Right heart adaptation to pulmonary arterial hypertension: physiology and pathobiology

Ventriculo-arterial coupling in pulmonary regurgitation following transannular patch repair of pulmonary stenosis

Pulmonary regurgitation is a common consequence following the repair of tetralogy of Fallot and can lead to heart failure. Early detection of right ventricular dysfunction remains challenging, and current clinical markers have limited predictive value to identify which patients are at risk for heart failure and require interventions. This study aimed to investigate the potential of ventriculo-arterial coupling as a marker of early right ventricular dysfunction in a porcine model of chronic pulmonary regurgitation following transannular patch repair of neonatal pulmonary stenosis. Neonatal swine were subjected to pulmonary artery banding for 1 mo to induce right ventricular (RV) pressure overload, followed by transannular patch repair (rTAP, n = 10) to create chronic pulmonary regurgitation, and were compared with Sham animals (n = 6). Longitudinal hemodynamic assessments, including pressure-volume analysis and cardiac magnetic resonance imaging, were performed. Ventriculo-arterial coupling (VAC) was defined as the ratio of end-systolic elastance to effective arterial elastance. Over the follow-up period of 4 mo, VAC was preserved in the rTAP group. Effective arterial elastance was significantly lower in rTAP animals (P = 0.001), whereas end-systolic elastance remained unchanged. Lower end-diastolic pulmonary artery pressures and increased early systolic ejection were observed in rTAP, correlating with higher VAC. Ventriculo-arterial coupling remains preserved in chronic pulmonary regurgitation due to decreased afterload, making it unsuitable as an early marker for right ventricular dysfunction. Low afterload, a consequence of diastolic emptying of the pulmonary artery into the right ventricle, may pseudo-normalize systolic function. Alternative markers, for example, focusing on diastolic function and atrio-ventricular interactions should be investigated.NEW & NOTEWORTHY We used a porcine model of sequential loading with pulmonary artery banding and transannular patch mimicking tetralogy of Fallot to test ventriculo-arterial coupling as a marker of early right ventricular dysfunction. Ventriculo-arterial coupling is preserved despite right ventricular dysfunction and afterload is decreased. Pulmonary regurgitation results in low afterload following pulmonary artery pressure drop during diastole. Early systolic ejection is increased and correlates with ventriculo-arterial coupling.

Graded response of the pulmonary circulation to progressive pulmonary embolism in sheep: From compensation to lethal right heart failure

Background

Severe pulmonary embolism (PE) with right heart failure (RHF) has high mortality. To more fully understand PE progression, we evaluated the right ventricle (RV) and pulmonary circulation response to graded PE in an acute PE sheep model.

Methods

Polydextran beads were intravenously administered every 15 minutes in 250 mg doses to adult female sheep (n = 8) until death. Concurrent pulmonary artery (PA) blood flow/pressure was measured. RV pressure-volume (P-V) loops were generated with a conductance catheter. Pulmonary vascular resistance was used to stage PE severity into mild, moderate, and severe groups.

Results

All sheep developed graded RHF. For mild, moderate, and severe PE, 3, 6, and 9 doses were needed, respectively. Only 1 additional dose triggered death. In severe PE, mean PA pressure reached 42 ± 6 mm Hg with significantly decreased cardiac output (CO). Pulmonary impedance spectra showed significantly increased Z0 (RV static load) and Z1 (RV pulsatile load). PE shifted the RV P-V loop from lower left triangular to upper right rectangular shape. PA elastance (Ea, RV afterload) and end-systolic elastance (Ees, RV contractility) progressively increased. Ees/Ea (RV-PA coupling) was initially maintained but became uncoupled in severe PE, causing RHF.

Conclusions

Compensatory increases in RV contractility initially maintain CO in PE despite RV afterload elevation. Increased RV contractility eventually fails to compensate for elevated RV afterload, causing RV-PA uncoupling in severe PE with RHF. Severe PE rapidly progresses to lethal RHF and will likely require immediate intervention to prevent death.

Right Ventricular Stiffening and Function Are Associated With Main Pulmonary Artery Remodeling in a Rat Model of Pulmonary Hypertension

BACKGROUND

Coupling between right ventricular (RV) function and the pulmonary vasculature determines outcomes in pulmonary arterial (PA) hypertension. The mechanics of the main PA (mPA) is an important but understudied determinant of RV-PA coupling. To investigate the histology and mechanics of PA in relationship to RV remodeling, mechanics, hemodynamics, and coupling in experimental PA hypertension.

METHODS

In a sugen-hypoxia rat model of PA hypertension, RV hemodynamics were assessed by conductance catheters. Active tension-strain curves were generated using echocardiography. mPA and RV free wall were harvested to determine their macrostructure and microstructure, composition, and mechanical properties. Comprehensive multivariate analyses elucidated relationships between PA and RV mechanics, structure, and coupling.

RESULTS

Pulmonary hypertensive mPAs developed fibrosis relative to healthy controls, as did RVs, which also hypertrophied, with reorientation of muscle fibers toward a trilayer architecture reminiscent of normal left ventricular architecture. Increased glycosaminoglycan deposition and increased collagen-to-elastin ratio in PA, and increased collagen, as well as hypertrophy and reorganization of myofibers in RV, led to increased stiffness. This increase in stiffness was more pronounced in the longitudinal direction in the high- and low-strain regime for PA and RV, respectively, causing increased mechanical anisotropy. mPA stiffening correlated significantly with RV tissue mechanical remodeling and reduced systolic performance, cardiac output, and RV-PA coupling.

CONCLUSIONS

Compositional, structural, and mechanical changes in mPA correlate with adverse RV remodeling, mechanics, function, and coupling in PA hypertension. Therefore, increasing mechanical compliance of the large PAs may be an important and novel therapeutic strategy for mitigating RV failure.

Prognostic value of non-invasive right ventricle-pulmonary artery coupling in patients with pulmonary hypertension associated with left heart disease

OBJECTIVE

This study aims to assess the prognostic significance of non-invasive right ventricle-pulmonary artery coupling in patients with pulmonary hypertension associated with left heart disease (PH-LHD) and identify the relevant clinical factors involved.

METHODS

A cohort of 362 patients diagnosed with PH-LHD was included in this study. Plasma N-terminal pro-B-type natriuretic peptide (NT-proBNP) levels were measured using enzyme-linked immunosorbent assay (ELISA). Echocardiography was employed to screen routine ultrasound parameters. The tricuspid annular plane systolic excursion/pulmonary artery systolic pressure (TAPSE/PASP) and S'/PASP ratios were calculated. Participants were categorized into two groups based on the TAPSE/PASP ratio: moderate-to-severe and mild uncoupling groups. Both groups underwent routine follow-up for a period of 3 to 15 months. Clinical events included all-cause mortality, heart failure rehospitalization, and stroke. Clinical events were documented, and a multivariate Cox regression model evaluated the correlation between the TAPSE/PASP ratio and prognosis. The Kaplan-Meier survival analysis was also conducted.

RESULTS

The moderate-to-severe uncoupling group exhibited significantly higher proportions of males; individuals with a history of smoking, valvular disease, diabetes mellitus, or stroke; and elevated levels of PASP, right ventricular diameter (RVD), left ventricular diameter (LVD), left ventricular end-diastolic (LVED), and lg (NT-proBNP) compared to the mild uncoupling group (P < 0.05). Conversely, parameters such as age, TAPSE, S', S' /PASP, and left ventricular ejection fraction (LVEF) were significantly lower in the moderate-to-severe uncoupling group compared to the mild uncoupling group (P < 0.05). Multivariate Cox regression analysis revealed that TAPSE/PASP (hazard ratio [HR] = 0.150, 95% confidence interval [CI] [0.023, 0.968], P = 0.046) was a protective factor for the recurrence of clinical events. In contrast, LVED (HR = 1.301, 95% CI (1.004, 1.059), P = 0.024) and lg (NT-proBNP) (HR = 1.870, 95%CI [1.304, 2.682], P = 0.001) were independent risk factors for the recurrence of clinical events. KaplanMeier survival analysis demonstrated that the mild uncoupling group exhibited a significantly higher overall survival rate compared to the moderate-to-severe uncoupling group (Log Rank P = 0.024).

CONCLUSIONS

The TAPSE/PASP ratio is a predictive marker for clinical outcomes in patients with PH-LHD.

Test-retest Assessment of Biventricular Myocardial Oxidative Metabolism and Perfusion in Pulmonary Hypertension Patients Using 11C-acetate PET Imaging: A Pilot Study

PURPOSE

11C-acetate PET is used to measure biventricular oxygen myocardial consumption rate (MVO2) and myocardial blood flow (MBF) changes associated with right ventricular (RV) remodelling. We studied PET reproducibility and repeatability for such RV assessments.

PROCEDURES

10 pulmonary hypertension (PH) patients underwent 11C-acetate PET. Five of these patients also had a repeat scan after 26 ± 2 weeks. A one-tissue compartment model was used to measure the myocardial tissue-activity washout rate (k2 [1/min] for MVO2 estimation) and the blood-to-tissue activity flux (K1 [1/min] for MBF calculation). Values were measured by 2 blinded observers and analyzed by ANOVA and Bland-Altman tests. The interquartile ranges (IQR), within-subject coefficients of variation (wCV), and intraclass correlation coefficients (ICC) were reported.

RESULTS

All patients had stable PH with the clinical assessments showed comparable biventricular function and size between baseline and follow-up. The k2-derived MVO2 and K1-derived MBF values were consistently higher in the LV than RV. The high inter- and intra-observer reproducibility (for biventricular MVO2 and MBF) was indicated by low IQR (≤ 7.6%) and wCV (≤ 8%) as well as high ICC (≥ 95%). The test-retest (baseline to follow-up) repeatability showed larger IQR (≤ 35.4%) and wCV (≤ 29%) but consistently high ICC (= 95%).

CONCLUSIONS

MVO2 and MBF values measured in the RV of patients with PH were highly reproducible and repeatable. This can help inform the design of clinical research studies using serial 11C-acetate PET imaging to evaluate RV metabolism.

Echocardiographic Parameters of the Right Ventricle in Patients With Pulmonary Hypertension: A Review

To diagnose pulmonary hypertension (PH) and assess its severity, accurate measurement of pulmonary artery (PA) pressure is crucial. However, there can be significant discrepancies between echocardiography (Echo) and invasive catheterization. The right ventricle (RV) has a complex structure, and its remodeling in PH is diverse, making it challenging to evaluate RV physiology with a single imaging modality. While right heart catheterization is the gold standard, its practicality in clinical settings is limited. Cardiac magnetic resonance imaging (MRI) is valuable for RV evaluation, with 4-dimensional flow MRI showing promise, yet accessibility remains a concern. Thus, in PH patient management, Echo plays a central role as a practical decision-making tool. This review aims to elucidate Echo parameters in PH patients, highlighting differences in PA systolic pressure measurements, RV-PA coupling, RV remodeling patterns crucial for understanding PH progression, and clinical evidence regarding RV strain. Additionally, it aims to introduce new Echo parameters that help understand RV in PH.

High-altitude pulmonary hypertension: a comprehensive review of mechanisms and management

High-altitude pulmonary hypertension (HAPH) is characterized by an increase in pulmonary artery pressure due to prolonged exposure to hypoxic environment at high altitudes. The development of HAPH involves various factors such as pressure changes, inflammation, oxidative stress, gene regulation, and signal transduction. The pathophysiological mechanisms of this condition operate at molecular, cellular, and genetic levels. Diagnosis of HAPH often relies on echocardiography, cardiac catheterization, and other methods to assess pulmonary artery pressure and its impact on cardiac function. Treatment options for HAPH encompass both nondrug and drug therapies. While advancements have been made in understanding the pathological mechanisms through research on animal models and clinical trials, there are still limitations to be addressed. Future research should focus on exploring molecular targets, personalized medicine, long-term management strategies, and interdisciplinary approaches. By leveraging advanced technologies like systems biology, omics technology, big data, and artificial intelligence, a comprehensive analysis of HAPH pathogenesis can lead to the identification of new treatment targets and strategies, ultimately enhancing patient quality of life and prognosis. Furthermore, research on health monitoring and preventive measures for populations living at high altitudes should be intensified to reduce the incidence and mortality of HAPH.

Sex-dependent Pathophysiology and Therapeutic Considerations in Right Heart Disease

Right ventricular (RV) adaptation to the increased afterload in the setting of pulmonary hypertension (PH) and other cardiac and pulmonary vascular conditions is a major determinant of survival. Although the RV remains understudied and less well understood than the left ventricle, recent advances have been made in understanding the function and biology of the RV in health and in disease, particularly in PH. RV adaptation in PH exhibits significant sexual dimorphisms in pathophysiology, adaptation, and outcomes. Despite a higher incidence of PH, women consistently demonstrate better RV adaptation and survival rates in the setting of increased RV afterload compared with men. Sexual dimorphisms extend to therapy responsiveness, with women benefiting more from certain pulmonary vasodilators and exhibiting superior RV recovery. In this review we discuss the current literature on sexual dimorphisms in RV structure, function, and molecular pathways in health and disease, as well as in RV-specific clinical manifestations, treatments, and outcomes in PH. Sex steroid-mediated effects as well as emerging studies on sex steroid-independent effects are reviewed. In general, sex steroids such as 17β-estradiol and dehydroepiandrosterone exert RV-protective effects. In contrast, testosterone negatively impacts RV structure and function. Emerging evidence highlights the influence of nonhormonal genetic determinants, such as BMPR1A and DMRT2 loci, which are associated with better RV function in women. A better understanding of the interplay between sex hormones, genetic factors, and RV biology is crucial for advancing and developing RV-directed therapies for patients of either sex.

Right Ventricular Stiffening and Anisotropy Alterations in Pulmonary Hypertension: Mechanisms and Relations to Right Heart Failure

BACKGROUND

Pulmonary hypertension (PH) results in increased right ventricular (RV) afterload, leading to RV dysfunction and failure. The mechanisms underlying maladaptive RV remodeling are poorly understood. In this study, we investigated the multiscale and mechanistic nature of RV free-wall (RVFW) biomechanical remodeling and its correlations with RV function adaptations.

METHODS

Mild and severe models of PH, consisting of a hypoxia model in Sprague-Dawley rats (n=6 each, control and PH) and a Sugen-hypoxia model in Fischer rats (n=6 each, control and PH), were used. Organ-level function, tissue-level stiffness, and microstructure were quantified through in vivo and ex vivo measures, respectively. Multiscale analysis was used to determine the association between fiber-level remodeling, tissue-level stiffness and anisotropy, and organ-level dysfunction.

RESULTS

Decreased RV-pulmonary artery coupling correlated strongly with RVFW stiffening but showed a weaker association with the loss of RVFW anisotropy. Machine-learning classification identified the range of adaptive and maladaptive RVFW stiffening. Multiscale modeling revealed that increased collagen fiber tautness was a key remodeling mechanism that differentiated severe from mild stiffening. Myofiber orientation analysis indicated a shift away from the predominantly circumferential fibers observed in healthy RVFW specimens, leading to a significant loss of tissue anisotropy.

CONCLUSIONS

Multiscale biomechanical analysis indicated that, although hypertrophy and fibrosis occur in both mild and severe PH, certain fiber-level remodeling events, including increased tautness of collagen fibers and significant reorientations of myofibers, contributed to excessive biomechanical maladaptation of the RVFW leading to severe RV-pulmonary artery uncoupling. Collagen fiber remodeling and the loss of tissue anisotropy can provide an improved understanding of the transition from adaptive to maladaptive RV remodeling.

Death-associated protein kinase 1 prevents hypoxia-induced metabolic shift and pulmonary arterial smooth muscle cell proliferation in PAH

Pulmonary hypertension (PH) is a general term used to describe high blood pressure in the lungs from any cause. Pulmonary arterial hypertension (PAH) is a progressive, and fatal disease that causes the walls of the pulmonary arteries to tighten and stiffen. One of the major characteristics of PAH is the hyperproliferation and resistance to apoptosis of vascular cells, which trigger excessive pulmonary vascular remodeling and vasoconstriction. The death-associated protein DAP-kinase (DAPK) is a tumor suppressor and Ser/Thr protein kinase, which was previously shown to regulate the hypoxia inducible factor (HIF)-1α. Against this background, we now show that DAPK1 regulates human pulmonary arterial smooth muscle cell (hPASMC) proliferation and energy metabolism in a HIF-dependent manner. DAPK1 expression is downregulated in pulmonary vessels and PASMCs of human and experimental PH lungs. Reduced expression of DAPK1 in hypoxia and non-hypoxia PAH-PASMCs correlates with increased expression of HIF-1/2α. RNA interference-mediated depletion of DAPK1 leads to fundamental metabolic changes, including a significantly decreased rate of oxidative phosphorylation associated with enhanced expression of both HIF-1α and HIF-2α and glycolytic enzymes, as hexokinase 2 (HK2), lactate dehydrogenase A (LDHA), and an integrator between the glycolysis and citric acid cycle, pyruvate dehydrogenase kinase 1 (PDK1). DAPK1 ablation in healthy donor hPASMCs leads to an increase in proliferation, while its overexpression provides the opposite effects. Together our data indicate that DAPK1 serves as a new inhibitor of the pro-proliferative and glycolytic phenotype of PH in PASMCs acting via HIF-signaling pathway.

Population Pharmacokinetic/Pharmacodynamic and Exposure-Response Modeling Analyses of Sotatercept in Healthy Participants and Patients with Pulmonary Arterial Hypertension

Sotatercept is a breakthrough, first-in-class biologic, recently approved by the Food and Drug Administration (FDA) for the treatment of pulmonary arterial hypertension (PAH). Exposure-response (E-R) analyses and pharmacokinetic/pharmacodynamic (PK/PD) modeling were performed for sotatercept after intravenous and subcutaneous (SC) administrations. Clinical endpoints included 6-minute walk distance (6MWD), pulmonary vascular resistance (PVR), and probability of N-terminal pro-B natriuretic peptide (NT-proBNP) concentrations < 300 pg/mL for efficacy, and hemoglobin (Hgb) for safety from two Phase 1 studies, two Phase 2 studies, and one Phase 3 study. E-R models using nonlinear mixed effect modeling approach were developed for 6MWD and PVR, while Cox proportional hazards model and semi-mechanistic PK/PD model were used for NT-proBNP and Hgb. Covariate analyses were conducted to identify significant predictors of variability for each of these clinical endpoints. Modeling results showed that increasing sotatercept average concentration (Cavg) at week 24 is associated with increased predicted 6MWD, increased probability of NT-proBNP concentration < 300 pg/mL, decreased predicted PVR, and increased Hgb which was clinically manageable. All these responses approached their corresponding plateaus at a Cavg range associated with the dose of 0.7 mg/kg Q3W SC. Statistically relevant covariates included age and iron supplementation which slightly increased Hgb-mediated effect for 6MWD, PAH disease duration, and baseline therapy infusion with prostacyclin for PVR, and WHO functional class for NT-proBNP. The magnitudes of the impact of these covariates are not clinically meaningful. Taken together, these results support an appropriate benefit-risk profile for the FDA-approved target dose for sotatercept of 0.7 mg/kg Q3W SC.

The role of the TAPSE/sPAP ratio as a predictor of mortality in Pulmonary Arterial Hypertension: Its value for patient risk stratification

Background

The tricuspid annular plane systolic excursion and systolic pulmonary artery pressure (TAPSE/sPAP) ratio has been proposed as an indicator of ventriculo-arterial coupling, predicting right ventricular failure (RVF) and mortality in patients with pulmonary arterial hypertension (PAH).

Objective

To evaluate the usefulness of the TAPSE/sPAP ratio in predicting outcomes and improving risk stratification in patients with PAH.

Methods

156 patients with PAH were included. Clinical, functional, echocardiographic, and haemodynamic variables, along with the TAPSE/sPAP ratio, were analysed based on etiological PAH subgroups and outcomes. Additional statistical measures, such as the area under the curve (AUC), net reclassification index (NRI), and integrated discrimination improvement, assessed the predictive ability of TAPSE/sPAP in combination with the ESC/ERS risk score, and other risk assessment strategies (COMPERA and Reveal Lite 2).

Results

Most patients were female (86.5%), with a median age of 45.5 (IQR: 29-58) years. The TAPSE/sPAP ratio for the whole group was 0.26 (IQR: 0.190-0.347) mm/mmHg, which was similar among different aetiologies, but different between deceased and surviving patients (0.14 vs. 0.27 mm/mmHg, respectively, P < 0.001). A TAPSE/sPAP ratio <0.18 mm/mmHg independently predicted mortality (AUC: 0.859, 95% CI: 0.766- 0.952; P < 0.001). Integration with the ESC/ERS risk score improved predicted mortality (AUC: 0.87 vs. 0.75, p = 0.002) and risk stratification, reclassifying 14.28% of events and 36.92% of non-events, with an NRI of 39.4% (P < 0.001). Likewise, integration with other scores improved predicted ability of COMPERA and REVEA Lite2; COMPERA+TAPSE/sPAP (AUC: 0.837 vs 0.742; p = 0.005) and REVEAL Lite 2 +TAPSE/sPAP (AUC: 0.840 vs. 0.713; p < 0.001).

Conclusions

A TAPSE/sPAP ratio <0.18 mm/mmHg predicts mortality in PAH. The combination of the TAPSE/sPAP ratio with the ESC/ERS risk score improved risk stratification, and reclassification emphasizing the potential of ESC/ERS+TAPSE/sPAP as a valuable tool for risk assessment and clinical decision-making in PAH patients. Integration of TAPSE/sPAP ratio with other scores (COMPERA and (REVEAL Lite 2) also improved the risk stratification and reclassification of these risk scores.

Prognostic Value of Echocardiographic Coupling Metrics in Systemic Sclerosis-Associated Pulmonary Vascular Disease

BACKGROUND

Ineffective right ventricular (RV) adaptation to increasing pulmonary arterial (PA) afterload in pulmonary vascular disease (PVD) significantly contributes to morbidity and mortality. Pulmonary vascular disease in systemic sclerosis (SSc) arises through various mechanisms, yet detecting abnormal contractile response remains challenging. Here we examine whether echocardiographic RV-PA coupling metrics correlate with invasive pressure-volume (PV) loops, enhancing the prediction of adverse clinical outcomes in SSc-PVD patients.

METHODS

Prospectively enrolled patients with SSc-PVD with paired echocardiogram and PV loops were included. Linear regression and receiver-operating curve analysis were used to assess the relationship between tricuspid annular plane systolic excursion/PA systolic pressure (PASP), fractional area change/PASP, tissue Doppler velocityS'/PASP, and RV free wall strain (RVFWS)/PASP and coupling thresholds defined by end-systolic to end-arterial elastance (Ees/Ea), obtained by the multibeat method. The contribution of right atrial strain (RAS) to RV-PA coupling parameters was also investigated. Kaplan-Meier analysis was used to identify the relationship between coupling ratios and composite outcomes including clinical worsening, lung transplant, and death.

RESULTS

Forty-two patients with SSc were studied, 91% female, with a mean age of 59 ± 12 years and varying degrees of PVD: mean pulmonary artery pressure 29.5 ± 12.8 mm Hg, PVR 4.7 ± 4.2 WU, and PCWP 10.3 ± 4.1 mm Hg. Echocardiographic coupling metrics including tricuspid annular plane systolic excursion/PASP, fractional area change/PASP, tissue Doppler velocity S'/PASP, RVFWSglobal and RVFWSbasal/PASP, and RASreservoir/PASP were linearly associated with Ees/Ea. At cut points obtained through receiver-operating curve analysis, all ratios were predictive of RV-PA uncoupling, defined by Ees/Ea, and composite outcomes. Additionally, RASreservoir/RVFWS correlated with Ees/Ea even after adjustment for PASP, suggesting that diminished RAS further impacts RV performance and coupling.

CONCLUSION

Echocardiographic RV-PA coupling ratios strongly correlate with invasive Ees/Ea and predict adverse clinical outcomes in SSc patients across the spectrum of PVD. Further, we demonstrate how RAS impacts RV performance. These findings may refine risk stratification and prognostication in this at-risk cohort.

From Pathophysiology to Practice: Evolving Pharmacological Therapies, Clinical Complications, and Pharmacogenetic Considerations in Portal Hypertension

Background: Portal hypertension is a major complication of chronic liver diseases, leading to serious issues such as esophageal variceal bleeding. The increase in portal vein pressure is driven by both an organic component and a functional component, including tonic contraction of hepatic stellate cells. These processes result in a pathological rise in intrahepatic vascular resistance, stemming from partial impairment of hepatic microcirculation, which is further exacerbated by abnormalities in extrahepatic vessels, including increased portal blood flow. Objectives: This review aims to provide a comprehensive overview of the evolving pharmacological therapies for portal hypertension, with consideration and discussion of pathophysiological mechanisms, clinical complications, and pharmacogenetic considerations, highlighting potential directions for future research. Methods: A review of recent literature was performed to evaluate current knowledge and potential therapeutic strategies in portal hypertension. Results: For over 35 years, non-selective beta-blockers have been the cornerstone therapy for portal hypertension by reducing portal vein inflow as an extrahepatic target, effectively preventing decompensation and variceal hemorrhages. However, since not all patients exhibit an adequate response to non-selective beta-blockers (NSBBs), and some may not tolerate NSBBs, alternative or adjunctive therapies that enhance the effects of NSBBs on portal pressure are being investigated in preclinical and early clinical studies. Conclusions: A better understanding of pharmacogenetic factors and pathophysiological mechanisms could lead to more individualized and effective treatments for portal hypertension. These insights highlight potential directions for future research.

Evolving perspectives on aortic stenosis: the increasing importance of evaluating the right ventricle before aortic valve intervention

Aortic stenosis (AS) was historically considered a disease of the left side of the heart, with the main pathophysiological impact being predominantly on the left ventricle (LV). However, progressive pressure overload in AS can initiate a cascade of extra-valvular myocardial remodeling that could also precipitate maladaptive alterations in the structure and function of the right ventricle (RV). The haemodynamic and clinical importance of these changes in patients with AS have been largely underappreciated in the past. Contemporary data indicates that RV dilatation or impairment identifies the AS patients who are at increased risk of adverse clinical outcomes after aortic valve replacement (AVR). It is now increasingly recognised that effective quantitative assessment of the RV plays a key role in delineating the late clinical stage of AS, which could improve patient risk stratification. Despite the increasing emphasis on the pathological significance of RV changes in AS, it remains to be established if earlier detection of these changes can improve the timing for intervention. This review will summarise the features of normal RV physiology and the mechanisms responsible for RV impairment in AS. In addition, we will discuss the multimodality approach to the comprehensive assessment of RV size, function and mechanics in AS patients. Finally, we will review the emerging evidence reinforcing the negative impact of RV dysfunction on clinical outcomes in AS patients treated with AVR.

Effect of Famotidine on Outcomes in Pulmonary Arterial Hypertension: A Randomized Controlled Trial

BACKGROUND

Adaptation of the right ventricle is a key determinant of outcomes in pulmonary arterial hypertension (PAH). Despite a compelling rationale to develop targeted therapies for the right ventricle in PAH, no such treatments exist. H2-receptor antagonism is a potential myocardial-focused paradigm in heart failure.

RESEARCH QUESTION

Do H2-receptor antagonists improve outcomes in patients with PAH?

STUDY DESIGN AND METHODS

We conducted a 24-week, single-center, 1:1 randomized, double-masked, placebo-controlled trial of the H2-receptor antagonist famotidine in patients with a diagnosis of PAH. The primary outcome was change in 6-minute walk distance (6MWD) at 24 weeks. Secondary end points included B-type natriuretic peptide levels, New York Heart Association functional class, right ventricular parameters measured from echocardiography, health-related quality of life, and escalation in PAH-focused care.

RESULTS

From May 2019 through July 2023, 80 participants were randomized with 79 receiving study drug. No significant difference in the primary outcome of 6MWD at 24 weeks was found, with an increase of 4.7 m seen in the placebo arm vs a decrease of 17.0 m in the famotidine arm (P = .24). Also no differences were found in secondary end points at 24 weeks. Study drug was well tolerated, and safety profiles were similar between arms. Adherence and study conduct were good overall. Participants with methamphetamine-associated PAH were similar in all aspects to the study participants more broadly.

INTERPRETATION

The results of this trial do not support the routine use of famotidine 20 mg daily as an adjunct therapy for the treatment of PAH. The findings of the Repurposing a Histamine Antagonist to Benefit Patients With Pulmonary Hypertension (REHAB-PH) trial argue against the practice of avoiding participants with methamphetamine-associated PAH in randomized clinical trials of novel therapies.

CLINICAL TRIAL REGISTRY

ClinicalTrials.gov; No.: NCT03554291; URL: www.

CLINICALTRIALS

gov.

Myocardial Disease in Systemic Sclerosis: Recent Updates and Clinical Implications

PURPOSE OF REVIEW

The present review aims to address systemic sclerosis (SSc)-associated myocardial disease, a significant cause of morbidity and mortality, by examining the mechanisms of inflammation, microvascular dysfunction, and fibrosis that drive cardiac involvement. The objective is to elucidate critical risk factors and explore advanced diagnostic tools for early detection, enhancing patient outcomes by identifying those at highest risk.

RECENT FINDINGS

Recent studies underscore the importance of specific autoantibody profiles, disease duration, and cardiovascular comorbidities as key risk factors for severe cardiac manifestations in SSc. Additionally, advanced imaging techniques and biomarker analyses have emerged as pivotal tools for early identification and risk stratification. These innovations enable clinicians to detect subclinical myocardial involvement, potentially averting progression to symptomatic disease. SSc-associated myocardial disease remains challenging to predict, yet novel imaging modalities and biomarker-guided strategies offer a promising pathway for early diagnosis and targeted intervention. Integrating these approaches may enable more effective early detection and screening strategies as well as mitigation of disease progression, ultimately enhancing clinical outcomes for patients with SSc at-risk for adverse clinical outcomes.

Serial and regional assessment of the right ventricular molecular and functional response to pressure loading

Right ventricular (RV) function determines outcomes in RV pressure loading. A better understanding of the time-course and regional distribution of RV remodeling may help optimize targets and timing for therapeutic intervention. We sought to characterize RV remodeling between zero and 6 wk after the initiation of RV pressure loading. Thirty-six rats were randomized to either sham surgery or to pulmonary artery banding (PAB). After echocardiography and conductance catheter studies, groups of rats were euthanized at 1 wk, 3 wk, and 6 wk after sham surgery, or induction of RV pressure loading, for RV histological, RNA, and molecular analysis. A vigorous inflammatory response characterized by increased RV inflammatory cytokines, chemokines, and macrophage markers was observed at 1 wk following PAB. Metabolic changes, transforming growth factor-β (TGF-β)1 canonical signaling, collagenous fibrosis deposition, and apoptosis were already significantly increased by 1 wk after PAB. Genes marking fibroblast activation were upregulated at 1 wk but not at 6 wk post-PAB surgery. Mitochondrial dysfunction was evidenced by increased pyruvate dehydrogenase kinase (PDK) activity and decreased pyruvate dehydrogenase (PDH) phosphorylation significantly at 6-wk post-PAB. These processes preceded the development of overt myocardial hypertrophy and impaired echo parameters of systolic and diastolic function that occurred significantly from 3 wk after PAB. RV myocardial inflammation, metabolic shift, metabolic gene transcription, and profibrotic signaling occur early after initiation of pressure loading when RV pressures are only moderately elevated, before the development of overt myocardial hypertrophy and dysfunction, suggesting that adaptive hypertrophy and maladaptive remodeling occur simultaneously. These results suggest that therapeutic intervention to reduce adverse RV remodeling may be needed earlier and at lower thresholds than currently used.NEW & NOTEWORTHY Exploring the dynamics of right ventricular remodeling: unveiling the intricate interplay between inflammation, metabolic shifts, and fibrotic signaling in response to pressure loading. Through a comprehensive study spanning from initiation to 6 wk post-pressure loading, our research sheds light on the early onset of crucial molecular processes preceding overt hypertrophy and dysfunction. These findings challenge conventional intervention timing, advocating for early, targeted therapeutic strategies to mitigate adverse remodeling in right ventricular pressure loading.

The Prognostic Value of Right Ventricular End-Diastolic Basal Diameter Index by Echocardiography in Connective Tissue Diseases Associated With Pulmonary Artery Hypertension

BACKGROUND

Right ventricular (RV) failure is a well-recognized pivotal prognostic factor of adverse outcomes in pulmonary artery hypertension (PAH), while RV dilation provides significant implications for adaptive or maladaptive changes. PAH is a predominant cause of mortality among patients with connective tissue disease (CTD). This study aims to elucidate the prognostic significance of RV morphology, as assessed by echocardiography (ECHO), in with CTD associated with PAH (CTD-PAH).

METHODS

In this ambispective cohort study, 143 CTD-PAH patients diagnosed by right-sided heart catheterization (RHC) from 2013 to 2023 were enrolled. Clinical characteristics, laboratory data, echocardiographic parameters (right ventricular end-diastolic basal diameter index (RVDDI), tricuspid annular plane systolic excursion (TAPSE) and pulmonary arterial systolic pressure (PASP)) and therapy were recorded. The primary endpoint was defined as clinical worsening within a five-year timeframe. Analytical methods included Kaplan-Meier survival analyses, the log-rank test, and multivariable Cox proportional hazards regression to evaluate prognostic factors.

RESULTS

The study enrolled a total of 143 patients with CTD-PAH, with a notable female predominance (95.1%) and a median age of 41.67 years; SLE-PAH (49%) and pSS-PAH (34%) were the most common subtypes, and 94% of the participants were in WHO-FC II-III. Among the participants, 34 (23.8%) patients experienced clinical worsening during a median follow-up period of 21 months. After adjusting for confounders such as age and sex, RVDDI, as determined by ECHO was correlated with clinical worsening (HR 1.090; 95% CI: 1.019-1.166; p = 0.012). RVDDI > 25.81 mm/m2 predicts higher incidence of clinical worsening in CTD-PAH. In the subgroup of TAPSE/PASP > 0.19 mm/mmHg, patients with RVDDI > 25.81 mm/m2 had a higher incidence of clinical worsening. The estimated event-free survival rates at 1 and 3 years were 93.5% and 53.7%, respectively.

CONCLUSION

The study demonstrates that RVDDI, as evaluated by ECHO, is a significant prognostic indicator for clinical worsening in CTD-PAH. Its inclusion in the assessment of RV function and risk stratification may provide valuable incremental prognostic information for this CTD-PAH population.

Normal Hemodynamic Response to Exercise

Exercise pulmonary hypertension has been invasively defined as mean pulmonary artery pressure/cardiac output slope greater than 3 mm Hg/L/min. Recent advances suggest the sustainable role of exercise Doppler echocardiography for the study of the right heart and pulmonary circulation unit (RH-PCU). Herein, the authors review the invasive versus non-invasive monitoring of the RH-PCU response to exercise in healthy subjects.

The tricuspid annular plane systolic excursion/PASP ratio's accuracy and validity in assessing the right ventricular function: A narrative review

The tricuspid annular plane systolic excursion (TAPSE) (transthoracic apical two-chamber stretch) and pulmonary artery systolic pressure (PASP) ratio is a measure of cardiac function that is used to assess left ventricular systolic function. PASP is typically measured using a catheterization procedure, in which a small tube is inserted into a blood vessel and advanced to the pulmonary artery. A TAPSE/PASP ratio higher than 0.36 mm/mmHg has been shown in several studies to be a good sign of normal or generally well-maintained right ventricular function. It is important to note that the TAPSE/PASP ratio should be interpreted in the context of other clinical findings and should not be used as the sole indicator of cardiac function. A decrease in the TAPSEpulmonary arterial systolic pressure (PASP) ratio (i.e., (RV)-arterial uncoupling), which quantitatively depicts the function of the RV, was detected in patients with heart failure. In pulmonary arterial hypertension patients, TAPSE/PASP is linked to hemodynamics and functional class. In diseases impacting right cardiac function, the TAPSE/PASP may also be beneficial. The purpose of this review is to demonstrate how the TAPSE/PASP impacts how the (RV) functions. We believe that this is the first review on the topic written.

Right ventricular reserve in cardiopulmonary disease: A simultaneous hemodynamic and three-dimensional echocardiographic study

BACKGROUND

Right ventricular (RV) reserve has been linked to exercise capacity and prognosis in cardiopulmonary diseases. However, evidence in this setting is limited, due to the complex shape and load dependency of the RV. We sought to study RV adaptation to exercise by simultaneous three-dimensional echocardiography (3DE) and right heart catheterization (RHC).

METHODS

Patients with heart failure with preserved ejection fraction (HFpEF) or pulmonary vascular disease (PVD) underwent simultaneous supine rest/exercise RHC-3DE. They were subdivided based on RV ejection fraction (EF) changes: (1) exhausted RV reserve, RVEF-; (2) preserved RV reserve, RVEF+.

RESULTS

Sixty percent of patients were RVEF-. Distribution of HFpEF/PVD, as well as RV volumes and RVEF at rest were similar in the 2 groups. Hemodynamic metrics of RV afterload, as well as their exercise-induced changes, were similar in the 2 groups. During exercise, RV end-diastolic volume increased more in RVEF- than in RVEF+ (29±29 vs 7±25 ml, p<0.05). RV end-systolic volume increased by 21[12;31] ml in RVEF- and decreased by 8[-15;1] ml in RVEF+ (p<0.001). RV-pulmonary artery coupling was lower in RVEF- at peak exercise (p<0.05). Peak RVEF was associated with left ventricular preload (R2=0.14, p=0.011). Cardiac output increased less in RVEF- than in RVEF+ (+2.3±2.0 vs +4.0±2.4 liter/min, p<0.05). Peak RVEF was associated with oxygen consumption (p<0.01).

CONCLUSIONS

Exhausted RV reserve, as evaluated by 3DE, was frequent in HFpEF and PVD, was relatively independent from classical afterload parameters, was associated with RV-pulmonary artery decoupling, RV dilation, enhanced ventricular interdependence, and cardiac limitation to exercise. Intrinsic RV dysfunction may contribute to exhausted RV reserve.

When pulmonary arterial hypertension and pregnancy meet: a multidisciplinary clinical experts review

Pulmonary hypertension (PH) is a rare condition characterized by elevated pulmonary arterial pressure and pulmonary vascular resistance, potentially leading to right ventricular failure. Pulmonary arterial hypertension (PAH) is the most common type of PH in women of childbearing age and, as per the modified World Health Organization (mWHO) classification of maternal cardiovascular risk, it falls into mWHO class IV and pregnancy is contraindicated. These patients face an exceptionally high risk of maternal mortality and morbidity, with estimated maternal cardiac event rates ranging from 40 to 100% during pregnancy, because physiological changes happening in pregnancy exacerbate the disorder. Despite these recommendations, there is a growing incidence of pregnancy among women with PAH. Early referral to specialized centers, personalized therapies and expert multidisciplinary care involving pulmonary hypertension specialists, obstetricians, critical care specialists, anesthesiologists, and neonatologists are crucial steps to ensure positive outcomes for both mother and fetus. This review aims to examine the current understanding of pregnancy in patients with PAH, drawing on the experience of our center in the multidisciplinary management of pregnant women with this condition. In particular, we want to focus the attention of clinicians on the following aspects: early referral of pregnant patients to specialized centers, detailed counseling on the implications of pregnancy, initiation of therapy in treatment-naive patients and potential adjustment of therapy in non-naive patients, periodic risk assessment, evaluation of the appropriate timing of delivery, multidisciplinary management of the most critical periods, which are delivery and the post-partum phase.

Cathepsin L Promotes Pulmonary Hypertension via BMPR2/GSDME-Mediated Pyroptosis

BACKGROUND

Pulmonary hypertension (PH) is a fatal progressive disease characterized by pulmonary endothelial injury and occlusive pulmonary vascular remodeling. Lysosomal protease cathepsin L degrades essential molecules to participate in the human pathophysiological process. BMPR2 (bone morphogenetic protein type II receptor) deficiency, an important cause of PH, results from mutational inactivation or excessive lysosomal degradation and induces caspase-3-mediated cell death. Given recent evidence that pyroptosis, as a new form of programmed cell death, is induced by caspase-3-dependent GSDME (gasdermin E) cleavage, we hypothesized that cathepsin L might promote PH through BMPR2/caspase-3/GSDME axis-mediated pyroptosis.

METHODS

Cathepsin L expression was evaluated in the lungs and plasma of patients with pulmonary arterial hypertension. The role of cathepsin L in the progression of PH and vascular remodeling was assessed in vivo. Small interfering RNA, specific inhibitors, and lentiviruses were used to explore the mechanisms of cathepsin L on human pulmonary arterial endothelial cell dysfunction.

RESULTS

Cathepsin L expression is elevated in pulmonary artery endothelium from patients with idiopathic pulmonary arterial hypertension and experimental PH models. Genetic ablation of cathepsin L in PH rats relieved right ventricular systolic pressure, pulmonary vascular remodeling, and right ventricular hypertrophy, also restoring endothelial integrity. Mechanistically, cathepsin L promotes caspase-3/GSDME-mediated endothelial cell pyroptosis and represses BMPR2 signaling activity. Cathepsin L degrades BMPR2 via the lysosomal pathway, and restoring BMPR2 signaling prevents the pro-pyroptotic role of cathepsin L in PAECs and experimental PH models.

CONCLUSIONS

These results show for the first time that cathepsin L promotes the development of PH by degrading BMPR2 to induce caspase-3/GSDME-mediated endothelial pyroptosis.

Association between right heart size and right ventricular output reserve in patients with pulmonary arterial hypertension

OBJECTIVES

Right ventricular (RV) output reserve, defined as increase of cardiac output during exercise, is reduced in patients with pulmonary arterial hypertension (PAH). Aim of this study was to evaluate the association of right heart size measured by echocardiography and invasively measured RV function at rest and during exercise in PAH patients.

METHODS

Adult PAH-patients who received routine haemodynamic assessment at rest and during exercise by right heart catheterisation and echocardiographic measurement of right heart size (right atrial (RA) and RV area) were included in this study. Clinical, echocardiographic, laboratory, exercise and invasive haemodynamic parameters were retrospectively analysed. The primary endpoint was to assess the association between right heart size and right ventricular function.

RESULTS

Data from 215 PAH patients (age 58.9 ± 15.9 years, 63.3% female, 62.2% double or triple combination treatment) were analysed in this cross-sectional study. Cardiac index was significantly lower for patients with enlarged RA-area > 18 cm2 at rest, and at 25 and 50 W (all p < 0.001) and for patients with enlarged RV area > 20 cm2 at rest, 25, 50 and 75 W (all p < 0.001). Furthermore, pulmonary vascular resistance and mPAP/CO slope (all p < 0.001) were significantly higher and pulmonary arterial compliance (all p < 0.05) was significantly lower in patients with enlarged RA or RV area. RA and RV area correlated with TAPSE/sPAP (both p < 0.001, R - 0.570 and - 0.530).

CONCLUSION

This study could underline that an enlargement of RA- and RV-area is associated with an impaired RV function at rest and during exercise in patients with PAH.

A combination of clinical, electrocardiographic, and echocardiographic parameters predicts pulmonary hypertension occurrence in patients with end-stage renal disease

Background

Pulmonary hypertension (PH) in patients with end-stage renal disease (ESRD) has a high incidence rate and mortality and its early identification is critical. However, whether a combination of clinical, electrocardiographic, and echocardiographic parameters can predict the occurrence of PH in patients with ESRD remains to be elucidated. Herein, we evaluated the predictive value of the combined score of these parameters.

Methods

Data from 370 patients with newly diagnosed ESRD who underwent routine echocardiography and electrocardiography between May 2016 and May 2017 were retrospectively evaluated. The incidence of PH during a 60-month follow-up period was investigated. Twenty-one patients were excluded due to incomplete data among other reasons. Finally, 349 patients were included in the analysis, of whom, 158 (45%) developed PH.

Results

Analysis of electrocardiogram reports suggested that a corrected Q-T interval (QTc) of >438.5 ms was associated with PH. Echocardiographic reports suggest that left atrial diameter (LAD), interventricular septum thickness in end-diastole (IVSd), stroke volume (SV), and pericardial effusion are also associated with PH development. Results of multivariate Cox analysis showed that LAD >3.785 cm, IVSd >1.165 cm, SV >79.5 ml, QTc >438.5 ms, and pericardial effusion were independent predictors of PH in patients with ESRD. The incidence of new-onset PH increased significantly with increasing composite scores, that is, the sum of risk scores determined using hazard ratios.

Conclusions

A total score that includes a combination of parameters such as LAD >3.785 cm, IVSd>1.165 cm, SV >79.5 ml, QTc >438.5 ms, and pericardial effusion can help describe the risk of new-onset PH.

Optical coherence tomography angiography of the retina and choroid in systemic diseases

Optical coherence tomography angiography (OCTA) has transformed ocular vascular imaging, revealing microvascular changes linked to various systemic diseases. This review explores its applications in diabetes, hypertension, cardiovascular diseases, and neurodegenerative diseases. While OCTA provides a valuable window into the body's microvasculature, interpreting the findings can be complex. Additionally, challenges exist due to the relative non-specificity of its findings where changes observed in OCTA might not be unique to a specific disease, variations between OCTA machines, the lack of a standardized normative database for comparison, and potential image artifacts. Despite these limitations, OCTA holds immense potential for the future. The review highlights promising advancements like quantitative analysis of OCTA images, integration of artificial intelligence for faster and more accurate interpretation, and multi-modal imaging combining OCTA with other techniques for a more comprehensive characterization of the ocular vasculature. Furthermore, OCTA's potential future role in personalized medicine, enabling tailored treatment plans based on individual OCTA findings, community screening programs for early disease detection, and longitudinal studies tracking disease progression over time is also discussed. In conclusion, OCTA presents a significant opportunity to improve our understanding and management of systemic diseases. Addressing current limitations and pursuing these exciting future directions can solidify OCTA as an indispensable tool for diagnosis, monitoring disease progression, and potentially guiding treatment decisions across various systemic health conditions.

In Vivo Anti-Inflammatory Activity of D-Limonene in a Rat Model of Monocrotaline-Induced Pulmonary Hypertension: Implications to the Heart Function

BACKGROUND

D-limonene (D-L) is the major monocyclic monoterpene in citrus plants with anti-inflammatory properties. Pulmonary hypertension (PH) can cause right heart dysfunction and increases the risk of death, partially due to inflammatory response in the heart.

OBJECTIVE

To evaluate the possible protective effect of D-L on cardiac function in a rat model of monocrotaline-induced PH (MCT-PH).

METHODS

Electrocardiogram was monitored in vivo. Masson Trichrome technique was deployed to verify fibrosis in the heart. Contractility function of isolated atrial tissue was studied using organ bath chamber. Real-time quantitative PCR was applied to quantify inflammation in the right ventricle.

RESULTS

The MCT-PH group showed electrical and structural heart remodeling, with the presence of fibrosis in the cardiac tissue and in vivo electrocardiographic changes. Treatment with D-L partially prevented the development of tissue fibrosis and the increase in P wave duration in the MCT-PH group. The contraction and relaxation velocity of isolated right and left atrium were accelerated in CTR and MCT-PH animals treated with D-L. Finally, D-L was able to prevent the abnormal expression of the key inflammatory cytokines (interleukin 1-β, interleukin 6 and tumor necrosis factor-α) in the right ventricle of MCT-PH animals. D-L was able to enhance the production of the anti-inflammatory cytokine Interleukin-10.

CONCLUSION

Our results showed that in vivo administration of D-L partially prevented the molecular, structural and functional remodeling of the heart in the MCT-PH model with attenuation of the inflammatory response in the heart.

Association between subclinical right ventricular alterations and aerobic exercise capacity in type 2 diabetes

BACKGROUND

Type 2 diabetes (T2D) leads to cardiovascular remodeling, and heart failure has emerged as a major complication of T2D. There is a limited understanding of the impact of T2D on the right heart. This study aimed to assess subclinical right heart alterations and their contribution to aerobic exercise capacity (peak oxygen consumption; peak VO2) in adults with T2D.

METHODS

Single center, prospective, case-control comparison of adults with and without T2D, and no prevalent cardiac disease. Comprehensive evaluation of the left and right heart was performed using transthoracic echocardiography and stress cardiovascular magnetic resonance. Cardiopulmonary exercise testing on a bicycle ergometer with expired gas analysis was performed to determine peak VO2. Between group comparison was adjusted for age, sex, race, and body mass index using analysis of covariance (ANCOVA). Multivariable linear regression, including key clinical and left heart variables, was undertaken in people with T2D to identify independent associations between measures of right ventricular (RV) structure and function with peak VO2.

RESULTS

Three hundred and forty people with T2D (median age 64years, 62% (211) male, mean glycated hemoglobin (HbA1c) 7.3%) and 66 controls (median age 58years, 58% (38) male, mean HbA1c 5.5%) were included. T2D participants had markedly lower peak VO2 (adjusted mean 20.3 (95% confidence interval (CI): 19.8-20.9) vs 23.3(22.2-24.5)mL/kg/min, P < 0.001) than controls and had smaller left ventricular (LV) volumes and LV concentric remodeling. Those with T2D had smaller RV volumes (indexed RV end-diastolic volume: 84 (82-86) vs 100 (96-104)mL/m, P < 0.001) with evidence of hyperdynamic RV systolic function (global longitudinal strain (GLS): 26.3 (25.8-26.8) vs 23.5 (22.5-24.5)%, P < 0.001) and impaired RV relaxation (longitudinal peak early diastolic strain rate (PEDSR): 0.77 (0.74-0.80) vs 0.92 (0.85-1.00) s-1, P < 0.001). Multivariable linear regression demonstrated that RV end-diastolic volume (β =-0.342, P = 0.004) and RV cardiac output (β = 0.296, P = 0.001), but not LV parameters, were independent determinants of peak VO2.

CONCLUSION

In T2D, markers of RV remodeling are associated with aerobic exercise capacity, independent of left heart alterations.

Pathophysiology of the right ventricle and its pulmonary vascular interaction

The right ventricle and its stress response is perhaps the most important arbiter of survival in patients with pulmonary hypertension of many causes. The physiology of the cardiopulmonary unit and definition of right heart failure proposed in the 2018 World Symposium on Pulmonary Hypertension have proven useful constructs in subsequent years. Here, we review updated knowledge of basic mechanisms that drive right ventricular function in health and disease, and which may be useful for therapeutic intervention in the future. We further contextualise new knowledge on assessment of right ventricular function with a focus on metrics readily available to clinicians and updated understanding of the roles of the right atrium and tricuspid regurgitation. Typical right ventricular phenotypes in relevant forms of pulmonary vascular disease are reviewed and recent studies of pharmacological interventions on chronic right ventricular failure are discussed. Finally, unanswered questions and future directions are proposed.

Screening and diagnosis of pulmonary hypertension associated with chronic lung disease (PH-CLD): A consensus statement from the pulmonary vascular research institute's innovative drug development initiative-group 3 pulmonary hypertension

Pulmonary hypertension (PH) is a frequent complication of chronic lung disease (CLD). However, PH is difficult to diagnose early since accompanying symptoms overlap and are similar to those of the underlying CLD. In most cases the PH is mild to moderate and therefore physical signs may be absent or subtle. This consensus paper provides insight into the clues that might suggest the presence of occult PH in patients with CLD. An overview of current diagnostic tools and emerging diagnostic technologies is provided as well as guidance for the work-up and diagnosis of PH in patients with CLD.

Effect of Preoperative Pulmonary Hypertension on the Course of Right Ventricular Function: A Three-dimensional Echocardiographic Study in Valvular Surgery Patients

Context

Postoperative right heart failure is a poor prognostic factor after cardiac surgery. However, the factors that influence perioperative right ventricular (RV) function remain unknown. This study investigated whether preoperative pulmonary hypertension (PH) affects changes in RV systolic function during the perioperative period.

Aims

This study aimed to determine the effect of preoperative PH on changes in RV systolic function in patients undergoing aortic or mitral valve surgery.

Settings and Design

This was a retrospective review of three-dimensional echocardiographic datasets of 157 patients undergoing aortic or mitral valve surgery.

Materials and Methods

Patients were classified into the PH (n = 105) or non-PH (n = 51) group based on preoperative right heart catheterization findings. RV ejection fraction and RV longitudinal strain (RVLS) of the free wall and septum were calculated using semiautomated image analysis software at four time points: before surgery, end of surgery, 3 months after surgery, and 1 year after surgery.

Statistical Analysis Used

A mixed-effects model was used to compare changes in RV function between groups.

Results

Over 1 year, no significant differences in trends were observed between groups for any of the parameters. However, a significant deterioration in free wall RVLS was observed in the non-PH group when focusing on the change from baseline to 1 year (P value for interaction = 0.013).

Conclusions

In patients undergoing valvular surgery, the presence of preoperative PH did not significantly influence changes in RV function throughout the perioperative period.

Deep phenotyping of unaffected carriers of pathogenic BMPR2 variants screened for pulmonary arterial hypertension

INTRODUCTION

Pathogenic variants in the gene encoding for BMPR2 are a major genetic risk factor for heritable pulmonary arterial hypertension. Owing to incomplete penetrance, deep phenotyping of unaffected carriers of a pathogenic BMPR2 variant through multimodality screening may aid in early diagnosis and identify susceptibility traits for future development of pulmonary arterial hypertension.

METHODS

28 unaffected carriers (44±16 years, 57% female) and 21 healthy controls (44±18 years, 48% female) underwent annual screening, including cardiac magnetic resonance imaging, transthoracic echocardiography, cardiopulmonary exercise testing and right heart catheterisation. Right ventricular pressure-volume loops were constructed to assess load-independent contractility and compared with a healthy control group. A transgenic Bmpr2Δ71Ex1/+ rat model was employed to validate findings from humans.

RESULTS

Unaffected carriers had lower indexed right ventricular end-diastolic (79.5±17.6 mL·m-2 versus 62.7±15.3 mL·m-2; p=0.001), end-systolic (34.2±10.5 mL·m-2 versus 27.1±8.3 mL·m-2; p=0.014) and left ventricular end-diastolic (68.9±14.1 mL·m-2 versus 58.5±10.7 mL·m-2; p=0.007) volumes than control subjects. Bmpr2Δ71Ex1/+ rats were also observed to have smaller cardiac volumes than wild-type rats. Pressure-volume loop analysis showed that unaffected carriers had significantly higher afterload (arterial elastance 0.15±0.06 versus 0.27±0.08 mmHg·mL-1; p<0.001) and end-systolic elastance (0.28±0.07 versus 0.35±0.10 mmHg·mL-1; p=0.047) in addition to lower right ventricular pulmonary artery coupling (end-systolic elastance/arterial elastance 2.24±1.03 versus 1.36±0.37; p=0.006). During the 4-year follow-up period, two unaffected carriers developed pulmonary arterial hypertension, with normal N-terminal pro-brain natriuretic peptide and transthoracic echocardiography indices at diagnosis.

CONCLUSION

Unaffected BMPR2 mutation carriers have an altered cardiac phenotype mimicked in Bmpr2Δ71Ex1/+ transgenic rats. Future efforts to establish an effective screening protocol for individuals at risk for developing pulmonary arterial hypertension warrant longer follow-up periods.

Defining Echocardiographic Degrees of Right Heart Size and Function in Pulmonary Vascular Disease from the PVDOMICS Study

Background

Defining qualitative grades of echocardiographic metrics of right heart chamber size and function is critical for screening, clinical assessment, and measurement of therapeutic response in individuals with pulmonary vascular disease (PVD). In a population enriched for PVD, we sought to establish qualitative grades and prognostic value of right heart chamber size and function.

Methods

We investigated 1053 study participants in the Redefining Pulmonary Hypertension through PVD Phenomics program (PVDOMICS) to determine clinical and echocardiographic differences associated with increasing pulmonary vascular resistance (PVR) severity. Right heart chamber size and function were qualitatively assessed using a percentile-based approach above the median values to create a clinical grading system for right heart adaptation. The relationship between echocardiographic categories and all-cause mortality was examined using survival analyses adjusted for potential confounders.

Results

A stepwise increase in adverse right heart remodeling was observed with a concomitant decrease in functional parameters by PVR strata (p<0.001 for all). Mild, moderate, and severe categories of right heart chamber size and dysfunction were defined using a percentile-based approach across the spectrum of PVD. During a median follow up of 2.07 years (interquartile range 1.23 - 3.01 years), 130 participants died (11.4%). Progressive PVR increase and 2DE evidence of right heart dysfunction inclusive of fractional area change, and right ventricular (RV) global longitudinal strain were independently associated with increased all-cause mortality risk in multivariate analysis adjusted for age, disease duration and male sex.

Conclusions

In this well-characterized sample of adults with diverse etiologies and varying PVD severity, we define categories of abnormal right heart chamber size and function. Further, we demonstrate a stepwise relationship between these categories of abnormal morphology and function and all-cause mortality. Defining grades of RV dysfunction in individuals with known PVD has important clinical implications for monitoring disease progression and response to therapies.

Asymmetric right ventricular myocardial work correlates with gold standard measurements of cardiac function in pulmonary hypertension

Right ventricular (RV) (dys)function determines outcomes in pulmonary hypertension (PH). We previously found that asymmetric RV myocardial work (MW) corresponds with inefficient RV function in experimental PH models. We therefore aimed to investigate regional distribution of RV MW and its correlation with catheter hemodynamics in children with PH. RV MW was calculated by longitudinal strain and simultaneous catheter pressure measurements in 14 patients with PH. Wasted MW was defined as the ratio of inappropriate myocardial lengthening to favorable shortening work. Segment-wise and averaged MW and wasted MW were evaluated at baseline and during pulmonary vasodilation therapy with oxygen and nitric oxide, and their relationship to hemodynamic measurements was analyzed. We found that MW was higher for the lateral wall than the septum: 1013 ± 374 mmHg · % versus 532 ± 190 mmHg · % at baseline. Wasted MW ratio did not differ significantly between wall regions. Pulmonary vasodilators slightly reduced mean pulmonary artery pressure and was accompanied by a more symmetrical MW distribution. Averaged MW correlated with the rate of RV pressure development (dP/dt maximum) and decay (dP/dt minimum) at all conditions (p ≤  0.047). The results suggest that MW contribute to, and may be used as a marker of, systolic and diastolic efficiency in the PH RV.

Right ventricular stroke work index in pulmonary arterial hypertension and chronic thromboembolic pulmonary hypertension: A retrospective observational study

The right ventricular stroke work index (RVSWI) reflects the active work of the right ventricle (RV), but its clinical usefulness is not yet fully known in pulmonary arterial hypertension (PAH) and chronic thromboembolic pulmonary hypertension (CTEPH). We aimed to evaluate the correlation of RVSWI to clinical parameters, the presence of comorbidities and response to therapy. We performed a retrospective observational study of 54 patients (PAH: N = 30, CTEPH: N = 24) and control patients (N = 11), and collected clinical data including RVSWI and comorbidities at baseline. We also compared changes in the parameters of the four-strata mortality risk score at follow-up (median time of 12 months) after the initiation of therapy between patients with low- (<1450 mmHg*mL/m2, N = 18) and high-RVSWI values (≥1450 mmHg*mL/m2, N = 19). RVSWI at diagnosis was higher in PAH/CTEPH compared to control subjects (1408 ± 391 vs. 704 ± 140 mmHg*mL/m2, p < 0.001, mean ± standard deviation, t-test), but did not differ between PAH and CTEPH patients (1406 ± 342 vs. 1409 ± 470 mmHg*mL/m2, p = 0.98). Patients without comorbidities had higher RVSWI than those with comorbidities (N = 23: 1522 ± 400 vs. N = 31: 1323 ± 384 mmHg*mL/m2, p = 0.04), which was also found in PAH (p < 0.001), but not in CTEPH (p = 0.37). A greater improvement in the four-strata mortality risk score (p < 0.05) and a trend for a larger reduction in N-terminal proB-type natriuretic peptide concentration (p = 0.06) were observed in the high-RVSWI subgroup than in the low-RVSWI patients at follow-up. In PAH and CTEPH, RVSWI provides additional information on RV function in comorbidities, and it may predict response to specific therapy. Regular monitoring of RVSWI may aid in optimizing therapy selection and timing.

Carotid Baroreceptor Stimulation Ameliorates Pulmonary Arterial Remodeling in Rats With Hypoxia-Induced Pulmonary Hypertension

BACKGROUND

Sympathetic hyperactivity plays an important role in the initiation and maintenance of pulmonary hypertension. Carotid baroreceptor stimulation (CBS) is an effective autonomic neuromodulation therapy. We aim to investigate the effects of CBS on hypoxia-induced pulmonary hypertension and its underlying mechanisms.

METHODS AND RESULTS

Rats were randomly assigned into 4 groups, including a Control-sham group (n=7), a Control-CBS group (n=7), a Hypoxia-sham group (n=10) and a Hypoxia-CBS group (n=10). Echocardiography, ECG, and hemodynamics examination were performed. Samples of blood, lung tissue, pulmonary arteries, and right ventricle were collected for the further analysis. In the in vivo study, CBS reduced wall thickness and muscularization degree in pulmonary arterioles, thereby improving pulmonary hemodynamics. Right ventricle hypertrophy, fibrosis and dysfunction were all improved. CBS rebalanced autonomic tone and reduced the density of sympathetic nerves around pulmonary artery trunks and bifurcations. RNA-seq analysis identified BDNF and periostin (POSTN) as key genes involved in hypoxia-induced pulmonary hypertension, and CBS downregulated the mRNA expression of BDNF and POSTN in rat pulmonary arteries. In the in vitro study, norepinephrine was found to promote pulmonary artery smooth muscle cell proliferation while upregulating BDNF and POSTN expression. The proliferative effect was alleviated by silence BDNF or POSTN.

CONCLUSIONS

Our results showed that CBS could rebalance autonomic tone, inhibit pulmonary arterial remodeling, and improve pulmonary hemodynamics and right ventricle function, thus delaying hypoxia-induced pulmonary hypertension progression. There may be a reciprocal interaction between POSTN and BDNF that is responsible for the underlying mechanism.

Effects of dopamine β-hydroxylase inhibition in pressure overload-induced right ventricular failure

Activation of the sympathetic nervous system is observed in pulmonary arterial hypertension patients. This study investigates whether inhibiting the conversion of dopamine into noradrenaline by dopamine β-hydroxylase (DβH) inhibition with BIA 21-5337 improved right ventricular (RV) function or remodeling in pressure overload-induced RV failure. RV failure was induced in male Wistar rats by pulmonary trunk banding (PTB). Two weeks after the procedure, PTB rats were randomized to vehicle (n = 8) or BIA 21-5337 (n = 11) treatment. An additional PTB group treated with ivabradine (n = 11) was included to control for the potential heart rate-reducing effects of BIA 21-5337. A sham group (n = 6) received vehicle treatment. After 5 weeks of treatment, RV function was assessed by echocardiography, magnetic resonance imaging, and invasive pressure-volume measurements before rats were euthanized. RV myocardium was analyzed to evaluate RV remodeling. PTB caused a fourfold increase in RV afterload which led to RV dysfunction, remodeling, and failure. Treatment with BIA 21-5337 reduced adrenal gland DβH activity and 24-h urinary noradrenaline levels confirming relevant physiological response to the treatment. At end-of-study, there were no differences in RV function or RV remodeling between BIA 21-5337 and vehicle-treated rats. In conclusion, treatment with BIA 21-5337 did not have any beneficial-nor adverse-effects on the development of RV failure after PTB despite reduced adrenal gland DβH activity.

Neurological and cardiopulmonary manifestations of pulmonary arteriovenous malformations

Pulmonary arteriovenous malformations (PAVMs) are direct pulmonary artery-to-vein connections without pulmonary capillaries that result in intrapulmonary right-to-left blood shunts. Although most patients with PAVMs may be entirely asymptomatic, PAVMs can induce a series of complications involving the neurological, cardiovascular, and respiratory systems that can lead to catastrophic and often fatal clinical sequelae. In this study we review the available literature and summarize the reported PAVM-related complications among patients with PAVMs. The reviewed studies included observational studies, case studies, prospective studies, and cohort studies, and we provide an overview of PAVM-related neurological and cardiopulmonary manifestations, including stroke, cerebral abscess, transient ischemic attack, cerebral hemorrhage, migraine, seizure, dizziness, cardiac failure, arrhythmia, myocardial infarction, cough, hypoxemia, dyspnea, respiratory failure, hemoptysis, and hemothorax. Identifying and treating PAVMs before the presentation of major complication is important because this can prevent the occurrence of complications and can result in better outcomes. PAVM patients should thus be better evaluated and managed by a multidisciplinary team because they may be in a treatable phase prior to their condition becoming life-threatening.

Right Ventricular Function in Takayasu's Arteritis Patients With Pulmonary Artery Involvement Using MRI Feature Tracking

BACKGROUND

Pulmonary artery involvement (PAI) is not rare in Takayasu arteritis (TA). Persistently elevated pulmonary arterial pressure in TA-PAI patients leads to pulmonary hypertension (PH), and eventually cardiac death. Thus, the early detection of right ventricular dysfunction before the onset of PH is important.

PURPOSE

To explore the potential of right ventricular global peak longitudinal and circumferential strain (RVGLS and RVGCS, respectively) in detecting right ventricular myocardial damage in TA-PAI patients without PH.

STUDY TYPE

Retrospective.

POPULATION

One hundred and six TA patients (39.6 ± 13.9 years), of whom 52 were non-PAI and 54 were PAI patients (36 without PH and 18 with PH), along with 58 sex- and age-matched healthy volunteers (HVs) (36.7 ± 13.2 years). The involved arteries were validated by aorta magnetic resonance (MR) angiography and pulmonary artery computed tomography angiography.

FIELD STRENGTH/SEQUENCE

3 T/Cine imaging sequence with a steady-state free precession readout.

ASSESSMENT

Cardiac MRI-derived parameters measured by two radiologists independently were compared among HVs, and TA patients with and without PAI. In addition, these indices were further compared among HVs, and TA-PAI patients with and without PH.

STATISTICAL TESTS

Student's t test, one-way ANOVA analysis, Pearson and Spearman correlation analysis, and reproducibility analysis. A P-value of <0.05 was considered statistically significant.

RESULTS

Although the TA-PAI patients without PH had a similar RV ejection fraction (RVEF) with HV (P = 0.348), RVGLS (non-PH 20.6 ± 3.7% vs. HV 24.0 ± 3.1%) was significantly lower and RVGCS (non-PH 14.8 ± 3.9% vs. HV 13.0 ± 2.7%) higher. The TA-PAI patients with PH had significantly poorer RVGLS (PH 13.5 ± 3.8% vs. non-PH 20.6 ± 3.7%) and RVGCS (PH 10.9 ± 3.2% vs. non-PH 14.8 ± 3.9%) than those without PH.

DATA CONCLUSION

Right ventricular dysfunction was detected in the TA-PAI patients without PH. MR-feature tracking may be an effective method for detecting early cardiac damage in the TA-PAI patients without PH.

LEVEL OF EVIDENCE

3 TECHNICAL EFFICACY: Stage 3.

Association of Male Sex With Worse Right Ventricular Function and Survival in Pulmonary Hypertension in the Redefining Pulmonary Hypertension Through Pulmonary Vascular Disease Phenomics Cohort

BACKGROUND

Sex-based differences are important in the development and progression of pulmonary arterial hypertension. However, it is not established whether these differences are generalizable to all forms of pulmonary hypertension (PH).

RESEARCH QUESTION

What are the sex-based differences in right ventricle (RV) function and transplant-free survival in patients with PH from the Redefining Pulmonary Hypertension Through Pulmonary Vascular Disease Phenomics (PVDOMICS) cohort?

STUDY DESIGN AND METHODS

Patients with PH enrolled in the PVDOMICS cohort study underwent right heart catheterization, cardiac MRI, and echocardiography. A multivariable linear regression model was used to investigate the interactive effect between sex and pulmonary vascular resistance (PVR) on RV ejection fraction (RVEF). Effects of sex, RVEF, and PVR on transplant-free survival were assessed using a Cox proportional hazards model.

RESULTS

Seven hundred fifty patients with PH (62.8% female) were enrolled, including 397 patients with groups 2 through 5 PH. Patients with group 1 PH were predominantly female (73.4%). Male patients showed multiple markers of worse RV function with significantly lower RVEF (adjusted difference, 5.5%; 95% CI, 3.2%-7.8%; P < .001) on cardiac MRI and lower RV fractional shortening (adjusted difference, 4.0%; 95% CI, 2.3%-5.8%; P < .001) and worse RV free-wall longitudinal strain (adjusted difference, 2.4%; 95% CI, 1.2%-3.6%; P < .001) on echocardiography. Significant interaction was noted between PVR and sex on RVEF, with the largest sex-based differences in RVEF noted at mild to moderate PVR elevation. Male sex was associated with decreased transplant-free survival (adjusted hazard ratio, 1.46; 95% CI, 1.07-1.98; P = .02), partially mediated by differences in RVEF (P = .003).

INTERPRETATION

In patients with PH in the PVDOMICS study, female sex was more common, whereas male sex was associated with worse RV function and decreased transplant-free survival, most notably at mild to moderate elevation of PVR.

The Relevance of the Endothelium in Cardiopulmonary Disorders

The endothelium is a cell monolayer that lines vessels and separates tissues from blood flow. Endothelial cells (ECs) have a multitude of functions, including regulating blood flow and systemic perfusion through changes in vessel diameter. When an injury occurs, the endothelium is affected by altering its functions and structure, which leads to endothelial dysfunction, a characteristic of many vascular diseases. Understanding the role that the endothelium plays in pulmonary vascular and cardiopulmonary diseases, and exploring new therapeutic strategies is of utmost importance to advance clinically. Currently, there are several treatments able to improve patients' quality of life, however, none are effective nor curative. This review examines the critical role of the endothelium in the pulmonary vasculature, investigating the alterations that occur in ECs and their consequences for blood vessels and potential molecular targets to regulate its alterations. Additionally, we delve into promising non-pharmacological therapeutic strategies, such as exercise and diet. The significance of the endothelium in cardiopulmonary disorders is increasingly being recognized, making ECs a relevant target for novel therapies aimed at preserving their functional and structural integrity.

Prognostic value of the tricuspid annular plane systolic excursion/systolic pulmonary artery pressure ratio in cardiac amyloidosis

INTRODUCTION AND OBJECTIVES

The tricuspid annular plane systolic excursion/systolic pulmonary artery pressure (TAPSE/SPAP) ratio is a noninvasive surrogate of right ventricular to pulmonary circulation that has prognostic implications in patients with heart failure (HF) or pulmonary hypertension. Our purpose was to evaluate the prognostic value of the TAPSE/SPAP ratio in patients with cardiac amyloidosis.

METHODS

We used the database of the AMIGAL study, a prospective, observational registry of patients with cardiac amyloidosis recruited in 7 hospitals of the Autonomous Community of Galicia, Spain, from January 1, 2018 to October 31, 2022. We selected patients whose baseline TAPSE/SPAP ratio was calculated with transthoracic echocardiography. Long-term survival and survival free of HF hospitalization were assessed by means of 5 different multivariable Cox regression models. Median follow-up was 680 days.

RESULTS

We studied 233 patients with cardiac amyloidosis, among whom 209 (89.7%) had transthyretin type. The baseline TAPSE/SPAP ratio correlated significantly with clinical outcomes. Depending on the multivariable model considered, the adjusted hazard ratios estimated per 0.1mm/mmHg increase of baseline TAPSE/SPAP ratio ranged from 0.76 to 0.84 for all-cause mortality. Similarly, the ratios for all-cause mortality of HF hospitalization ranged from 0.79 to 0.84. The addition of the baseline TAPSE/SPAP ratio to the predictive model of the United Kingdom National Amyloidosis Centre resulted in an increase in Harrell's c-statistic from 0.662 to 0.705 for all-cause mortality and from 0.668 to 0.707 for all-cause mortality or HF hospitalization.

CONCLUSIONS

Reduced TAPSE/SPAP ratio is an independent adverse prognostic marker in patients with cardiac amyloidosis.

Pulmonary arterial compliance as a measure of right ventricular loading in mitral regurgitation

Pulmonary hypertension (PH) is a common and prognostically important complication of mitral regurgitation (MR). Mean pulmonary arterial pressure (mPAP) and pulmonary vascular resistance (PVR) are traditionally used to diagnose PH, however these indices measure static rather than pulsatile load, leading to an incomplete representation of pulmonary vascular load on the right ventricle (RV). Pulmonary arterial compliance (PAC) is one method for quantifying pulsatile load, and is both a stronger predictor of prognosis in left heart failure, as well as a more sensitive measure of early pulmonary vascular dysfunction than PVR. With the expansion of transcatheter mitral and tricuspid valve therapies, there is renewed interest to more accurately define the load imposed by the pulmonary vasculature on the RV, especially in the early phase, prior to the onset of chronic PH. This review discusses the pathophysiology of pH in left heart failure and MR, the utility of PAC as a measure of RV afterload, and its calculation for clinical use and interpretation, underlining the utility of PAC as an adjunct for assessing pulmonary vascular haemodynamics.

Right ventricular diastolic adaptation to pressure overload in different rat strains

Different rat strains are used in various animal models of pulmonary hypertension and right ventricular (RV) failure. No systematic assessment has been made to test differences in RV response to pressure overload between rat strains. We compared RV adaptation to pulmonary trunk banding (PTB) in Wistar (W), Sprague Dawley (SD), and Fischer344 (F) rats by hemodynamic profiling focusing on diastolic function. Age-matched male rat weanlings were randomized to sham surgery (W-sham, n = 5; SD-sham, n = 4; F-sham, n = 4) or PTB (W-PTB, n = 8; SD-PTB, n = 8; F-PTB, n = 8). RV function was evaluated after 5 weeks by echocardiography, cardiac MRI, and invasive pressure-volume measurements. PTB caused RV failure and increased RV systolic pressures four-fold in all three PTB groups compared with sham. W- and SD-PTB had a 2.4-fold increase in RV end-systolic volume index compared with sham, while F-PTB rats were less affected. Diastolic and right atrial impairment were evident by increased RV end-diastolic elastance, filling pressure, and E/e' in PTB rats compared with sham, again F-PTB the least affected. In conclusions, PTB caused RV failure with signs of diastolic dysfunction. Despite a similar increase in RV systolic pressure, F-PTB rats showed less RV dilatation and a more preserved diastolic function compared with W- and SD-PTB.

Seralutinib in adults with pulmonary arterial hypertension (TORREY): a randomised, double-blind, placebo-controlled phase 2 trial

BACKGROUND

Morbidity and mortality in pulmonary arterial hypertension (PAH) remain high. Activation of platelet-derived growth factor receptor, colony stimulating factor 1 receptor, and mast or stem cell growth factor receptor kinases stimulates inflammatory, proliferative, and fibrotic pathways driving pulmonary vascular remodelling in PAH. Seralutinib, an inhaled kinase inhibitor, targets these pathways. We aimed to evaluate the efficacy and safety of seralutinib in patients with PAH receiving standard background therapy.

METHODS

The TORREY trial was a phase 2, randomised, multicentre, multinational, double-blind, placebo-controlled study. Patients with PAH from 40 hospital and community sites were randomly assigned 1:1 via interactive response technologies to receive seralutinib (60 mg twice daily for 2 weeks, then increased to 90 mg twice daily as tolerated) or placebo by dry powder inhaler twice daily for 24 weeks. Randomisation was stratified by baseline pulmonary vascular resistance (PVR; <800 dyne·s/cm5 and ≥800 dyne·s/cm5). Patients were eligible if classified as WHO Group 1 PH (PAH), WHO Functional Class II or III, with a PVR of 400 dyne·s/cm5 or more, and a 6 min walk distance of between 150 m and 550 m. The primary endpoint was change in PVR from baseline to 24 weeks. Analyses for efficacy endpoints were conducted in randomly assigned patients (intention-to-treat population). Safety analyses included all patients who received the study drug. TORREY was registered with ClinicalTrials.gov (NCT04456998) and EudraCT (2019-002669-37) and is completed.

FINDINGS

From Nov 12, 2020, to April 20, 2022, 151 patients were screened for eligibility, and following exclusions, 86 adults receiving PAH background therapy were randomly assigned to seralutinib (n=44; four male, 40 female) or placebo (n=42; four male, 38 female), and comprised the intention-to-treat population. At baseline, treatment groups were balanced except for a higher representation of WHO Functional Class II patients in the seralutinib group. The least squares mean change from baseline to week 24 in PVR was 21·2 dyne·s/cm5 (95% CI -37·4 to 79·8) for the placebo group and -74·9 dyne·s/cm5 (-139·7 to -10·2) for the seralutinib group. The least squares mean difference between the seralutinib and placebo groups for change in PVR was -96·1 dyne·s/cm5 (95% CI -183·5 to -8·8; p=0·03). The most common treatment-emergent adverse event in both treatment groups was cough: 16 (38%) of 42 patients in the placebo group; 19 (43%) of 44 patients in the seralutinib group.

INTERPRETATION

Treatment with inhaled seralutinib significantly decreased PVR, meeting the primary endpoint of the study among patients receiving background therapy for PAH.

FUNDING

Gossamer Bio.

The echocardiographic pulmonary to left atrial ratio: A noninvasive variable for the hemodynamic classification of pulmonary hypertension in dogs

BACKGROUND

Hemodynamic classification of pulmonary hypertension (PH) has important clinical implications. However, only a few echocardiographic variables have been used to hemodynamically classify PH in dogs.

OBJECTIVE

To evaluate the echocardiographic pulmonary to left atrial ratio index (ePLAR) in dogs with PH.

ANIMALS

Forty-six dogs with intermediate to high probability of PH.

METHODS

Cross-sectional study. Variables were compared between dogs with precapillary PH [PrePH (n = 24)] vs postcapillary PH [PostPH (n = 22)], and with combined PH [CombPH (n = 14)] vs isolated PH [IsoPH (n = 8)] using the t-, Mann-Whitney, Pearson's Chi, or Fisher's exact test. The receiver operating characteristic curve and Youden index were used to identify the optimal ePLAR cutoff value to differentiate among the groups, intraclass correlation coefficients (ICC) were used to determine the reliability of measurements.

RESULTS

The mean (SD) ePLAR of the PrePH was higher than that of the PostPH group [0.36 (0.13) vs 0.26 (0.09), respectively; P = .005]. The median (interquartile range) ePLAR of the CombPH was higher than that of the IsoPH subgroup [0.29 (0.24-0.38), vs 0.20 (0.16-0.23), respectively; P = .001]. The best cutoff value of ePLAR for identifying IsoPH was <0.245 [AUC at cutoff point = 0.86; sensitivity (95% confidence interval [CI]) = 0.71 (0.47-0.95); specificity (95% CI) = 1 (0.76-1)]. The ICC analysis indicated a high degree of reliability.

CONCLUSIONS AND CLINICAL IMPORTANCE

ePLAR can be considered a valid noninvasive variable to hemodynamically classify PH in dogs with an intermediate to high probability of PH. Assessment of ePLAR can be useful in the therapeutic management of PH in dogs.

Current trends and latest developments in echocardiographic assessment of right ventricular function: load dependency perspective

Right ventricle (RV) failure is a common complication of many cardiopulmonary diseases. Since it has a significant adverse impact on prognosis, precise determination of RV function is crucial to guide clinical management. However, accurate assessment of RV function remains challenging owing to the difficulties in acquiring its intricate pathophysiology and imaging its complex anatomical structure. In addition, there is historical attention focused exclusively on the left ventricle assessment, which has led to overshadowing and delayed development of RV evaluation. Echocardiography is the first-line and non-invasive bedside clinical tool for assessing RV function. Tricuspid annular plane systolic excursion (TAPSE), RV systolic tissue Doppler velocity of the tricuspid annulus (RV S'), and RV fractional area change (RV FAC) are conventional standard indices routinely used for RV function assessment, but accuracy has been subject to several limitations, such as load-dependency, angle-dependency, and localized regional assessment. Particularly, load dependency is a vexing issue, as the failing RV is always in a complex loading condition, which alters the values of echocardiographic parameters and confuses clinicians. Recently, novel echocardiographic methods for improved RV assessment have been developed. Specifically, "strain", "RV-pulmonary arterial (PA) coupling", and "RV myocardial work" are newly applied methods for RV function assessment, a few of which are designed to surmount the load dependency by taking into account the afterload on RV. In this narrative review, we summarize the latest data on these novel RV echocardiographic parameters and highlight their strengths and limitations. Since load independency is one of the primary advantages of these, we particularly emphasize this aspect.

Iron deficiency and supplementation in heart failure

Non-anaemic iron deficiency (NAID) is a strategic target in cardiovascular medicine because of its association with a range of adverse effects in various conditions. Endeavours to tackle NAID in heart failure have yielded mixed results, exposing knowledge gaps in how best to define 'iron deficiency' and the handling of iron therapies by the body. To address these gaps, we harness the latest understanding of the mechanisms of iron homeostasis outside the erythron and integrate clinical and preclinical lines of evidence. The emerging picture is that current definitions of iron deficiency do not assimilate the multiple influences at play in patients with heart failure and, consequently, fail to identify those with a truly unmet need for iron. Additionally, current iron supplementation therapies benefit only certain patients with heart failure, reflecting differences in the nature of the unmet need for iron and the modifying effects of anaemia and inflammation on the handling of iron therapies by the body. Building on these insights, we identify untapped opportunities in the management of NAID, including the refinement of current approaches and the development of novel strategies. Lessons learned from NAID in cardiovascular disease could ultimately translate into benefits for patients with other chronic conditions such as chronic kidney disease, chronic obstructive pulmonary disease and cancer.