Right ventricular remodeling in idiopathic pulmonary arterial hypertension: adaptive versus maladaptive morphology

NOTCH3 and Pulmonary Arterial Hypertension

NOTCH3 receptor signaling has been linked to the regulation of smooth muscle cell proliferation and the maintenance of smooth muscle cells in an undifferentiated state. Pulmonary arterial hypertension (World Health Organization Group 1 idiopathic disease: PAH) is a fatal disease characterized clinically by elevated pulmonary vascular resistance caused by extensive vascular smooth muscle cell proliferation, perivascular inflammation, and asymmetric neointimal hyperplasia in precapillary pulmonary arteries. In this review, a detailed overview of the specific role of NOTCH3 signaling in PAH, including its mechanisms of activation by a select ligand, downstream signaling effectors, and physiologic effects within the pulmonary vascular tree, is provided. Animal models showing the importance of the NOTCH3 pathway in clinical PAH will be discussed. New drugs and biologics that inhibit NOTCH3 signaling and reverse this deadly disease are highlighted.

A computational study of right ventricular mechanics in a rat model of pulmonary arterial hypertension

Pulmonary arterial hypertension (PAH) presents a significant challenge to right ventricular (RV) function due to progressive pressure overload, necessitating adaptive remodeling in the form of increased wall thickness, enhanced myocardial contractility and stiffness to maintain cardiac performance. However, the impact of these remodeling mechanisms on RV mechanics in not clearly understood. In addition, there is a lack of quantitative understanding of how each mechanism individually influences RV mechanics. Utilizing experimental data from a rat model of PAH at three distinct time points, we developed biventricular finite element models to investigate how RV stress and strain evolved with PAH progression. The finite element models were fitted to hemodynamic and morphological data to represent different disease stages and used to analyze the impact of RV remodeling as well as the altered RV pressure. Furthermore, we performed a number of theoretical simulation studies with different combinations of morphological and physiological remodeling, to assess and quantify their individual impact on overall RV load and function. Our findings revealed a substantial 4-fold increase in RV stiffness and a transient 2-fold rise in contractility, which returned to baseline by week 12. These changes in RV material properties in addition to the 2-fold increase in wall thickness significantly mitigated the increase in wall stress and strain caused by the progressive increase in RV afterload. Despite the PAH-induced cases showing increased wall stress and strain at end-diastole and end-systole compared to the control, our simulations suggest that without the observed remodeling mechanisms, the increase in stress and strain would have been much more pronounced. Our model analysis also indicated that while changes in the RV's material properties-particularly increased RV stiffness - have a notable effect on its mechanics, the primary compensatory factor limiting the stress and strain increase in the early stages of PAH was the significant increase in wall thickness. These findings underscore the importance of RV remodeling in managing the mechanical burden on the right ventricle due to pressure overload.

Biventricular intraventricular mechanical and electrical dyssynchrony in pulmonary arterial hypertension

Background

Pulmonary arterial hypertension (PAH) leads to myocardial remodeling, manifesting as mechanical dyssynchrony (M-dys) and electrical dyssynchrony (E-dys), in both right (RV) and left ventricles (LV). However, the impacts of layer-specific intraventricular M-dys on biventricular functions and its association with E-dys in PAH remain unclear.

Methods

Seventy-nine newly diagnosed patients with PAH undergoing cardiac magnetic resonance scanning were consecutively recruited between January 2011 and December 2017. The biventricular volumetric and layer-specific intraventricular M-dys were analyzed. The QRS duration z-scores were calculated after adjusting for age and sex.

Results

77.22 % of patients were female (mean age 30.30 ± 9.79 years; median follow-up 5.53 years). Further, 29 (36.71 %) patients succumbed to all-cause mortality by the end of the study. At the baseline, LV layer-specific intraventricular M-dys had apparent transmural gradients compared with RV in the radial and circumferential directions. However, deceased patients lost the transmural gradients. The LV longitudinal strain rate time to late diastolic peak in the myocardial region (LVmyoLSRTTLDPintra) predicted long-term survival. The Kaplan-Meier curve revealed that patients with PAH with LVmyoLSRTTLDPintra <20.01 milliseconds had a worse prognosis. Larger right ventricle (RV) intraventricular M-dys resulted in worse RV ejection fraction. However, larger LV intraventricular M-dys in the late diastolic phase indicated remarkable exercise capacity and higher LV stroke volume index. E-dys and intraventricular M-dys had no direct correlations.

Conclusions

The layer-specific intraventricular M-dys had varying impacts on biventricular functions in PAH. PAH patients with LVmyoLSRTTLDPintra <20.01 milliseconds had a worse prognosis. LV intraventricular M-dys in the late diastolic phase needs more attention to precisely evaluate LV function.

Cardiac magnetic resonance imaging-derived septum swing index detects pulmonary hypertension: A diagnostic study

Background and Objectives

Because of pressure differences between the pulmonary artery and aorta, the ventricular septum moves in a swinging motion that is commonly observed on cardiac MR (CMR) cine sequences in patients with pulmonary hypertension (PH). We aimed to assess the use of septum swing index (SSI) derived by CMR for detecting PH.

Methods

We retrospectively identified consecutive patients with suspected PH who underwent right heart catheterization (RHC) and CMR at a PH referral center between July 2019 and December 2020. The diagnostic accuracy of SSI for identifying PH (mean pulmonary artery pressure [mPAP] ≥ 25 mmHg) was assessed by receiver operating characteristic curves, sensitivity, specificity, and positive and negative predictive values.

Results

A total of 105 patients (mean age: 47.8 ± 15.0 years; 68 females) were included in the final analysis. SSI and mPAP were negatively correlated in the total study population and patients with PH, but not in patients without PH. SSI was an independent predictor of PH (adjusted odds ratio: 12.9, 95% confidence interval: 3.6 to 45.5, P = 0.003). The area under the curve for SSI was 0.91, with a cut-off value of 0.9673 yielding the best balance of sensitivity (86.4%), specificity (88.2%), positive predictive value (97.4%), negative predictive value (55.6%), and accuracy (86.7%) for detecting PH.

Conclusions

Septum swing index was lower in patients with PH and is a simple, reliable method for detecting PH.

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.

Classification and Predictors of Right Ventricular Functional Recovery in Pulmonary Arterial Hypertension

BACKGROUND

Normative changes in right ventricular (RV) structure and function have not been characterized in the context of treatment-associated functional recovery (RV functional recovery [RVFnRec]). The aim of this study is to assess the clinical relevance of a proposed RVFnRec definition.

METHODS

We evaluated 63 incident patients with pulmonary arterial hypertension by right heart catheterization and cardiac magnetic resonance imaging at diagnosis and cardiac magnetic resonance imaging and invasive cardiopulmonary exercise testing following treatment (≈11 months). Sex, age, ethnicity matched healthy control subjects (n=62) with 1-time cardiac magnetic resonance imaging and noninvasive cardiopulmonary exercise testing were recruited from the PVDOMICS (Redefining Pulmonary Hypertension through Pulmonary Vascular Disease Phenomics) project. We examined therapeutic cardiac magnetic resonance imaging changes relative to the evidence-based peak oxygen consumption (VO2peak)>15 mL/(kg·min) to define RVFnRec by receiver operating curve analysis. Afterload was measured as mean pulmonary artery pressure, resistance, compliance, and elastance.

RESULTS

A drop in RV end-diastolic volume of -15 mL best defined RVFnRec (area under the curve, 0.87; P=0.0001) and neared upper 95% CI RV end-diastolic volume of controls. This cutoff was met by 22 out of 63 (35%) patients which was reinforced by freedom from clinical worsening, RVFnRec 1 out of 21 (5%) versus no RVFnRec 17 out of 42, 40% (log-rank P=0.006). A therapy-associated increase of 0.8 mL/mm Hg in compliance had the best predictive value of RVFnRec (area under the curve, 0.76; [95% CI, 0.64-0.88]; P=0.001). RVFnRec patients had greater increases in stroke volume, and cardiac output at exercise.

CONCLUSIONS

RVFnRec defined by RV end-diastolic volume therapeutic decrease of -15 mL predicts exercise capacity, freedom from clinical worsening, and nears normalization. A therapeutic improvement of compliance is superior to other measures of afterload in predicting RVFnRec. RVFnRec is also associated with increased RV output reserve at exercise.

Left ventricular underfilling in PAH: A potential indicator for adaptive-to-maladaptive transition

Pulmonary arterial hypertension (PAH) still remains a life-threatening disorder with poor prognosis. The right ventricle (RV) adapts to the increased afterload by a series of prognostically significant morphological and functional changes, the adaptive nature should also be understood in the context of ventricular interdependence. We hypothesized that left ventricle (LV) underfilling could serve as an important imaging marker for identifying maladaptive changes and predicting clinical outcomes in PAH patients. We prospectively enrolled patients with PAH who underwent both cardiac magnetic resonance and right heart catheterization between October 2013 and December 2020. Patients were categorized into four groups based on their LV and RV mass/volume ratio (M/V). LV M/V was stratified using the normal value (0.7 g/mL for males and 0.6 g/mL for females) to identify patients with LV underfilling (M/V ≥ normal value), while RV M/V was stratified based on the median value. The primary endpoint was all-cause mortality, and the composite endpoints included all-cause mortality and heart failure-related readmissions. A total of 190 PAH patients (53 male, mean age 37 years) were included in this study. Patients with LV underfilling exhibited higher NT-proBNP levels, increased RV mass, larger RV but smaller LV, lower right ventricular ejection fraction, and shorter 6-min walking distance. Patients with LV underfilling had a 2.7-fold higher risk of mortality than those without and LV M/V (hazard ratio [per 0.1 g/mL increase]: 1.271, 95% confidence interval: 1.082-1.494, p = 0.004) was also independent predictors of all-cause mortality. Moreover, patients with low LV M/V had a better prognosis regardless of the level of RV M/V. Thus, LV underfilling is an independent predictor of adverse clinical outcomes in patients with PAH, and it could be an important imaging marker for identifying maladaptive changes in these patients.

Medical Management of Right Ventricular Dysfunction in Pulmonary Arterial Hypertension

PURPOSE OF REVIEW

The purpose of this review is to overview the most relevant and recent knowledge regarding medical management in pulmonary arterial hypertension (PAH).

RECENT FINDINGS

Evidence has shown that PAH patients' quality of life and prognosis depend on the capability of the RV to adapt to increased afterload and to fully recover in response to substantially reduced pulmonary vascular resistance obtained with medical therapy. Data from recent clinical studies show that more aggressive treatment strategies, especially in higher risk categories, determine larger afterload reductions, consequentially increasing the probability of achieving right heart reverse remodeling, therefore improving the patients' survival and quality of life. Remarkable progress has been observed over the past decades in the medical treatment of PAH, related to the development of drugs that target multiple biological pathways, strategies for earlier and more aggressive treatment interventions. New hopes for treatment of patients who are unable to achieve low-risk status have been derived from the phase 2 trial PULSAR and the phase 3 trial STELLAR, which show improvement in the hemodynamic status of patients treated with sotatercept on top of background therapy. Promising results are expected from several ongoing clinical trials targeting new pathways involved in the pathophysiology of PAH.

Ventricular global function index is associated with clinical outcomes in pediatric pulmonary hypertension

BACKGROUND

Multiple right ventricular (RV) metrics have prognostic value in pulmonary hypertension (PH). A cardiac magnetic resonance imaging (CMR) derived global ventricular function index (GFI) provided improved prediction of composite adverse outcome (CAO) in adults with atherosclerosis. GFI has not yet been explored in a PH population. We explored the feasibility of GFI as a predictor of CAO in a pediatric PH population.

METHODS

Two center retrospective chart review identified pediatric PH patients undergoing CMR from Jan 2005-June 2021. GFI, defined as the ratio of the stroke volume to the sum of mean ventricular cavity and myocardial volume, was calculated for each patient. CAO was defined as death, lung transplant, Potts shunt, or parenteral prostacyclin initiation after CMR. Cox proportional hazards regression was used to estimate associations and assess model performance between CMR parameters and CAO.

RESULTS

The cohort comprised 89 patients (54% female, 84% World Health Organization (WHO) Group 1; 70% WHO-FC ≤ 2; and 27% on parenteral prostacyclin). Median age at CMR was 12 years (IQR 8.1-17). Twenty-one (24%) patients experienced CAO during median follow up of 1.5 years. CAO cohort had higher indexed RV volumes (end systolic-145 vs 99 mL/m2, p = 0.003; end diastolic-89 vs 46 mL/m2, p = 0.004) and mass (37 vs 24 gm/m2, p = 0.003), but lower ejection fraction (EF) (42 vs 51%, p < 0.001) and GFI (40 vs 52%, p < 0.001). Higher indexed RV volumes (hazard ratios [HR] 1.01, CI 1.01-1.02), lower RV EF (HR 1.09, CI 1.05-1.12) and lower RV GFI (HR 1.09, CI 1.05-1.11) were associated with increased risk of CAO. In survival analysis, patients with RV GFI < 43% demonstrated decreased event-free survival and increased hazard of CAO compared to those with RV GFI ≥ 43%. In multivariable models, inclusion of GFI provided improved prediction of CAO compared to models incorporating ventricular volumes, mass or EF.

CONCLUSIONS

RV GFI was associated with CAO in this cohort, and inclusion in multivariable models had increased predictive value compared to RVEF. GFI uses readily available CMR data without additional post-processing and may provide additional prognostic value in pediatric PH patients beyond traditional CMR markers.

Assessment of Right Ventricular Function-a State of the Art

PURPOSE OF REVIEW

The right ventricle (RV) has a complex geometry and physiology which is distinct from the left. RV dysfunction and failure can be the aftermath of volume- and/or pressure-loading conditions, as well as myocardial and pericardial diseases.

RECENT FINDINGS

Echocardiography, magnetic resonance imaging and right heart catheterisation can assess RV function by using several qualitative and quantitative parameters. In pulmonary hypertension (PH) in particular, RV function can be impaired and is related to survival. An accurate assessment of RV function is crucial for the early diagnosis and management of these patients. This review focuses on the different modalities and indices used for the evaluation of RV function with an emphasis on PH.

Idiopathic Pulmonary Arterial Hypertension in Paediatrics Represents Still a Serious Challenge: A Case Series Study

Introduction: Paediatric pulmonary hypertension (PH) represents a heterogeneous illness that is responsible for high morbidity and mortality if left without treatment. Idiopathic pulmonary arterial hypertension (IPAH) is a subtype of PAH rarely seen in paediatrics. Limited long-term data are available. Methods: Over a period of 20 years, 10 paediatric patients were enrolled at two tertiary centres. Their clinical, echocardiographic, and right heart catheterisation (RHC) features and outcome were evaluated. Results: The mean age at first diagnosis was 5.7 ± 5.7 years. The age at the last follow-up was 12.4 ± 6.1 years. The average follow-up was 6.6 ± 0.8 years. There was a female prevalence of 60% (p < 0.05) in this case series. Regarding the NYHA functional class, 80% of IPAH subjects were in class III or IV. The mean saturation was 91 ± 5%. In this regard, 70% of the patients were on a combination of three drugs, with sildenafil (90%) included. On echocardiography, longitudinal right ventricular contractility (TAPSE) was slightly reduced (13.4 ± 2.6 mm), whilst RVSP was severely elevated (101 ± 19 mmHg). The RHC data showed that mPAP was 61.8 ± 23.1 mmHg (p = 0.0017 with RVSP on echocardiography), mRAP was 10.7 ± 3.8 mmHg, CI was 2.6 ± 1 L·min−1·m−2, PVRi was 16.8 ± 12.6 WU·m2, and SVO2 was 63.6 ± 14.8%. Regarding the outcome, two male IPAH patients (20%) died, and 50% underwent lung transplant or were on transplant assessment or already on the waiting list for lung transplantation. One patient underwent a ductus arteriosus stenting (reverse Potts shunt) and another underwent atrial septostomy and stenting. Conclusions: Notwithstanding the progress in medical therapy, IPAH continues to represent a serious challenge, particularly in the paediatric population, with the need for lung transplantation and significant mortality.

Classification and Predictors of Right Ventricular Functional Recovery in Pulmonary Arterial Hypertension

Background

Normative changes in right ventricular (RV) structure and function have not been characterized in the context of treatment-associated functional recovery (RVFnRec). The aim of this study is to assess the clinical relevance of a proposed RVFnRec definition.

Methods

We evaluated 63 incident patients with PAH by right heart catheterization and cardiac MRI (CMR) at diagnosis and CMR and invasive cardiopulmonary exercise (CPET) following treatment (∼11 months). Sex, age, race/ethnicity matched healthy control subjects (n=62) with one-time CMR and non-invasive CPET were recruited from the PVDOMICS project. We examined therapeutic CMR changes relative to the evidence-based peak oxygen consumption (VO2 peak )>15mL/kg/min to define RVFnRec by receiver operating curve analysis. Afterload was measured in the as mean pulmonary artery pressure, resistance, compliance, and elastance.

Results

A drop in RV end-diastolic volume of -15 mL best defined RVFnRec (AUC 0.87, P=0.0001) and neared upper 95% CI RVEDV of controls. 22/63 (35%) of subjects met this cutoff which was reinforced by freedom from clinical worsening, RVFnRec 1/21 (5%) versus no RVFnRec 17/42, 40%, (log rank P=0.006). A therapy-associated increase of 0.8 mL/mmHg in compliance had the best predictive value of RVFnRec (AUC 0.76, CI 0.64-0.88, P=0.001). RVFnRec subjects had greater increases in stroke volume, and cardiac output at exercise.

Conclusions

RVFnRec defined by RVEDV therapeutic decrease of -15mL predicts exercise capacity, freedom from clinical worsening, and nears normalization. A therapeutic improvement of compliance is superior to other measures of afterload in predicting RVFnRec. RVFnRec is also associated with increased RV output reserve at exercise.

Clinical Perspective

What is new?: Right ventricular functional recovery (RVFnRec) represents a novel endpoint of therapeutic success in PAH. We define RVFnRec as treatment associated normative RV changes related to function (peak oxygen consumption). Normative RV imaging changes are compared to a well phenotyped age, sex, and race/ethnicity matched healthy control cohort from the PVDOMICS project. Previous studies have focused on RV ejection fraction improvements. However, we show that changes in RVEDV are perhaps more important in that improvements in LV function also occur. Lastly, RVFnRec is best predicted by improvements in pulmonary artery compliance versus pulmonary vascular resistance, a more often cited metric of RV afterload.What are the clinical implications?: RVFnRec represents a potential non-invasive assessment of clinical improvement and therapeutic response. Clinicians with access to cardiac MRI can obtain a limited scan (i.e., ventricular volumes) before and after treatment. Future study should examine echocardiographic correlates of RVFnRec.

Riociguat and the right ventricle in pulmonary arterial hypertension and chronic thromboembolic pulmonary hypertension

Pulmonary arterial hypertension (PAH) and chronic thromboembolic pulmonary hypertension (CTEPH) are progressive diseases that can lead to right heart failure and death. Right ventricular dysfunction, hypertrophy and maladaptive remodelling are consequences of increased right ventricular (RV) afterload in PAH and CTEPH and are indicative of long-term outcomes. Because RV failure is the main cause of morbidity and mortality in PAH and CTEPH, successful treatments should lead to improvements in RV parameters. Riociguat is a soluble guanylate cyclase stimulator approved for the treatment of PAH and inoperable or persistent/recurrent CTEPH after pulmonary endarterectomy. This review examines the current evidence showing the effect of riociguat on the right ventricle, with particular focus on remodelling, function and structural parameters in preclinical models and patients with PAH or CTEPH.

Right ventricular failure in left heart disease: from pathophysiology to clinical manifestations and prognosis

Right heart failure (RHF) is a clinical syndrome in which symptoms and signs are caused by dysfunction and/or overload of the right heart structures, predominantly the right ventricle (RV), resulting in systemic venous hypertension, peripheral oedema and finally, the impaired ability of the right heart to provide tissue perfusion. Pathogenesis of RHF includes the incompetence of the right heart to maintain systemic venous pressure sufficiently low to guarantee an optimal venous return and to preserve renal function. Virtually, all myocardial diseases involving the left heart may be responsible for RHF. This may result from coronary artery disease, hypertension, valvular heart disease, cardiomyopathies and myocarditis. The most prominent clinical signs of RHF comprise swelling of the neck veins with an elevation of jugular venous pressure and ankle oedema. As the situation worsens, fluid accumulation becomes generalised with extensive oedema of the legs, congestive hepatomegaly and eventually ascites. Diagnosis of RHF requires the presence of signs of elevated right atrial and venous pressures, including dilation of neck veins, with at least one of the following criteria: (1) compromised RV function; (2) pulmonary hypertension; (3) peripheral oedema and congestive hepatomegaly. Early recognition of RHF and identifying the underlying aetiology as well as triggering factors are crucial to treating patients and possibly reversing the clinical manifestations effectively and improving prognosis.

Long-term prognostic value of cardiac catheterization and acute vasodilator testing with inhaled iloprost in pediatric idiopathic pulmonary arterial hypertension

To assess the long-term prognostic value of cardiac catheterization and acute vasodilator testing (AVT) with inhaled iloprost in children with idiopathic pulmonary arterial hypertension (IPAH). Data on 81 consecutive children with IPAH referred to our center who underwent cardiac catheterization and AVT between June 2008 and August 2019 were collected. The correlation between the invasive hemodynamic data and transplant-free survival was analyzed. Twenty-four patients died and 1 underwent lung transplantation during a median follow-up of 3.8 years, with a 5-year transplant-free survival rate of 64.9%. Univariate analysis showed that predictors associated with improved survival included a lower pulmonary vascular resistance index (PVRI), PVRI/systemic vascular resistance index (SVRI), mean pulmonary arterial pressure (mPAP)/mean systemic arterial pressure, mean right atrial pressure, and a higher cardiac index (CI), mixed systemic venous oxygen saturations (SvO₂), and acute vasodilator response (AVR) according to the Barst criteria (decrease in mPAP and PVRI/SVRI ratio of >20% without a decrease in CI). In multivariate Cox regression analysis, Barst AVR and SvO₂ were independently related to transplant-free survival. Multiple hemodynamic variables from cardiac catheterization and AVT with inhaled iloprost have important prognostic value for long-term survival in children with IPAH, of which pulmonary vasoreactivity defined by the Barst criteria and SvO₂ are independent prognostic factors.

Right ventricular remodelling in pulmonary arterial hypertension predicts treatment response

OBJECTIVES

To determine the prognostic value of patterns of right ventricular adaptation in patients with pulmonary arterial hypertension (PAH), assessed using cardiac magnetic resonance (CMR) imaging at baseline and follow-up.

METHODS

Patients attending the Sheffield Pulmonary Vascular Disease Unit with suspected pulmonary hypertension were recruited into the ASPIRE (Assessing the Spectrum of Pulmonary hypertension Identified at a REferral Centre) Registry. With exclusion of congenital heart disease, consecutive patients with PAH were followed up until the date of census or death. Right ventricular end-systolic volume index adjusted for age and sex and ventricular mass index were used to categorise patients into four different volume/mass groups: low-volume-low-mass, low-volume-high-mass, high-volume-low-mass and high-volume-high-mass. The prognostic value of the groups was assessed with one-way analysis of variance and Kaplan-Meier plots. Transition of the groups was studied.

RESULTS

A total of 505 patients with PAH were identified, 239 (47.3%) of whom have died at follow-up (median 4.85 years, IQR 4.05). The mean age of the patients was 59±16 and 161 (32.7%) were male. Low-volume-low-mass was associated with CMR and right heart catheterisation metrics predictive of improved prognosis. There were 124 patients who underwent follow-up CMR (median 1.11 years, IQR 0.78). At both baseline and follow-up, the high-volume-low-mass group had worse prognosis than the low-volume-low-mass group (p<0.001). With PAH therapy, 73.5% of low-volume-low-mass patients remained in this group, whereas only 17.4% of high-volume-low-mass patients transitioned into low-volume-low-mass.

CONCLUSIONS

Right ventricular adaptation assessed using CMR has prognostic value in patients with PAH. Patients with maladaptive remodelling (high-volume-low-mass) are at high risk of treatment failure.

Multiparametric evaluation of right ventricular function in pulmonary arterial hypertension associated with congenital heart disease

INTRODUCTION AND OBJECTIVES

Outcome in patients with congenital heart diseases and pulmonary arterial hypertension (PAH) is closely related to right ventricular (RV) function. Two-dimensional echocardiographic parameters, such as strain imaging or RV end-systolic remodeling index (RVESRI) have emerged to quantify RV function.

METHODS

We prospectively studied 30 patients aged 48±12 years with pretricuspid shunt and PAH and investigated the accuracy of multiple echocardiographic parameters of RV function (tricuspid annular plane systolic excursion, tricuspid annular peak systolic velocity, RV systolic-to-diastolic duration ratio, right atrial area, RV fractional area change, RV global longitudinal strain and RVESRI) to RV ejection fraction measured by cardiac magnetic resonance.

RESULTS

RV ejection fraction <45% was observed in 13 patients (43.3%). RV global longitudinal strain (ρ [Spearman's correlation coefficient]=-0.75; P=.001; R²=0.58; P=.001), right atrium area (ρ=-0.74; P <.0001; R²=0.56; P <.0001), RVESRI (ρ=-0.64; P <.0001; R²=0.47; P <.0001), systolic-to-diastolic duration ratio (ρ=-0.62; P=.0004; R²=0.47; P <.0001) and RV fractional area change (ρ=0.48; P=.01; R²=0.37; P <.0001) were correlated with RV ejection fraction. RV global longitudinal strain, RVESRI and right atrium area predicted RV ejection fraction <45% with the greatest area under curve (0.88; 95%CI, 0.71-1.00; 0.88; 95%CI, 0.76-1.00, and 0.89; 95%CI, 0.77-1.00, respectively). RV global longitudinal strain >-16%, RVESRI ≥ 1.7 and right atrial area ≥ 22 cm² predicted RV ejection fraction <45% with a sensitivity and specificity of 87.5% and 85.7%; 76.9% and 88.3%; 92.3% and 82.4%, respectively.

CONCLUSIONS

RVESRI, right atrial area and RV global longitudinal strain are strong markers of RV dysfunction in patients with pretricuspid shunt and PAH.

Hemodynamic Evaluation of the Right Heart-Pulmonary Circulation Unit in Patients Candidate to Transjugular Intrahepatic Portosystemic Shunt

In Europe, liver cirrhosis represents the fourth-most common cause of death, being responsible for 170,000 deaths and 5500 liver transplantations per year. The main driver of its decompensation is portal hypertension, whose progression radically changes the prognosis of affected patients. Transjugular intrahepatic portosystemic shunt (TIPS) is one of the main therapeutic strategies for these patients as it reverts portal hypertension, thus improving survival. However, the coexistence of portal hypertension and pulmonary hypertension or heart failure is considered a contraindication to TIPS. Nevertheless, in the latest guidelines, the definition of heart failure has not been specified. It is unclear whether the contraindication concerns the presence of clinical signs and symptoms of heart failure or hemodynamic changes in the right heart-pulmonary circulation. Moreover, data about induced right heart volume overload after TIPS and the potential development of heart failure and pulmonary hypertension is currently scanty and controversial. In this article we revise this issue in finding predictors of cardiac performance after TIPS procedure. Performing a fluid challenge during right heart catheterization might be a promising expedient to test the adaptation of the right ventricle to a sudden increase in preload in the first few months after TIPS. This test may unmask a potential cardiac inability to sustain the hemodynamic load after TIPS, allowing for a clearer definition of heart failure and, consequently, a more robust indication to TIPS.

Systolic and diastolic functional reserve of the subpulmonary and systemic right ventricles as assessed by pharmacologic and exercise stress: A systematic review

We performed a systematic review of the literature on the assessment of subpulmonary and systemic right ventricular (RV) functional reserve during pharmacological and exercise stress in congenital heart patients and patients with pulmonary arterial hypertension (PAH). Literature search was conducted using PubMed, EMBASE, and MEDLINE from their inception up to August 2020. Of 913 records identified, 56 studies with a total of 1730 patients were included. Of the 56 studies, 23 assessed subpulmonary RV functional reserve in repaired tetralogy of Fallot patients, 19 assessed systemic RV reserve in patients with transposition of the great arteries (TGA) after atrial switch and those with congenitally corrected TGA, and 14 assessed subpulmonary RV research in patients with PAH. Pharmacological and exercise stress was used, respectively, in 22 and 34 studies. The main findings were (1) impairment of RV systolic and diastolic functional reserve, (2) associations between impaired functional reserve and worse baseline functional parameters, and (3) prognostic implications of RV systolic functional reserve on clinical outcomes in patients with volume and/or pressure-loaded subpulmonary and systemic right ventricles. Further studies are required to establish the incremental value of incorporating stress studies of RV systolic and diastolic function in the clinical management algorithm of congenital heart patients and patients with PAH.

Computational Simulator Models and Invasive Hemodynamic Monitoring as Tools for Precision Medicine in Pulmonary Arterial Hypertension

Precision medicine, providing the right therapeutic strategy for the right patient, could revolutionize management and prognosis of patients affected by cardiovascular diseases. Big data and artificial intelligence are pivotal for the realization of this ambitious design. In the setting of pulmonary arterial hypertension (PAH), the use of computational models and data derived from ambulatory implantable hemodynamic monitors could provide useful information for tailored treatment, as requested by precision medicine.

Novel Echocardiographic Algorithm for Right Ventricular Mass Quantification: Cardiovascular Magnetic Resonance and Clinical Prognosis Validation

BACKGROUND

Right ventricular hypertrophy (RVH) provides a key remodeling index alterable by pulmonary hypertension. Although echocardiography commonly integrates linear wall thickness and chamber dimensions to quantify left ventricular remodeling, the utility of an equivalent right ventricular (RV)-based approach is unknown.

METHODS

This was a retrospective analysis of 200 patients undergoing transthoracic echocardiography and cardiac magnetic resonance (CMR) within 30 days (median = 3 days; interquartile range, 15 days), stratified by echocardiography-quantified pulmonary artery systolic pressure (<35, 35 to <55, 55 to <75, or ≥75 mm Hg). Echocardiographic assessment included RV linear dimensions in parasternal long-axis and apical four-chamber views and wall thicknesses in parasternal long-axis, four-chamber, and subcostal views. Subcostal wall thickness was integrated with chamber diameters to calculate RV mass, which was tested in relation to CMR-quantified RV mass and all-cause mortality.

RESULTS

Echocardiography-based quantification of all linear dimensions was feasible in 95% of patients (190 of 200). RV wall thicknesses in all orientations increased in relation to pulmonary artery systolic pressure (P < .001) and was greater among patients with, versus those without, CMR-evidenced RVH (P < .001 for all). Correlations between echocardiography and CMR were greatest for RV basal diameter (r = 0.73), RV subcostal wall thickness (r = 0.71), and global RV mass (r = 0.82; P < .001 for all). Echocardiography-derived global RV mass cutoffs were established in a derivation cohort and tested in a validation cohort. Results demonstrated good sensitivity and specificity (75.5% and 74.0%, respectively) in relation to CMR-quantified RVH. During follow-up (median, 4.2 years), 18% of patients (n = 36) died. Echocardiography-evidenced RVH (hazard ratio, 1.98; 95% CI, 1.09-3.88; P = .048) conferred similar mortality risk compared with RVH on CMR (hazard ratio, 2.41; 95% CI, 1.22-4.78; P = .01).

CONCLUSIONS

Echocardiography-quantified RV parameters provide a robust index of RV afterload. Global RV mass calculated using a novel echocardiographic formula based on readily available linear indices yields good diagnostic performance for CMR-evidenced RVH and confers increased mortality risk.

Appropriate use criteria for cardiovascular MRI: SIC - SIRM position paper Part 2 (myocarditis, pericardial disease, cardiomyopathies and valvular heart disease)

Cardiovascular magnetic resonance (CMR) has emerged as an accurate diagnostic technique for the evaluation of patients with cardiac disease in the majority of clinical settings, thanks to an established additional diagnostic and prognostic value. This document has been developed by a joined group of experts of the Italian Society of Cardiology (SIC) and Italian Society of Radiology (SIRM) to provide a summary about the current state of technology and clinical applications of CMR, to improve the clinical diagnostic pathways and to promote its inclusion in clinical practice. The writing committee consisted of members and experts of both societies in order to develop a more integrated approach in the field of cardiac imaging. This section 2 will cover myocarditis, pericardial disease, cardiomyopathies and valvular heart disease.

Diverse Right Ventricular Remodeling Evaluated by MRI and Prognosis in Eisenmenger Syndrome With Different Shunt Locations

BACKGROUND

Congenital shunt location is related to Eisenmenger syndrome (ES) survival. Moreover, right ventricular (RV) remodeling is associated with poor survival in pulmonary hypertension.

PURPOSE

To investigate RV remodeling using comprehensive magnetic resonance imaging (MRI) techniques and identify its relationship with prognosis in ES subgroups classified by shunt location.

STUDY TYPE

Prospective observational study.

POPULATION

Fifty-four adults with ES (16 with pre-tricuspid shunt and 38 with post-tricuspid shunt).

FIELD STRENGTH/SEQUENCE

3.0 T/cine MRI with balanced steady-state free precession sequence, late gadolinium enhancement with inversion recovery segmented gradient echo sequence and phase-sensitive reconstruction, and T1 mapping with modified Look-Locker inversion recovery sequence.

ASSESSMENT

Demographics, clinical characteristics, hemodynamics, RV remodeling features (morphology, systolic function, RV-pulmonary artery (PA) coupling and myocardial fibrosis), and prognosis were compared between ES subgroups. The adverse endpoint was all-cause mortality or readmission for heart failure.

STATISTICAL TESTS

The independent samples t-test, Fisher's exact test or Chi-squared test, and the Kaplan-Meier method were used. P < 0.05 was considered significant.

RESULTS

Compared to patients with post-tricuspid shunt, patients with pre-tricuspid shunt were significantly older and had higher N-terminal pro-B-type natriuretic peptide concentrations and poorer exercise tolerance. Pre-tricuspid shunt showed significantly larger RV dimensions (end-diastolic volume index: 185.81 ± 37.49 vs. 98.20 ± 36.26 mL/m² ), worse RV ejection fraction (23.54% ± 12.35% vs. 40.82% ± 10.77%), and RV-PA decoupling (0.35 ± 0.31 vs. 0.72 ± 0.29). Biventricular myocardial fibrosis was significantly more severe in pre-tricuspid shunt than post-tricuspid shunt (extracellular volume, left ventricle: 35.85% ± 2.58% vs. 29.10% ± 5.20%; RV free wall: 30.93% ± 5.65% vs. 26.75% ± 5.15%). In addition, pre-tricuspid shunt demonstrated a significantly increased risk of adverse endpoint (hazard ratio: 2.938, 95% confidence interval: 1.204-7.172).

DATA CONCLUSION

ES with pre-tricuspid shunt might be a unique subtype with worse clinically decompensated RV remodeling and poor prognosis.

LEVEL OF EVIDENCE

2 Technical Efficacy Stage: 5.

Echocardiographic Prognosis Relevance of Attenuated Right Heart Remodeling in Idiopathic Pulmonary Arterial Hypertension

Background: Right ventricular (RV) function is a great determination of the fate in patients with pulmonary arterial hypertension (PAH). Monitoring RV structure back to normal or improvement should be useful for evaluation of RV function. The aims of this study were to assess the prognostic relevance of changed right heart (RH) dimensions by echocardiography and attenuated RH remodeling (ARHR) in idiopathic PAH (IPAH).

Methods: We retrospectively analyzed 232 consecutive adult IPAH patients at baseline assessment and included RH catheterization and echocardiography. ARHR at the mean 20 ± 12 months' follow-up was defined by a decreased right atrium area, RV mid-diameter, and left ventricular end-diastolic eccentricity index. The follow-up end point was all-cause mortality.

Results: At mean 20 ± 12 months' follow-up, 33 of 232 patients (14.2%) presented with ARHR. The remaining 199 surviving patients were monitored for another 25 ± 20 months. At the end of follow-up, the survival rates at 1, 3, and 5 years were 89, 89, and 68% in patients with ARHR, respectively, and 84, 65 and 41% in patients without ARHR (log-rank p = 0.01). ARHR was an independent prognostic factor for mortality. Besides, ARHR was available to further stratify patients' risk assessment through the French PAH non-invasive-risk criteria.

Conclusions: Echocardiographic ARHR is an independent determinant of prognosis in IPAH at long-term follow-up. ARHR might be a useful tool to indicate the RV morphologic and functional improvement associated with better prognostic likelihood.

Predictors and prognosis of right ventricular function in pulmonary hypertension due to heart failure with reduced ejection fraction

Aims

Failure of right ventricular (RV) function worsens outcome in pulmonary hypertension (PH). The adaptation of RV contractility to afterload, the RV‐pulmonary artery (PA) coupling, is defined by the ratio of RV end‐systolic to PA elastances (Ees/Ea). Using pressure–volume loop (PV‐L) technique we aimed to identify an Ees/Ea cut‐off predictive for overall survival and to assess hemodynamic and morphologic conditions for adapted RV function in secondary PH due to heart failure with reduced ejection fraction (HFREF).

Methods and results

This post hoc analysis is based on 112 patients of the prospective Magdeburger Resynchronization Responder Trial. All patients underwent right and left heart echocardiography and a baseline PV‐L and RV catheter measurement. A subgroup of patients (n = 50) without a pre‐implanted cardiac device underwent magnetic resonance imaging at baseline. The analysis revealed that 0.68 is an optimal Ees/Ea cut‐off (area under the curve: 0.697, P < 0.001) predictive for overall survival (median follow up = 4.7 years, Ees/Ea ≥ 0.68 vs. <0.68, log‐rank 8.9, P = 0.003). In patients with PH (n = 76, 68%) multivariate Cox regression demonstrated the independent prognostic value of RV‐Ees/Ea in PH patients (hazard ratio 0.2, P < 0.038). Patients without PH (n = 36, 32%) and those with PH but RV‐Ees/Ea ≥ 0.68 showed comparable RV‐Ees/Ea ratios (0.88 vs. 0.9, P = 0.39), RV size/function, and survival. In contrast, secondary PH with RV‐PA coupling ratio Ees/Ea < 0.68 corresponded extremely close to cut‐off values that define RV dilatation/remodelling (RV end‐diastolic volume >160 mL, RV‐mass/volume‐ratio ≤0.37 g/mL) and dysfunction (right ventricular ejection fraction <38%, tricuspid annular plane systolic excursion <16 mm, fractional area change <42%, and stroke‐volume/end‐systolic volume ratio <0.59) and is associated with a dramatically increased short and medium‐term all‐cause mortality. Independent predictors of prognostically unfavourable RV‐PA coupling (Ees/Ea < 0.68) in secondary PH were a pre‐existent dilated RV [end‐diastolic volume >171 mL, odds ratio (OR) 0.96, P = 0.021], high pulsatile load (PA compliance <2.3 mL/mmHg, OR 8.6, P = 0.003), and advanced systolic left heart failure (left ventricular ejection fraction <30%, OR 1.23, P = 0.028).

Conclusions

The RV‐PA coupling ratio Ees/Ea predicts overall survival in PH due to HFREF and is mainly affected by pulsatile load, RV remodelling, and left ventricular dysfunction. Prognostically favourable coupling (RV‐Ees/Ea ≥ 0.68) in PH was associated with preserved RV size/function and mid‐term survival, comparable with HFREF without PH.

Cardiac-MRI Predicts Clinical Worsening and Mortality in Pulmonary Arterial Hypertension: A Systematic Review and Meta-Analysis

OBJECTIVES

This meta-analysis evaluates assessment of pulmonary arterial hypertension (PAH), with a focus on clinical worsening and mortality.

BACKGROUND

Cardiac magnetic resonance (CMR) has prognostic value in the assessment of patients with PAH. However, there are limited data on the prediction of clinical worsening, an important composite endpoint used in PAH therapy trials.

METHODS

The Cochrane Central Register of Controlled Trials, MEDLINE, EMBASE, and Web of Science databases were searched in May 2020. All CMR studies assessing clinical worsening and the prognosis of patients with PAH were included. Pooled hazard ratios of univariate regression analyses for CMR measurements, for prediction of clinical worsening and mortality, were calculated.

RESULTS

Twenty-two studies with 1,938 participants were included in the meta-analysis. There were 18 clinical worsening events and 8 deaths per 100 patient-years. The pooled hazard ratios show that every 1% decrease in right ventricular (RV) ejection fraction is associated with a 4.9% increase in the risk of clinical worsening over 22 months of follow-up and a 2.1% increase in the risk of death over 54 months. For every 1 ml/m2 increase in RV end-systolic volume index or RV end-diastolic volume index, the risk of clinical worsening increases by 1.3% and 1%, respectively, and the risk of mortality increases by 0.9% and 0.6%. Every 1 ml/m2 decrease in left ventricular stroke volume index or left ventricular end-diastolic volume index increased the risk of death by 2.5% and 1.8%. Left ventricular parameters were not associated with clinical worsening.

CONCLUSIONS

This review confirms CMR as a powerful prognostic marker in PAH in a large cohort of patients. In addition to confirming previous observations that RV function and RV and left ventricular volumes predict mortality, RV function and volumes also predict clinical worsening. This study provides a strong rationale for considering CMR as a clinically relevant endpoint for trials of PAH therapies.

Prognostic Implication of Right Ventricle Parameters Measured on Preoperative Cardiac MRI in Patients with Functional Tricuspid Regurgitation

OBJECTIVE

To investigate the prognostic value of preoperative cardiac magnetic resonance imaging (MRI) for long-term major adverse cardiac and cerebrovascular events (MACCEs) in patients undergoing tricuspid valve (TV) surgery for functional tricuspid regurgitation (TR).

MATERIALS AND METHODS

The preoperative cardiac MR images, New York Heart Association functional class, comorbidities, and clinical events of 78 patients (median [interquartile range], 59 [51-66.3] years, 28.2% male) who underwent TV surgery for functional TR were comprehensively reviewed. Cox proportional hazards analyses were performed to assess the associations of clinical and imaging parameters with MACCEs and all-cause mortality.

RESULTS

For the median follow-up duration of 5.4 years (interquartile range, 1.2-6.6), MACCEs and all-cause mortality were 51.3% and 23.1%, respectively. The right ventricular (RV) end-systolic volume index (ESVI) and the systolic RV mass index (RVMI) were higher in patients with MACCEs than those without them (77 vs. 68 mL/m², p = 0.048; 23.5 vs. 18.0%, p = 0.011, respectively). A high RV ESVI was associated with all-cause mortality (hazard ratio [HR] per value of 10 higher ESVI = 1.10, p = 0.03). A high RVMI was also associated with all-cause mortality (HR per increase of 5 mL/m² RVMI = 1.75, p < 0.001). After adjusting for age and sex, only RVMI remained a significant predictor of MACCEs and all-cause mortality (p < 0.05 for both). After adjusting for multiple clinical variables, RVMI remained significantly associated with all-cause mortality (p = 0.005).

CONCLUSION

RVMI measured on preoperative cardiac MRI was an independent predictor of long-term outcomes in patients who underwent TV surgery for functional TR.

Cardio-pulmonary involvement in pulmonary arterial hypertension: A perfusion and innervation scintigraphic evaluation

BACKGROUND

Pulmonary arterial hypertension (PAH) is characterized by the right ventricle (RV) remodeling and pulmonary endothelial dysfunction. We studied cardiac perfusion and innervation in PAH with a cadmium-zinc-telluride (CZT) scanner and lung uptake impairment of 123I-metaiodobenzylguanidine (123I-MIBG).

METHODS

In 13 patients with newly diagnosed PAH and 11 dilated cardiomyopathies (DCM, for comparative purposes), we assessed early and delayed 123I-MIBG uptake ratios of lung-to-mediastinum (L/M) and heart-to-mediastinum (H/M) on anterior planar images. A quantitative myocardial innervation with 123I-MIBG and perfusion with 99mTc-tetrofosmin using CZT-SPECT was performed. All patients underwent right heart catheterization.

RESULTS

Early and delayed L/M ratios in PAH were lower than DCM (1.47 ± 0.14 vs 1.98 ± 0.11 and 1.40 ± 0.13 vs 1.83 ± 0.09; P < .001), while early and delayed H/M were impaired but not different (1.73 ± 0.20 vs 1.65 ± 0.18 and 1.73 ± 0.27 vs 1.58 ± 0.19). RV perfusion and early innervation were significantly higher in PAH compared to DCM (68.4 ± 13.4 vs 28.6 ± 4.1 and 58.8 ± 9.3 vs 27 ± 2.2; P < .001); delayed RV innervation was not evaluable. RV/LV perfusion and innervation ratios were significantly related (R = 0.74; P < .0001) and had a significant correlation with clinical, hemodynamic, and morpho-functional parameters, including L/M ratios.

CONCLUSION

Cardio-pulmonary scintigraphy through a perfusion and innervation study is feasible and may identify pulmonary vascular and RV remodeling, as in PAH.

Appropriate use criteria for cardiovascular magnetic resonance imaging (CMR): SIC-SIRM position paper part 1 (ischemic and congenital heart diseases, cardio-oncology, cardiac masses and heart transplant)

Cardiac magnetic resonance (CMR) has emerged as new mainstream technique for the evaluation of patients with cardiac diseases, providing unique information to support clinical decision-making. This document has been developed by a joined group of experts of the Italian Society of Cardiology and Italian society of Radiology and aims to produce an updated consensus statement about the current state of technology and clinical applications of CMR. The writing committee consisted of members and experts of both societies who worked jointly to develop a more integrated approach in the field of cardiac radiology. Part 1 of the document will cover ischemic heart disease, congenital heart disease, cardio-oncology, cardiac masses and heart transplant.

The Growing Role of Echocardiography in Pulmonary Arterial Hypertension Risk Stratification: The Missing Piece

Pulmonary arterial hypertension (PAH) is a rare, progressive disease with a poor prognosis. The pathophysiologic model is mainly characterized by an afterload mismatch in which an increased right ventricle afterload, driven by increased pulmonary vascular resistance (PVR), leads to right heart failure. International guidelines recommend optimization of treatment based on regular risk assessments to achieve or maintain a low-risk status. Current risk scores are based on a multi-modality approach, including demographic, clinical, functional, exercise, laboratory, and hemodynamic parameters, which lack significant echocardiographic parameters. The originality of echocardiography relies on the opportunity to assess in a non-invasive way a physiologically meaningful combination of easy to measure variables tightly related to right ventricle adaptation/maladaptation to increased afterload, the main determinant of a patient's prognosis. Echo-derived morphological and functional parameters have been investigated in PAH, proving to have prognostic relevance. Different therapeutic strategies proved to have different effects in reducing PVR. An upfront combination of drugs, including a parenteral prostacyclin, has shown to be associated with right heart reverse remodeling in a greater proportion of patients than other treatment strategies as a function of PVR reduction. Adding echocardiographic data to current risk scores would allow better identification of right ventricle (RV) adaptation in PAH patients' follow-up. This additional information would allow better stratification of the patient, leading to optimized and personalized therapeutic management.

Role of biomarkers in evaluation, treatment and clinical studies of pulmonary arterial hypertension

Pulmonary arterial hypertension is a complex disease resulting from the interplay of myriad biological and environmental processes that lead to remodeling of the pulmonary vasculature with consequent pulmonary hypertension. Despite currently available therapies, there remains significant morbidity and mortality in this disease. There is great interest in identifying and applying biomarkers to help diagnose patients with pulmonary arterial hypertension, inform prognosis, guide therapy, and serve as surrogate endpoints. An extensive literature on potential biomarker candidates is available, but barriers to the implementation of biomarkers for clinical use in pulmonary arterial hypertension are substantial. Various omic strategies have been undertaken to identify key pathways regulated in pulmonary arterial hypertension that could serve as biomarkers including genomic, transcriptomic, proteomic, and metabolomic approaches. Other biologically relevant components such as circulating cells, microRNAs, exosomes, and cell-free DNA have recently been gaining attention. Because of the size of the datasets generated by these omic approaches and their complexity, artificial intelligence methods are being increasingly applied to decipher their meaning. There is growing interest in imaging the lung with various modalities to understand and visualize processes in the lung that lead to pulmonary vascular remodeling including high resolution computed tomography, Xenon magnetic resonance imaging, and positron emission tomography. Such imaging modalities have the potential to demonstrate disease modification resulting from therapeutic interventions. Because right ventricular function is a major determinant of prognosis, imaging of the right ventricle with echocardiography or cardiac magnetic resonance imaging plays an important role in the evaluation of patients and may also be useful in clinical studies of pulmonary arterial hypertension.

Treatment of right ventricular dysfunction and heart failure in pulmonary arterial hypertension

Right heart dysfunction and failure is the principal determinant of adverse outcomes in patients with pulmonary arterial hypertension (PAH). In addition to right ventricular (RV) dysfunction, systemic congestion, increased afterload and impaired myocardial contractility play an important role in the pathophysiology of RV failure. The behavior of the RV in response to the hemodynamic overload is primarily modulated by the ventricular interaction and its coupling to the pulmonary circulation. The presentation can be acute with hemodynamic instability and shock or chronic producing symptoms of systemic venous congestion and low cardiac output. The prognostic factors associated with poor outcomes in hospitalized patients include systemic hypotension, hyponatremia, severe tricuspid insufficiency, inotropic support use and the presence of pericardial effusion. Effective therapeutic management strategies involve identification and effective treatment of the triggering factors, improving cardiopulmonary hemodynamics by optimization of volume to improve diastolic ventricular interactions, improving contractility by use of inotropes, and reducing afterload by use of drugs targeting pulmonary circulation. The medical therapies approved for PAH act primarily on the pulmonary vasculature with secondary effects on the right ventricle. Mechanical circulatory support as a bridge to transplantation has also gained traction in medically refractory cases. The current review was undertaken to summarize recent insights into the evaluation and treatment of RV dysfunction and failure attributable to PAH.

Diagnostic and prognostic value of right ventricular eccentricity index in pulmonary artery hypertension

The right ventricle experiences dynamic changes under pressure overload in pulmonary artery hypertension. This study aimed to evaluate the diagnostic and prognostic value of right ventricular eccentricity index (RVEI) in pulmonary artery hypertension. A total of 100 pulmonary artery hypertension patients (mean age, 36.85 (SD, 13.60) years; males, 30.0%) confirmed by right heart catheterization and 147 healthy volunteers (mean age 45.58 (SD, 17.58) years; males, 42.50%) were enrolled in this prospective study. All participants underwent cardiac magnetic resonance imaging (MRI) examination, and balanced steady-state free precession (bSSFP) cine sequences were acquired. RVEI was measured on short-axis cine images at the mid-ventricular level of the right ventricle in end systole. The study found that RVEI was significantly lower in pulmonary artery hypertension patients than in healthy volunteers (1.84 (SD, 0.40) vs. 2.46 (SD, 0.40); p < 0.001). In pulmonary artery hypertension patients, RVEI was correlated with log(NT-proBNP) (r = -0.388; p < 0.001), right ventricular end-diastolic volume index (r = -0.452; p < 0.001), right ventricular end-systolic volume index (r = -0.518; p < 0.001), and right ventricular ejection fraction (r = 0.552; p < 0.001). RVEI could discriminate pulmonary artery hypertension patients from healthy volunteers with 91.8% sensitivity and 68.0% specificity. Over median follow-up of 14.8 months (interquartile range: 6.7-26.9 months), RVEI was demonstrated to be an independent predictor for adverse outcome (HR = 0.076; 95% CI, 0.013-0.458; p = 0.005). In conclusion, MRI-derived RVEI appears to be a useful diagnostic and prognostic value in pulmonary artery hypertension, and it provides incremental value to risk stratification strategy.

Pulmonary Hypertension and Right Ventricular Failure: Lung Transplant Versus Heart-Lung Transplant

Pulmonary arterial hypertension is a highly morbid disease with limited treatment options that improve survival and currently the only curative treatment is transplantation. There is a small body of literature comparing the efficacy of lung and heart-lung transplantation in this population. The bulk of evidence suggests that most patients with severe right ventricular failure undergoing transplant will have recovery of right ventricular function after lung transplantation. Existing data suggest that, in the absence of complex congenital heart disease or significant left ventricular dysfunction, double-lung transplant is the surgical procedure of choice.

Right heart failure in pulmonary hypertension: Diagnosis and new perspectives on vascular and direct right ventricular treatment

Adaptation of right ventricular (RV) function to increased afterload-known as RV-arterial coupling-is a key determinant of prognosis in pulmonary hypertension. However, measurement of RV-arterial coupling is a complex, invasive process involving analysis of the RV pressure-volume relationship during preload reduction over multiple cardiac cycles. Simplified methods have therefore been proposed, including echocardiographic and cardiac MRI approaches. This review describes the available methods for assessment of RV function and RV-arterial coupling and the effects of pharmacotherapy on these variables. Overall, pharmacotherapies for pulmonary hypertension have shown beneficial effects on various measures of RV function, but it is often unclear if these are direct RV effects or indirect results of afterload reduction. Studies of the effects of pharmacotherapies on RV-arterial coupling are limited and mostly restricted to experimental models. Simplified methods to assess RV-arterial coupling should be validated and incorporated into routine clinical follow-up and future clinical trials. LINKED ARTICLES: This article is part of a themed issue on Risk factors, comorbidities, and comedications in cardioprotection. To view the other articles in this section visit http://onlinelibrary.wiley.com/doi/10.1111/bph.v178.1/issuetoc.

The value of three-dimensional echocardiography in risk stratification in pulmonary arterial hypertension: a cross-sectional study

To explore the value of right ventricular (RV) parameters detected by three-dimensional echocardiography (3DE) in risk stratification in pulmonary arterial hypertension (PAH) patients. We prospectively recruited 130 pulmonary hypertension patients from National Center for Cardiovascular Diseases, Fuwai Hospital. Each participant was performed a transthoracic echocardiography and 3DE parameters were measured using an off-line software (4D RV Function 2.0, TomTec). Patients were classified into low, intermediate-high risk group based on 2015 ESC Guidelines. A total of 91 PAH patients (34 ± 12 years old, 25 males) were enrolled, among which, 42 were classified into low risk group, while 49 were intermediate-high risk group. Compared with low-risk patients, those with intermediate-high risk had significantly larger 3DE-RV volumes, worse ejection fraction (EF) and tricuspid annular plane systolic excursion, and decreased longitudinal strain (LS). Receive operating characteristic curves illustrated all the 3DE parameters were able to predict intermediate-high risk stratification, especially 3D-RVEF (area under curve, 0.82, 95% CI 0.73-0.91, P < 0.001). And 3D-RVEF < 26.39% had a 81.6% sensibility and 73.8% specificity to predict intermediate-high risk stratification. Univariate and multivariate Logistic regression analyses identified 3D-RV end-diastolic (OR 1.02, 95% CI 1.01-1.03, P = 0.002) and end-systolic (OR 1.03, 95% CI 1.01-1.04, P < 0.001) volumes, 3D-RVEF (OR 0.82, 95% CI 0.75-0.90, P < 0.001) and LS of free wall (OR 1.17, 95% CI 1.05-1.31, P = 0.005) as independent predictors of intermediate-high risk stratification. In conclusion, RV volumes, EF and free wall strain detected by 3DE were independent predictors of intermediate-high risk stratification in PAH patients, among which, RVEF showed the best predictive capacity.

Right ventricular function in pulmonary (arterial) hypertension

The right ventricle (RV) is the main determinant of prognosis in pulmonary hypertension. Adaptation and maladaptation of the RV are of crucial importance. In the course of disease, RV contractility increases through changes in muscle properties and muscle hypertrophy. At a certain point, the point of "uncoupling," the afterload exceeds contractility, and maladaptation as well as dilation occurs to maintain stroke volume (SV). To understand the adaptational processes and to further develop targeted medication directly affecting load-independent contractility, an accurate and precise assessment of contractility and RV-pulmonary artery (PA) coupling should be performed. In this review, we shed light on existing methods to assess RV function, including the gold standard measurement of contractility and RV-PA coupling, and we evaluate existing surrogates of RV-PA coupling.

Noninvasive Assessment of Right Ventricular Function in Patients with Pulmonary Arterial Hypertension and Left Ventricular Assist Device

PURPOSE OF REVIEW

Right ventricular (RV) failure in patients with pulmonary arterial hypertension (PAH) and left ventricular assist device (LVAD) is associated with increased hospitalizations, worsening functional class, and poor survival. Accurate RV function assessment is essential in diagnosing RV failure, guiding therapies, and determining prognosis. Noninvasive imaging techniques provide fast and reliable quantification of RV morphology and function.

RECENT FINDINGS

We review echocardiography, nuclear medicine, and cardiac magnetic resonance imaging (MRI) uses for RV function assessment in patients with PAH and LVAD. We identify current knowledge gaps in utilizing noninvasive tests to assess RV function. Echocardiography is most widely used to quantify RV function in patients with PAH and LVAD, followed by cardiac MRI for RV morphology and function measurement in PAH patients. The first-pass radionuclide angiography with radiolabeled RBC is the gold standard for calculating RV function. Gated blood pool SPECT can be an alternative as it separates the cardiac chambers well and provides accurate assessment of the RV function with high reproducibility, which is particularly useful for monitoring treatment. More research is needed to compare and validate these modalities in evaluating RV function.

EXPRESS: Left ventricular early diastolic strain rate detected by two-dimensional speckle tracking echocardiography and disease severity in pre-capillary pulmonary hypertension

We investigated and compared the correlations between two-dimensional speckle tracking echocardiography detected left ventricular peak early diastolic strain rates (global: left ventricular global peak early diastolic strain rate; septum: left ventricular peak early diastolic strain rate of septum; free wall: left ventricular peak early diastolic strain rate of free wall) and disease severity in pre-capillary pulmonary hypertension. Seventy-four pre-capillary pulmonary hypertension patients (23 males and 51 females, 35 ± 13 years) and thirty healthy controls were consecutively recruited for two-dimensional speckle tracking echocardiography analyses in our study. Medical records of pre-capillary pulmonary hypertension patients were reviewed to capture clinical data; risk assessments were performed based on the 2015 ESC Guidelines. Compared with healthy controls, left ventricular global peak early diastolic strain rate was lower in pre-capillary pulmonary hypertension patients (1.11 ± 0.60 s−1 versus 1.47 ± 0.45 s−1, P = 0.001), especially that of the septum (1.13 ± 0.58 s−1 versus 1.68 ± 0.46 s−1, P<0.001). Linear correlation analyses showed significant but weak correlations between left ventricle diastolic parameters and peak oxygen consumption, N-terminal pro-brain natriuretic peptide, and conventional echocardiographic right ventricle parameters: E/E′, tricuspid annular plane systolic excursion, S′, and fractional area change. No or weak correlations were observed between left ventricle diastolic parameters and hemodynamics. Multivariate logistic regression analyses showed left ventricular global peak early diastolic strain rate (OR: 0.304; 95%CI: 0.101–0.911) and left ventricular peak early diastolic strain rate of septum (OR: 0.252; 95%CI: 0.075–0.848) independently predict intermediate–high risk of pulmonary hypertension patients, even adjusted by age, gender, and body mass index. Receive operating characteristic curves showed that all the three models had the capacity to predict intermediate–high risk of pulmonary hypertension patients, and the model including left ventricular peak early diastolic strain rate of septum showed the strongest predictive capacity (area under the curve = 0.76, 95%CI: 0.59–0.93). Two-dimensional speckle tracking echocardiography detected left ventricle diastolic function parameters are significantly correlated with clinical data and can independently predict intermediate–high risk in pre-capillary pulmonary hypertension patients; the dysfunction of interventricular septum may make major contribution.

Interactions between structural remodeling and volumetric growth in right ventricle in response to pulmonary arterial hypertension

Pulmonary arterial hypertension (PAH) exerts substantial pressure overload on the right ventricle (RV). The associated RV free wall (RVFW) adaptation could consist of myocardial hypertrophy, augmented intrinsic contractility, collagen fibrosis, and structural remodeling in an attempt to cope with pressure overload. If RVFW adaptation cannot maintain the RV stroke volume, RV dilation will prevail as an exit mechanism which usually decompensates the RV function leading to RV failure. Our knowledge of the factors determining the transition from the upper limit of RVFW adaptation to RV decompensation and the role of fiber remodeling events in this transition remains very limited. Computational heart models that connect the growth and remodeling (G\&R) events at the fiber and tissue levels with alterations in the organ-level function are essential to predict the temporal order and the compensatory level of the underlying mechanisms. In this work, building upon our recent rodent heart models (RHM) of PAH, we integrated mathematical models that describe time-evolution volumetric growth of the RV and structural remodeling of the RVFW. Results suggest that augmentation of the intrinsic contractility of myofibers accompanied by an increase in passive stiffness of RVFW is among the first remodeling events through which the RV strives to maintain the cardiac output. Interestingly, we found that the observed reorientation of the myofibers towards the longitudinal (apex-to-base) direction was a maladaptive mechanism that impaired the contractile pattern of RVFW and advanced along with RV dilation at later stages of PAH development.

Highlights from the ERS International Congress 2018: Assembly 13 - Pulmonary Vascular Diseases

The 2018 European Respiratory Society (ERS) International Congress in Paris, France, highlighted the subject of pulmonary vascular disease (PVD). 2018 was an exciting year for the PVD community as it was the first ERS International Congress since the formation of Assembly 13, which is dedicated to PVD, pulmonary embolism and the right ventricle. This article aims to summarise the high-quality studies presented at the 2018 Congress into four subject areas: the use of risk stratification in pulmonary arterial hypertension, the molecular mechanisms and treatment of pulmonary hypertension (PH), understanding and improving the right ventricle in PH, and finally, advances in the field of acute pulmonary embolus.

The importance of right ventricular function in patients with pulmonary arterial hypertension

INTRODUCTION

Pulmonary arterial hypertension (PAH) is a progressive, life-threatening, and incurable disease. Its prognosis is based on right ventricular (RV) function. Therefore, adequate assessment of RV function is mandatory. Areas covered: This article presents the case of a patient with PAH in which the traditional diagnostic approach did not provide a complete assessment of RV function. The authors show how the analysis of other parameters yielded additional information that improved the management of this patient. Expert commentary: Despite current treatments, PAH often worsens due to progressive RV dysfunction. Appropriate assessment of RV function may facilitate the early identification of patients at risk of RV function impairment. More aggressive treatment of PAH might delay progression of the disease. Traditional risk stratification, which is based on New York Heart Association/World Health Organization (NYHA/WHO) functional class evaluation, the 6-minute walk test, and right heart catheterization, proves insufficient in many PAH patients, as it does not provide complete information about RV function. Thus, further parameters are required. Analysis of RV function, in addition to echocardiography and cardiopulmonary exercise testing, may add relevant prognostic information and improve therapy.

Impact of the Right Ventricular Sokolow-Lyon Index in Children with Idiopathic Pulmonary Arterial Hypertension

Right ventricular (RV) hypertrophy is regarded as the adaptation on chronic RV pressure load in pulmonary hypertension. As the RV Sokolow-Lyon index (RVSLI) is an electrocardiographic marker of RV hypertrophy, we hypothesized that RVSLI might be able to reflect RV pressure load. Therefore, the purpose of this study was to characterize the diagnostic impact of the RVSLI in children with idiopathic pulmonary arterial hypertension (IPAH) in order to assess disease severity and to evaluate its value for the prediction of worse outcome. Forty-two children (aged 3-17 years) with IPAH were included in this retrospective study. The follow-up after baseline examination was 59 ± 17 months. Receiver-operating characteristic (ROC) curves and Kaplan-Meier analysis were used to discriminate a cut-off value of RVSLI and to assess its predictive value regarding morbidity and mortality. In 12/42 patients (29%) severe cardiovascular events (defined as death, lung transplantation, or Potts shunt) were observed (time to event 20 ± 22 months). Patients with an event showed higher RVSLI values (3.6 ± 1.2 mV vs. 2.6 ± 1.6 mV; p < 0.05). ROC analysis discriminated an RVSLI of 2.1 as the best cut-off value (area under the ROC curve: 0.79, sensitivity: 0.91, specificity: 0.70, p < 0.05) to detect patients with high-risk PAH (mPAP/mSAP ratio > 0.75). Relative risk for a severe event with an index > 2.1 mV was 1.76 (95% CI 1.21-3.20). Relative risk for death with RVSLI > 2.1 mV was 2.01 (95% CI 1.61-4.80). Our study demonstrates a strong relationship between RVSLI and disease severity in children with IPAH. An RVSLI > 2.1 mV at the time of first diagnosis is a predictor for patients at risk for cardiac events. As an adjunct to the usual diagnostic assessment this parameter may therefore contribute to the initial prognostic estimation.

Inflammatory Mediators Drive Adverse Right Ventricular Remodeling and Dysfunction and Serve as Potential Biomarkers

Adverse right ventricular (RV) remodeling leads to ventricular dysfunction and failure that represents an important determinant of outcome in patients with pulmonary hypertension (PH). Recent evidence indicates that inflammatory activation contributes to the pathogenesis of adverse RV remodeling and dysfunction. It has been shown that accumulation of inflammatory cells such as macrophages and mast cells in the right ventricle is associated with maladaptive RV remodeling. In addition, inhibition of inflammation in animal models of RV failure ameliorated RV structural and functional impairment. Furthermore, a number of circulating inflammatory mediators have been demonstrated to be associated with RV performance. This work reviews the role of inflammation in RV remodeling and dysfunction and discusses anti-inflammatory strategies that may attenuate adverse structural alterations while promoting improvement of RV function.