Prognostic Value of Cardiac Magnetic Resonance–Derived Right Ventricular Remodeling Parameters in Pulmonary Hypertension

Impact of Cardiac Magnetic Resonance-Derived Right Ventricular Ejection Fraction on Adverse Outcomes: A Robust Bayesian Model-Averaged Meta-Analysis

BACKGROUND

There are few meta-analyses examining the prognostic value of right ventricular ejection fraction (RVEF) for a specific type of cardiovascular disease (CVD). The aim of this study was to compare the association of cardiac magnetic resonance (CMR)-derived RVEF with adverse outcomes for several specific types of CVD, using a robust Bayesian model-averaged meta-analysis.

METHODS

Three databases were searched for CMR articles reporting hazard ratios (HRs) of RVEF restricted to a specific type of CVD. For each specific type of CVD, Bayesian model-averaged meta-analyses with and without publication bias adjustments were conducted to evaluate the strength of evidence for RVEF according to the Bayes Factor (BF).

RESULTS

Among 108 articles (21,166 patients) analyzing 11 CVD types, pooled HR for 5% reduction in RVEF assessed by publication bias-unadjusted, Bayesian model-averaged meta-analysis offered moderate or strong evidence of an association with outcomes for all types of CVD (HR: 1.07-1.37, BF10: 4.3-9.6*107). In contrast, a robust Bayesian model-averaged meta-analysis, adjusted for publication bias, found moderate or strong evidence in favor of an association of RVEF with outcomes only in hypertrophic cardiomyopathy (HR: 1.19, 95% CrI: 0.98-1.42, BF10: 5.0), dilated cardiomyopathy (HR: 1.16, 95% CrI: 1-1.22, BF10: 23.3), pulmonary hypertension (HR: 1.05, 95% CrI: 1-1.12, BF10: 3.0), and aortic stenosis (HR: 1.15, 95% CrI: 0.97-1.34, BF10: 4.2). There was weak evidence for an association of RVEF with adverse outcomes in seven other CVDs.

CONCLUSIONS

In a Bayesian meta-analysis adjusted for publication bias, there was moderate or strong evidence for an association of RVEF with outcomes for only four CVDs. Additional data may strengthen evidence regarding other CVDs.

Novel insights into the pathobiology of pulmonary hypertension in heart failure with preserved ejection fraction

Heart failure (HF) with preserved ejection fraction (HFpEF) is the most common cause of pulmonary hypertension (PH) worldwide and is strongly associated with adverse clinical outcomes. The American Heart Association recently highlighted a call to action regarding the distinct lack of evidence-based treatments for PH due to poorly understood pathophysiology of PH attributable to HFpEF (PH-HFpEF). Prior studies have described cardiophysiological mechanisms to explain the development of isolated postcapillary PH (ipc-PH); however, the consequent increase in pulmonary vascular (PV) resistance (PVR) may lead to the less understood and more fatal combined pre- and postcapillary PH (cpc-PH). Metabolic disease and inflammatory dysregulation have been suggested to predispose PH, yet the molecular mechanisms are unknown. Although PH-HFpEF has been studied to partly share vasoactive neurohormonal mediators with primary pulmonary arterial hypertension (PAH), clinical trials that have targeted these pathways have been unsuccessful. The increased mortality of patients with PH-HFpEF necessitates further study into viable mechanistic targets involved in disease progression. We aim to summarize the current pathophysiological and clinical understanding of PH-HFpEF, highlight the role of known molecular mechanisms in the progression of PV disease, and introduce a novel concept that lipid metabolism may be attenuating and propagating PH-HFpEF.NEW & NOTEWORTHY Our review addresses pulmonary hypertension (PH) attributable to heart failure (HF) with preserved ejection fraction (HFpEF; PH-HFpEF). Current knowledge gaps in PH-HFpEF pathophysiology have led to a lack of therapeutic targets. Thus, we address identified knowledge gaps in a comprehensive review, focusing on current clinical epidemiology, known pathophysiology, and previously studied molecular mechanisms. We also introduce a comprehensive review of polyunsaturated fatty acid (PUFA) lipid inflammatory mediators in PH-HFpEF.

Evaluation of the Truncated Cone-Rhomboid Pyramid Formula for Simplified Right Ventricular Quantification: A Cardiac Magnetic Resonance Study

Background/Objective: Cardiac magnetic resonance (CMR) is the reference method for right ventricular (RV) volume and function analysis, but time-consuming manual segmentation and corrections of imperfect automatic segmentations are needed. This study sought to evaluate the applicability of an echocardiographically established truncated cone-rhomboid pyramid formula (CPF) for simplified RV quantification using CMR. Methods: A total of 70 consecutive patients assigned to RV analysis using CMR were included. As standard method, the manual contouring of RV-short axis planes was performed for the measurement of end-diastolic volume (EDV) and end-systolic volume (ESV). Additionally, two linear measurements in four-chamber views were obtained in systole and diastole: basal diameters at the level of tricuspid valve (Dd and Ds) and baso-apical lengths from the center of tricuspid valve to the RV apex (Ld and Ls) were measured for the calculation of RV-EDV = 1.21 × Dd2 × Ld and RV-ESV = 1.21 × Ds 2 × Ls using CPF. Results: RV volumes using CPF were slightly higher than those using standard CMR analysis (RV-EDV index: 86.2 ± 29.4 mL/m2 and RV-ESV index: 51.5 ± 22.5 mL/m2 vs. RV-EDV index: 81.7 ± 24.1 mL/m2 and RV-ESV index: 44.5 ± 23.2 mL/m2) and RV-EF was lower (RV-EF: 41.1 ± 13.5% vs. 48.4 ± 13.7%). Both methods had a strong correlation of RV volumes (ΔRV-EDV index = -4.5 ± 19.0 mL/m2; r = 0.765, p < 0.0001; ΔRV-ESV index = -7.0 ± 14.4 mL/m2; r = 0.801, p < 0.0001). Conclusions: Calculations of RV volumes and function using CPF assuming the geometrical model of a truncated cone-rhomboid pyramid anatomy of RV is feasible, with a strong correlation to measurements using standard CMR analysis, and only two systolic and diastolic linear measurements in four-chamber views are needed.

State-of-the Art Cardiac Magnetic Resonance in Pulmonary Hypertension - An Update on Diagnosis, Risk Stratification and Treatment

Pulmonary hypertension (PH) is a globally under-recognized but life-shortening disease with a poor prognosis if untreated, delayed or inappropriately treated. One of the most important issues for PH is to improve patient quality of life and survival through timely and accurate diagnosis, precise risk stratification and prognosis prediction. Cardiac magnetic resonance (CMR), a non-radioactive, non-invasive image-based examination with excellent tissue characterization, provides a comprehensive assessment of not only the disease severity but also secondary changes in cardiac structure, function and tissue characteristics. The purpose of this review is to illustrate an updated status of CMR for PH assessment, focusing on the application of both conventional and emerging technologies as well as the latest clinical trials.

Quantitative Prediction of Right Ventricular Size and Function From the ECG

BACKGROUND

Right ventricular ejection fraction (RVEF) and end-diastolic volume (RVEDV) are not readily assessed through traditional modalities. Deep learning-enabled ECG analysis for estimation of right ventricular (RV) size or function is unexplored.

METHODS AND RESULTS

We trained a deep learning-ECG model to predict RV dilation (RVEDV >120 mL/m2), RV dysfunction (RVEF ≤40%), and numerical RVEDV and RVEF from a 12-lead ECG paired with reference-standard cardiac magnetic resonance imaging volumetric measurements in UK Biobank (UKBB; n=42 938). We fine-tuned in a multicenter health system (MSHoriginal [Mount Sinai Hospital]; n=3019) with prospective validation over 4 months (MSHvalidation; n=115). We evaluated performance with area under the receiver operating characteristic curve for categorical and mean absolute error for continuous measures overall and in key subgroups. We assessed the association of RVEF prediction with transplant-free survival with Cox proportional hazards models. The prevalence of RV dysfunction for UKBB/MSHoriginal/MSHvalidation cohorts was 1.0%/18.0%/15.7%, respectively. RV dysfunction model area under the receiver operating characteristic curve for UKBB/MSHoriginal/MSHvalidation cohorts was 0.86/0.81/0.77, respectively. The prevalence of RV dilation for UKBB/MSHoriginal/MSHvalidation cohorts was 1.6%/10.6%/4.3%. RV dilation model area under the receiver operating characteristic curve for UKBB/MSHoriginal/MSHvalidation cohorts was 0.91/0.81/0.92, respectively. MSHoriginal mean absolute error was RVEF=7.8% and RVEDV=17.6 mL/m2. The performance of the RVEF model was similar in key subgroups including with and without left ventricular dysfunction. Over a median follow-up of 2.3 years, predicted RVEF was associated with adjusted transplant-free survival (hazard ratio, 1.40 for each 10% decrease; P=0.031).

CONCLUSIONS

Deep learning-ECG analysis can identify significant cardiac magnetic resonance imaging RV dysfunction and dilation with good performance. Predicted RVEF is associated with clinical outcome.

Myocardial strain parameters in pulmonary hypertension are determined by changes in volumetric function rather than by hemodynamic alterations

PURPOSE

To investigate associations of cardiac magnetic resonance feature-tracking-derived left (LV) and right ventricular (RV) global myocardial peak strains and strain rates with volumetric function and hemodynamic parameters to identify the major determinants of myocardial strain alterations in pulmonary hypertension (PH).

METHODS

Sixty-seven patients with PH or at risk of developing PH underwent right heart catheterization (RHC) and cine realtime imaging at 3 T. RHC parameters included mean pulmonary arterial pressure (mPAP), which was used for the diagnosis of PH. LV and RV volumetric function and feature-tracking-derived global radial, circumferential, and longitudinal (GLS) peak strains, together with their strain rates, were evaluated from cine images using routine software. Furthermore, myocardial strain parameters of 24 healthy subjects were evaluated as controls. Means were compared by t-test; relationships between parameters were investigated by correlation and regression analysis.

RESULTS

Compared to controls, RV-GLS, all RV systolic strain rates and the LV systolic longitudinal strain rate showed lower magnitudes in PH (RV-GLS: -21 ± 4% vs. -16 ± 5%, p < 0.0001); the strongest univariate correlate to mPAP was the RV-GLS (r = 0.59). All LV and RV strain parameters yielded stronger correlations with their respective ejection fractions. In bi-linear models using mPAP and ejection fraction as predictors, mPAP remained significant only for diastolic LV radial and circumferential strain rates.

CONCLUSION

Impairment of myocardial strains is more strongly associated with alterations in LV and RV volumetric function parameters than elevated mPAP, therefore limiting diagnostic information of myocardial strain parameters in PH.

Untangling the mechanisms of pulmonary arterial hypertension-induced right ventricular stiffening in a large animal model

Pulmonary hypertension (PHT) is a devastating disease with low survival rates. In PHT, chronic pressure overload leads to right ventricle (RV) stiffening; thus, impeding diastolic filling. Multiple mechanisms may contribute to RV stiffening, including wall thickening, microstructural disorganization, and myocardial stiffening. The relative importance of each mechanism is unclear. Our objective is to use a large animal model to untangle these mechanisms. Thus, we induced pulmonary arterial hypertension (PAH) in sheep via pulmonary artery banding. After eight weeks, the hearts underwent anatomic and diffusion tensor MRI to characterize wall thickening and microstructural disorganization. Additionally, myocardial samples underwent histological and gene expression analyses to quantify compositional changes and mechanical testing to quantify myocardial stiffening. Finally, we used finite element modeling to disentangle the relative importance of each stiffening mechanism. We found that the RVs of PAH animals thickened most at the base and the free wall and that PAH induced excessive collagen synthesis, increased cardiomyocyte cross-sectional area, and led to microstructural disorganization, consistent with increased expression of fibrotic genes. We also found that the myocardium itself stiffened significantly. Importantly, myocardial stiffening correlated significantly with collagen synthesis. Finally, our computational models predicted that myocardial stiffness contributes to RV stiffening significantly more than other mechanisms. Thus, myocardial stiffening may be the most important predictor for PAH progression. Given the correlation between myocardial stiffness and collagen synthesis, collagen-sensitive imaging modalities may be useful for estimating myocardial stiffness and predicting PAH outcomes. STATEMENT OF SIGNIFICANCE: Ventricular stiffening is a significant contributor to pulmonary hypertension-induced right heart failure. However, the mechanisms that lead to ventricular stiffening are not fully understood. The novelty of our work lies in answering this question through the use of a large animal model in combination with spatially- and directionally sensitive experimental techniques. We find that myocardial stiffness is the primary mechanism that leads to ventricular stiffening. Clinically, this knowledge may be used to improve diagnostic, prognostic, and therapeutic strategies for patients with pulmonary hypertension.

Differential biventricular adaption to pulmonary vascular disease in patients with idiopathic/heritable and congenital heart disease: a prospective cardiac magnetic resonance and invasive study

AIMS

Despite shared pathophysiological mechanisms, patients with idiopathic/heritable pulmonary arterial hypertension (IPAH/HPAH) have a poorer prognosis than those with PAH after congenital heart defect repair. Ventricular adaption remains unclear and could provide a basis for explaining differences in clinical outcomes. The aim of this prospective study was to assess clinical status, haemodynamic profile, and biventricular adaptation to PAH in children with various forms of PAH.

METHODS AND RESULTS

Consecutive patients with IPAH/HPAH or post-operative PAH were prospectively recruited (n = 64). All patients underwent a comprehensive, protocolized assessment including functional assessment, measurement of brain natriuretic peptide (BNP) levels, invasive measurements, and a cardiac magnetic resonance (CMR) assessment. A cohort of age- and sex-matched healthy subjects served as controls. Patients with post-operative PAH had a better functional class (61.5 vs. 26.3% in Class I/II, P = 0.02) and a longer 6-min walk distance (320 ± 193 vs. 239 ± 156 m, P = 0.008) than IPAH/HPAH. While haemodynamic parameters were not significantly different between IPAH/HPAH and post-operative patients, post-operative patients with PAH presented with higher left ventricular volumes and better right ventricular function compared with patients with IPAH/HPAH (P < 0.05). On correlation analyses, left ventricular volumetric parameters were highly correlated with BNP and 6-min walk test distance in this population.

CONCLUSION

Despite comparable haemodynamic profiles, patients with post-operative PAH had less functional limitation than their IPAH/HPAH counterparts. This is potentially related to the differential biventricular adaptation pattern evident on CMR with better myocardial contractility and higher left ventricular volumes in post-operative patients with PAH, highlighting the importance of ventriculo-ventricular interaction in the setting of PAH.

Pulmonary Hypertension Is Associated with Worse Outcomes in Patients Hospitalized for Sick Sinus Syndrome

Sick sinus syndrome (SSS) is a condition of the sinoatrial node that arises from a constellation of aberrant rhythms, resulting in reduced pacemaker activity and impulse transmission. According to the World Health Organization, pulmonary hypertension (PH) is defined by a mean pulmonary arterial pressure of >25 mmHg at rest, measured during right heart catheterization. It can result in right atrial remodeling, which may predispose the patient to sinus node dysfunction. This study sought to estimate the impact of PH on clinical outcomes of hospitalizations with SSS. The U.S. National Inpatient Sample database from 2016-2019 was searched for hospitalized adult patients with SSS as a principal diagnosis with and without PH as a secondary diagnosis using the International Classification of Diseases, Tenth Revision, codes. The primary outcome was inpatient mortality. The secondary outcomes were acute kidney injury (AKI), cardiogenic shock (CS), cardiac arrest, rates of pacemaker insertion, total hospital charges (THCs), and length of stay (LOS). Multivariate regression analysis was used to adjust for confounders. A total of 181,230 patients were admitted for SSS; 8.3% (14,990) had underlying PH. Compared to patients without PH, patients admitted with coexisting PH had a statistically significant increase in mortality (95% confidence interval, 1.21-2.32; P = .002), AKI (P < .001), CS (P = .004), THC (P = .037), and LOS (P < .001). In conclusion, patients admitted primarily for SSS with coexisting PH had a statistically significant increase in mortality, AKI, CS, THC, and LOS. Additional studies geared at identifying and addressing the underlying etiologies for PH in this population may be beneficial in the management of this patient group.

Defining Biventricular Abnormalities by Cardiac Magnetic Resonance in Pre-Dialysis Patients with Chronic Kidney Disease

Introduction

The aim of the study was to investigate biventricular structural and functional abnormalities in pre-dialysis patients across stages of chronic kidney disease (CKD) by cardiac magnetic resonance (CMR).

Methods

Fifty-one CKD patients with CMR exams were retrospectively analyzed. Patients were divided into three groups according to estimated glomerular filtration rate (eGFR): CKD 1 group (patients with normal eGFR≥90 mL/min/1.73 m2, n = 20), CKD 2-3 group (patients with eGFR< 90 to ≥30 mL/min/1.73 m2, n = 14), and CKD 4-5 group (patients with eGFR<30 mL/min/1.73 m2, n = 17). Twenty-one age- and sex-matched healthy controls (HC) were recruited. CMR-derived left ventricular (LV) and right ventricular (RV) structural and functional measures were compared. Association between CMR parameters and clinical measures was assessed.

Results

There was an increasing trend in RV mass index (RVMi) and LV mass index (LVMi) with the occurrence and development of CKD from HC group to CKD 4-5 group although no significant difference was observed between CKD 1 group and HC group. LV global radial strain and LV global circumferential strain dropped and native T1 value elevated significantly in CKD 4-5 group compared with the other three groups (all p < 0.05), while RV strain measures, RV ejection fraction, and LV ejection fraction showed no significant difference among 4 groups (all p > 0.05). Elevated LV end-diastolic volume index (β = 0.356, p = 0.016) and RV end-systolic volume index (β = 0.488, p = 0.001) were independently associated with RVMi. Increased systolic blood pressure (β = 0.309, p = 0.004), LV end-systolic volume index (β = 0.633, p < 0.001), and uric acid (β = 0.261, p = 0.013) were independently associated with LVMi. Meanwhile, serum phosphorus (β = 0.519, p = 0.001) was independently associated with native T1 value.

Conclusion

In pre-dialysis CKD patients, left and right ventricular remolding has occurred. RVMi and LVMi were the first changed CMR indexes in the development of CKD when eGFR began to drop. Because fluid volume overload was the independent risk factor for RVMi and LVMi increase, reasonable controlling fluid volume overload may slow down the progression of biventricular remolding and may reduce related cardiovascular disease risk.

Prognostic value of the right ventricular ejection fraction using three-dimensional echocardiography: Systematic review and meta-analysis

AIMS

Three-dimensional echocardiography (3DE) is a robust method for measuring the right ventricular (RV) ejection fraction (EF), which is closely associated with outcomes. We performed a systematic review and meta-analysis (1) to examine the prognostic value of RVEF and (2) to compare its prognostic value with that of left ventricular (LV) EF and LV global longitudinal strain (GLS). We also performed individual patient data analysis to validate the results.

METHODS AND RESULTS

We searched articles reporting the prognostic value of RVEF. Hazard ratios (HR) were re-scaled using the within-study standard deviation (SD). To compare predictive values of RVEF and LVEF or LVGLS, the ratio of HR related to a 1-SD reduction of RVEF versus LVEF or LVGLS was calculated. Pooled HR of RVEF and pooled ratio of HR were analyzed in a random-effects model. Fifteen articles with 3,228 subjects were included. Pooled HR of a 1-SD reduction of RVEF was 2.54 (95% confidence interval (CI): 2.15-3.00). In subgroup analysis, RVEF was significantly associated with outcome in pulmonary arterial hypertension (PAH) (HR: 2.79, 95% CI: 2.04-3.82) and cardiovascular (CV) diseases (HR: 2.23, 95%CI: 1.76-2.83). In studies reporting HRs for both RVEF and LVEF or RVEF and LVGLS in the same cohort, RVEF had 1.8-fold greater prognostic power per 1-SD reduction than LVEF (ratio of HR: 1.81, 95%CI: 1.20-2.71), but had predictive value similar to that of LVGLS (ratio of HR: 1.10, 95%CI: 0.91-1.31) and to LVEF in patients with reduced LVEF (ratio of HR: 1.34, 95%CI: 0.94-1.91). In individual patient data analysis (n = 1,142), RVEF < 45% was significantly associated with worse CV outcome (HR: 4.95, 95% CI: 3.66-6.70), even in patients with reduced or preserved LVEF.

CONCLUSIONS

The findings of this meta-analysis highlight and support the use of RVEF assessed by 3DE to predict CV outcomes in routine clinical practice in patients with CV diseases and in those with PAH.

Multimodality Imaging of Right Heart Function: JACC Scientific Statement

Right ventricular (RV) size and function assessed by multimodality imaging are associated with outcomes in a variety of cardiovascular diseases. Understanding RV anatomy and physiology is essential in appreciating the strengths and weaknesses of current imaging methods and gives these measurements greater context. The adaptation of the right ventricle to different types and severity of stress, particularly over time, is specific to the cardiovascular disease process. Multimodality imaging parameters, which determine outcomes, reflect the ability to image the initial and longitudinal RV response to stress. This paper will review the standard and novel imaging methods for assessing RV function and the impact of these parameters on outcomes in specific disease states.

Qualification of Ventricular Flow in Patients With Precapillary Pulmonary Hypertension With 4-dimensional Flow Magnetic Resonance Imaging

PURPOSE

Our goal was to study both right and left ventricular blood flow in patients with precapillary pulmonary hypertension (pre-PH) with 4-dimensional (4D) flow magnetic resonance imaging (MRI) and to analyze their correlation with cardiac functional metrics on cardiovascular magnetic resonance (CMR) and hemodynamics from right heart catheterization (RHC).

MATERIALS AND METHODS

129 patients (64 females, mean age 47 ± 13 y) including 105 patients with pre-PH (54 females, mean age 49 ± 13 y) and 24 patients without PH (10 females, mean age 40 ± 12 y) were retrospectively included. All patients underwent CMR and RHC within 48 hours. 4D flow MRI was acquired using a 3-dimensional retrospectively electrocardiograph-triggered, navigator-gated phase contrast sequence. Right and left ventricular flow components including the percentages of direct flow (PDF), retained inflow (PRI), delayed ejection flow (PDE), and residual volume (PRVo) were respectively quantified. The ventricular flow components between patients with pre-PH and non-PH were compared and correlations of flow components with CMR functional metrics and hemodynamics measured with RHC were analyzed. Biventricular flow components were compared between survivors and deceased patients during the perioperative period.

RESULTS

Right ventricular (RV) PDF and PDE significantly correlated with RVEDV and RV ejection fraction. RV PDF negatively correlated with pulmonary arterial pressure (PAP) and pulmonary vascular resistance. When the RV PDF was <11%, the sensitivity and specificity of RV PDF for predicting mean PAP ≥25 mm Hg were 88.6% and 98.7%, respectively, with an area under the curve value of 0.95 ± 0.02. When RV PRVo was more than 42%, the sensitivity and specificity of RV PRVo for predicting mean PAP ≥25 mm Hg were 85.7% and 98.5%, respectively, with an area under the curve value of 0.95 ± 0.01. Nine patients died during the perioperative period. Biventricular PDF, RV PDE, and PRI of survivors were higher than nonsurvivors whereas RV PRVo increased in deceased patients.

CONCLUSIONS

Biventricular flow analysis with 4D flow MRI provides comprehensive information about the severity and cardiac remodeling of PH and may be a predictor of perioperative death of patients with pre-PH.

Quantitative prediction of right ventricular and size and function from the electrocardiogram

Background

Right ventricular ejection fraction (RVEF) and end-diastolic volume (RVEDV) are not readily assessed through traditional modalities. Deep-learning enabled 12-lead electrocardiogram analysis (DL-ECG) for estimation of RV size or function is unexplored.

Methods

We trained a DL-ECG model to predict RV dilation (RVEDV>120 mL/m2), RV dysfunction (RVEF≤40%), and numerical RVEDV/RVEF from 12-lead ECG paired with reference-standard cardiac MRI (cMRI) volumetric measurements in UK biobank (UKBB; n=42,938). We fine-tuned in a multi-center health system (MSHoriginal; n=3,019) with prospective validation over 4 months (MSHvalidation; n=115). We evaluated performance using area under the receiver operating curve (AUROC) for categorical and mean absolute error (MAE) for continuous measures overall and in key subgroups. We assessed association of RVEF prediction with transplant-free survival with Cox proportional hazards models.

Results

Prevalence of RV dysfunction for UKBB/MSHoriginal/MSHvalidation cohorts was 1.0%/18.0%/15.7%, respectively. RV dysfunction model AUROC for UKBB/MSHoriginal/MSHvalidation cohorts was 0.86/0.81/0.77, respectively. Prevalence of RV dilation for UKBB/MSHoriginal/MSHvalidation cohorts was 1.6%/10.6%/4.3%. RV dilation model AUROC for UKBB/MSHoriginal/MSHvalidation cohorts 0.91/0.81/0.92, respectively. MSHoriginal MAE was RVEF=7.8% and RVEDV=17.6 ml/m2. Performance was similar in key subgroups including with and without left ventricular dysfunction. Over median follow-up of 2.3 years, predicted RVEF was independently associated with composite outcome (HR 1.37 for each 10% decrease, p=0.046).

Conclusions

DL-ECG analysis can accurately identify significant RV dysfunction and dilation both overall and in key subgroups. Predicted RVEF is independently associated with clinical outcome.

Untangling the mechanisms of pulmonary hypertension-induced right ventricular stiffening in a large animal model

Background

Pulmonary arterial hypertension (PHT) is a devastating disease with low survival rates. In PHT, chronic pressure overload leads to right ventricle (RV) remodeling and stiffening; thus, impeding diastolic filling and ventricular function. Multiple mechanisms contribute to RV stiffening, including wall thickening, microstructural disorganization, and myocardial stiffening. The relative importance of each mechanism is unclear. Our objective is to use a large animal model as well as imaging, experimental, and computational approaches to untangle these mechanisms.

Methods

We induced PHT in eight sheep via pulmonary artery banding. After eight weeks, the hearts underwent anatomic and diffusion tensor MRI to characterize wall thickening and microstructural disorganization. Additionally, myocardial samples underwent histological and gene expression analyses to quantify compositional changes and mechanical testing to quantify myocardial stiffening. All findings were compared to 12 control animals. Finally, we used computational modeling to disentangle the relative importance of each stiffening mechanism.

Results

First, we found that the RVs of PHT animals thickened most at the base and the free wall. Additionally, we found that PHT induced excessive collagen synthesis and microstructural disorganization, consistent with increased expression of fibrotic genes. We also found that the myocardium itself stiffened significantly. Importantly, myocardial stiffening correlated significantly with excess collagen synthesis. Finally, our model of normalized RV pressure-volume relationships predicted that myocardial stiffness contributes to RV stiffening significantly more than other mechanisms.

Conclusions

In summary, we found that PHT induces wall thickening, microstructural disorganization, and myocardial stiffening. These remodeling mechanisms were both spatially and directionally dependent. Using modeling, we show that myocardial stiffness is the primary contributor to RV stiffening. Thus, myocardial stiffening may be an important predictor for PHT progression. Given the significant correlation between myocardial stiffness and collagen synthesis, collagen-sensitive imaging modalities may be useful for non-invasively estimating myocardial stiffness and predicting PHT outcomes.

Comparison between pre- and post-contrast cardiac MRI cine images: the impact on ventricular volume and strain measurement

To explore whether contrast agent administration will affect ventricular volume and strain parameters measured on cardiac magnetic resonance cine images. This prospective study enrolled 88 patients, including 32 patients with cardiac amyloidosis (CA), 32 patients with hypertrophic cardiomyopathy (HCM), and 24 control participants, to perform steady-state free precession (SSFP)-cine imaging twice, respectively before and after contrast agent injection. Indexed left and right ventricular (LV and RV) volume and LV strain parameters (peak radial strain [PRS], peak circumferential strain [PCS], peak longitudinal strain [PLS]) were analyzed and compared between the pre- and post-contrast cine groups. Compared to the group of pre-contrast cine, the end-diastolic volume index (EDVi) and end-systolic volume index (ESVi) significantly increased in the group using post-contrast cine images (all p < 0.05), especially in the right ventricle. After contrast injection, the right ventricular ejection fraction (RVEF) decreased significantly (p < 0.05), while the left ventricular ejection fraction (LVEF) only reduced for patients with HCM (p < 0.05). The PRS (37.1 ± 15.2 vs. 32.0 ± 15.4, p < 0.001) and PCS (- 14.9 ± 4.3 vs. - 14.0 ± 4.1, p < 0.001) derived from post-contrast cine images reduced significantly in all patients and this tendency remained in subgroup analysis except for PCS in the control group. The administration of a contrast agent may influence the measurements of ventricular volume and strain. Acquiring pre-contrast cine images were suggested for patients who required more accurate right ventricle evaluation or precise strain assessment.

Association of Right Ventricular Functional Parameters With Adverse Cardiopulmonary Outcomes: A Meta-analysis

AIMS

We aimed to confirm that three-dimensional echocardiography-derived right ventricular ejection fraction (RVEF) is better associated with adverse cardiopulmonary outcomes than the conventional echocardiographic parameters.

METHODS

We performed a meta-analysis of studies reporting the impact of unit change of RVEF, tricuspid annular plane systolic excursion (TAPSE), fractional area change (FAC), and free-wall longitudinal strain (FWLS) on clinical outcomes (all-cause mortality and/or adverse cardiopulmonary outcomes). Hazard ratios (HRs) were rescaled by the within-study SDs to represent standardized changes. Within each study, we calculated the ratio of HRs related to a 1 SD reduction in RVEF versus TAPSE, or FAC, or FWLS, to quantify the association of RVEF with adverse outcomes relative to the other metrics. These ratios of HRs were pooled using random-effects models.

RESULTS

Ten independent studies were identified as suitable, including data on 1,928 patients with various cardiopulmonary conditions. Overall, a 1 SD reduction in RVEF was robustly associated with adverse outcomes (HR = 2.64 [95% CI, 2.18-3.20], P < .001; heterogeneity: I² = 65%, P = .002). In studies reporting HRs for RVEF and TAPSE, or RVEF and FAC, or RVEF and FWLS in the same cohort, head-to-head comparison revealed that RVEF showed significantly stronger association with adverse outcomes per SD reduction versus the other 3 parameters (vs TAPSE, HR = 1.54 [95% CI, 1.04-2.28], P = .031; vs FAC, HR = 1.45 [95% CI, 1.15-1.81], P = .001; vs FWLS, HR = 1.44 [95% CI, 1.07-1.95], P = .018).

CONCLUSION

Reduction in three-dimensional echocardiography-derived RVEF shows stronger association with adverse clinical outcomes than conventional right ventricular functional indices; therefore, it might further refine the risk stratification of patients with cardiopulmonary diseases.

Increased biventricular hemodynamic forces in precapillary pulmonary hypertension

Precapillary pulmonary hypertension (PHprecap) is a condition with elevated pulmonary vascular pressure and resistance. Patients have a poor prognosis and understanding the underlying pathophysiological mechanisms is crucial to guide and improve treatment. Ventricular hemodynamic forces (HDF) are a potential early marker of cardiac dysfunction, which may improve evaluation of treatment effect. Therefore, we aimed to investigate if HDF differ in patients with PHprecap compared to healthy controls. Patients with PHprecap (n = 20) and age- and sex-matched healthy controls (n = 12) underwent cardiac magnetic resonance imaging including 4D flow. Biventricular HDF were computed in three spatial directions throughout the cardiac cycle using the Navier-Stokes equations. Biventricular HDF (N) indexed to stroke volume (l) were larger in patients than controls in all three directions. Data is presented as median N/l for patients vs controls. In the RV, systolic HDF diaphragm-outflow tract were 2.1 vs 1.4 (p = 0.003), and septum-free wall 0.64 vs 0.42 (p = 0.007). Diastolic RV HDF apex-base were 1.4 vs 0.87 (p < 0.0001), diaphragm-outflow tract 0.80 vs 0.47 (p = 0.005), and septum-free wall 0.60 vs 0.38 (p = 0.003). In the LV, systolic HDF apex-base were 2.1 vs 1.5 (p = 0.005), and lateral wall-septum 1.5 vs 1.2 (p = 0.02). Diastolic LV HDF apex-base were 1.6 vs 1.2 (p = 0.008), and inferior-anterior 0.46 vs 0.24 (p = 0.02). Hemodynamic force analysis conveys information of pathological cardiac pumping mechanisms complementary to more established volumetric and functional parameters in precapillary pulmonary hypertension. The right ventricle compensates for the increased afterload in part by augmenting transverse forces, and left ventricular hemodynamic abnormalities are mainly a result of underfilling rather than intrinsic ventricular dysfunction.

Prognostic Value of Hepatic Native T1 and Extracellular Volume Fraction in Patients with Pulmonary Arterial Hypertension

Background

Right heart failure may lead to impaired liver perfusion and venous congestion, resulting in different extents of liver fibrosis. However, whether hepatic tissue deterioration determined by native T1 mapping and extracellular volume fraction using cardiac magnetic resonance imaging is associated with poor outcomes in patients with pulmonary arterial hypertension remains unclear.

Methods and Results

A total of 131 participants with pulmonary arterial hypertension (mean age, 36±13 years) and 64 healthy controls (mean age, 44±18) between October 2013 and December 2019 were prospectively enrolled. Hepatic native T1 and extracellular volume fraction values were measured using modified Look–Locker inversion recovery T1 mapping sequences. The primary end point was all‐cause mortality; the secondary end point was all‐cause mortality and repeat hospitalization attributable to heart failure. Cox regression models and Kaplan–Meier survival analysis were used to identify the association between variables and clinical outcome. During a median follow‐up of 34.5 months (interquartile range: 25.3–50.8), hepatic native T1 (hazard ratio per 30‐ms increase, 1.22 [95% CI, 1.07–1.39]; P =0.003) and extracellular volume fraction (hazard ratio per 3% increase, 1.18 [95% CI, 1.04–1.34]; P =0.010) values were associated with a higher risk of death. In the multivariate Cox model, hepatic native T1 value (hazard ratio per 30‐ms increase, 1.15 [95% CI, 1.04–1.27]; P =0.009) remained as an independent prognostic factor for the secondary end point.

Conclusions

Hepatic T1 mapping values were predictors of adverse cardiovascular events in participants with pulmonary arterial hypertension and could be novel imaging biomarkers for poor prognosis recognition.

Global Research Trends on Ventricular Remodeling: A Bibliometric Analysis From 2012 to 2022

Ventricular remodeling is the progressive pathologic change of the original substance and morphology of the ventricle caused by various injuries and has attracted increasing attention in the past decade. This study aims to conduct a bibliometric analysis of articles on ventricular remodeling published in the Web of Science Core Collection database from 2012 to 2022 to understand the current research state in the field of ventricular remodeling and provide insights for clinicians and researchers. As a result, a total of 1710 articles on ventricular remodeling were included. Annual publications have been gradually increasing and have remained at a high level over the past 10 years. The United States of America contributed the most publications, followed by China. Circulation was the most mainstream and authoritative journal focusing on ventricular remodeling. Research hotspot analysis suggested that myocardial infarction was the primary risk factor for ventricular remodeling, and emerging risk factor studies have focused on pulmonary hypertension, aortic stenosis, and diabetes. The mechanisms in the pathogenesis of ventricular remodeling were mainly closely associated with inflammation, apoptosis, oxidative stress, and myocardial fibrosis. Intensive investigation of the interactions between different mechanisms might be a future research direction. In terms of treatment, cardiac resynchronization therapy was a hot topic of research. These findings can help researchers grasp the research status of ventricular remodeling and determine future research directions.

Atrioventricular plane displacement and regional function to predict outcome in pulmonary arterial hypertension

To investigate if left and right atrioventricular plane displacement (AVPD) or regional contributions to SV are prognostic for outcome in patients with pulmonary arterial hypertension (PAH). Seventy-one patients with PAH and 20 sex- and age-matched healthy controls underwent CMR. Myocardial borders and RV insertion points were defined at end diastole and end systole in cine short-axis stacks to compute biventricular volumes, lateral (SVlat%) and septal (SVsept%) contribution to stroke volume. Eight atrioventricular points were defined at end diastole and end systole in 2-, 3- and 4-chamber cine long-axis views for computation of AVPD and longitudinal contribution to stroke volume (SVlong%). Cut-off values for survival analysis were defined as two standard deviations above or below the mean of the controls. Outcome was defined as death or lung transplantation. Median follow-up time was 3.6 [IQR 3.7] years. Patients were 57 ± 19 years (65% women) and controls 58 ± 15 years (70% women). Biventricular AVPD, SVlong% and ejection fraction (EF) were lower and SVlat% was higher, while SVsept% was lower in PAH compared with controls. In PAH, transplantation-free survival was lower below cut-off for LV-AVPD (hazard ratio [HR] = 2.1, 95%CI 1.2-3.9, p = 0.02) and RV-AVPD (HR = 9.8, 95%CI 4.6-21.1, p = 0.005). In Cox regression analysis, lower LV-AVPD and RV-AVPD inferred lower transplantation-free survival (LV: HR = 1.16, p = 0.007; RV: HR = 1.11, p = 0.01; per mm decrease). LV-SVlong%, RV-SVlong%, LV-SVlat%, RV-SVlat%, SVsept% and LV- and RVEF did not affect outcome. Low left and right AVPD were associated with outcome in PAH, but regional contributions to stroke volume and EF were not.

Elucidating the Clinical Implications and Pathophysiology of Pulmonary Hypertension in Heart Failure With Preserved Ejection Fraction: A Call to Action: A Science Advisory From the American Heart Association

This science advisory focuses on the need to better understand the epidemiology, pathophysiology, and treatment of pulmonary hypertension in patients with heart failure with preserved ejection fraction. This clinical phenotype is important because it is common, is strongly associated with adverse outcomes, and lacks evidence-based therapies. Our goal is to clarify key knowledge gaps in pulmonary hypertension attributable to heart failure with preserved ejection fraction and to suggest specific, actionable scientific directions for addressing such gaps. Areas in need of additional investigation include refined disease definitions and interpretation of hemodynamics, as well as greater insights into noncardiac contributors to pulmonary hypertension risk, optimized animal models, and further molecular studies in patients with combined precapillary and postcapillary pulmonary hypertension. We highlight translational approaches that may provide important biological insight into pathophysiology and reveal new therapeutic targets. Last, we discuss the current and future landscape of potential therapies for patients with heart failure with preserved ejection fraction and pulmonary vascular dysfunction, including considerations of precision medicine, novel trial design, and device-based therapies, among other considerations. This science advisory provides a synthesis of important knowledge gaps, culminating in a collection of specific research priorities that we argue warrant investment from the scientific community.

Characteristics of Right Ventricular Blood Flow in Patients With Chronic Thromboembolic Pulmonary Hypertension: An Analysis With 4-Dimensional Flow Cardiovascular Magnetic Resonance Imaging

Background

Blood flow is closely related to function, but currently, the relationship of right ventricular (RV) blood flow components with RV function and hemodynamics in patients with chronic thromboembolic pulmonary hypertension (CTEPH) remains unclear. Our objective is to qualify RV function with 4-dimensional flow cardiovascular magnetic resonance (4D-Flow CMR) imaging and to investigate the correlation between RV flow and hemodynamics in patients with CTEPH.

Methods

Retrospective enrollment included 67 patients with CTEPH (mean age 47.8±14.2 years, 47 men) who underwent CMR and right heart catheterization (RHC) within 2 days. RHC was used to evaluate hemodynamics. RV flow components including the percentages of direct flow (PDF), retained inflow (PRI), delayed ejection flow (PDEF), and residual volume (PRVo) were quantified on 4D-Flow sequence. RV functional metrics were determined with the CINE balanced steady-state free precession sequence. The sum of PDF and PDEF was compared with RV eject fraction (RVEF). The correlation among RV flow components, RV functional metrics and hemodynamics was analyzed with spearman correlation analysis.

Results

The median (interquartile range) of RVEF, PDF, PDEF, PRI, and PRVo, respectively was 35.5% (18.2, 45.6%), 18% (8.4, 21.4%), 15.1% (13.5, 19.0%), 15.9% (13.8, 20.8%), and 50.6% (35.6, 60.4%). The sum of PDF and PDEF is 35.1% (24.8, 46.6%), which was similar to RVEF (z = 0.58, p = 0.561). PDF negatively correlated with right ventricular end-systolic volume index (RVESVI), right ventricular myocardial mass index (RVMI) and right ventricular global longitudinal strain (r = −0.61, −0.65, −0.64, p &lt; 0.001). PRVo positively correlated with RVESVI and RVMI (r = 0.50, 0.58, p &lt; 0.001). PDF negatively correlated with pulmonary vascular resistance (PVR) (r = −0.72, p &lt; 0.001) while it positively correlated with cardiac output (CO) and cardiac index (CI) (r = 0.64 &amp; 0.52, p &lt; 0.001). PRVo positively correlated with mean pulmonary pressure and PVR (r = 0.57&amp;0.54, p &lt; 0.001). Total five patients died in the perioperative period. RVEF in the deceased patients was similar to survivors (z = −1.163, p = 0.092). In comparison with the survivors, RVPDF in the deceased patients significantly reduced (z = −2.158, p = 0.029) while RVPDEF, RVPRI, and RVPRVo in deceased patients were similar to survivors.

Conclusion

4D-Flow CMR can provide simultaneous quantification of RV function and hemodynamics in the assessment of CTEPH without breath-holding. The reduced PDF and increased PRVo were the main characteristics of RV flow in CTEPH.

A Study of the Efficacy and Safety of Aerobic Exercise Training in Pulmonary Arterial Hypertension (the Saturday Study): Protocol for a Prospective, Randomized, and Controlled Trial

Background

Patients with pulmonary arterial hypertension (PAH) have reduced exercise capacity and poor quality of life. Exercise-based rehabilitation in PAH results in clinically relevant improvements in exercise capacity and hemodynamics. To clarify the mechanism, we will evaluate the effect of aerobic exercise training rehabilitation on right ventricular (RV) remodeling and function as determined measured by cardiac magnetic resonance imaging (CMR).

Methods

We will conduct a 26-week multicenter randomized controlled trial. Patients on stable and unchanged PAH-targeted medication are randomly assigned (1:1) to the control and training groups. The primary endpoint is the RV stroke volume (RVSV) change from baseline to Week 26, determined by CMR. Comprehensive RV function is also performed using CMR. Other characteristics of the RV and left ventricle, World Health Organization functional class, 6-min walk distance, and N-terminal pro-B-type natriuretic peptide are included in secondary endpoints. We also investigate the proteomic, metabolomic, and transcriptomic changes after exercise training as exploratory endpoints.

Ethics and Dissemination

The study and protocol were approved by the Ethics Committee of Shanghai Pulmonary Hospital (Approved No. of ethics committee: L20-17). The results will be disseminated at medical conferences and in journal publications. All participants will sign written informed consent.

Trial Registration Number

ChiCTR2000031650.

Clinical Application of 4D Flow MR Imaging to Pulmonary Hypertension

Pulmonary hypertension (PH) is characterized by elevated pulmonary arterial pressure (PAP). Although right-heart catheterization is the gold standard method for the diagnosis of PH by definition, various less-invasive imaging tests have been used for screening, detection of underlying diseases-causing PH, and monitoring of diseases. Among them, 4D flow MRI is an emerging and unique imaging test that allows for comprehensive visualization of blood flow in the right heart and proximal pulmonary arteries. The characteristic blood flow pattern observed in patients with PH is vortical flow formation in the main pulmonary artery. Recent studies have proposed the use of these findings to determine not only the presence of PH but also estimate the mean PAP. Other applications of 4D flow MRI for PH include measurement of wall shear stress, helicity, and 3D flow balance in the pulmonary arteries. It is worth noting that 4D flow has also the potential for longitudinal follow-ups. In this review, the clinical definition of PH, summary of conventional imaging tests, characteristics of pulmonary arterial flow as shown by 4D flow MRI, and clinical application of 4D flow MRI in the management of patients with PH will be discussed.

Ventricular mass discriminates pulmonary arterial hypertension as redefined at the Sixth World Symposium on Pulmonary Hypertension

Cardiac magnetic resonance (CMR) measures of right ventricular (RV) mass, volumes, and function have diagnostic and prognostic value in pulmonary arterial hypertension (PAH). We hypothesized that RV mass-based metrics would discriminate incident PAH as redefined by the lower mean pulmonary arterial pressure (mPAP) threshold of >20 mmHg at the Sixth World Symposium on Pulmonary Hypertension (6th WSPH). Eighty-nine subjects with suspected PAH underwent CMR imaging, including 64 subjects with systemic sclerosis (SSc). CMR metrics, including RV and left ventricular (LV) mass, were measured. All subjects underwent right heart catheterization (RHC) for assessment of hemodynamics within 48 h of CMR. Using generalized linear models, associations between CMR metrics and PAH were assessed, the best subset of CMR variables for predicting PAH were identified, and relationships between mass-based metrics, hemodynamics, and other predictive CMR metrics were examined. Fifty-nine subjects met 6th WSPH criteria for PAH. RV mass metrics, including ventricular mass index (VMI), demonstrated the greatest magnitude difference between subjects with versus without PAH. Overall and in SSc, VMI and RV mass measured by CMR were among the most predictive variables discriminating PAH at RHC, with areas under the receiver operating characteristic curve 0.86 and 0.83. respectively. VMI increased linearly with pulmonary vascular resistance and with mPAP in PAH, including in lower ranges of mPAP associated with mild PAH. VMI ≥ 0.37 yielded a positive predictive value of 90% for discriminating PAH. RV mass metrics measured by CMR, including VMI, discriminate incident, treatment-naïve PAH as defined by 6th WSPH criteria.

Clinical Significance of Right Ventricular Function in Pulmonary Hypertension

Pulmonary hypertension (PH) is a progressive disease characterized by increased pulmonary vascular resistance that leads to right ventricular (RV) failure, a condition that determines its prognosis. This review focuses on the clinical value of the evaluation of RV function in PH. First, the pathophysiology of PH, including hemodynamics, RV function, and their interaction (known as ventriculoarterial coupling), are summarized. Next, non-invasive imaging modalities and the parameters of RV function, mainly assessed by echocardiography, are reviewed. Finally, the clinical impacts of RV function in PH are described. This review will compare the techniques that yield comprehensive information on RV function and their roles in the assessment of PH.

Effects of sildenafil on right ventricle remodelling in Portopulmonary hypertension

Portopulmonary hypertension (PoPH) is a clinical condition associated with end-stage liver disease, described by the coexistence of pulmonary arterial hypertension (PAH) and portal hypertension. In PoPH patients, there is a right ventricle (RV) remodeling to compensate for the increased resistance in the lung circulation. There are no studies on the effects of the PAH-targeted pharmacological treatment on the RV dimension and function. The present study summarizes our experience in patients with PoPH treated with sildenafil in a period of 6 years (from 2013 to 2019). We enrolled 64 consecutive patients identified as PoPH, all treated with sildenafil (57.6% in monotherapy; in the other cases in association with macitentan; in 19.0% with initial combination therapy). A hemodynamic invasive cardiopulmonary study was performed at baseline and after 6 months of sildenafil treatment. In our population we showed a significative improvement in RV performance, with a significant increase in RV stroke volume (+33%), RV ejection fraction (+31%) and RV stroke work index (+17.5%). We registered the reduction of the RV cavity dimension over time in all patients treated with sildenafil (RV end diastolic diameter decreased by 15% after 6 months of follow-up). Regarding diastolic function, we highlighted a very significant reduction in RV end-diastolic pressure (-50% concerning baseline). Sildenafil was effective both when used as monotherapy and in combination with macitentan. In conclusion, Sildenafil had a positive impact on RV systolic and diastolic function in patients with PoPH and was able to conditionate the reverse remodeling of the RV.

Right ventricular systolic function in severe tricuspid regurgitation: prognostic relevance of longitudinal strain

AIMS

The aim of this study is to analyse the prognostic implications of right ventricular (RV) dysfunction as detected by strain analysis in patients with severe tricuspid regurgitation (TR). The evaluation of RV systolic function in presence of severe TR is of paramount importance for operative risk stratification; however, it remains challenging, as conventional echocardiographic indexes usually lead to overestimation.

METHODS AND RESULTS

We enrolled 250 consecutive patients with severe TR referred to our centre. Baseline clinical and echocardiographic data and follow-up outcomes were collected. Patients were predominantly female, with multiple cardiovascular risk factors and comorbidities, history of heart failure, and atrial fibrillation. Most of them had presented with clinical signs of RV heart failure (RVHF) and advanced New York Heart Association class. The RV strain analysis [both RV free wall longitudinal strain (RVFWLS) and RV global longitudinal strain (RVGLS)] reclassified ∼42-56% of patients with normal RV systolic function according to conventional parameters in patients with impaired RV systolic function. RVFWLS ≤17% (absolute values, AUC: 0.66, P = 0.002) predicted the presence of RVHF [odds ratio (OR) 0.93, P = 0.01]. At follow-up, patients with RVFWLS >14% (absolute values, AUC: 0.70, P = 0.001, sensitivity 72%, specificity 54%) showed a better survival (P = 0.01).

CONCLUSION

Different ranges of RVFWLS have different implications in patients with severe TR, allowing to identify a preclinical and a clinical window, with correlations to RVHF and survival.

Echocardiography in Pulmonary Arterial Hypertension: Is It Time to Reconsider Its Prognostic Utility?

Pulmonary arterial hypertension (PAH) is characterized by an insult in the pulmonary vasculature, with subsequent right ventricular (RV) adaptation to the increased afterload that ultimately leads to RV failure. The awareness of the importance of RV function in PAH has increased considerably because right heart failure is the predominant cause of death in PAH patients. Given its wide availability and reduced cost, echocardiography is of paramount importance in the evaluation of the right heart in PAH. Several echocardiographic parameters have been shown to have prognostic implications in PAH; however, the role of echocardiography in the risk assessment of the PAH patient is limited under the current guidelines. This review discusses the echocardiographic evaluation of the RV in PAH and during therapy, and its prognostic implications, as well as the potential significant role of repeated echocardiographic assessment in the follow-up of patients with PAH.

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.

The Predictive Value of Right Ventricular Longitudinal Strain in Pulmonary Hypertension, Heart Failure, and Valvular Diseases

Right ventricular (RV) systolic function has an important role in the prediction of adverse outcomes, including mortality, in a wide range of cardiovascular (CV) conditions. Because of complex RV geometry and load dependency of the RV functional parameters, conventional echocardiographic parameters such as RV fractional area change (FAC) and tricuspid annular plane systolic excursion (TAPSE), have limited prognostic power in a large number of patients. RV longitudinal strain overcame the majority of these limitations, as it is angle-independent, less load-dependent, highly reproducible, and measure regional myocardial deformation. It has a high predictive value in patients with pulmonary hypertension, heart failure, congenital heart disease, ischemic heart disease, pulmonary embolism, cardiomyopathies, and valvular disease. It enables detection of subclinical RV damage even when conventional parameters of RV systolic function are in the normal range. Even though cardiac magnetic resonance-derived RV longitudinal strain showed excellent predictive value, echocardiography-derived RV strain remains the method of choice for evaluation of RV mechanics primarily due to high availability. Despite a constantly growing body of evidence that support RV longitudinal strain evaluation in the majority of CV patients, its assessment has not become the part of the routine echocardiographic examination in the majority of echocardiographic laboratories. The aim of this clinical review was to summarize the current data about the predictive value of RV longitudinal strain in patients with pulmonary hypertension, heart failure and valvular heart diseases.

Cardiac Magnetic Resonance Imaging in Pulmonary Arterial Hypertension: Ready for Clinical Practice and Guidelines?

Purpose of Review

Pulmonary arterial hypertension (PAH) is a progressive disease with high mortality. A greater understanding of the physiology and function of the cardiovascular system in PAH will help improve survival. This review covers the latest advances within cardiovascular magnetic resonance imaging (CMR) regarding diagnosis, evaluation of treatment, and prognostication of patients with PAH.

Recent Findings

New CMR measures that have been proven relevant in PAH include measures of ventricular and atrial volumes and function, tissue characterization, pulmonary artery velocities, and arterio-ventricular coupling.

Summary

CMR markers carry prognostic information relevant for clinical care such as treatment response and thereby can affect survival. Future research should investigate if CMR, as a non-invasive method, can improve existing measures or even provide new and better measures in the diagnosis, evaluation of treatment, and determination of prognosis of PAH.

A novel non-invasive and echocardiography-derived method for quantification of right ventricular pressure-volume loops

AIMS

We sought to assess the feasibility of constructing right ventricular (RV) pressure-volume (PV) loops solely by echocardiography.

METHODS AND RESULTS

We performed RV conductance and pressure wire (PW) catheterization with simultaneous echocardiography in 35 patients with pulmonary hypertension. To generate echocardiographic PV loops, a reference RV pressure curve was constructed using pooled PW data from the first 20 patients (initial cohort). Individual pressure curves were then generated by adjusting the reference curve according to RV isovolumic and ejection phase duration and estimated RV systolic pressure. The pressure curves were synchronized with echocardiographic volume curves. We validated the reference curve in the remaining 15 patients (validation cohort). Methods were compared with correlation and Bland-Altman analysis. In the initial cohort, echocardiographic and conductance-derived PV loop parameters were significantly correlated {rho = 0.8053 [end-systolic elastance (Ees)], 0.8261 [Ees/arterial elastance (Ea)], and 0.697 (stroke work); all P < 0.001}, with low bias [-0.016 mmHg/mL (Ees), 0.1225 (Ees/Ea), and -39.0 mmHg mL (stroke work)] and acceptable limits of agreement. Echocardiographic and PW-derived Ees were also tightly correlated, with low bias (-0.009 mmHg/mL) and small limits of agreement. Echocardiographic and conductance-derived Ees, Ees/Ea, and stroke work were also tightly correlated in the validation cohort (rho = 0.9014, 0.9812, and 0.9491, respectively; all P < 0.001), with low bias (0.0173 mmHg/mL, 0.0153, and 255.1 mmHg mL, respectively) and acceptable limits.

CONCLUSION

The novel echocardiographic method is an acceptable alternative to invasively measured PV loops to assess contractility, RV-arterial coupling, and RV myocardial work. Further validation is warranted.