Right ventricular dysfunction in systemic sclerosis-associated pulmonary arterial hypertension

A Word of Caution-Potential Limitations of Pulmonary Artery Pressure Monitoring in Detecting Congestion Caused by Right-Sided Heart Failure

Background/Objectives: Patients with New York Heart Association (NYHA) class III heart failure (HF) suffer from frequent hospitalizations. Non-invasive pulmonary artery pressure (PAP) sensor-guided HF care has been shown to reduce hospitalizations. However, it is unknown whether the PAP changes prior to hospitalization differ between clinical right, left or global cardiac decompensation. Methods: Sensor-derived PAP data and HF hospitalization records from 41 patients with NYHA class III HF were classified retrospectively into predominantly left, right or global decompensation. Linear mixed-effect regression models were used for statistical evaluations of the PAP in selected hospitalizations for which admission was at least 28 days after the last admission and 14 days after the last hospital discharge and with readings in between. Results: During 24.4 months of follow-up, 127 hospitalizations in 38 patients were evaluated. The global cardiac decompensation (n = 13) had the highest PAP before hospitalization, followed by left-sided (n = 20) decompensation. Patients with right-sided decompensation (n = 9) had comparable PAP values before hospitalization to the cohort without any cardiac decompensation (n = 85). The diastolic PAP showed a significant increase of 0.035 mmHg/day (p = 0.0097) in left-sided decompensation and of 0.13 mmHg/day (p < 0.0001) in global cardiac decompensation, whereas no significant change in the diastolic PAP occurred prior to the right-sided decompensation. The baseline right ventricular function and right ventricle-pulmonary arterial coupling (TAPSE/PASP ratio) were impaired in patients with subsequent global cardiac decompensation. Conclusion: PAP telemonitoring-guided therapy can reliably detect early signs of left and global cardiac decompensation but may be limited in detecting right-sided cardiac congestion. The routine assessment of RV-PA coupling may improve the detection of global cardiac decompensation, as severe impairments could indicate impending deterioration. In contrast, monitoring the RV contractility may aid in identifying isolated right-sided congestion and imminent decompensation.

Dysregulated Tricarboxylic Acid Cycle Metabolism Is Associated With Right Ventricular Maladaptation in Pulmonary Vascular Disease

BACKGROUND

Right ventricular (RV) maladaptation to elevated pulmonary afterload is the primary determinant of outcomes in pulmonary artery (PA) hypertension; however, the pathobiological mechanisms underlying RV decompensation remain poorly understood.

METHODS

We performed global untargeted metabolomics on plasma from 55 patients who underwent gold-standard RV-PA coupling measurements using multibeat pressure volume loop assessment in a single-center cohort and from 1027 patients with coupling surrogate measurements in a larger multicenter cohort, the PVDOMICS (Pulmonary Vascular Disease Phenomics) study. Age and sex-adjusted linear regression was performed to identify associations between metabolites and coupling metrics. Additionally, we performed a metabolic flux analysis using gene expression data from RV tissue in an independent cohort of 32 patients. Partial least squares-discriminant analysis was used to identify metabolites and reactions characteristic of the decompensated RV.

RESULTS

RV-PA coupling was negatively associated with tricarboxylic acid (TCA) cycle intermediate levels. Specifically, plasma α-ketoglutarate and fumarate were significantly associated with all coupling metrics in both cohorts. Metabolic flux analysis indicated that decompensated RVs exhibited aberrant TCA cycle activity, including reduced acetyl coenzyme A entry and increased lactate elimination, suggesting a shift from the TCA cycle toward glycolysis at the RV tissue level.

CONCLUSIONS

We identify an association between circulating TCA cycle intermediate levels and RV-PA uncoupling in 2 independent cohorts, and dysregulated TCA cycle metabolism in decompensated PA hypertension RVs, suggesting that aberrant TCA cycle metabolism could represent a hallmark of RV maladaptation in PA hypertension. Further study of this pathway is warranted to develop novel biomarkers of RV function or RV-targeted therapies.

Assessing Right Ventricular Function in the Perioperative Setting, Part II: What About Catheters?

Echocardiography is a standard tool for assessing right ventricular (RV) function in the perioperative setting, but in high-risk cases, additional monitoring may be required. Patients with pulmonary hypertension, pre-existing RV failure, or undergoing complex surgeries (eg, pulmonary endarterectomy, LVAD implantation, or transplantation) are particularly vulnerable. Catheter-based techniques, such as pulmonary artery catheterization (PAC), provide continuous, functional data and may be valuable in intensive care or when echocardiography is limited. Despite concerns over complications, PACs can help assess hemodynamics, cardiac output, and RV performance, aiding early detection of RV failure in select high-risk patients.

Molecular Pathogenesis of Connective Tissue Disease-Associated Pulmonary Arterial Hypertension: A Narrative Review

Pulmonary arterial hypertension (PAH) is a lethal condition marked by the proliferation and remodeling of small pulmonary arteries, ultimately leading to right ventricular hypertrophy and right heart failure. PAH secondary to connective tissue diseases (CTDs) is a progressive complication with a complex pathogenesis that results in the reduced efficacy of vasodilation-based therapies and poor clinical outcomes. Systemic sclerosis is the most commonly associated CTD with PAH in Western countries and has been most extensively investigated. Systemic lupus erythematosus and other CTDs may also be associated with PAH; however, they are less studied. In this review, we explore the general pathobiology of PAH, with a particular emphasis on recent advances in the molecular pathogenesis of CTD-PAH, including endothelial cell dysfunction, dysregulated cell proliferation and vascular remodeling, extracellular matrix remodeling, in situ thrombosis, right ventricular dysfunction, genetic aberrations, and immune dysregulation. We also conduct a thorough investigation into the potential serum biomarkers and immune dysregulation associated with CTD-PAH, summarizing the associated autoantibodies, cytokines, and chemokines. Furthermore, relevant animal models that may help unravel the pathogenesis and contribute to the development of new treatments are also reviewed.

The effect of hematopoietic stem cell transplantation on cardiac mechanics in systemic sclerosis

Systemic sclerosis (SSc) is an autoimmune disease that causes inflammation and fibrosis. Cardiac involvement in SSc is often subclinical and portends a worse prognosis. Autologous hematopoietic stem cell transplant (HSCT) improves survival in SSc but its effect on cardiac function is unknown. This study aimed to assess HSCT's effect on cardiac mechanics in SSc. Participants with SSc who received HSCT at a single academic center between 2009 and 2018 were identified from a prospective registry. All participants underwent comprehensive conventional and speckle-tracking echocardiography (STE) pre- and post-HSCT, and right heart catheterization before HSCT. Baseline and follow-up clinical and echocardiographic variables were compared. Among 88 HSCT recipients (age 51±11 years, 75% female), there was significant improvement of right ventricular (RV) strain globally (18.1±3.9% versus 20.0±4.5%, p < 0.01) and within the RV free wall (20.7±5.3% versus 23.2±5.6%, p < 0.01). Regionally, RV free wall strain improved in the mid (20.4±9.5% versus 23.7±8.0%, p = 0.04) and apical (15.3±8.6% versus 20.9±9.0%, p < 0.01) segments, but not the basal segment. While left ventricular (LV) strain did not change, left atrial (LA) reservoir strain improved (35.9±8.7% versus 47.8±11.4%, p < 0.01) and LA stiffness index (0.24±0.12 versus 0.18±0.08, p < 0.01) decreased post-HSCT. RV and LA mechanics significantly improve after HSCT among patients with SSc. This suggests a favorable effect of HSCT on the underlying myocardial pathology caused by SSc.

Determinants of cardiac output in health and heart failure

Sustained physical exercise depends on delivery of oxygenated blood to exercising muscle. At least among healthy individuals, bulk transport of blood is tightly matched to metabolic demand, such that cardiac output increases by ∼6 L/min for every 1 L/min increase in oxygen uptake. Multiple factors contribute to the regulation of cardiac output, including central command, the exercise pressor reflex (EPR) and arterial baroreceptors. Pulmonary arterial and left ventricular pressures increase in proportion to the rise in cardiac output and exercise intensity. The right ventricle augments contractility to maintain ventricular-arterial (VA) coupling and lusitropy to facilitate venous return. Among patients with heart failure (HF), however, the ability to deliver blood to exercising muscle is compromised as a result of multiple abnormalities impacting EPR, ventricular contractility, haemodynamics and VA coupling. The purpose of this review is to provide an overview of the factors limiting exercise capacity and cardiac output among patients with HF compared to what is known about normal physiology among healthy individuals.

Gaps and Knowledge in the Contemporary Management of Acute Right Ventricular Failure

Acute right ventricular failure (ARVF) is commonly seen in the intensive care unit and constitutes a significant clinical challenge, with associated high in-hospital mortality. Recently, the treatment of ARVF has significantly changed, with the progressive implementation of mechanical circulatory support devices that now represent important tools for clinicians in treating this condition. However, despite recent advancements, the optimal approach for ARVF remains elusive, and precise treatment algorithms and comprehensive management protocols are still lacking. In the present review, we explore the pathophysiology of ARVF, highlighting the different mechanisms that may lead to this clinical entity and emphasizing the left and right heart's complex interplay. We analyze the different therapeutic options that are now available for short- and long-term management of ARVF, with a particular focus on the advantages and disadvantages of the mechanical circulatory support devices actually used. Furthermore, we propose future directions in the field and a possible flowchart for the treatment of this condition.

Cellular Communication Network Protein 2 in the Right Ventricle of Pulmonary Arterial Hypertension

Cellular communication network 2 (CCN2) is a secreted matricellular protein associated with pulmonary arterial hypertension (PAH) but has not been studied relative to PAH severity, outcomes, or right ventricle (RV) structure and function in a large human cohort and preclinical animal model. This study assessed the associations between CCN2 and PAH severity, survival, hemodynamic measurements, and cardiovascular dysfunction. Serum CCN2 levels were compared in 2548 adults with PAH and 216 controls. CCN2 levels in PAH patients were compared to functional and hemodynamic measurements, and survival outcomes. RV-pulmonary artery coupling and RV morphology were also assessed in a small subset of patients via pressure-volume loops and cardiac magnetic resonance imaging. In a preclinical PAH model, plasma CCN2 levels were compared between ventricles with PAH progression. CCN2 mRNA levels in both ventricles in the preclinical model were measured to compare with morphologic histologic variables. CCN2 serum levels were significantly higher in PAH compared to controls (p < 0.0001). Higher CCN2 levels were associated with reduced RV contractility (p = 0.003). Higher CCN2 levels were associated with worse 6MWD (p = 0.035), and higher risk of mortality or transplant (p = 0.025). In the preclinical model, prepulmonary CCN2 plasma levels increased with the progression of disease. CCN2 mRNA levels in the RV were associated with decreased RV capillary density (p = 0.015) and increased RV fibrosis (p = 0.045). Though more investigation is needed, it appears that CCN2 plays a role in the development of PAH and potentially in RV maladaptation in PAH.

Risk Factors for Adverse Outcomes in Connective Tissue Disease-Associated Pulmonary Hypertension

Pulmonary hypertension (PH) is a rare, life-threatening condition that can be associated with connective tissue disease (CTD). The incidence and prevalence of PH in CTD varies by disease, whereby certain disease manifestations are particularly associated with PH; nonetheless, once present, PH is almost uniformly a major driver of adverse outcomes. In this paper, the authors review the published literature on major CTDs, including systemic sclerosis and systemic lupus erythematosus, and summarize the risk factors for developing PH in each disease and risk factors for adverse outcomes and mortality among patients with CTD-PH. This review highlights the need for early diagnosis of PH in CTD and the impact of PH overlap syndromes on patient outcomes, providing the practicing clinician with a practical summary of CTD-PH.

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.

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.

Precision Medicine for Pulmonary Vascular Disease: The Future Is Now (2023 Grover Conference Series)

Pulmonary vascular disease is not a single condition; rather it can accompany a variety of pathologies that impact the pulmonary vasculature. Applying precision medicine strategies to better phenotype, diagnose, monitor, and treat pulmonary vascular disease is increasingly possible with the growing accessibility of powerful clinical and research tools. Nevertheless, challenges exist in implementing these tools to optimal effect. The 2023 Grover Conference Series reviewed the research landscape to summarize the current state of the art and provide a better understanding of the application of precision medicine to managing pulmonary vascular disease. In particular, the following aspects were discussed: (1) Clinical phenotypes, (2) genetics, (3) epigenetics, (4) biomarker discovery, (5) application of precision biology to clinical trials, (6) the right ventricle (RV), and (7) integrating precision medicine to clinical care. The present review summarizes the content of these discussions and the prospects for the future.

Multimodal Screening for Pulmonary Arterial Hypertension in Systemic Scleroderma: Current Methods and Future Directions

Systemic sclerosis (SSc) is an immuno-inflammatory rheumatic disease that can affect both the skin and internal organs through fibrosis. Pulmonary arterial hypertension (PAH) is one of the most severe secondary complications. Structural changes in the vascular bed lead to increased pressures in the pulmonary circulation, severely impacting the right heart and significantly affecting mortality. The gold standard for diagnosing PAH is right heart catheterization (RHC), an invasive method for measuring cardiac pressure. Due to the high risk of complications, procedural difficulties, and significant costs, non-invasive screening for SSc-PAH has garnered significant interest. Echocardiography is likely the most important screening tool, providing structural and functional information about the right heart through measurements that have proven their utility over time. In addition to imagistic investigations, serum biomarkers aid in identifying patients at risk for PAH and can provide prognostic information. Currently, well-known serum biomarkers (NT-proBNP, uric acid) are used in screening; however, in recent years, researchers have highlighted new biomarkers that can enhance diagnostic accuracy for SSc patients. Pulmonary involvement can also be assessed through pulmonary function tests, which, using established thresholds, can provide additional information and help select patients requiring RHC. In conclusion, given the invasiveness of RHC, non-invasive screening methods are particularly important for SSc patients.

The Prognostic Role of Pulmonary Arterial Elastance in Patients Undergoing Left Ventricular Assist Device Implantation: A Pilot Study

Background: Pulmonary arterial elastance (Ea) is a helpful parameter to predict the risk of acute postoperative right ventricular failure (RVF) after left ventricular assist device (LVAD) implantation. A new method for calculating Ea, obtained by the ratio between transpulmonary gradient and stroke volume (EaB), has been proposed as a more accurate measure than the Ea obtained as the ratio between pulmonary artery systolic pressure and stroke volume (EaC). However, the role of EaB in predicting acute RVF post-LVAD implantation remains unclear. Methods and Results: A total of 35 patients who underwent LVAD implantation from 2018 to 2021 were reviewed in this retrospective analysis. Acute RVF after LVAD implantation occurred in 12 patients (34%): 5 patients with moderate RVF (14% of total) and 7 patients with severe RVF. The EaB was not significantly different between the "severe RVF" vs. "not-severe RVF" groups (0.27 ± 0.04 vs 0.23 ± 0.1, p < 0.403). However, the combination of arterial elastance and central venous pressure was significantly different between the "not-severe RVF" group (central venous pressure < 14 mmHg and EaC < 0.88 mmHg/mL or EaB < 0.24 mmHg/mL; p < 0.005) and the "severe RVF" group (central venous pressure > 14 mmHg and EaC > 0.88 mmHg/mL or EaB > 0.24 mmHg/mL; p < 0.005). Conclusions: Ea is a reliable parameter of right ventricular afterload and helps discriminate the risk of acute RVF after LVAD implantation. The combined analysis of Ea and central venous pressure can also risk stratify patients undergoing LVAD implantation for the development of RVF.

Right ventricular performance during acute hypoxic exercise

Acute hypoxia increases pulmonary arterial (PA) pressures, though its effect on right ventricular (RV) function is controversial. The objective of this study was to characterize exertional RV performance during acute hypoxia. Ten healthy participants (34 ± 10 years, 7 males) completed three visits: visits 1 and 2 included non-invasive normoxic (fraction of inspired oxygen (F i O 2 ${F_{{\mathrm{i}}{{\mathrm{O}}_{\mathrm{2}}}}}$ ) = 0.21) and isobaric hypoxic (F i O 2 ${F_{{\mathrm{i}}{{\mathrm{O}}_{\mathrm{2}}}}}$  = 0.12) cardiopulmonary exercise testing (CPET) to determine normoxic/hypoxic maximal oxygen uptake (V ̇ O 2 max ${\dot V_{{{\mathrm{O}}_{\mathrm{2}}}{\mathrm{max}}}}$ ). Visit 3 involved invasive haemodynamic assessments where participants were randomized 1:1 to either Swan-Ganz or conductance catheterization to quantify RV performance via pressure-volume analysis. Arterial oxygen saturation was determined by blood gas analysis from radial arterial catheterization. During visit 3, participants completed invasive submaximal CPET testing at 50% normoxicV ̇ O 2 max ${\dot V_{{{\mathrm{O}}_{\mathrm{2}}}{\mathrm{max}}}}$ and again at 50% hypoxicV ̇ O 2 max ${\dot V_{{{\mathrm{O}}_{\mathrm{2}}}{\mathrm{max}}}}$ (F i O 2 ${F_{{\mathrm{i}}{{\mathrm{O}}_{\mathrm{2}}}}}$  = 0.12). Median (interquartile range) values for non-invasiveV ̇ O 2 max ${\dot V_{{{\mathrm{O}}_{\mathrm{2}}}{\mathrm{max}}}}$ values during normoxic and hypoxic testing were 2.98 (2.43, 3.66) l/min and 1.84 (1.62, 2.25) l/min, respectively (P < 0.0001). Mean PA pressure increased significantly when transitioning from rest to submaximal exercise during normoxic and hypoxic conditions (P = 0.0014). Metrics of RV contractility including preload recruitable stroke work, dP/dtmax, and end-systolic pressure increased significantly during the transition from rest to exercise under normoxic and hypoxic conditions. Ventricular-arterial coupling was maintained during normoxic exercise at 50%V ̇ O 2 max ${\dot V_{{{\mathrm{O}}_{\mathrm{2}}}{\mathrm{max}}}}$ . During submaximal exercise at 50% of hypoxicV ̇ O 2 max ${\dot V_{{{\mathrm{O}}_{\mathrm{2}}}{\mathrm{max}}}}$ , ventricular-arterial coupling declined but remained within normal limits. In conclusion, resting and exertional RV functions are preserved in response to acute exposure to hypoxia at anF i O 2 ${F_{{\mathrm{i}}{{\mathrm{O}}_{\mathrm{2}}}}}$  = 0.12 and the associated increase in PA pressures. KEY POINTS: The healthy right ventricle augments contractility, lusitropy and energetics during periods of increased metabolic demand (e.g. exercise) in acute hypoxic conditions. During submaximal exercise, ventricular-arterial coupling decreases but remains within normal limits, ensuring that cardiac output and systemic perfusion are maintained. These data describe right ventricular physiological responses during submaximal exercise under conditions of acute hypoxia, such as occurs during exposure to high altitude and/or acute hypoxic respiratory failure.

Single-cell transcriptomics reveal diverging pathobiology and opportunities for precision targeting in scleroderma-associated versus idiopathic pulmonary arterial hypertension

Introduction

Pulmonary arterial hypertension (PAH) involves progressive cellular and molecular change within the pulmonary vasculature, leading to increased vascular resistance. Current therapies targeting nitric oxide (NO), endothelin, and prostacyclin pathways yield variable treatment responses. Patients with systemic sclerosis-associated PAH (SSc-PAH) often experience worse outcomes than those with idiopathic PAH (IPAH).

Methods

Lung tissue samples from four SSc-PAH, four IPAH, and four failed donor specimens were obtained from the Pulmonary Hypertension Breakthrough Initiative (PHBI) lung tissue bank. Single-cell RNA sequencing (scRNAseq) was performed using the 10X Genomics Chromium Flex platform. Data normalization, clustering, and differential expression analysis were conducted using Seurat. Additional analyses included gene set enrichment analysis (GSEA), transcription factor activity analysis, and ligand-receptor signaling. Pharmacotranscriptomic screening was performed using the Connectivity Map.

Results

SSc-PAH samples showed a higher proportion of fibroblasts and dendritic cells/macrophages compared to IPAH and donor samples. GSEA revealed enriched pathways related to epithelial-to-mesenchymal transition (EMT), apoptosis, and vascular remodeling in SSc-PAH samples. There was pronounced differential gene expression across diverse pulmonary vascular cell types and in various epithelial cell types in both IPAH and SSc-PAH, with epithelial to endothelial cell signaling observed. Macrophage to endothelial cell signaling was particularly pronounced in SSc-PAH. Pharmacotranscriptomic screening identified TIE2, GSK-3, and PKC inhibitors, among other compounds, as potential drug candidates for reversing SSc-PAH gene expression signatures.

Discussion

Overlapping and distinct gene expression patterns exist in SSc-PAH versus IPAH, with significant molecular differences suggesting unique pathogenic mechanisms in SSc-PAH. These findings highlight the potential for precision-targeted therapies to improve SSc-PAH patient outcomes. Future studies should validate these targets clinically and explore their therapeutic efficacy.

Incidence of Right Ventricular Dysfunction in an Echocardiographic Referral Cohort

Introduction

Incidence rates (IRs) of RV dysfunction (RVD) are unknown. We examined the rates, risk factors, and heart failure (HF) hospitalization hazard associated with incident RVD in patients referred for Transthoracic Echocardiogram (TTE).

Methods

In this retrospective cohort study, we extracted tricuspid regurgitant velocity (TRV) and tricuspid annular systolic plane excursion (TAPSE) from TTEs at Vanderbilt (2010-2023). We followed patients from their earliest TTE with normal RV function (TAPSE≥17mm) and a reported TRV. The primary outcome was new RVD (TAPSE<17mm), and the secondary outcome was HF hospitalization after second TTE. Poisson regression and multivariable cox models estimated IRs and hazard ratios, adjusted for demographics, comorbidities, and TTE measures.

Results

Among 45,753 patients (63 years [IQR 50-72], 45% Male, 13% Black) meeting inclusion criteria, 13,735 (30.1%) underwent a follow up TTE and 4,198 (9.2%) developed RVD. The IR of RVD in the full cohort was 3.2/100 person/years (95%CI 3.1-3.3) and 8.2 (95%CI 8.0-8.5) in the repeat TTE cohort. IRs increased with rising RVSP. Risk factors for incident RVD were most prominently HF (HR 1.88; 95%CI 1.75-2.03), left-sided valvular disease (HR 1.68; 95%CI 1.53-1.85), and other cardiovascular comorbidities. Baseline RVSP >35 mmHg associated with TAPSE decline over time. Incident RVD increased hazard of HF hospitalization (HR 2.02; 95%CI 1.85-2.21). Hazard of HF hospitalization increased when TAPSE declined by ≥5mm.

Conclusions

RVD incidence is substantial among patients referred for TTE. Clinical monitoring is warranted if RVSP >35mmHg. Cardiovascular comorbidities drive RVD in this population. Incident RVD associates with increased hazard of HF hospitalization.

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.

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.

Transplantation, bridging, and support technologies in pulmonary hypertension

Despite the progress made in medical therapies for treating pulmonary hypertension (PH), a subset of patients remain susceptible to developing a maladaptive right ventricular phenotype. The effective management of end-stage PH presents substantial challenges, necessitating a multidisciplinary approach and early identification of patients prone to acute decompensation. Identifying potential transplant candidates and assessing the feasibility of such a procedure are pivotal tasks that should be undertaken early in the treatment algorithm. Inclusion on the transplant list is contingent upon a comprehensive risk assessment, also considering the specific type of PH and various factors affecting waiting times, all of which should inform the decision-making process. While bilateral lung transplantation is the preferred option, it demands expert intra- and post-operative management to mitigate the heightened risks of pulmonary oedema and primary graft dysfunction in PH patients. Despite the availability of risk assessment tools, the occurrence of acute PH decompensation episodes can be unpredictable, potentially leading to refractory right ventricular failure even with optimal medical intervention, necessitating the use of rescue therapies. Advancements in right ventricular assist techniques and adjustments to graft allocation protocols for the most critically ill patients have significantly enhanced the survival in intensive care, affording the opportunity to endure while awaiting an urgent transplant. Given the breadth of therapeutic options available, specialised centres capable of delivering comprehensive care have become indispensable for optimising patient outcomes. These centres are instrumental in providing holistic support and management tailored to the complex needs of PH patients, ultimately enhancing their chances of a successful transplant and improved long-term prognosis.

The prognostic value of right ventricular outflow tract velocity time integral in patients with pulmonary hypertension

AIMS

Right ventricular (RV) failure is one of the leading causes of death in patients with pulmonary hypertension (PH). Conventional echocardiographic parameters are not included in risk stratification and follow-up for prognostic assessment due to PH's diverse nature and the RV's complex geometry. RV outflow tract velocity time integral (RVOT VTI) is a simple, non-invasive estimate of pulmonary flow and an echocardiographic surrogate of RV stroke volume. In this study, we aimed to define the prognostic value of RVOT VTI in PH patients.

METHODS

Sixty-three subjects with idiopathic PAH (IPAH) (n = 23), connective tissue disease-associated PAH (CTD-associated PAH) (n = 19) and chronic thromboembolic pulmonary hypertension (CTEPH) (n = 21) were retrospectively included. A comprehensive two-dimensional echocardiographic evaluation, including RVOT-VTI measurement, was performed during the follow-up and the New York Heart Association functional class (NYHA FC), 6 min walk distance (6MWD) and brain natriuretic peptide (BNP) levels were recorded.

RESULTS

The median age of the whole cohort was 63 years (52-68), and 47 (74.6%) of the patients were women. The median follow-up period was 20 months (11-33), and 20 (31.7%) patients died in this period. BNP values were higher [317 (210-641) vs 161 (47-466), P = 0.02], and 6MWD values were lower [197.5 ± 89.5 vs 339 ± 146.3, P < 0.0001] in the non-survivor group, and the non-survivor group had a worse NYHA-FC (P = 0.02). Among echocardiographic data, tricuspid annular plane systolic excursion (TAPSE) (15.4 ± 4.8 vs 18.6 ± 4.2, P = 0.01) and RVOT VTI (11.9 ± 4.1 vs 17.2 ± 4.3, P < 0.0001) values were lower whereas right atrial area (RAA) (26.9 ± 10.1 vs 22.2 ± 7.1, P = 0.04) values were higher in the non-survivor group. The area under curve of the RVOT VTI for predicting mortality was 0.82 [95% confidence interval (CI) 0.715-0.940, P < 0.0001], and the best cut-off value was 14.7 cm with a sensitivity of 80% and specificity of 77%. Survival was significantly lower in subjects with RVOT VTI ≤ 14.7 cm (log-rank P < 0.0001). Survival rates for patients with RVOT VTI ≤ 14.7 cm were 70% at 1 year, 50% at 2 years, %29 at 3 years and 21% at 5 years. The univariate determinants of all-cause mortality were BNP [hazard ratio (HR) 1.001 (1.001-1.002), P = 0.001], 6MWD [HR 0.994 (0.990-0.999), P = 0.012] and NYHA-FC III-IV [HR 3.335 (1.103-10.083), P = 0.03], TAPSE [HR 0.838 (0.775-0.929), P = 0.001], RAA [HR 1.072 (1.013-1.135), P = 0.016] and RVOT VTI [HR 0.819 (0.740-0.906), P < 0.0001]. RVOT VTI was found to be the only independent determinant of mortality [HR 0.857 (0.766-0.960), P = 0.008].

CONCLUSIONS

The decreased RVOT VTI predicts mortality in patients with PH and each 1 mm decrease in RVOT VTI increases the risk of mortality by 14.3%. This parameter might serve as an additional parameter in the follow-up of these patients especially when 6MWD and NYHA-FC could not be determined.

Pulmonary Hypertension and Right Ventricle: A Pathophysiological Insight

Background

Pulmonary hypertension (PH) is a pulmonary vascular disease characterized by elevated pulmonary vascular pressure. Long-term PH, irrespective of its etiology, leads to increased right ventricular (RV) pressure, RV hypertrophy, and ultimately, RV failure.

Main body

Research indicates that RV failure secondary to hypertrophy remains the primary cause of mortality in pulmonary arterial hypertension (PAH). However, the impact of PH on RV structure and function under increased overload remains incompletely understood. Several mechanisms have been proposed, including extracellular remodeling, RV hypertrophy, metabolic disturbances, inflammation, apoptosis, autophagy, endothelial-to-mesenchymal transition, neurohormonal dysregulation, capillary rarefaction, and ischemia.

Conclusions

Studies have demonstrated the significant role of oxidative stress in the development of RV failure. Understanding the interplay among these mechanisms is crucial for the prevention and management of RV failure in patients with PH.

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.

Pulmonary Hypertension Associated with Connective Tissue Disease

Pulmonary hypertension (PH), a syndrome characterized by elevated pulmonary pressures, commonly complicates connective tissue disease (CTD) and is associated with increased morbidity and mortality. The incidence of PH varies widely between CTDs; patients with systemic sclerosis are most likely to develop PH. Several different types of PH can present in CTD, including PH related to left heart disease and respiratory disease. Importantly, CTD patients are at risk for developing pulmonary arterial hypertension, a rare form of PH that is associated with high morbidity and mortality. Future therapies targeting pulmonary vascular remodeling may improve outcomes for patients with this devastating disease.

Poor cardiac output reserve in pulmonary arterial hypertension is associated with right ventricular stiffness and impaired interventricular dependence

BACKGROUND

Pulmonary arterial hypertension (PAH) is characterised by poor exercise tolerance. The contribution of right ventricular (RV) diastolic function to the augmentation of cardiac output during exercise is not known. This study leverages pressure-volume (P-V) loop analysis to characterise the impact of RV diastology on poor flow augmentation during exercise in PAH.

METHODS

RV P-V loops were measured in 41 PAH patients at rest and during supine bike exercise. Patients were stratified by median change in cardiac index (CI) during exercise into two groups: high and low CI reserve. Indices of diastolic function (end-diastolic elastance (E ed)) and ventricular interdependence (left ventricular transmural pressure (LVTMP)) were compared at matched exercise stages.

RESULTS

Compared to patients with high CI reserve, those with low reserve exhibited lower exercise stroke volume (36 versus 49 mL·m-2; p=0.0001), with higher associated exercise afterload (effective arterial elastance (E a) 1.76 versus 0.90 mmHg·mL-1; p<0.0001), RV stiffness (E ed 0.68 versus 0.26 mmHg·mL-1; p=0.003) and right-sided pressures (right atrial pressure 14 versus 8 mmHg; p=0.002). Higher right-sided pressures led to significantly lower LV filling among the low CI reserve subjects (LVTMP -4.6 versus 3.2 mmHg; p=0.0001). Interestingly, low exercise flow reserve correlated significantly with high afterload and RV stiffness, but not with RV contractility nor RV-PA coupling.

CONCLUSIONS

Patients with poor exercise CI reserve exhibit poor exercise RV afterload, stiffness and right-sided filling pressures that depress LV filling and stroke work. High afterload and RV stiffness were the best correlates to low flow reserve in PAH. Exercise unmasked significant pathophysiological PAH differences unapparent at rest.

Combined peripheral and central ultrasound for the diagnosis of PAH-SSc patients

BACKGROUND

Systemic Sclerosis (SSc), an intricate autoimmune disease causing tissue fibrosis, introduces cardiovascular complexities, notably pulmonary hypertension (PH), affecting both survival and quality of life. This study centers on evaluating echocardiographic parameters and endothelial function using flow-mediated dilatation (FMD) in SSc patients, aiming to differentiate those with and without pulmonary arterial hypertension (PAH). The emphasis lies in early detection, given the heightened vulnerability of the right ventricle (RV) in the presence of PH.

METHODS

Fifty-nine SSc patients and 48 healthy subjects participated, undergoing clinical examinations, echocardiography, FMD assessments, blood analyses, and right heart catheterization (RHC) according to the ESC/ERS guidelines for diagnosis and treatment of PH.

RESULTS

SSc-PAH patients displayed lower FMD, higher frequency of TAPSE < 18 mm, RA area > 18 cm2, act RVOT < 105 ms and TRV > 280 cm/s compared to those without PAH and healthy controls. Resting resistivity index (RI) was higher in SSc patients, with no significant difference between those with and without PAH. Lower FMD% serves as a predictive marker for adverse cardiovascular outcomes in both SSc and SSc-PAH patients. Stratification by TRV levels and PAH presence reveals notable FMD% variations, emphasizing its potential utility.

CONCLUSIONS

Early identification of endothelial dysfunction and impaired RV echocardiographic parameters, such as TAPSE and TRV, could aid in predicting right ventricular dysfunction and PAH in SSc patients.

Non-invasive imaging techniques for early diagnosis of bilateral cardiac dysfunction in pulmonary hypertension: current crests, future peaks

Pulmonary arterial hypertension (PAH) is a chronic and progressive disease that eventually leads to heart failure (HF) and subsequent fatality if left untreated. Right ventricular (RV) function has proven prognostic values in patients with a variety of heart diseases including PAH. PAH is predominantly a right heart disease; however, given the nature of the continuous circulatory system and the presence of shared septum and pericardial constraints, the interdependence of the right and left ventricles is a factor that requires consideration. Accurate and timely assessment of ventricular function is very important in the management of patients with PAH for disease outcomes and prognosis. Non-invasive modalities such as cardiac magnetic resonance (CMR) and echocardiography (two-dimensional and three-dimensional), and nuclear medicine, positron emission tomography (PET) play a crucial role in the assessment of ventricular function and disease prognosis. Each modality has its own strengths and limitations, hence this review article sheds light on (i) ventricular dysfunction in patients with PAH and RV-LV interdependence in such patients, (ii) the strengths and limitations of all available modalities and parameters for the early assessment of ventricular function, as well as their prognostic value, and (iii) lastly, the challenges faced and the potential future advancement in these modalities for accurate and early diagnosis of ventricular function in PAH.

Peripheral microvascular function is linked to cardiac involvement on cardiovascular magnetic resonance in systemic sclerosis-related pulmonary arterial hypertension

AIMS

Systemic sclerosis (SSc) is characterized by vasculopathy, inflammation, and fibrosis, and carries one of the worst prognoses if patients also develop pulmonary arterial hypertension (PAH). Although PAH is a known prognosticator, patients with SSc-PAH demonstrate disproportionately high mortality, presumably due to cardiac involvement. In this cross-sectional study, the relationship between cardiac involvement revealed by cardiovascular magnetic resonance (CMR) and systemic microvascular disease severity measured with nailfold capillaromicroscopy (NCM) in patients with SSc-PAH is evaluated and compared with patients with idiopathic PAH (IPAH).

METHODS AND RESULTS

Patients with SSc-PAH and IPAH underwent CMR, echocardiography, and NCM with post-occlusive reactivity hyperaemia (PORH) testing on the same day. CMR imaging included T2 (oedema), native, and post-contrast T1 mapping to measure the extracellular volume fraction (ECV, fibrosis) and adenosine-stress-perfusion imaging measuring the relative myocardial upslope (microvascular coronary perfusion). Measures of peripheral microvascular function were related to CMR indices of oedema, fibrosis, and myocardial perfusion. SSc-PAH patients (n = 20) had higher T2 values and a trend towards a higher ECV, compared with IPAH patients (n = 5), and a lower nailfold capillary density (NCD) and reduced capillary recruitment after PORH. NCD correlated with ECV and T2 (r = -0.443 and -0.464, respectively, P < 0.05 for both) and with markers of diastolic dysfunction on echocardiography. PORH testing, but not NCD, correlated with the relative myocardial upslope (r = 0.421, P < 0.05).

CONCLUSION

SSc-PAH patients showed higher markers of cardiac fibrosis and inflammation, compared with IPAH patients. These markers correlated well with peripheral microvascular dysfunction, suggesting that SSc-driven inflammation and vasculopathy concurrently affect peripheral microcirculation and the heart. This may contribute to the disproportionate high mortality in SSc-PAH.

Systemic Sclerosis-Associated Pulmonary Arterial Hypertension: From Bedside to Bench and Back Again

Systemic sclerosis (SSc) is a heterogeneous disease characterized by autoimmunity, vasculopathy, and fibrosis which affects the skin and internal organs. One key aspect of SSc vasculopathy is pulmonary arterial hypertension (SSc-PAH) which represents a leading cause of morbidity and mortality in patients with SSc. The pathogenesis of pulmonary hypertension is complex, with multiple vascular cell types, inflammation, and intracellular signaling pathways contributing to vascular pathology and remodeling. In this review, we focus on shared molecular features of pulmonary hypertension and those which make SSc-PAH a unique entity. We highlight advances in the understanding of the clinical and translational science pertinent to this disease. We first review clinical presentations and phenotypes, pathology, and novel biomarkers, and then highlight relevant animal models, key cellular and molecular pathways in pathogenesis, and explore emerging treatment strategies in SSc-PAH.

Exploratory analysis of the accuracy of echocardiographic parameters for the assessment of right ventricular function and right ventricular-pulmonary artery coupling

Echocardiography is a widely used modality for the assessment of right ventricular (RV) function; however, few studies have comprehensively compared the accuracy of echocardiographic parameters using invasively obtained reference values. Therefore, this exploratory study aimed to compare the accuracy of echocardiographic parameters of RV function and RV-pulmonary artery (PA) coupling. We calculated four indices of RV function (end-systolic elastance [Ees] for systolic function [contractility], τ for relaxation, and β and end-diastolic elastance [Eed] for stiffness), and an index of RV-PA coupling (Ees/arterial elastance [Ea]), using pressure catheterization, cardiac magnetic resonance imaging, and a single-beat method. We then compared the correlations of RV indices with echocardiographic parameters. In 63 participants (54 with pulmonary hypertension (PH) and nine without PH), Ees and τ correlated with several echocardiographic parameters, such as RV diameter and area, but the correlations were moderate (|correlation coefficients (ρ)| < 0.5 for all parameters). The correlations of β and Eed with echocardiographic parameters were weak, with |ρ| < 0.4. In contrast, Ees/Ea closely correlated with RV free wall longitudinal strain (RVFW-LS)/estimated systolic PA pressure (eSPAP) (ρ = -0.72). Ees/Ea also correlated with tricuspid annular plane systolic excursion/eSPAP, RV diameter, and RV end-systolic area, with |ρ | >0.65. In addition, RVFW-LS/eSPAP yielded high sensitivity (0.84) and specificity (0.75) for detecting reduced Ees/Ea. The present study indicated a limited accuracy of echocardiographic parameters in assessing RV systolic and diastolic function. In contrast to RV function, they showed high accuracy for assessing RV-PA coupling, with RVFW-LS/eSPAP exhibiting the highest accuracy.

Right ventricle-pulmonary artery coupling in pulmonary artery hypertension its measurement and pharmacotherapy

The right ventricular (RV) function correlates with prognosis in severe pulmonary artery hypertension (PAH) but which metric of it is most clinically relevant is still uncertain. Clinical methods to estimate RV function from simplified pressure volume loops correlate with disease severity but the clinical relevance has not been assessed. Evaluation of right ventricle pulmonary artery coupling in pulmonary hypertensive patients may help to elucidate the mechanisms of right ventricular failure and may also help to identify patients at risk or guide the timing of therapeutic interventions in pulmonary hypertension. Complete evaluation of RV failure requires echocardiographic or magnetic resonance imaging, and right heart catheterization measurements. Treatment of RV failure in PAH relies on decreasing afterload with drugs targeting pulmonary circulation; fluid management to optimize ventricular diastolic interactions; and inotropic interventions to reverse cardiogenic shock. The ability to relate quantitative metrics of RV function in pulmonary artery hypertension to clinical outcomes can provide a powerful tool for management. Such metrics could also be utilized in the future as surrogate endpoints for outcomes and evaluation of response to therapies. This review of literature gives an insight on RV-PA coupling associated with PAH, its types of measurement and pharmacological treatment.

Occult right ventricular dysfunction and right ventricular-vascular uncoupling in left ventricular assist device recipients

BACKGROUND

Detecting right heart failure post left ventricular assist device (LVAD) is challenging. Sensitive pressure-volume loop assessments of right ventricle (RV) contractility may improve our appreciation of post-LVAD RV dysfunction.

METHODS

Thirteen LVAD patients and 20 reference (non-LVAD) subjects underwent comparison of echocardiographic, right heart cath hemodynamic, and pressure-volume loop-derived assessments of RV contractility using end-systolic elastance (Ees), RV afterload by effective arterial elastance (Ea), and RV-pulmonary arterial coupling (ratio of Ees/Ea).

RESULTS

LVAD patients had lower RV Ees (0.20 ± 0.08 vs 0.30 ± 0.15 mm Hg/ml, p = 0.01) and lower RV Ees/Ea (0.37 ± 0.14 vs 1.20 ± 0.54, p < 0.001) versus reference subjects. Low RV Ees correlated with reduced RV septal strain, an indicator of septal contractility, in both the entire cohort (r = 0.68, p = 0.004) as well as the LVAD cohort itself (r = 0.78, p = 0.02). LVAD recipients with low RV Ees/Ea (below the median value) demonstrated more clinical heart failure (71% vs 17%, p = 0.048), driven by an inability to augment RV Ees (0.22 ± 0.11 vs 0.19 ± 0.02 mm Hg/ml, p = 0.95) to accommodate higher RV Ea (0.82 ± 0.38 vs 0.39 ± 0.08 mm Hg/ml, p = 0.002). Pulmonary artery pulsatility index (PAPi) best identified low baseline RV Ees/Ea (≤0.35) in LVAD patients ((area under the curve) AUC = 0.80); during the ramp study, change in PAPi also correlated with change in RV Ees/Ea (r = 0.58, p = 0.04).

CONCLUSIONS

LVAD patients demonstrate occult intrinsic RV dysfunction. In the setting of excess RV afterload, LVAD patients lack the RV contractile reserve to maintain ventriculo-vascular coupling. Depression in RV contractility may be related to LVAD left ventricular unloading, which reduces septal contractility.

Association of serum uric acid with right cardiac chamber remodeling assessed by cardiovascular magnetic resonance feature tracking in patients with connective tissue disease

Background

Right cardiac chamber remodeling is widespread in patients with connective tissue disease (CTD). Serum uric acid (SUA) is considered a potential independent risk factor for cardiovascular disease, and elevated SUA levels are often observed in patients with CTD. The correlation between SUA levels and right cardiac chamber remodeling remains unclear. This study investigated the association of SUA with right cardiac chamber remodeling as assessed by cardiac magnetic resonance feature-tracking (CMR-FT) in CTD patients.

Methods and results

In this cross-sectional study, a total of 104 CTD patients and 52 age- and sex-matched controls were consecutively recruited. All individuals underwent CMR imaging, and their SUA levels were recorded. The patients were divided into three subgroups based on the tertiles of SUA level in the present study. CMR-FT was used to evaluate the right atrial (RA) longitudinal strain and strain rate parameters as well as right ventricular (RV) global systolic peak strain and strain rate in longitudinal and circumferential directions for each subject. Univariable and multivariable linear regression analyses were used to explore the association of SUA with RV and RA strain parameters. Compared with the controls, the CTD patients showed significantly higher SUA levels but a lower RV global circumferential strain (GCS) and RA phasic strain parameters (all p < 0.05), except the RA booster strain rate. RV GCS remained impaired even in CTD patients with preserved RV ejection fraction. Among subgroups, the patients in the third tertile had significantly impaired RV longitudinal strain (GLS), RV GCS, and RA reservoir and conduit strain compared with those in the first tertile (all p < 0.05). The SUA levels were negatively correlated with RV GLS and RV GCS as well as with RA reservoir and conduit strain and strain rates (the absolute values of β were 0.250 to 0.293, all P < 0.05). In the multivariable linear regression analysis, the SUA level was still an independent determinant of RA conduit strain (β = -0.212, P = 0.035) and RV GCS (β = 0.207, P = 0.019).

Conclusion

SUA may be a potential risk factor of right cardiac chamber remodeling and is independently associated with impaired RA conduit strain and RV GCS in CTD patients.

Right ventricular-pulmonary arterial coupling ratio derived from 3-dimensional echocardiography predicts outcomes in systemic lupus erythematosus-associated pulmonary arterial hypertension patients

BACKGROUND

Systemic lupus erythematosus (SLE) is a complex autoimmune connective tissue disease (CTD) that is an important cause of devastating pulmonary arterial hypertension (PAH), and persistent progression of PAH can lead to right heart failure, predicting a poor prognosis for SLE patients. Right ventricular-pulmonary arterial (RV-PA) coupling with echocardiography has been demonstrated to be a noninvasive alternative method for evaluating PAH patients' predictive outcomes. Whether the ratio of right ventricular stroke volume (RVSV) to right ventricular end-systolic volume (RVESV) measured by three-dimensional echocardiography (3DE) is a new index of RV-PA coupling has not been discussed as a new predictor for the clinical outcome of systemic lupus erythematosus-associated pulmonary arterial hypertension (SLE-PAH).

METHODS

From June 2019 to February 2023, 46 consecutive patients with SLE-PAH were enrolled prospectively, and their clinical data and echocardiographs were studied and analyzed. The control group consisted of 30 healthy subjects matched for age, sex, and body surface area (BSA). The main endpoints of this study were a composite of all-cause mortality and adverse clinical events. Baseline clinical characteristics and echocardiographic assessments were analyzed.

RESULTS

During a median of 24 months (IQR 18-31), 16 of 46 SLE-PAH patients (34.7%) experienced endpoint-related events. At baseline, patients who experienced mortality or adverse events had a worse WHO functional class (WHO FC) and lower anti-double-stranded DNA (dsDNA) antibody levels. The right ventricular (RV) systolic dysfunction in SLE-PAH subjects was significantly worse than that in the healthy control group, especially in SLE-PAH patients in the endpoint event group. Compared to controls, patients with SLE-PAH had a lower RVSV/RVESV ratio. In the group comparison, patients who had experienced an endpoint event had a sequentially worse ratio (1.86 (1.65-2.3) versus 1.30 (1.09-1.46) versus 0.64 (0.59-0.67), p < .001). There were statistically significant associations between the RVSV/RVESV ratio to routine RV systolic function and clinical parameters. The RVSV/RVESV ratio was negatively correlated with the WHO FC (r = -0.621, p < .001) and positively correlated with the anti-dsDNA level. The ROC curve showed that the optimal cutoff for RVSV/RVESV < 0.712 determined a higher risk of poor prognosis. Kaplan‒Meier survival curves showed that an RVSV/RVESV ratio >0.712 was associated with more favorable long-term outcomes.

CONCLUSIONS

The 3DE-derived SV/ESV ratio as a noninvasive alternative surrogate of RV-PA coupling was an eximious indicator for identifying endpoint events in SLE-PAH patients and can provide a diagnostic basis for clinical intervention.

Pulmonary Hypertension Associated with Left Heart Disease

Pulmonary hypertension (PH) is a common complication of diseases affecting the left heart, mostly found in patients suffering from heart failure, with or without preserved left ventricular ejection fraction. Initially driven by a passive increase in left atrial pressure (postcapillary PH), several mechanisms may lead in a subset of patient to significant structural changes of the pulmonary vessels or a precapillary component. In addition, the right ventricle may be independently affected, which results in right ventricular to pulmonary artery uncoupling and right ventricular failure, all being associated with a worse outcome. The differential diagnosis of PH associated with left heart disease versus pulmonary arterial hypertension (PAH) is especially challenging in patients with cardiovascular comorbidities and/or heart failure with preserved ejection fraction (HFpEF). A stepwise approach to diagnosis is proposed, starting with a proper clinical multidimensional phenotyping to identify patients in whom hemodynamic confirmation is deemed necessary. Provocative testing (exercise testing, fluid loading, or simple leg raising) is useful in the cath laboratory to identify patients with abnormal response who are more likely to suffer from HFpEF. In contrast with group 1 PH, management of PH associated with left heart disease must focus on the treatment of the underlying condition. Some PAH-approved targets have been unsuccessfully tried in clinical studies in a heterogeneous group of patients, some even leading to an increase in adverse events. There is currently no approved therapy for PH associated with left heart disease.

Novel Imaging Approaches to Cardiac Manifestations of Systemic Inflammatory Diseases: JACC Scientific Statement

Derangements in the innate and adaptive immune responses observed in systemic inflammatory syndromes contributes to unique elevated atherosclerotic risk and incident cardiovascular disease. Novel multimodality imaging techniques may improve diagnostic precision for the screening and monitoring of disease activity. The integrated application of these technologies lead to earlier diagnosis and noninvasive monitoring of cardiac involvement in systemic inflammatory diseases that will aid in preclinical studies, enhance patient selection, and provide surrogate endpoints in clinical trials, thereby improving clinical outcomes. We review the common cardiovascular manifestations of immune-mediated systemic inflammatory diseases and address the clinical and investigational role of advanced multimodality cardiac imaging.

iCPET Calculator: A Web-Based Application to Standardize the Calculation of Alpha Distensibility in Patients With Pulmonary Arterial Hypertension

Background Pulmonary vascular distensibility associates with right ventricular function and clinical outcomes in patients with unexplained dyspnea and pulmonary hypertension. Alpha distensibility coefficient is determined from a nonlinear fit to multipoint pressure-flow plots. Study aims were to (1) create and test a user-friendly tool to standardize analysis of exercise hemodynamics including distensibility, and (2) investigate changes in distensibility following treatment in patients with pulmonary arterial hypertension. Methods and Results Participants with an exercise right heart catherization were retrospectively identified from the University of Arizona Pulmonary Hypertension (UA PH) registry and split into a pulmonary arterial hypertension group, a comparator group, and a control group. Right ventricular function was quantified using the coupling ratio and diastolic stiffness. Prototypes of the invasive cardiopulmonary exercise testing (iCPET) calculator were developed using Matlab, Python, and RShiny to analyze exercise hemodynamics and alpha distensibility coefficient, α (%/mm Hg) from multipoint pressure flow plots. Interclass correlation coefficients were calculated for interplatform and interobserver variability in alpha. No significant bias in the intraplatform (Matlab versus RShiny; intraclass correlation coefficient: 0.996) or interobserver (intraclass correlation coefficient: 0.982) comparison of alpha values. Afterload significantly decreased (P<0.05) with no change in alpha distensibility in the pulmonary arterial hypertension group at follow-up. The comparator group had no change in pressure, resistance or alpha distensibility. There were no significant changes in RV diastolic stiffness at follow-up. Conclusions The interactive user interface in the iCPET calculator allows exploration of alpha distensibility using standardized methods. No significant change in alpha distensibility at follow-up suggests that alpha may be less modifiable in patients with long-standing pulmonary arterial hypertension.

Clinical features of pulmonary arterial hypertension associated with systemic sclerosis

Systemic sclerosis is an autoimmune disorder of the connective tissue characterized by disordered inflammation and fibrosis leading to skin thickening and visceral organ complications. Pulmonary involvement, in the form of pulmonary arterial hypertension and/or interstitial lung disease, is the leading cause of morbidity and mortality among individuals with scleroderma. There are no disease-specific therapies for pulmonary involvement of scleroderma, and pulmonary arterial hypertension in this cohort has typically been associated with worse outcomes and less clinical response to modern therapy compared to other forms of Group I pulmonary hypertension in the classification from the World Symposium on Pulmonary Hypertension. Ongoing research aims to delineate how pathologic microvascular remodeling and fibrosis contribute to this poor response and offer a window into future therapeutic targets.

Exertional Cardiac and Pulmonary Vascular Hemodynamics in Patients With Heart Failure With Reduced Ejection Fraction

BACKGROUND

Exertional dyspnea is a cardinal manifestation of heart failure with reduced ejection fraction (HFrEF), but quantitative data regarding exertional hemodynamics are lacking.

OBJECTIVES

We sought to characterize exertional cardiopulmonary hemodynamics in patients with HFrEF.

METHODS

We studied 35 patients with HFrEF (59 ± 12 years old, 30 males) who completed invasive cardiopulmonary exercise testing. Data were collected at rest, at submaximal exercise and at peak effort on upright cycle ergometry. Cardiovascular and pulmonary vascular hemodynamics were recorded. Fick cardiac output (Qc) was determined. Hemodynamic predictors of peak oxygen uptake (VO2) were identified.

RESULTS

Left ventricular ejection fraction and cardiac index were 23% ± 8% and 2.9 ± 1.1 L/min/m2, respectively. Peak VO2 was 11.8 ± 3.3 mL/kg/min, and the ventilatory efficiency slope was 53 ± 13. Right atrial pressure increased from rest to peak exercise (4 ± 5 vs 7 ± 6 mmHg,). Mean pulmonary arterial pressure increased from rest to peak exercise (27 ± 13 vs 38 ± 14 mmHg). Pulmonary artery pulsatility index increased from rest to peak exercise, while pulmonary arterial capacitance and pulmonary vascular resistance declined.

CONCLUSIONS

Patients with HFrEF suffer from marked increases in filling pressures during exercise. These findings provide new insight into cardiopulmonary abnormalities contributing to impairments in exercise capacity in this population.

CLINICAL TRIAL REGISTRATION

clinicaltrials.gov identifier: NCT03078972.

Right Heart Adaptation to Exercise in Pulmonary Hypertension: An Invasive Hemodynamic Study

BACKGROUND

Right heart failure (RHF) is associated with a dismal prognosis in patients with pulmonary hypertension (PH). Exercise right heart catheterization may unmask right heart maladaptation as a sign of RHF. We sought to (1) define the normal limits of right atrial pressure (RAP) increase during exercise; (2) describe the right heart adaptation to exercise in PH owing to heart failure with preserved ejection fraction (PH-HFpEF) and in pulmonary arterial hypertension (PAH); and (3) identify the factors associated with right heart maladaptation during exercise.

METHODS AND RESULTS

We analyzed rest and exercise right heart catheterization from patients with PH-HFpEF and PAH. Right heart adaptation was described by absolute or cardiac output (CO)-normalized changes of RAP during exercise. Individuals with noncardiac dyspnea (NCD) served to define abnormal RAP responses (>97.5th percentile). Thirty patients with PH-HFpEF, 30 patients with PAH, and 21 patients with NCD were included. PH-HFpEF were older than PAH, with more cardiovascular comorbidities, and a higher prevalence of severe tricuspid regurgitation (P < .05). The upper limit of normal for peak RAP and RAP/CO slope in NCD were >12 mm Hg and ≥1.30 mm Hg/L/min, respectively. PH-HFpEF had higher peak RAP and RAP/CO slope than PAH (20 mm Hg [16-24 mm Hg] vs 12 mm Hg [9-19 mm Hg] and 3.47 mm Hg/L/min [2.02-6.19 mm Hg/L/min] vs 1.90 mm Hg/L/min [1.01-4.29 mm Hg/L/min], P < .05). A higher proportion of PH-HFpEF had RAP/CO slope and peak RAP above normal (P < .001). Estimated stressed blood volume at peak exercise was higher in PH-HFpEF than PAH (P < .05). In the whole PH cohort, the RAP/CO slope was associated with age, the rate of increase in estimated stressed blood volume during exercise, severe tricuspid regurgitation, and right atrial dilation.

CONCLUSIONS

Patients with PH-HFpEF display a steeper increase of RAP during exercise than those with PAH. Preload-mediated mechanisms may play a role in the development of exercise-induced RHF.

Exercise Testing in the Risk Assessment of Pulmonary Hypertension

TOPIC IMPORTANCE

Right ventricular dysfunction in pulmonary hypertension (PH) contributes to reduced exercise capacity, morbidity, and mortality. Exercise can unmask right ventricular dysfunction not apparent at rest, with negative implications for prognosis.

REVIEW FINDINGS

Among patients with pulmonary vascular disease, right ventricular afterload may increase during exercise out of proportion to increases observed among healthy individuals. Right ventricular contractility must increase to match the demands of increased afterload to maintain ventricular-arterial coupling (the relationship between contractility and afterload) and ultimately cardiac output. Impaired right ventricular contractile reserve leads to ventricular-arterial uncoupling, preventing cardiac output from increasing during exercise and limiting exercise capacity. Abnormal pulmonary vascular response to exercise can signify early pulmonary vascular disease and is associated with increased mortality. Impaired right ventricular contractile reserve similarly predicts poor outcomes, including reduced exercise capacity and death. Exercise provocation can be used to assess pulmonary vascular response to exercise and right ventricular contractile reserve. Noninvasive techniques (including cardiopulmonary exercise testing, transthoracic echocardiography, and cardiac MRI) as well as invasive techniques (including right heart catheterization and pressure-volume analysis) may be applied selectively to the screening, diagnosis, and risk stratification of patients with suspected or established PH. Further research is required to determine the role of exercise stress testing in the management of pulmonary vascular disease.

SUMMARY

This review describes the current understanding of clinical applications of exercise testing in the risk assessment of patients with suspected or established PH.

Pathophysiology of the right ventricle in health and disease: an update

The contribution of the right ventricle (RV) to cardiac output is negligible in normal resting conditions when pressures in the pulmonary circulation are low. However, the RV becomes relevant in healthy subjects during exercise and definitely so in patients with increased pulmonary artery pressures both at rest and during exercise. The adaptation of RV function to loading rests basically on an increased contractility. This is assessed by RV end-systolic elastance (Ees) to match afterload assessed by arterial elastance (Ea). The system has reserve as the Ees/Ea ratio or its imaging surrogate ejection fraction has to decrease by more than half, before the RV undergoes an increase in dimensions with eventual increase in filling pressures and systemic congestion. RV-arterial uncoupling is accompanied by an increase in diastolic elastance. Measurements of RV systolic function but also of diastolic function predict outcome in any cause pulmonary hypertension and heart failure with or without preserved left ventricular ejection fraction. Pathobiological changes in the overloaded RV include a combination of myocardial fibre hypertrophy, fibrosis and capillary rarefaction, a titin phosphorylation-related displacement of myofibril tension-length relationships to higher pressures, a metabolic shift from mitochondrial free fatty acid oxidation to cytoplasmic glycolysis, toxic lipid accumulation, and activation of apoptotic and inflammatory signalling pathways. Treatment of RV failure rests on the relief of excessive loading.

Pressure Overload and Right Ventricular Failure: From Pathophysiology to Treatment

Right ventricular failure (RVF) is often caused by increased afterload and disrupted coupling between the right ventricle (RV) and the pulmonary arteries (PAs). After a phase of adaptive hypertrophy, pressure-overloaded RVs evolve towards maladaptive hypertrophy and finally ventricular dilatation, with reduced stroke volume and systemic congestion. In this article, we review the concept of RV-PA coupling, which depicts the interaction between RV contractility and afterload, as well as the invasive and non-invasive techniques for its assessment. The current principles of RVF management based on pathophysiology and underlying etiology are subsequently discussed. Treatment strategies remain a challenge and range from fluid management and afterload reduction in moderate RVF to vasopressor therapy, inotropic support and, occasionally, mechanical circulatory support in severe RVF.

Role of Exercise Stress Echocardiography in Pulmonary Hypertension

Resting and exercise right heart catheterisation is the gold standard method to diagnose and differentiate types of pulmonary hypertension (PH). As it carries technical challenges, the question arises if non-invasive exercise stress echocardiography may be used as an alternative. Exercise echocardiography can unmask exercise PH, detect the early stages of left ventricular diastolic dysfunction, and, therefore, differentiate between pre- and post-capillary PH. Regardless of the underlying aetiology, a developed PH is associated with increased mortality. Parameters of overt right ventricle (RV) dysfunction, including RV dilation, reduced RV ejection fraction, and elevated right-sided filling pressures, are detectable with resting echocardiography and are associated with worse outcome. However, these measures all fail to identify occult RV dysfunction. Echocardiographic measures of RV contractile reserve during exercise echocardiography are very promising and provide incremental prognostic information on clinical outcome. In this paper, we review pulmonary haemodynamic response to exercise, briefly describe the modalities for assessing pulmonary haemodynamics, and discuss in depth the contemporary key clinical application of exercise stress echocardiography in patients with PH.