIONS

This is the first and largest multicenter study evaluating the "treat-to-close" approach in non-correctable ASD-PAH. Our new data supports further study of this strategy in patients who have reversibility of PAH in response to targeted therapy. We demonstrate that in the carefully selected patient with non-correctable ASD-PAH, successful shunt repair is possible if post-therapy PVR is ≤6.5 Wood units. Patients who underwent repair had improved RV function following PAH targeted therapy. Divergent survival curves suggest that with further study, defect repair may affect medium-term to late survival.

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.

Evaluating the effect of nasal septoplasty on atrial electromechanical features

BACKGROUND

Recent studies have demonstrated that right ventricular (RV) dysfunction and increased pulmonary artery pressure may be frequent in patients with upper airway obstruction. In this study, we evaluated atrial conduction delays in patients with upper airway obstruction secondary to nasal septum deviation (NSD).

METHODS

A total of 32 patients with upper airway obstruction secondary to NSD undergoing a septoplasty procedure were enrolled in this study. Preoperative electrocardiography and transthoracic echocardiography were performed in all patients who underwent surgery. The mean pulmonary artery pressure (mPAP) and atrial conduction time (ACT) were recorded before and 6 months after the surgical procedures.

RESULTS

The PAP was significantly lower postoperatively than preoperatively (20.75 ± 4.83 vs. 24.68 ± 5.26; P < 0.001). The postoperative Electromechanical Delay of Mitral septal wall (EMD-MS) value was significantly lower than that preoperatively (46.20 ± 8.5 vs. 40.5 ± 9.9; P < 0.001). The postoperative Electromechanical Delay of Mitral lateral wall (EMD-ML) value decreased significantly compared to the preoperative period (46.3 ± 7.4 vs. 40.6 ± 9.3; P < 0.001). The postoperative Electromechanical Delay of Tricuspit lateral wall (EMD-TL) value was significantly lower than that preoperatively (43.8 ± 7.0 vs. 38.1 ± 9.1; P < 0.001). There was no significant change in pre- or postoperative measurements of inter- and intra-atrial conduction delays.

CONCLUSIONS

We demonstrated that upper airway obstruction secondary to NSD causes a significant increase in mPAP and a significant delay in ACT, which improved after nasal septoplasty. According to these results, we conclude that upper airway obstruction may be an important risk factor for pulmonary arterial hypertension, RV dysfunction, and atrial arrhythmias, especially in unoperated cases.

Gasometric gradients between blood obtained from the pulmonary artery wedge and pulmonary artery positions in pulmonary arterial hypertension

INTRODUCTION

Little is known on the pulmonary gradients of oxyhemoglobin, carboxyhemoglobin and methemoglobin in pulmonary arterial hypertension (PAH). We sought to determine these gradients in group 1 PAH and assess their association with disease severity and survival.

METHODS

During right heart catheterization (RHC) we obtained blood from pulmonary artery (PA) and pulmonary artery wedge (PAW) positions and used co-oximetry to test their gasometric differences.

RESULTS

We included a total of 130 patients, 65 had group 1 PAH, 40 had pulmonary hypertension (PH) from groups 2-5 and 25 had no PH during RHC. In all groups, PAW blood had higher pH, carboxyhemoglobin and lactate as well as lower pCO2 than PA blood. In group 1 PAH (age 58 ± 15 years, 72% females), methemoglobin in the PAW was lower than in the PA blood (0.83% ± 0.43 vs 0.95% ± 0.50, p = 0.03) and was directly associated with the degree of change in pulmonary vascular resistance (R = 0.35, p = 0.02) during inhaled nitric oxide test. Oxyhemoglobin in PA (HR (95%CI): 0.90 (0.82-0.99), p = 0.04) and PAW (HR (95%CI): 0.91 (0.84-0.98), p = 0.003) blood was associated with adjusted survival in PAH.

CONCLUSIONS

Marked differences were observed in the gasometric determinations between PAW and PA blood. The pulmonary gradient of methemoglobin was lower in PAH patients compared to controls and a higher PAW blood methemoglobin was associated with a more pronounced pulmonary vascular response to inhaled nitric oxide. Pulmonary artery and PAW oxyhemoglobin tracked with disease severity and survival in PAH.

GPCRs in pulmonary arterial hypertension: tipping the balance

Pulmonary arterial hypertension (PAH) is a progressive, fatal disease characterised by increased pulmonary vascular resistance and excessive proliferation of pulmonary artery smooth muscle cells (PASMC). GPCRs, which are attractive pharmacological targets, are important regulators of pulmonary vascular tone and PASMC phenotype. PAH is associated with the altered expression and function of a number of GPCRs in the pulmonary circulation, which leads to the vasoconstriction and proliferation of PASMC and thereby contributes to the imbalance of pulmonary vascular tone associated with PAH; drugs targeting GPCRs are currently used clinically to treat PAH and extensive preclinical work supports the utility of a number of additional GPCRs. Here we review how GPCR expression and function changes with PAH and discuss why GPCRs continue to be relevant drug targets for the disease.

Right heart dysfunction: from pathophysiologic insights to therapeutic options: a translational overview

: The right ventricle has become increasingly studied in cardiovascular research. In this article, we describe specific pathophysiological characteristics of the right ventricle, with special focus on functional and molecular modifications as well as therapeutic strategies in right ventricular dysfunction, underlining the differences with the left ventricle. Then we analyze the main imaging modalities to assess right ventricular function in different clinical settings. Finally, we acknowledge main therapeutic advances for treatment of right heart diseases.

Increased Drp1-Mediated Mitochondrial Fission Promotes Proliferation and Collagen Production by Right Ventricular Fibroblasts in Experimental Pulmonary Arterial Hypertension

Introduction: Right ventricular (RV) fibrosis contributes to RV failure in pulmonary arterial hypertension (PAH). The mechanisms underlying RV fibrosis in PAH and the role of RV fibroblasts (RVfib) are unknown. Activation of the mitochondrial fission mediator dynamin-related protein 1 (Drp1) contributes to dysfunction of RV myocytes in PAH through interaction with its binding partner, fission protein 1 (Fis1). However, the role of mitochondrial fission in RVfib and RV fibrosis in PAH is unknown. Objective: We hypothesize that mitochondrial fission is increased in RVfib of rats with monocrotaline (MCT)-induced PAH. We evaluated the contribution of Drp1 and Drp1-Fis1 interaction to RVfib proliferation and collagen production in culture and to RV fibrosis in vivo. Methods: Vimentin (+) RVfib were enzymatically isolated and cultured from the RVs of male Sprague-Dawley rats that received MCT (60 mg/kg) or saline. Mitochondrial morphology, proliferation, collagen production, and expression of Drp1, Drp1 binding partners and mitochondrial fusion mediators were measured. The Drp1 inhibitor mitochondrial division inhibitor 1 (Mdivi-1), P110, a competitive peptide inhibitor of Drp1-Fis1 interaction, and siRNA targeting Drp1 were assessed. Subsequently, prevention and regression studies tested the antifibrotic effects of P110 (0.5 mg/kg) in vivo. At week 4 post MCT, echocardiography and right heart catheterization were performed. The RV was stained for collagen. Results: Mitochondrial fragmentation, proliferation rates and collagen production were increased in MCT-RVfib versus control-RVfib. MCT-RVfib had increased expression of activated Drp1 protein and a trend to decreased mitofusin-2 expression. Mdivi-1 and P110 inhibited mitochondrial fission, proliferation and collagen III expression in MCT-RVfib. However, P110 was only effective at high doses (1 mM). siDrp1 also reduced fission in MCT-RVfib. Despite promising results in cell therapy, in vivo therapy with P110 failed to prevent or regress RV fibrosis in MCT rats, perhaps due to failure to achieve adequate P110 levels or to the greater importance of interaction of Drp1 with other binding partners. Conclusion: PAH RVfib have increased Drp1-mediated mitochondrial fission. Inhibiting Drp1 prevents mitochondrial fission and reduces RVfib proliferation and collagen production. This is the first description of disordered mitochondrial dynamics in RVfib and suggests that Drp1 is a potential new antifibrotic target.

Treatment strategies for the right heart in pulmonary hypertension

The function of the right ventricle (RV) determines the prognosis of patients with pulmonary hypertension. While much progress has been made in the treatment of pulmonary hypertension, therapies for the RV are less well established. In this review of treatment strategies for the RV, first we focus on ways to reduce wall stress since this is the main determinant of changes to the ventricle. Secondly, we discuss treatment strategies targeting the detrimental consequences of increased RV wall stress. To reduce wall stress, afterload reduction is the essential. Additionally, preload to the ventricle can be reduced by diuretics, by atrial septostomy, and potentially by mechanical ventricular support. Secondary to ventricular wall stress, left-to-right asynchrony, altered myocardial energy metabolism, and neurohumoral activation will occur. These may be targeted by optimising RV contraction with pacing, by iron supplement, by angiogenesis and improving mitochondrial function, and by neurohumoral modulation, respectively. We conclude that several treatment strategies for the right heart are available; however, evidence is still limited and further research is needed before clinical application can be recommended.

Right ventricle performances with echocardiography and 99mTc myocardial perfusion imaging in pulmonary arterial hypertension patients

Right heart catheterization is commonly used to measure right ventricle hemodynamic parameters and is the gold standard for pulmonary arterial hypertension diagnosis; however, it is not suitable for patients' long-term follow-up. Non-invasive echocardiography and nuclear medicine have been applied to measure right ventricle anatomy and function, but the guidelines for the usefulness of clinical parameters remain to be established. The goal of this study is to identify reliable clinical parameters of right ventricle function in pulmonary arterial hypertension patients and analyze the relationship of these clinical parameters with the disease severity of pulmonary arterial hypertension. In this study, 23 normal subjects and 23 pulmonary arterial hypertension patients were recruited from January 2015 to March 2016. Pulmonary arterial hypertension patients were classified into moderate and severe pulmonary arterial hypertension groups according to their mean pulmonary arterial pressure levels. All the subjects were subjected to physical examination, chest X-ray, 12-lead electrocardiogram, right heart catheterization, two-dimensional echocardiography, and technetium 99m (^99mTc) myocardial perfusion imaging. Compared to normal subjects, the right heart catheterization indexes including right ventricle systolic pressure, right ventricle end diastolic pressure, pulmonary artery systolic pressure, pulmonary artery diastolic pressure, pulmonary vascular resistance, and right ventricle end systolic pressure increased in pulmonary arterial hypertension patients and were correlated with mean pulmonary arterial pressure levels. Echocardiography parameters, including tricuspid regurgitation peak velocity, tricuspid regurgitation pressure gradient, tricuspid annular plane systolic excursion and fractional area, right ventricle-myocardial performance index, were significantly associated with the mean pulmonary arterial pressure levels in pulmonary arterial hypertension patients. Furthermore, myocardial perfusion imaging was not observed in the normal subjects but in pulmonary arterial hypertension patients, especially severe pulmonary arterial hypertension subgroup, and showed potential diagnostic properties for pulmonary arterial hypertension. In conclusion, mean pulmonary arterial pressure levels are correlated with several right heart catheterization and echocardiography markers in pulmonary arterial hypertension patients; echocardiography and ^99mTc myocardial perfusion can be used to evaluate right ventricle performance in pulmonary arterial hypertension patients. Impact statement In this study, we analyzed the clinical parameters for evaluating RV function, including right ventricle catheterization (RHC), echocardiography, and technetium 99m (^99mTc) myocardial perfusion imaging (MPI) in normal Asian subjects and PAH patients ( n = 23 for each group). Our results demonstrated that six RHC indexes, four echocardiography indexes and MPI index were significantly altered in PAH patients and correlated with the levels of mean pulmonary arterial pressure. Importantly, we evaluated the diagnostic performance of MPI and found that MPI has a strong diagnostic accuracy in PAH patients. The findings from this study will be of interest to clinical investigators who make diagnosis and therapeutic strategies for PAH patients.

Creation of a restrictive atrial communication in pulmonary arterial hypertension (PAH): effective palliation of syncope and end-stage heart failure

Atrial septostomy (AS) is recommended for pulmonary arterial hypertension (PAH)-associated right ventricular (RV) failure, recurrent syncope, or pulmonary hypertensive crisis (PHC). We aimed to evaluate the feasibility and efficacy of AS to manage PAH from infancy to adulthood. From June 2009 to December 2016, transcatheter atrial communications were created in 11 PAH patients (4 girls/women; median age = 4.3 years; range = 33 days-26 years; median body weight = 14 kg; range = 3-71 kg; NYHA-/Ross class IV; n = 11). PAH was classified as idiopathic (n = 6) or secondary (n = 5). History of syncope was dominant (n = 6); two with patent foramen ovale (PFO) admitted with recurrent PHC, three patients required resuscitation before AS. Three patients had PAH-associated low cardiac output. The average pulmonary arterial pressures (PAP systolic/diastolic) were 101/50 (±34/23); the corresponding systemic arterial pressures (SAP) were 99/54 (±23/11); and the mean ratio of PAPd / SAPd was 0.97 (±0.4). Percutaneous trans-septal puncture was uneventfully performed in nine patients; a PFO was dilated in two patients. There was no procedure-related mortality. The median balloon size was 10 mm (range = 6-14 mm); the mean catheter time was 174.6 ± 48 min; fluoroscopy time was 19.8 (±11) min. Syncope and PHC were successfully treated in all patients. The mean arterial oxygen saturation decreased from 97 ± 2 to 89 ± 11.7. One patient died awaiting lung transplantation, one continues to be listed; two patients received a reverse Potts-shunt, one patient died during follow-up; seven patients are stable with PAH-specific treatment. Percutaneous AS is an effective method palliating PAH-associated syncope, PHCs or right (bi-) ventricular heart failure.

Haemodynamically Derived Pulmonary Artery Pulsatility Index Predicts Mortality in Pulmonary Arterial Hypertension

BACKGROUND

Pulmonary artery (PA) pulsitility index (PAPi) is a novel haemodynamic index shown to predict right ventricular failure in acute inferior myocardial infarction and post left ventricular assist device surgery. We hypothesised that PAPi calculated as [PA systolic pressure - PA diastolic pressure]/right atrial pressure (RAP) would be associated with mortality in the National Institutes of Health Registry for Primary Pulmonary Hypertension (NIH-RPPH).

METHODS

The impact of PAPi, the Pulmonary Hypertension Connection (PHC) risk score, right ventricular stroke work, pulmonary artery capacitance (PAC), other haemodynamic indices, and demographic characteristics was evaluated in 272 NIH-RPPH patients using multivariable Cox proportional hazards (CPH) regression and receiver operating characteristic (ROC) analysis.

RESULTS

In the 272 patients (median age 37.7+/-15.9years, 63% female), the median PAPi was 5.8 (IQR 3.7-9.2). During 5years of follow-up, 51.8% of the patients died. Survival was markedly lower (32.8% during the first 3years) in PAPi quartile 1 compared with the remaining patients (58.5% over 3years in quartiles 2-4; p<0.0001). The best multivariable CPH survival model included PAPi, the PHC-Risk score, PAC, and body mass index (BMI). In this model, the adjusted hazard ratio for death with increasing PAPi was 0.946 (95% CI 0.905-0.989). The independent ROC areas for 5-year survival based on bivariable logistic regression for PAPi, BMI, PHC Risk, and PAC were 0.63, 0.62, 0.64, and 0.65, respectively (p<0.01). The ROC area for 5-year survival for the multivariable logistic model with all four covariates was 0.77 (p<0.0001).

CONCLUSIONS

Pulmonary artery pulsatility index was independently associated with survival in PAH, highlighting the utility of PAPi in combination with other key measures for risk stratification in this population.

Hospital and intensive care unit management of decompensated pulmonary hypertension and right ventricular failure

Pulmonary hypertension and concomitant right ventricular failure present a diagnostic and therapeutic challenge in the intensive care unit and have been associated with a high mortality. Significant co-morbidities and hemodynamic instability are often present, and routine critical care unit resuscitation may worsen hemodynamics and limit the chances of survival in patients with an already underlying poor prognosis. Right ventricular failure results from structural or functional processes that limit the right ventricle’s ability to maintain adequate cardiac output. It is commonly seen as the result of left heart failure, acute pulmonary embolism, progression or decompensation of pulmonary hypertension, sepsis, acute lung injury, or in the perioperative setting. Prompt recognition of the underlying cause and institution of treatment with a thorough understanding of the elements necessary to optimize preload, cardiac contractility, enhance systemic arterial perfusion, and reduce right ventricular afterload are of paramount importance. Moreover, the emergence of previously uncommon entities in patients with pulmonary hypertension (pregnancy, sepsis, liver disease, etc.) and the availability of modern devices to provide support pose additional challenges that must be addressed with an in-depth knowledge of this disease.

Defining the molecular signatures of human right heart failure

AIMS

Right ventricular failure (RVF) varies significantly from the more common left ventricular failure (LVF). This study was undertaken to determine potential molecular pathways that are important in human right ventricular (RV) function and may mediate RVF.

MATERIALS AND METHODS

We analyzed mRNA of human non-failing LV and RV samples and RVF samples from patients with pulmonary arterial hypertension (PAH), and post-LVAD implantation. We then performed transcript analysis to determine differential expression of genes in the human heart samples. Immunoblot quantification was performed followed by analysis of non-failing and failing phenotypes.

KEY FINDINGS

Inflammatory pathways were more commonly dysregulated in RV tissue (both non-failing and failing phenotypes). In non-failing human RV tissue we found important differences in expression of FIGF, TRAPPAC, and CTGF suggesting that regulation of normal RV and LV function are not the same. In failing RV tissue, FBN2, CTGF, SMOC2, and TRAPP6AC were differentially expressed, and are potential targets for further study.

SIGNIFICANCE

This work provides some of the first analyses of the molecular heterogeneity between human RV and LV tissue, as well as key differences in human disease (RVF secondary to pulmonary hypertension and LVAD mediated RVF). Our transcriptional data indicated that inflammatory pathways may be more important in RV tissue, and changes in FIGF and CTGF supported this hypothesis. In PAH RV failure samples, upregulation of FBN2 and CTGF further reinforced the potential significance that altered remodeling and inflammation play in normal RV function and failure.