Right ventricular ejection fraction is better reflected by transverse rather than longitudinal wall motion in pulmonary hypertension

Relationship of TAPSE Normalized by Right Ventricular Area With Pulmonary Compliance, Exercise Capacity, and Clinical Outcomes

BACKGROUND

While tricuspid annular plane systolic excursion (TAPSE) captures the predominant longitudinal motion of the right ventricle (RV), it does not account for ventricular morphology and radial motion changes in various forms of pulmonary hypertension. This study aims to account for both longitudinal and radial motions by dividing TAPSE by RV area and to assess its clinical significance.

METHODS

We performed a retrospective analysis of 71 subjects with New York Heart Association class II to III dyspnea who underwent echocardiogram and invasive cardiopulmonary exercise testing (which defined 4 hemodynamic groups: control, isolated postcapillary pulmonary hypertension, combined postcapillary pulmonary hypertension, and pulmonary arterial hypertension). On the echocardiogram, TAPSE was divided by RV area in diastole (TAPSE/RVA-D) and systole (TAPSE/RVA-S). Analyses included correlations (Pearson and linear regression), receiver operating characteristic, and survival curves.

RESULTS

On linear regression analysis, TAPSE/RVA metrics (versus TAPSE) had a stronger correlation with pulmonary artery compliance (r=0.48-0.54 versus 0.38) and peak VO2 percentage predicted (0.23-0.30 versus 0.18). Based on the receiver operating characteristic analysis, pulmonary artery compliance ≥3 mL/mm Hg was identified by TAPSE/RVA-D with an under the curve (AUC) of 0.79 (optimal cutoff ≥1.1) and by TAPSE/RVA-S with an AUC of 0.83 (optimal cutoff ≥1.5), but by TAPSE with only an AUC of 0.67. Similarly, to identify peak VO2 <50% predicted, AUC of 0.66 for TAPSE/RVA-D and AUC of 0.65 for TAPSE/RVA-S. Death or cardiovascular hospitalization at 12 months was associated with TAPSE/RVA-D ≥1.1 (HR, 0.38 [95% CI, 0.11-0.56]) and TAPSE/RVA-S ≥1.5 (HR, 0.44 [95% CI, 0.16-0.78]), while TAPSE was not associated with adverse outcomes (HR, 0.99 [95% CI, 0.53-1.94]). Among 31 subjects with available cardiac magnetic resonance imaging, RV ejection fraction was better correlated with novel metrics (TAPSE/RVA-D r=0.378 and TAPSE/RVA-S r=0.328) than TAPSE (r=0.082).

CONCLUSIONS

In a broad cohort with suspected pulmonary hypertension, TAPSE divided by RV area was superior to TAPSE alone in correlations with pulmonary compliance and exercise capacity. As a prognostic marker of right heart function, TAPSE/RVA-D <1.1 and TAPSE/RVA-S <1.5 predicted adverse cardiovascular outcomes.

Right Ventricular Function on Cardiovascular Magnetic Resonance Imaging and Long-Term Outcomes in Stable Heart Transplant Recipients

BACKGROUND

In heart transplant recipients, right ventricular (RV) dysfunction may occur for a variety of reasons. Whether RV dysfunction in the stable phase after heart transplantation is associated with long-term adverse outcomes is unknown. We aimed to determine the long-term prognostic significance of RV dysfunction identified on cardiovascular magnetic resonance imaging (CMR) at least 1 year after heart transplantation.

METHODS

In consecutive heart transplant recipients who underwent CMR for surveillance, we assessed 2 CMR measures of RV function: RV ejection fraction and RV global longitudinal strain (RVGLS). We investigated associations between RV dysfunction and a composite end point of death or major adverse cardiac events, including retransplantation, nonfatal myocardial infarction, coronary revascularization, and heart failure hospitalization.

RESULTS

A total of 257 heart transplant recipients (median age, 59 years; 75% men) who had CMR at a median of 4.3 years after heart transplantation were included. Over a median follow-up of 4.4 years after the CMR, 108 recipients experienced death or major adverse cardiac events. In a multivariable Cox regression analysis adjusted for age, time since transplantation, indication for transplantation, cardiac allograft vasculopathy, history of rejection, and CMR covariates, RV ejection fraction was not associated with the composite end point, but RVGLS was independently associated with the composite end point with a hazard ratio of 1.08 per 1% worsening in RVGLS ([95% CI, 1.00-1.17]; P=0.046). RVGLS provided incremental prognostic value over other variables in multivariable analyses. The association was replicated in subgroups of recipients with normal RV ejection fraction and recipients with late gadolinium enhancement imaging. A similar association was seen with a composite end point of cardiovascular death or major adverse cardiac events.

CONCLUSIONS

CMR feature tracking-derived RVGLS assessed at least 1 year after heart transplantation was independently associated with the long-term risk of death or major adverse cardiac events. Future studies should investigate its role in guiding clinical decision-making in heart transplant recipients.

Acute right ventricular geometric change predicts outcomes in HeartMate 3 patients

BACKGROUND

The physiological response of the right ventricle (RV) following left ventricular assist device (LVAD) implantation is difficult to predict. We aimed to investigate RV geometric and functional changes after LVAD insertion and their effects on clinical outcomes.

METHODS

We retrospectively reviewed 188 patients who underwent HeartMate 3 implantation at our center between November 2014 and September 2021. The RV end-diastolic diameter (RVEDD) and RV end-diastolic area (RVEDA) were measured on preoperative and predischarge transthoracic echocardiography. The nonadapted group included patients with increased RVEDD and RVEDA at discharge. The composite outcome was defined as death or readmission due to worsening right heart failure.

RESULTS

There were 82 patients (44%) who had a nonadapted and 106 patients (56%) who had an adapted RV. Preoperatively, the nonadapted group had smaller RVEDD (46 vs 49 mm, p < 0.001) and RVEDA (27 vs 31 cm2, p < 0.001). At discharge, the nonadapted group had larger RVEDD (51 vs 43 mm, p < 0.001) and RVEDA (33 vs 27 cm2, p < 0.001). Kaplan-Meier analysis demonstrated worse 3-year survival (77% vs 91%, p = 0.006) and freedom from composite outcome (58% vs 85%, p < 0.001) in the nonadapted group. A multivariable Cox proportional hazards model showed that nonadaption (hazard ratio [HR] 3.09, 95% confidence interval [CI] 1.29-7.40, p = 0.01) and age (HR 3.73, 95% CI 1.42-9.77, p = 0.007) were independent predictors of composite outcome.

CONCLUSIONS

Acute RV dimensional changes after LVAD insertion may represent intrinsic RV function and may be a useful prognostic marker.

Identifying consistent echocardiographic thresholds for risk stratification in pulmonary arterial hypertension

Several indices of right heart remodeling and function have been associated with survival in pulmonary arterial hypertension (PAH). Outcome analysis and physiological relationships between variables may help develop a consistent grading system. Patients with Group 1 PAH followed at Stanford Hospital who underwent right heart catheterization and echocardiography within 2 weeks were considered for inclusion. Echocardiographic variables included tricuspid annular plane systolic excursion (TAPSE), right ventricular (RV) fractional area change (RVFAC), free wall strain (RVFWS), RV dimensions, and right atrial volumes. The main outcome consisted of death or lung transplantation at 5 years. Mathematical relationships between variables were determined using weighted linear regression and severity thresholds for were calibrated to a 20% 1-year mortality risk. PAH patients (n = 223) had mean (SD) age of 48.1 (14.1) years, most were female (78%), with a mean pulmonary arterial pressure of 51.6 (13.8) mmHg and pulmonary vascular resistance index of 22.5(6.3) WU/m2. Measures of right heart size and function were strongly related to each other particularly RVFWS and RVFAC (R 2 = 0.82, p < 0.001), whereas the relationship between TAPSE and RVFWS was weaker (R 2 = 0.28, p < 0.001). Death or lung transplantation at 5 years occurred in 78 patients (35%). Guided by outcome analysis, we ascertained a uniform set of parameter thresholds for grading the severity of right heart adaptation in PAH. Using these quantitative thresholds, we, then, validated the recently reported REVEAL-echo score (AUC 0.68, p < 0.001). This study proposes a consistent echocardiographic grading system for right heart adaptation in PAH guided by outcome analysis.

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

Background

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

Methods and results

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

Conclusion

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

Right ventricle: current knowledge of echocardiographic evaluation of this "forgotten" chamber

In the past the right ventricle (RV) has been traditionally regarded as a simple conduit between the venous system and the pulmonary circulation and it has aroused little interest in both clinical and echocardiographic cardiologists to such an extent that it has been defined as the "forgotten chamber." Subsequently it was clearly shown that the right heart (RH) plays an important physiologic role in cardiac activity, and that congenital or acquired alterations in its structure and function have an important prognostic value. Aim of this review is to shed the light on the echocardiographic approach to this cardiac chamber. In this narrative review we critically explored the most recent literature on this topic using PubMed and Medline and examining the most recent guidelines on the echocardiographic approach to the RV. Echocardiographic approach to RV presents some technical difficulties, which stem from the position of the RV inside the thorax and around the LV and from its particular anatomy, which precludes geometric assumptions. However, RV may now be evaluated quantitatively and qualitatively in many ways, and some new methods can partially overcome some of the limits imposed by its complex anatomy, thereby yielding a quantitative evaluation. Furthermore, due to the wide range of pathologies which may involve the RV a disease-oriented approach should be considered in the echocardiographic investigation of right heart disease.

The association of Pulmonary Hypertension and right ventricular systolic function - updates in diagnosis and treatment

Right ventricular (RV) systolic function is an essential but neglected component in cardiac evaluation, and its importance to the contribution to overall cardiac function is undermined. It is not only sensitive to the effect of left heart valve disease but is also more sensitive to changes in pressure overload than the left ventricle. Pulmonary Hypertension is the common and well-recognized complication of RV systolic dysfunction. It is also the leading cause of pulmonary valve disease and right ventricular dysfunction. Patients with a high pulmonary artery pressure (PAP) and a low RV ejection fraction have a seven-fold higher risk of death than heart failure patients with a normal PAP and RV ejection fraction. Furthermore, it is an independent predictor of survival in these patients. In this review, we examine the association of right ventricular systolic function with Pulmonary Hypertension by focusing on various pathological and clinical manifestations while assessing their impact. We also explore new 2022 ESC/ERS guidelines for diagnosing and treating right ventricular dysfunction in Pulmonary Hypertension.

Three-dimensional echocardiographic evaluation of longitudinal and non-longitudinal components of right ventricular contraction: results from the World Alliance of Societies of Echocardiography study

AIMS

Right ventricular (RV) functional assessment is mainly limited to its longitudinal contraction. Dedicated three-dimensional echocardiography (3DE) software enabled the separate assessment of the non-longitudinal components of RV ejection fraction (EF). The aims of this study were (i) to establish normal values for RV 3D-derived longitudinal, radial, and anteroposterior EF (LEF, REF, and AEF, respectively) and their relative contributions to global RVEF, (ii) to calculate 3D RV strain normal values, and (iii) to determine sex-, age-, and race-related differences in these parameters in a large group of normal subjects (WASE study).

METHODS AND RESULTS

3DE RV wide-angle datasets from 1043 prospectively enrolled healthy adult subjects were analysed to generate a 3D mesh model of the RV cavity (TomTec). Dedicated software (ReVISION) was used to analyse RV motion along the three main anatomical planes. The EF values corresponding to each plane were identified as LEF, REF, and AEF. Relative contributions were determined by dividing each EF component by the global RVEF. RV strain analysis included longitudinal, circumferential, and global area strains (GLS, GCS, and GAS, respectively). Results were categorized by sex, age (18-40, 41-65, and >65 years), and race. Absolute REF, AEF, LEF, and global RVEF were higher in women than in men (P < 0.001). With aging, both sexes exhibited a decline in all components of longitudinal shortening (P < 0.001), which was partially compensated in elderly women by an increase in radial contraction. Black subjects showed lower RVEF and GAS values compared with white and Asian subjects of the same sex (P < 0.001), and black men showed significantly higher RV radial but lower longitudinal contributions to global RVEF compared with Asian and white men.

CONCLUSION

3DE evaluation of the non-longitudinal components of RV contraction provides additional information regarding RV physiology, including sex-, age-, and race-related differences in RV contraction patterns that may prove useful in disease states involving the right ventricle.

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.

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.

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

BACKGROUND

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

PURPOSE

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

STUDY TYPE

Retrospective.

POPULATION

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

FIELD STRENGTH/SEQUENCE

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

ASSESSMENT

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

STATISTICAL TESTS

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

RESULTS

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

DATA CONCLUSION

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

LEVEL OF EVIDENCE

3 TECHNICAL EFFICACY: Stage 3.

Clinical and functional relevance of right ventricular contraction patterns in pulmonary hypertension

BACKGROUND

The right ventricle has a complex contraction pattern of uncertain clinical relevance. We aimed to assess the relationship between right ventricular (RV) contraction pattern and RV-pulmonary arterial (PA) coupling defined by the gold-standard pressure-volume loop-derived ratio of end-systolic/arterial elastance (Ees/Ea).

METHODS

Prospectively enrolled patients with suspected or confirmed pulmonary hypertension underwent three-dimensional echocardiography, standard right heart catheterization, and RV conductance catheterization. RV-PA uncoupling was categorized as severe (Ees/Ea < 0.8), moderate (Ees/Ea 0.8-1.29), and none/mild (Ees/Ea ≥ 1.3). Clinical severity was determined from hemodynamics using a truncated version of the 2022 European Society of Cardiology/European Respiratory Society risk stratification scheme.

RESULTS

Fifty-three patients were included, 23 with no/mild, 24 with moderate, and 6 with severe uncoupling. Longitudinal shortening was decreased in patients with moderate vs no/mild uncoupling (p <0.001) and intermediate vs low hemodynamic risk (p < 0.001), discriminating low risk from intermediate/high risk with an optimal threshold of 18% (sensitivity 80%, specificity 87%). Anteroposterior shortening was impaired in patients with severe vs moderate uncoupling (p = 0.033), low vs intermediate risk (p = 0.018), and high vs intermediate risk (p = 0.010), discriminating high risk from intermediate/low risk with an optimal threshold of 15% (sensitivity 100%, specificity 83%). Left ventricular (LV) end-diastolic volume was decreased in patients with severe uncoupling (p = 0.035 vs no/mild uncoupling).

CONCLUSIONS

Early RV-PA uncoupling is associated with reduced longitudinal function, whereas advanced RV-PA uncoupling is associated with reduced anteroposterior movement and LV preload, all in a risk-related fashion.

CLINICALTRIALS

GOV: NCT04663217.

Right Ventricular Dysfunction Patterns among Patients with COVID-19 in the Intensive Care Unit: A Retrospective Cohort Analysis

Rationale: Right ventricular (RV) dysfunction is common among patients hospitalized with coronavirus disease (COVID-19); however, its epidemiology may depend on the echocardiographic parameters used to define it. Objectives: To evaluate the prevalence of abnormalities in three common echocardiographic parameters of RV function among patients with COVID-19 admitted to the intensive care unit (ICU), as well as the effect of RV dilatation on differential parameter abnormality and the association of RV dysfunction with 60-day mortality. Methods: We conducted a retrospective cohort study of ICU patients with COVID-19 between March 4, 2020, and March 4, 2021, who received a transthoracic echocardiogram within 48 hours before to at most 7 days after ICU admission. RV dysfunction and dilatation, respectively, were defined by guideline thresholds for tricuspid annular plane systolic excursion (TAPSE), RV fractional area change, RV free wall longitudinal strain (RVFWS), and RV basal dimension or RV end-diastolic area. Association of RV dysfunction with 60-day mortality was assessed through logistic regression adjusting for age, prior history of congestive heart failure, invasive ventilation at the time of transthoracic echocardiogram, and Acute Physiology and Chronic Health Evaluation II score. Results: A total of 116 patients were included, of whom 69% had RV dysfunction by one or more parameters, and 36.3% of these had RV dilatation. The three most common patterns of RV dysfunction were the presence of three abnormalities, the combination of abnormal RVFWS and TAPSE, and isolated TAPSE abnormality. Patients with RV dilatation had worse RV fractional area change (24% vs. 36%; P = 0.001), worse RVFWS (16.3% vs. 19.1%; P = 0.005), higher RV systolic pressure (45 mm Hg vs. 31 mm Hg; P = 0.001) but similar TAPSE (13 mm vs. 13 mm; P = 0.30) compared with those with normal RV size. After multivariable adjustment, 60-day mortality was significantly associated with RV dysfunction (odds ratio, 2.91; 95% confidence interval, 1.01-9.44), as was the presence of at least two parameter abnormalities. Conclusions: ICU patients with COVID-19 had significant heterogeneity in RV function abnormalities present with different patterns associated with RV dilatation. RV dysfunction by any parameter was associated with increased mortality. Therefore, a multiparameter evaluation may be critical in recognizing RV dysfunction in COVID-19.

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.

Approach to optimal assessment of right ventricular remodelling in heart transplant recipients: insights from myocardial work index, T1 mapping, and endomyocardial biopsy

AIMS

Right ventricular (RV) dysfunction is an important cause of graft failure after heart transplantation (HTx). We sought to investigate relative merits of echocardiographic tools and cardiac magnetic resonance (CMR) with T1 mapping for the assessment of functional adaptation and remodelling of the RV in HTx recipients.

METHODS AND RESULTS

Sixty-one complete data set of echocardiography, CMR, right heart catheterization, and biopsy were obtained. Myocardial work index (MWI) was quantified by integrating longitudinal strain (LS) with invasively measured pulmonary artery pressure. CMR derived RV volumes, T1 time, and extracellular volume (ECV) were quantified. Endomyocardial biopsy findings were used as the reference standard for myocardial microstructural changes. In HTx recipients who never had a previous allograft rejection, longitudinal function parameters were lower than healthy organ donors, while ejection fraction (EF) (52.0 ± 8.7%) and MWI (403.2 ± 77.2 mmHg%) were preserved. Rejection was characterized by significantly reduced LS, MWI, longer T1 time, and increased ECV that improved after recovery, whereas RV volumes and EF did not change MWI was the strongest determinant of rejection related myocardial damage (area under curve: 0.812, P < 0.0001, 95% CI: 0.69-0.94) with good specificity (77%), albeit modest sensitivity. In contrast, T1 time and ECV were sensitive (84%, both) but not specific to detect subclinical RV damage.

CONCLUSION

Subclinical adaptive RV remodelling is characterized by preserved RV EF despite longitudinal function abnormalities, except for MWI. While ultrastructural damage is reflected by MWI, ECV, and T1 time, only MWI has the capability to discriminate functional adaptation from transition to subclinical structural damage.

Right Ventricular Architectural Remodeling and Functional Adaptation in Pulmonary Hypertension

BACKGROUND

Global indices of right ventricle (RV) function provide limited insights into mechanisms underlying RV remodeling in pulmonary hypertension (PH). While RV myocardial architectural remodeling has been observed in PH, its effect on RV adaptation is poorly understood.

METHODS

Hemodynamic assessments were performed in 2 rodent models of PH. RV free wall myoarchitecture was quantified using generalized Q-space imaging and tractography analyses. Computational models were developed to predict RV wall strains. Data from animal studies were analyzed to determine the correlations between hemodynamic measurements, RV strains, and structural measures.

RESULTS

In contrast to the PH rats with severe RV maladaptation, PH rats with mild RV maladaptation showed a decrease in helical range of fiber orientation in the RV free wall (139º versus 97º; P=0.029), preserved global circumferential strain, and exhibited less reduction in right ventricular-pulmonary arterial coupling (0.029 versus 0.017 mm/mm Hg; P=0.037). Helical range correlated positively with coupling (P=0.036) and stroke volume index (P<0.01). Coupling correlated with global circumferential strain (P<0.01) and global radial strain (P<0.01) but not global longitudinal strain.

CONCLUSIONS

Data analysis suggests that adaptive RV architectural remodeling could improve RV function in PH. Our findings suggest the need to assess RV architecture within routine screenings of PH patients to improve our understanding of its prognostic and therapeutic significance in PH.

Adaptive versus maladaptive right ventricular remodelling

Right ventricular (RV) function and its adaptation to increased afterload [RV-pulmonary arterial (PA) coupling] are crucial in various types of pulmonary hypertension, determining symptomatology and outcome. In the course of disease progression and increasing afterload, the right ventricle undergoes adaptive remodelling to maintain right-sided cardiac output by increasing contractility. Exhaustion of compensatory RV remodelling (RV-PA uncoupling) finally leads to maladaptation and increase of cardiac volumes, resulting in heart failure. The gold-standard measurement of RV-PA coupling is the ratio of contractility [end-systolic elastance (Ees)] to afterload [arterial elastance (Ea)] derived from RV pressure-volume loops obtained by conductance catheterization. The optimal Ees/Ea ratio is between 1.5 and 2.0. RV-PA coupling in pulmonary hypertension has considerable reserve; the Ees/Ea threshold at which uncoupling occurs is estimated to be ~0.7. As RV conductance catheterization is invasive, complex, and not widely available, multiple non-invasive echocardiographic surrogates for Ees/Ea have been investigated. One of the first described and best validated surrogates is the ratio of tricuspid annular plane systolic excursion to estimated pulmonary arterial systolic pressure (TAPSE/PASP), which has shown prognostic relevance in left-sided heart failure and precapillary pulmonary hypertension. Other RV-PA coupling surrogates have been formed by replacing TAPSE with different echocardiographic measures of RV contractility, such as peak systolic tissue velocity of the lateral tricuspid annulus (S'), RV fractional area change, speckle tracking-based RV free wall longitudinal strain and global longitudinal strain, and three-dimensional RV ejection fraction. PASP-independent surrogates have also been studied, including the ratios S'/RV end-systolic area index, RV area change/RV end-systolic area, and stroke volume/end-systolic volume. Limitations of these non-invasive surrogates include the influence of severe tricuspid regurgitation (which can cause distortion of longitudinal measurements and underestimation of PASP) and the angle dependence of TAPSE and PASP. Detection of early RV remodelling may require isolated analysis of single components of RV shortening along the radial and anteroposterior axes as well as the longitudinal axis. Multiple non-invasive methods may need to be applied depending on the level of RV dysfunction. This review explains the mechanisms of RV (mal)adaptation to its load, describes the invasive assessment of RV-PA coupling, and provides an overview of studies of non-invasive surrogate parameters, highlighting recently published works in this field. Further large-scale prospective studies including gold-standard validation are needed, as most studies to date had a retrospective, single-centre design with a small number of participants, and validation against gold-standard Ees/Ea was rarely performed.

IMproving PULmonary hypertension Screening by Echocardiography: IMPULSE

BACKGROUND

The world symposium on pulmonary hypertension (PH) has proposed that PH be defined as a mean pulmonary artery pressure (mPAP) > 20 mmHg as assessed by right heart catheterisation (RHC). Transthoracic echocardiography (TTE) is an established screening tool used for suspected PH. International guidelines recommend a multi-parameter assessment of the TTE PH probability although effectiveness has not been established using real world data.

STUDY AIMS

To determine accuracy of the European Society of Cardiology (ESC) and British Society of Echocardiography (BSE) TTE probability algorithm in detecting PH in patients attending a UK PH centre. To identify echocardiographic markers and revised algorithms to improve the detection of PH in those with low/intermediate BSE/ESC TTE PH probability.

METHODS

TTE followed by RHC (within 4 months after) was undertaken in patients for suspected but previously unconfirmed PH. BSE/ESC PH TTE probabilities were calculated alongside additional markers of right ventricular (RV) longitudinal and radial function, and RV diastolic function. A refined IMPULSE algorithm was devised and evaluated in patients with low and/or intermediate ESC/BSE TTE PH probability.

RESULTS

Of 310 patients assessed, 236 (76%) had RHC-confirmed PH (average mPAP 42.8 ± 11.7). Sensitivity and specificity for detecting PH using the BSE/ESC recommendations was 89% and 68%, respectively. 36% of those with low BSE/ESC TTE probability had RHC-confirmed PH and BSE/ESC PH probability parameters did not differ amongst those with and without PH in the low probability group. Conversely, RV free wall longitudinal strain (RVFWLS) was lower in patients with vs. without PH in low BSE/ESC probability group (- 20.6 ± 4.1% vs - 23.8 ± 3.9%) (P < 0.02). Incorporating RVFWLS and TTE features of RV radial and diastolic function (RVFAC and IVRT) within the IMPULSE algorithm reduced false negatives in patients with low BSE/ESC PH probability by 29%. The IMPULSE algorithm had excellent specificity and positive predictive value in those with low (93%/80%, respectively) or intermediate (82%/86%, respectively) PH probability.

CONCLUSION

Existing TTE PH probability guidelines lack sensitivity to detect patients with milder haemodynamic forms of PH. Combining additional TTE makers assessing RV radial, longitudinal and diastolic function enhance identification of milder forms of PH, particularly in those who have a low BSE/ESC TTE PH probability.

Right Ventricle to Pulmonary Artery Coupling Predicts the Risk Stratification in Patients With Systemic Sclerosis-Associated Pulmonary Arterial Hypertension

Background

Pulmonary arterial hypertension (PAH) is a serious complication of systemic sclerosis (SSc). PAH has high mortality, and risk assessment is critical for proper management. Whether the right ventricle to pulmonary artery (RV-PA) coupling accurately assesses risk status and predicts prognosis in patients with SSc-associated PAH has not been investigated.

Methods

Between March 2010 and July 2018, 60 consecutive patients with SSc-associated PAH diagnosed by right heart catheterization were enrolled prospectively, and the mean follow-up period was 52.9 ± 27.0 months. The RV-PA coupling was assessed by the ratio of tricuspid annular plane systolic excursion (TAPSE) and pulmonary artery systolic pressure (PASP) which was obtained by transthoracic echocardiography. The simplified risk stratification strategy was applied to assess the risk level of participants, and the endpoint was a composite of all-cause death and clinical worsening.

Results

The receiver operating characteristic (ROC) curve of the ability to determine high-risk patients identified the optimal cut-off value of the TAPSE/PASP ratio as 0.194 mm/mmHg, and the ratio appeared to be a reliable indicator in the stratification of patients with high risk (area under the curve = 0.878, ROC P-value = 0.003), which showed the highest positive likelihood ratio (LR) (5.4) and the lowest negative LR (0) among a series of echocardiographic parameters. The TAPSE/PASP ratio was an independent predictive factor (HR = 0.01, 95% CI: 0.00–0.77, P = 0.037) for the composite endpoint, and patients with a TAPSE/PASP ratio >0.194 had a better overall survival for both the composite endpoint (log-rank χ² = 5.961, P = 0.015) and all-cause mortality (log-rank χ² = 8.004, P = 0.005) compared to the patients with a TAPSE/PASP ≤ 0.194.

Conclusion

RV-PA coupling assessed by the TAPSE/PASP ratio provides added value as a straightforward and non-invasive approach for predicting risk stratification of patients with SSc-associated PAH. Meanwhile, a lower TAPSE/PASP ratio identified a subgroup with worse prognosis.

Assessment of Right Ventricular Mechanics by 3D Transesophageal Echocardiography in the Early Phase of Acute Respiratory Distress Syndrome

Aim

To compare global and axial right ventricular ejection fraction in ventilated patients for moderate-to-severe acute respiratory distress syndrome (ARDS) secondary to early SARS-CoV-2 pneumonia or to other causes, and in ventilated patients without ARDS used as reference.

Methods

Retrospective single-center cross-sectional study including 64 ventilated patients: 21 with ARDS related to SARS-CoV-2 (group 1), 22 with ARDS unrelated to SARS-CoV-2 (group 2), and 21 without ARDS (control group). Real-time three-dimensional transesophageal echocardiography was performed for hemodynamic assessment within 24 h after admission. Contraction pattern of the right ventricle was decomposed along the three anatomically relevant axes. Relative contribution of each spatial axis was evaluated by calculating ejection fraction along each axis divided by the global right ventricular ejection fraction.

Results

Global right ventricular ejection fraction was significantly lower in group 2 than in both group 1 and controls [median: 43% (25–75th percentiles: 40–57) vs. 58% (55–62) and 65% (56–68), respectively: p < 0.001]. Longitudinal shortening had a similar relative contribution to global right ventricular ejection fraction in all groups [group 1: 32% (28–39), group 2: 29% (24–40), control group: 31% (28–38), p = 0.6]. Radial shortening was lower in group 2 when compared to both group 1 and controls [45% (40–53) vs. 57% (51–62) and 56% (50–60), respectively: p = 0.005]. The relative contribution of right ventricular shortening along the anteroposterior axis was not statistically different between groups [group 1: 51% (41–55), group 2: 56% (46–63), control group; 56% (50–64), p = 0.076].

Conclusion

During early hemodynamic assessment, the right ventricular systolic function appears more impaired in ARDS unrelated to SARS-CoV-2 when compared to early stage SARS-CoV-2 ARDS. Radial shortening appears more involved than longitudinal and anteroposterior shortening in patients with ARDS unrelated to SARS-CoV-2 and decreased right ventricular ejection fraction.

Crossbridge thermodynamics in pulmonary arterial hypertensive right-ventricular failure

Right-ventricular (RV) failure is an event consequent to pathological RV hypertrophy commonly resulting from pulmonary arterial hypertension. This pathology is well characterized by RV diastolic dysfunction, impaired ejection, and reduced mechanical efficiency. However, whether the dynamic stiffness and cross-bridge thermodynamics in the failing RV muscles are compromised remains uncertain. Pulmonary arterial hypertension was induced in the rat by injection of monocrotaline, and RV trabeculae were isolated from RV failing rats. Cross-bridge mechano-energetics were characterized by subjecting the trabeculae to two interventions: 1) force-length work-loop contractions over a range of afterloads while measuring heat output, followed by careful partitioning of heat components into activation heat and cross-bridge heat to separately assess mechanical efficiency and cross-bridge efficiency, and 2) sinusoidal-perturbation of muscle length while trabeculae were actively contracting to interrogate cross-bridge dynamic stiffness. We found that reduced mechanical efficiency is correlated with increased passive stress, reduced shortening, and elevated activation heat. In contrast, the thermodynamics, specifically the efficiency of, and the stiffness characteristics of, cross bridges did not differ between the control and failing trabeculae and were not correlated with elevated passive stress or reduced shortening. We thus conclude that, despite diastolic dysfunction and mechanical inefficiency, cross-bridge stiffness and thermodynamics are unaffected in RV failure following pulmonary arterial hypertension.

NEW & NOTEWORTHY This study characterizes cross-bridge mechano-energetics and dynamic stiffness of right-ventricular trabeculae isolated from a rat model of pulmonary hypertensive right-ventricular failure. Failing trabeculae showed increased passive force but normal active force. Their lower mechanical efficiency is found to be driven by an increase in the energy expenditure arising from contractile activation. This does not reflect a change in their cross-bridge stiffness and efficiency.

Lack of right ventricular hypertrophy is associated with right heart failure in patients with left ventricular failure

Presence of right heart failure (RHF) is associated with a worse prognosis in patients with left ventricular failure (LVF). While the cause of RHF secondary to LVF is multifactorial, an increased right ventricular (RV) afterload is believed as the major cause of RHF. However, data are scarce on the adaptive responses of the RV in patients with LVF. Our aim was to understand the relationship of right ventricular hypertrophy (RVH) with RHF and RV systolic and diastolic properties in patients with LVF. 55 patients with a left ventricular ejection fraction of 40% or less were included in the present study. A comprehensive two-dimensional transthoracic echocardiographic examination was done to all participants. 12 patients (21.8%) had RHF, and patients with RHF had a significantly lower right ventricular free wall thickness (RVFWT) as compared to patients without RHF (5.3 ± 1.7 mm vs. 6.6 ± 0.9 mm, p = 0.02) and the difference remained statistically significant after adjusting for confounders (Δx̅:1.34 mm, p = 0.002). RVFWT had a statistically significant correlation with tricuspid annular plane systolic excursion (r = 0.479, p < 0.001) and tricuspid annular lateral systolic velocity (r = 0.360, p = 0.007), but not with the indices of the RV diastolic function. None of the patients with concentric RVH had RHF, while 22.2% of patients with eccentric RVH and 66.7% of patients without RVH had RHF (p < 0.01 as compared to patients with concentric RVH). In patients with left ventricular systolic dysfunction, absence of RVH was associated with worse RV systolic performance and a significantly higher incidence of RHF.

Predicting the Severity and Outcome of Persistent Pulmonary Hypertension of the Newborn Using New Echocardiography Parameters

OBJECTIVE

To examine echocardiographic (ECHO) parameters correlation with clinical severity indices, Alveolar- arterial gradient (A-a gradient), oxygenation index (OI) and clinical outcomes in newborns with persistent pulmonary hypertension of the newborn (PPHN).

STUDY DESIGN

Retrospective cohort study of 67 subjects, >35 weeks' gestation with the diagnosis of PPHN admitted to the University of Kentucky neonatal intensive care unit (NICU) between September 2014 and December 2016.

RESULTS

High left ventricular end-systolic eccentricity index (EIs) correlates with the overall clinical severity of PPHN as it is associated with higher A-a gradient and OI (p=0.0003 and p<0.0001, respectively). Elevated EIs was also predictive for the use of inhaled nitric oxide (iNO) and extracorporeal membrane oxygenation (ECMO) (p=0.0004 and p<0.0001, respectively). EIs value of >1.38 provides cutoff value as an objective marker for the need for ECMO.

CONCLUSION

EIs can be used to assess clinical severity and outcomes and should be reported routinely. Further studies are warranted to confirm these results.

The right ventricle under pressure: Anatomy and imaging in sickness and health

The right ventricle (RV) is an important structure which serves a multitude of vital physiological functions in health. For many years, the left ventricle has dominated the focus of understanding in both biology and pathophysiology and the RV was felt to be more of a passive structure which rarely had an effect on disease states. However, it is increasingly recognised that the RV is essential to the homoeostasis of normal physiology and disturbances in RV structure and function have a substantial effect on patient outcomes. Indeed, the prognosis of diseases of lung diseases affecting the pulmonary vasculature and left heart disease is intimately linked to the function of the right ventricle. This review sets out to describe the developmental and anatomical complexities of the right ventricle while exploring the modern techniques employed to image and understand its function from a clinical perspective.

Association between Right Ventricular Function and Exercise Capacity in Patients with Chronic Heart Failure

Background: The association between right ventricular function and exercise capacity in patients with chronic heart failure remains uncertain. Several studies very recently mentioned the association between right ventricular reserve and exercise capacity, whereas the implication of tricuspid annular plane systolic excursion (TAPSE) remains uninvestigated. We aimed to assess the impact of TAPSE on exercise capacity in cardiac rehabilitation candidates. Methods: Data from patients with chronic heart failure who received cardiopulmonary exercise tests and transthoracic echocardiography prior to cardiac rehabilitation were retrospectively collected, and their association was investigated. Results: A total of 169 patients with chronic heart failure (70.3 ± 11.7 years old, 74.6% men) were included. Tertiled tricuspid annular plane systolic excursion significantly stratified anaerobic threshold (10.2 ± 2.2, 11.4 ± 2.2, and 12.2 ± 2.8 mm; p < 0.01) and peak oxygen consumption (15.9 ± 4.5, 18.3 ± 5.3, and 19.8 ± 5.6 mm; p < 0.01). In the multivariate logistic regression analyses, TAPSE was an independent factor associated with anaerobic threshold and peak oxygen consumption (p < 0.05 for both). Conclusions: Right ventricular impairment was associated with reduced exercise capacity in patients with chronic heart failure. Such knowledge would be useful to estimate patients’ exercise capacity and prescribe cardiac rehabilitation. Its longitudinal association and clinical implication need further studies.

Characterization and clinical significance of biventricular mechanics in patients with systemic lupus erythematosus by 3T cardiovascular magnetic resonance tissue tracking

BACKGROUND

Detecting impaired left ventricle (LV) or right ventricle (RV) mechanics could aid in fully understanding the process of cardiac involvement in patients with systemic lupus erythematosus (SLE). This study aimed to evaluate biventricular strain parameters derived from cardiac magnetic resonance (CMR) tissue tracking in SLE patients and their association with other clinical variables.

METHODS

A group of 47 SLE patients and 27 healthy controls were enrolled and underwent CMR examination, including cine and late gadolinium enhancement (LGE) imaging. Aside from RV strain parameters in the radial direction, biventricular global peak strain and peak systolic/diastolic global strain rate in radial, circumferential, and longitudinal directions were assessed for each participant. Multivariate linear regression analysis was used to analyze the factors related to the biventricular strain parameters. Receiver operating characteristic (ROC) analysis was used to identify RV dysfunction.

RESULTS

Compared with the controls, part of the biventricular strain parameters in the SLE subgroup with preserved ejection fraction (EF) were impaired, which was more significant in the SLE subgroup with reduced EF (all P<0.05). The SLE patients with RV dysfunction (15/47) included patients with LV dysfunction (8/47). The RVEF was associated with impaired LV global peak strain and peak diastolic strain rate in the SLE patients (absolute value of β=0.406-0.715, all P<0.05). The LV LGE in SLE patients (12/47) was associated with LV global longitudinal peak strain and peak diastolic global longitudinal strain rate (β=0.378 and -0.342; all P<0.05). There were independent correlations between pulmonary arterial hypertension and RV global longitudinal peak strain, anti-ribonucleoprotein (RNP) antibody and RV global circumferential peak strain, and pericardial effusion and RV peak diastolic global circumferential strain rate, respectively (β=0.319, 0.359, and -0.285, respectively; all P<0.05). The LV global longitudinal peak strain had greater diagnostic accuracy for RV dysfunction RV dysfunction [area under curve (AUC): 0.933, cut-off value: -13.38%).

CONCLUSIONS

Biventricular strain parameters derived from CMR are sensitive markers of subclinical ventricular function impairment before EF reduction at an early stage of SLE. Biventricular strain analysis could be considered for inclusion in early cardiac functional assessment in SLE patients, particularly LV global longitudinal peak strain, which might assist in therapeutic decision-making and disease monitoring.

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.

Global and regional right ventricular mechanics in repaired tetralogy of Fallot with chronic severe pulmonary regurgitation: a three-dimensional echocardiography study

BACKGROUND

Data about the right ventricular (RV) mechanics adaptation to volume overload in patients with repaired tetralogy of Fallot (rToF) are limited. Accordingly, we sought to assess the mechanics of the functional remodeling occurring in the RV of rToF with severe pulmonary regurgitation.

METHODS

We used three-dimensional transthoracic echocardiography (3DTE) to obtain RV data sets from 33 rToF patients and 30 age- and sex- matched controls. A 3D mesh model of the RV was generated, and RV global and regional longitudinal (LS) and circumferential (CS) strain components, and the relative contribution of longitudinal (LEF), radial (REF) and anteroposterior (AEF) wall motion to global RV ejection fraction (RVEF) were computed using the ReVISION method.

RESULTS

Corresponding to decreased global RVEF (45 ± 6% vs 55 ± 5%, p < 0.0001), rToF patients demonstrated lower absolute values of LEF (17 ± 4 vs 28 ± 4), REF (20 ± 5 vs 25 ± 4) and AEF (17 ± 5 vs 21 ± 4) than controls (p < 0.01). However, only the relative contribution of LEF to global RVEF (0.39 ± 0.09 vs 0.52 ± 0.05, p < 0.0001) was significantly decreased in rToF, whereas the contribution of REF (0.45 ± 0.08 vs 0.46 ± 0.04, p > 0.05) and AEF (0.38 ± 0.09 vs 0.39 ± 0.04, p > 0.05) to global RVEF was similar to controls. Accordingly, rToF patients showed lower 3D RV global LS (-16.94 ± 2.9 vs -23.22 ± 2.9, p < 0.0001) and CS (-19.79 ± 3.3 vs -22.81 ± 3.5, p < 0.01) than controls. However, looking at the regional RV deformation, the 3D CS was lower in rToF than in controls only in the basal RV free-wall segment (p < 0.01). 3D RV LS was reduced in all RV free-wall segments in rToF (p < 0.0001), but similar to controls in the septum (p > 0.05).

CONCLUSIONS

3DTE allows a quantitative evaluation of the mechanics of global RVEF. In rToF with chronic volume overload, the relative contribution of the longitudinal shortening to global RVEF is affected more than either the radial or the anteroposterior components.

A randomized controlled trial of enhancing hypoxia-mediated right cardiac mechanics and reducing afterload after high intensity interval training in sedentary men

Hypoxic exposure increases right ventricular (RV) afterload by triggering pulmonary hypertension, with consequent effects on the structure and function of the RV. Improved myocardial contractility is a critical circulatory adaptation to exercise training. However, the types of exercise that enhance right cardiac mechanics during hypoxic stress have not yet been identified. This study investigated how high-intensity interval training (HIIT) and moderate-intensity continuous training (MICT) influence right cardiac mechanics during hypoxic exercise A total of 54 young and healthy sedentary males were randomly selected to engage in either HIIT (3-min intervals at 40% and 80% of oxygen uptake reserve, n = 18) or MICT (sustained 60% of oxygen uptake reserve, n = 18) for 30 min/day and 5 days/week for 6 weeks or were included in a control group (CTL, n = 18) that did not engage in any exercise. The primary outcome was the change in right cardiac mechanics during semiupright bicycle exercise under hypoxic conditions (i.e., 50 watts under 12% FiO₂ for 3 min) as measured by two-dimensional speckle tracking echocardiography.: After 6 weeks of training, HIIT was superior to MICT in improving maximal oxygen consumption (VO_2max). Furthermore, the HIIT group showed reduced pulmonary vascular resistance (PVR, pre-HIIT:1.16 ± 0.05 WU; post-HIIT:1.05 ± 0.05 WU, p < 0.05) as well as an elevated right ventricular ejection fraction (RVEF, pre-HIIT: 59.5 ± 6.0%; post-HIIT: 69.1 ± 2.8%, p < 0.05) during hypoxic exercise, coupled with a significant enhancement of the right atrial (RA) reservoir and conduit functions. HIIT is superior to MICT in dilating RV chamber and reducing radial strain but ameliorating radial strain rate in either systole (post-HIIT: 2.78 ± 0.14 s^-1; post-MICT: 2.27 ± 0.12 s^-1, p < 0.05) or diastole (post-HIIT: - 2.63 ± 0.12 s^-1; post-MICT: - 2.36 ± 0.18 s^-1, p < 0.05). In the correlation analysis, the changes in RVEF were directly associated with improved RA reservoir (r = 0.60, p < 0.05) and conduit functions (r = 0.64, p < 0.01) but inversely associated with the change in RV radial strain (r = - 0.70, p < 0.01) and PVR (r = - 0.70, p < 0.01) caused by HIIT. HIIT is superior to MICT in improving right cardiac mechanics by simultaneously increasing RA reservoir and conduit functions and decreasing PVR during hypoxic exercise.

Partitioning the Right Ventricle Into 15 Segments and Decomposing Its Motion Using 3D Echocardiography-Based Models: The Updated ReVISION Method

Three main mechanisms contribute to global right ventricular (RV) function: longitudinal shortening, radial displacement of the RV free wall (bellows effect), and anteroposterior shortening (as a consequence of left ventricular contraction). Since the importance of these mechanisms may vary in different cardiac conditions, a technology being able to assess their relative influence on the global RV pump function could help to clarify the pathophysiology and the mechanical adaptation of the chamber. Previously, we have introduced our 3D echocardiography (3DE)-based solution-the Right VentrIcular Separate wall motIon quantificatiON (ReVISION) method-for the quantification of the relative contribution of the three aforementioned mechanisms to global RV ejection fraction (EF). Since then, our approach has been applied in several clinical scenarios, and its strengths have been demonstrated in the in-depth characterization of RV mechanical pattern and the prognostication of patients even in the face of maintained RV EF. Recently, various new features have been implemented in our software solution to enable the convenient, standardized, and more comprehensive analysis of RV function. Accordingly, in our current technical paper, we aim to provide a detailed description of the latest version of the ReVISION method with special regards to the volumetric partitioning of the RV and the calculation of longitudinal, circumferential, and area strains using 3DE datasets. We also report the results of the comparison between 3DE- and cardiac magnetic resonance imaging-derived RV parameters, where we found a robust agreement in our advanced 3D metrics between the two modalities. In conclusion, the ReVISION method may provide novel insights into global and also segmental RV function by defining parameters that are potentially more sensitive and predictive compared to conventional echocardiographic measurements in the context of different cardiac diseases.

Ventricular systolic dysfunction with and without altered myocardial contractility: Clinical value of echocardiography for diagnosis and therapeutic decision-making

The inability of one of the two or both ventricles to contract normally and expel sufficient blood to meet the functional demands of the body results from a complex interplay between intrinsic abnormalities and extracardiac factors that limit ventricular pump function and is a major cause for heart failure (HF). Even if impaired myocardial contractile function was the primary cause for ventricular dysfunction, with the progression of systolic dysfunction, additionally developed diastolic dysfunction can also contribute to the severity of HF. Although at the first sight, the diagnosis of systolic HF appears quite easy because it is usually defined by reduction of the ejection fraction (EF), in reality this issue is far more complex because ventricular pumping performance depends not only on myocardial contractility, but also largely on loading conditions (preload and afterload), being also influenced by valvular function, ventricular interdependence, pericardial constraint, synchrony of ventricular contrac-tion and heart rhythm. Conventional echocardiography (ECHO) combined with new imaging techniques such as tissue Doppler and tissue tracking can detect early subclinical alteration of ventricular systolic function. However, no single ECHO parameter reveals alone the whole picture of systolic dysfunction. Multiparametric ECHO evaluation and the use of integrative approaches using ECHO-parameter combinations which include also the ventricular loading conditions appeared particularly useful especially for differentiation between primary (myocardial damage-induced) and secondary (hemodynamic overload-induced) systolic dysfunction. This review summarizes the available evidence on the usefulness and limitations of comprehensive evaluation of LV and RV systolic function by using all the currently available ECHO techniques.

Mechanics of right ventricular dysfunction in pulmonary arterial hypertension and heart failure with preserved ejection fraction

Right ventricular (RV) dysfunction is the most important determinant of survival in patients with pulmonary hypertension (PH). The manifestations of RV dysfunction not only include changes in global RV systolic function but also abnormalities in the pattern of contraction and synchrony. The effects of PH on the right ventricle have been mainly studied in patients with pulmonary arterial hypertension (PAH). However, with the demographic shift towards an aging population, heart failure with preserved ejection fraction (HFpEF) has become an important etiology of PH in recent years. There are significant differences in RV mechanics, function and adaptation between patients with PAH and HFpEF (with or without PH), which are related to different patterns of remodeling and dysfunction. Due to the unique features of the RV chamber, its connection with the main pulmonary artery and the pulmonary circulation, an understanding of the mechanics of RV function and its clinical significance is mandatory for both entities. In this review, we describe the mechanics of the pressure overloaded right ventricle. We review the different mechanical components of RV dysfunction and ventricular dyssynchrony, followed by insights via analysis of pressure-volume loop, energetics and novel blood flow patterns, such as vortex imaging. We conduct an in-depth comparison of prevalence and characteristics of RV dysfunction in HFpEF and PAH, and summarize key outcome studies. Finally, we provide a perspective on needed and expected future work in the field of RV mechanics.

Emerging role of cardiovascular magnetic resonance imaging in the management of pulmonary hypertension

Pulmonary hypertension (PH) is a clinical condition characterised by elevation of pulmonary arterial pressure (PAP) above normal range due to various aetiologies. While cardiac right-heart catheterisation (RHC) remains the gold standard and mandatory for establishing the diagnosis of PH, noninvasive imaging of the heart plays a central role in the diagnosis and management of all forms of PH. Although Doppler echocardiography (ECHO) can measure a range of haemodynamic and anatomical variables, it has limited utility for visualisation of the pulmonary artery and, oftentimes, the right ventricle. Cardiovascular magnetic resonance (CMR) provides comprehensive information about the anatomical and functional aspects of the pulmonary artery and right ventricle that are of prognostic significance for assessment of long-term outcomes in disease progression. CMR is suited for serial follow-up of patients with PH due to its noninvasive nature, high sensitivity to changes in anatomical and functional parameters, and high reproducibility. In recent years, there has been growing interest in the use of CMR derived parameters as surrogate endpoints for early-phase PH clinical trials. This review will discuss the role of CMR in the diagnosis and management of PH, including current applications and future developments, in comparison to other existing major imaging modalities.

Cardiac MRI in Pulmonary Hypertension: From Magnet to Bedside

Pulmonary hypertension (PH) is a disease characterized by progressive rise of pulmonary artery (PA) pressure, which can lead to right ventricular (RV) failure. It is usually diagnosed late because of the nonspecificity of its symptoms. RV performance and adaptation to an increased afterload, reflecting the interaction of the PA and RV as a morphofunctional unit, constitute a critical determinant of morbidity and mortality in these patients. Therefore, early detection of dysfunction may prevent treatment failure. Cardiac MRI constitutes one of the most complete diagnostic modalities for diagnosing PH. It allows evaluation of the morphology and hemodynamics of the PA and RV. Several cine steady-state free-precession (SSFP)-derived parameters (indexed RV end-diastolic volume or RV systolic volume) and phase-contrast regional area change have been suggested as powerful biomarkers for prognosis and treatment. Recently, new cardiac MRI sequences have been added to clinical protocols for PH evaluation, providing brand-new information. Strain analysis with myocardial feature tracking can help detect early RV dysfunction, even with preserved ejection fraction. Four-dimensional flow cardiac MRI can enhance assessment of advanced RV and PA hemodynamics. Late gadolinium enhancement (LGE) imaging may allow detection of replacement fibrosis in PH patients, which is associated with poor outcome. T1 mapping may help detect interstitial fibrosis, even with normal LGE imaging results. The authors analyze the imaging workup of PH with a focus on the role of morphologic and functional cardiac MRI in diagnosis and management of PH, including some of the newer techniques. Online supplemental material is available for this article. ^©RSNA, 2020.

Importance of Nonlongitudinal Motion Components in Right Ventricular Function: Three-Dimensional Echocardiographic Study in Healthy Volunteers

BACKGROUND

Global right ventricular (RV) function is determined by the interplay of different motion components related to the myofiber architecture, and the relative importance of these components is still not thoroughly characterized. The aims of this study were to quantify the relative contributions of longitudinal, radial, and anteroposterior motion components to global RV function and to examine their determining factors in a large cohort of healthy volunteers using three-dimensional echocardiography.

METHODS

Three hundred healthy adults with a balanced age range and an equal sex distribution were investigated at two centers. A three-dimensional mesh model of the right ventricle was generated, and its motion was decomposed along the three anatomically relevant axes. Multiplicative relative contributions were measured by dividing the ejection fraction (EF) values generated by shortening in the longitudinal, radial, and anteroposterior directions by global RV EF (longitudinal EF index [LEFi], radial EF index [REFi], and anteroposterior EF index, respectively). The circumferential contribution was defined as shortening in the radial and anteroposterior directions, omitting only longitudinal shortening.

RESULTS

Circumferential EF index was markedly higher compared with LEFi (79 ± 7% vs 47 ± 9%, P < .001). LEFi (47 ± 9%) and anteroposterior EF index (49 ± 7%) were found to be similar in the pooled population, whereas REFi (44 ± 10%) was lower (P < .001). In younger individuals (20-39 years of age), the relative contribution of longitudinal shortening was significantly higher compared with the radial component; however, in the older age groups, LEFi and REFi were comparable. Age, body surface area, heart rate, and RV end-diastolic volume were independent predictors of LEFi and REFi, but all with opposite effects on the two motion directions.

CONCLUSIONS

In contrast to the traditional viewpoint, the contributions of the radial and anteroposterior motion directions may be of comparable significance with that of longitudinal shortening in determining global RV function. Standard parameters referring only to longitudinal shortening of the right ventricle may be inadequate to characterize RV function thoroughly.

Right ventricular function parameters in pulmonary hypertension: echocardiography vs. cardiac magnetic resonance

BACKGROUND

Right ventricular (RV) function is a major determinant of outcome in patients with pulmonary hypertension. Cardiac magnetic resonance (CMR) is gold standard to assess RV ejection fraction (RVEF_CMR), however this is a crude measure. New CMR measures of RV function beyond RVEF_CMR have emerged, such as RV lateral atrio-ventricular plane displacement (AVPD_lat), maximum emptying velocity (S'_CMR), RV fractional area change (FAC_CMR) and feature tracking of the RV free wall (FWS_CMR). However, it is not fully elucidated if these CMR measures are in parity with the equivalent echocardiography-derived measurements: tricuspid annular plane systolic excursion (TAPSE), S'-wave velocity (S'_echo), RV fractional area change (FAC_echo) and RV free wall strain (FWS_echo). The aim of this study was to compare regional RV function parameters derived from CMR to their echocardiographic equivalents in patients with pulmonary hypertension and to RVEF_CMR.

METHODS

Fifty-five patients (37 women, 62 ± 15 years) evaluated for pulmonary hypertension underwent CMR and echocardiography. AVPD_lat, S'_CMR, FAC_CMR and FWS_CMR from cine 4-chamber views were compared to corresponding echocardiographic measures and to RVEF_CMR delineated in cine short-axis stack.

RESULTS

A strong correlation was demonstrated for FAC whereas the remaining measurements showed moderate correlation. The absolute bias for S' was 2.4 ± 3.0 cm/s (relative bias 24.1 ± 28.3%), TAPSE/AVPD_lat 5.5 ± 4.6 mm (33.2 ± 25.2%), FWS 4.4 ± 5.8% (20.2 ± 37.5%) and for FAC 5.1 ± 8.4% (18.5 ± 32.5%). In correlation to RVEF_CMR, FAC_CMR and FWS_echo correlated strongly, FAC_echo, AVPD_lat, FWS_CMR and TAPSE moderately, whereas S' had only a weak correlation.

CONCLUSION

This study has demonstrated a moderate to strong correlation of regional CMR measurements to corresponding echocardiographic measures. However, biases and to some extent wide limits of agreement, exist between the modalities. Consequently, the equivalent measures are not interchangeable at least in patients with pulmonary hypertension. The echocardiographic parameter that showed best correlation with RVEF_CMR was FWS_echo. At present, FAC_echo and FWS_echo as well as RVEF_CMR are the preferred methods to assess and follow up RV function in patients with pulmonary hypertension. Future investigations of the CMR right ventricular measures, beyond RVEF, are warranted.

Right Ventricular Global Longitudinal Strain and Outcomes in Heart Failure with Preserved Ejection Fraction

BACKGROUND

Right ventricular (RV) strain has emerged as an accurate tool for RV function assessment and is a powerful predictor of survival in patients with heart failure with reduced ejection fraction. However, its prognostic impact in patients with heart failure with preserved ejection fraction (HFpEF) remains unclear. The aim of this study was to compare the prognostic value of RV global longitudinal strain (RVGLS) by two-dimensional speckle-tracking echocardiographic (STE) imaging in patients with HFpEF against conventional RV function parameters.

METHODS

Patients with HFpEF were prospectively recruited, and 149 of 183 (81%) with analyzable STE RVGLS images constituted the final study population (mean age, 78 ± 9 years; 61% women), compared with 28 control subjects of similar age and sex. All control subjects and 120 patients also underwent cardiac magnetic resonance imaging. Patients were followed up for a primary end point of all-cause mortality and first heart failure hospitalization, and Cox regression analysis was performed.

RESULTS

Mean STE RVGLS was significantly altered in patients with HFpEF compared with control subjects (-21.7 ± 4.9% vs -25.9 ± 4.2%, P < .001). STE RVGLS correlated well with RV ejection fraction by cardiac magnetic resonance (r = -0.617, P < .001). Twenty-eight patients with HFpEF (19%) had impaired STE RVGLS (>-17.5%). During a mean follow-up period of 30 ± 9 months, 91 patients with HFpEF (62%) reached the primary end point. A baseline model was created using independent predictors of the primary end point: New York Heart Association functional class III or IV, hemoglobin level, estimated glomerular filtration rate, and the presence of moderate or severe tricuspid regurgitation. Impaired STE RVGLS provided significant additional prognostic value over this model (χ² to enter = 7.85, P = .005). Impaired tricuspid annular plane systolic excursion and fractional area change, however, did not.

CONCLUSIONS

In patients with HFpEF, impaired RVGLS has strong prognostic value. STE RVGLS should be considered for systematic evaluation of RV function to identify patients at high risk for adverse events.

Right ventricular mechanical pattern in health and disease: beyond longitudinal shortening

Right ventricular (RV) function has proven to be a prognostic factor in heart failure with reduced and preserved ejection fraction and in pulmonary hypertension. RV function is also a cornerstone in the management of novel clinical issues, such as mechanical circulatory support devices or grown-up congenital heart disease patients. Despite the notable amount of circumferentially oriented myofibers in the subepicardial layer of the RV myocardium, the non-longitudinal motion directions are often neglected in the everyday assessment of RV function by echocardiography. However, the complex RV contraction pattern incorporates different motion components along three anatomically relevant axes: longitudinal shortening with traction of the tricuspid annulus towards the apex, radial motion of free wall often referred as the “bellows effect”, and anteroposterior shortening of the chamber by stretching the free wall over the septum. Advanced echocardiographic techniques, such as speckle-tracking and 3D echocardiography allow an in-depth characterization of RV mechanical pattern, providing better understanding of RV systolic and diastolic function. In our current review, we summarize the existing knowledge regarding RV mechanical adaptation to pressure- and/or volume-overloaded states and also other physiologic or pathologic conditions.

Regional right ventricular longitudinal systolic strain for detection of severely impaired right ventricular performance in pulmonary hypertension

OBJECTIVES

Right ventricular (RV) function is identified as a key determinant of the outcome in patients with pulmonary hypertension (PH). Several studies have assessed the role of peak global longitudinal RV strain in PH patients; however, less emphasis was given to the RV regional longitudinal strain. The aim of this study was to evaluate the regional RV systolic strain in PH patients and investigate the relationship of these parameters with the severity of PH.

METHODS

RV regional longitudinal peak systolic strain (LPSS) and strain rate (LPSSR) were measured using speckle tracking echocardiography on 100 patients with PH who underwent right heart catheterization, and 29 control subjects. Severe PH was identified by a decreased cardiac index (CI) (<2.0 L/min/m² ).

RESULTS

LPSS and LPSSR of the RV free wall were significantly lower in PH patients than control subjects, especially when comparing the basal and mid regions (P < .001). When comparing severe PH and nonsevere PH, basal and mid LPSS and LPSSR were significantly lower (P < .001). RV free wall mid LPSSR correlated with CI (r = -.703, P < .001). In the multiple logistic regression analysis, mid LPSSR was identified as an independent predictor of severe PH (odds ratio 1.82; 95% confidential interval 1.39-2.40; P < .001). In the receiver operating characteristics curve analysis, a cutoff value of mid LPSSR of -0.92 s^-1 predicted severe PH, with a sensitivity and specificity of 75.0% and 93.7%, respectively (AUC = 0.889, P < .001).

CONCLUSIONS

RV free wall mid longitudinal peak systolic strain rate may be useful for the detection of severely impaired RV performance in PH.

Right ventricular mechanical pattern in patients undergoing mitral valve surgery: a predictor of post-operative dysfunction?

Aims

The PREPARE‐MVR study (PRediction of Early PostoperAtive Right vEntricular failure in Mitral Valve Replacement/Repair patients) sought to investigate the alterations of right ventricular (RV) contraction pattern in patients undergoing mitral valve replacement/repair (MVR) and to explore the associations between pre‐operative RV mechanics and early post‐operative RV dysfunction (RVD).

Methods and results

We prospectively enrolled 42 patients (63 ± 11 years, 69% men) undergoing open‐heart MVR. Transthoracic three‐dimensional (3D) echocardiography was performed pre‐operatively, at intensive care unit discharge, and 6 months after surgery. The 3D model of the RV was reconstructed, and RV ejection fraction (RVEF) was calculated. We decomposed the motion of the ventricle to compute longitudinal ejection fraction (LEF) and radial ejection fraction (REF). Pulmonary artery catheterization was performed to monitor RV stroke work index (RVSWi). RVEF was slightly decreased after MVR [52 (50–55) vs. 51 (46–54)%; P = 0.001], whereas RV contraction pattern changed notably. Before MVR, the longitudinal shortening was the main contributor to global systolic RV function [LEF/RVEF vs. REF/RVEF; 0.53 (0.47–0.58) vs. 0.33 (0.22–0.42); P < 0.001]. Post‐operatively, the radial motion became dominant [0.33 (0.28–0.43) vs. 0.46 (0.37–0.51); P = 0.004]. However, this shift was temporary as 6 months later the two components contributed equally to global RV function [0.44 (0.38–0.50) vs. 0.41 (0.36–0.49); P = 0.775]. Pre‐operative LEF was an independent predictor of post‐operative RVD defined as RVSWi < 300 mmHg⋅mL/m² [OR = 1.33 (95% CI: 1.08–1.77), P < 0.05].

Conclusions

MVR induces a significant shift in the RV mechanical pattern. Advanced indices of RV mechanics are associated with invasively measured parameters of RV contractility and may predict post‐operative RVD.

Echocardiographic assessment of the right heart in adults: a practical guideline from the British Society of Echocardiography

The structure and function of the right side of the heart is influenced by a wide range of physiological and pathological conditions. Quantification of right heart parameters is important in a variety of clinical scenarios including diagnosis, prognostication, and monitoring response to therapy. Although echocardiography remains the first-line imaging investigation for right heart assessment, published guidance is relatively sparse in comparison to that for the left ventricle. This guideline document from the British Society of Echocardiography describes the principles and practical aspects of right heart assessment by echocardiography, including quantification of chamber dimensions and function, as well as assessment of valvular function. While cut-off values for normality are included, a disease-oriented approach is advocated due to the considerable heterogeneity of structural and functional changes seen across the spectrum of diseases affecting the right heart. The complex anatomy of the right ventricle requires special considerations and echocardiographic techniques, which are set out in this document. The clinical relevance of right ventricular diastolic function is introduced, with practical guidance for its assessment. Finally, the relatively novel techniques of three-dimensional right ventricular echocardiography and right ventricular speckle tracking imaging are described. Despite these techniques holding considerable promise, issues relating to reproducibility and inter-vendor variation have limited their clinical utility to date.

Transverse Right Ventricle Strain and Strain Rate Assessed by 2-Dimensional Speckle Tracking Echocardiography in Dogs with Pulmonary Hypertension

Right ventricular (RV) strain analysis using 2-dimensional speckle tracking echocardiography (2D STE) permits practitioners to assess regional and global deformation of the myocardium. Recently, assessment of the longitudinal right ventricle (RV) strain and strain rate using 2D STE has been reported in dogs. Although longitudinal deformation is the dominant component of the RV systole, RV myocardial fibers of the superficial layer are oriented circumferentially and these contribute to the RV pump function (radial deformation). Because this strain component has not been investigated in dogs, we have assessed radial RV strain and strain rate using 2D STE in healthy dogs and dogs with pulmonary hypertension (PH). We have recruited 74 dogs (40 healthy dogs and 34 dogs with PH) in which we have analyzed radial RV free wall strain and strain rate using XstrainTM software. We have used the left apical 4-chamber view optimized for the RV for analysis of the radial strain and strain rate variables (XstrainTM software denoted radial strain as "transverse"). Seven dogs were excluded during the analysis for low quality images. Transverse strain and strain rate obtained in healthy dogs showed no relationship with heart rate, body weight or age (r2 < 0.09 and p > 0.05 for all variables). Moreover, no relationship between transverse strain/strain rate variables and left atrial-to-aortic ratios was observed (r2 < 0.06 and p = 0.2, for both). Transverse strain and strain rate obtained in dogs with PH, showed weak negative relationships with tricuspid regurgitation velocity (r2 < 0.25 and p = 0.006, for both). Transverse RV strain and strain rate using 2D STE is feasible in most dogs and decrease with worsening of the PH, but these advanced echocardiographic indices do not help in identifying dogs with PH.

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

BACKGROUND

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

Validation of the Tricuspid Annular Plane Systolic Excursion/Systolic Pulmonary Artery Pressure Ratio for the Assessment of Right Ventricular-Arterial Coupling in Severe Pulmonary Hypertension

BACKGROUND

The ratios of tricuspid annular plane systolic excursion (TAPSE)/echocardiographically measured systolic pulmonary artery pressure (PASP), fractional area change/invasively measured mean pulmonary artery pressure, right ventricular (RV) area change/end-systolic area, TAPSE/pulmonary artery acceleration time, and stroke volume/end-systolic area have been proposed as surrogates of RV-arterial coupling. The relationship of these surrogates with the gold standard measure of RV-arterial coupling (invasive pressure-volume loop-derived end-systolic/arterial elastance [Ees/Ea] ratio) and RV diastolic stiffness (end-diastolic elastance) in pulmonary hypertension remains incompletely understood. We evaluated the relationship of these surrogates with invasive pressure-volume loop-derived Ees/Ea and end-diastolic elastance in pulmonary hypertension.

METHODS

We performed right heart echocardiography and cardiac magnetic resonance imaging 1 day before invasive measurement of pulmonary hemodynamics and single-beat RV pressure-volume loops in 52 patients with pulmonary arterial hypertension or chronic thromboembolic pulmonary hypertension. The relationships of the proposed surrogates with Ees/Ea and end-diastolic elastance were evaluated by Spearman correlation, multivariate logistic regression, and receiver operating characteristic analyses. Associations with prognosis were evaluated by Kaplan-Meier analysis.

RESULTS

TAPSE/PASP, fractional area change/mean pulmonary artery pressure, RV area change/end-systolic area, and stroke volume/end-systolic area but not TAPSE/pulmonary artery acceleration time were correlated with Ees/Ea and end-diastolic elastance. Of the surrogates, only TAPSE/PASP emerged as an independent predictor of Ees/Ea (multivariate odds ratio: 18.6; 95% CI, 0.8-96.1; P=0.08). In receiver operating characteristic analysis, a TAPSE/PASP cutoff of 0.31 mm/mm Hg (sensitivity: 87.5% and specificity: 75.9%) discriminated RV-arterial uncoupling (Ees/Ea <0.805). Patients with TAPSE/PASP <0.31 mm/mm Hg had a significantly worse prognosis than those with higher TAPSE/PASP.

CONCLUSIONS

Echocardiographically determined TAPSE/PASP is a straightforward noninvasive measure of RV-arterial coupling and is affected by RV diastolic stiffness in severe pulmonary hypertension.

CLINICAL TRIAL REGISTRATION

URL: https://www.clinicaltrials.gov. Unique identifier: NCT03403868.