RV-pulmonary arterial coupling predicts outcome in patients referred for pulmonary hypertension

The Right Ventricular-Arterial Compliance Index: A Novel Hemodynamic Marker to Predict Right Heart Failure Following Left Ventricular Assist Device

The development of right heart failure (RHF) in patients with advanced heart failure following left ventricular assist device (LVAD) implantation remains difficult to predict. We proposed a novel composite hemodynamic index-the right ventricular-arterial compliance index (RVACi), derived from pulmonary artery pulse pressure (PAPP), ejection time (ET), heart rate (HR), and cardiac output (CO), with and expressed as mm Hg·s/L. We then conducted a retrospective, single-center analysis comparing the predictive value of RVACi for the development of RHF or unplanned right ventricular (RV) mechanical circulatory support following LVAD implantation against existing hemodynamic indices. One hundred patients were enrolled after screening 232 patients over a 10 year period, with 74 patients having complete hemodynamic data for RVACi calculation. There was good correlation between pulmonary arterial capacitance (R² = 0.48) and pulmonary vascular resistance (R² = 0.63) with RVACi, but not RV stroke work index or pulmonary artery pulsatility index. Reduced baseline RVACi (52 ± 23 vs. 92 ± 55 mm Hg·s/L; p = 0.02) was the strongest hemodynamic predictor of unplanned RV mechanical circulatory support requirement in patients following LVAD insertion. Composite pulsatile hemodynamic indices including RVACi may provide additional insight over existing hemodynamic indices for the prediction of RHF and need for RV mechanical circulatory support.

Echocardiographic Predictors of Readiness for Double Switch Operation and Postoperative Ejection Fraction in Patients With Congenitally Corrected Transposition of the Great Arteries Undergoing Left Ventricular Retraining

BACKGROUND

In patients with congenitally corrected transposition of the great arteries (ccTGA), assessment of readiness for the double switch operation (DSO) after pulmonary arterial band (PAB) placement involves cardiac magnetic resonance imaging (cMRI) to measure left ventricular ejection fraction (LVEF) and mass and cardiac catheterization (catheterization) to assess the ratio of left ventricular to right ventricular pressure (LV:RVp). The aims of this study were to describe the relationships between echocardiographic and catheterization and cMRI measures of readiness for DSO and to develop risk factors for left ventricular (LV) dysfunction after DSO on the basis of echocardiographic measures of ventricular-arterial coupling (VAC).

METHODS

Patients with ccTGA undergoing LV retraining at a DSO referral center were reviewed. LVEF measured by echocardiography was compared with that measured by cMRI, and LV:RVp measured by echocardiography was compared with that measured by catheterization using Bland-Altman analysis. The relationship between preoperative VAC markers and postoperative echocardiography was analyzed using ventricular end-systolic elastance (EES) and a novel marker consisting of the product of LVEF and LV:RVp (EFPR).

RESULTS

Thirty-one patients with 56 evaluations for DSO were included, 24 of whom underwent DSO. Echocardiographic LVEF correlated well with cMRI LVEF (r = 0.79), and Bland-Altman analysis slightly overestimated cMRI LVEF (mean difference, +3%). Echocardiographic LVEF had a moderate ability to identify normal cMRI LVEF (area under the curve, 0.80) and at an optimal cut point of echocardiographic LVEF threshold of 61%, there was 71% sensitivity and 76% specificity to detect cMRI LVEF ≥ 55%. Echocardiographic LV:RVp correlated well with LV/RVp by catheterization (r = 0.77) and slightly underestimated the catheterization value (mean difference, -0.11). Echocardiographic LV:RVp had a good ability to identify adequate LV:RVp by catheterization (area under the curve, 0.95) and at an optimal echocardiography cut point of 0.75 had 100% sensitivity and 85% specificity to detect a catheterization LV:RVp >0.9. Echocardiography-based criteria for DSO readiness (echocardiographic LVEF of 61% and LV:RVp of 0.75) demonstrated specificity of 97% and positive predictive value of 96% for published criteria of DSO readiness (cMRI LVEF of 55% and catheterization LV:RVp of 0.9). EES and EFPR correlated with post-DSO LVEF (ρ = 0.72 and ρ = 0.60, respectively). EFPR of 0.51 demonstrated 78% sensitivity and 100% specificity for post-DSO LV dysfunction (LVEF < 55%). Age at first PAB also strongly correlated with post-DSO LVEF (ρ = 0.75). No patient with first PAB at <1 year of age exhibited post-DSO LV dysfunction.

CONCLUSIONS

Echocardiographic measures of LVEF and LV:RVp are reliable indicators of reference standard modalities and can guide management during retraining. The preoperative VAC markers EES and EFPR may be useful markers of post-DSO LV dysfunction. Values of echocardiographic LV:RVp >0.75 are likely to meet pressure-generation criteria for DSO and should be considered for referral to catheterization and cMRI evaluation for DSO. PAB placement before 1 year of life may optimize LV outcomes in patients considered for DSO.

Clinical impact of novel CMR technology on patients with congenital heart disease. A scientific statement of the Association for European Pediatric and Congenital Cardiology (AEPC) and the European Association of Cardiovascular Imaging (EACVI) of the ESC

Cardiovascular magnetic resonance (CMR) imaging is recommended in patients with congenital heart disease (CHD) in clinical practice guidelines as the imaging standard for a large variety of diseases. As CMR is evolving, novel techniques are becoming available. Some of them are already used clinically, whereas others still need further evaluation. In this statement the authors give an overview of relevant new CMR techniques for the assessment of CHD. Studies with reference values for these new techniques are listed in the supplement.

Right Ventriculoarterial Coupling Surrogates and Long-Term Survival in LVAD Recipients: Results of the ASSIST-ICD Multicentric Registry

BACKGROUND

Prediction of outcomes remains an unmet need in candidates for LVADs. The development of right-heart failure portends an excess in mortality rates, but imaging parameters of right ventricular systolic function have failed to demonstrate a prognostic role. By integrating pulmonary pressure, right ventriculoarterial coupling could fill this gap.

METHODS

The ASSIST-ICD registry was used to test right ventriculoarterial coupling as a surrogate parameter at implantation for the prediction of all-cause mortality.

RESULTS

The ratio of the tricuspid annular-plane systolic excursion over the estimated systolic pulmonary pressure (TAPSE/sPAP) was not associated with long-term survival in univariate analysis (P = 0.89), nor was the pulmonary artery pulsatility index (PAPi) (P = 0.13). Conversely, the ratio of the right atrial pressure over the pulmonary capillary wedge pressure (RAP/PCWP) was associated with all-cause mortality (P < 0.01). After taking tricuspid regurgitation severity, LVAD indication, LVAD model, age, blood urea nitrogen levels, and pulmonary vascular resistance into account, RAP/PCWP remained associated with survival (HR 1.35 [1.10 - 1.65]; P < 0.01).

CONCLUSION

Among pre-implant RVAC surrogates, only RAP/PCWP was associated with long-term all-cause mortality in LVAD recipients. This association was independent of established risk factors.

Tricuspid regurgitation in pulmonary arterial hypertension: a right ventricular volumetric and functional analysis

BACKGROUND

The consequences of tricuspid regurgitation (TR) for right ventricular (RV) function and prognosis in pulmonary arterial hypertension (PAH) are poorly described and effects of tricuspid valve repair on the RV are difficult to predict.

METHODS

In 92 PAH patients with available cardiac magnetic resonance (CMR) studies, TR volume was calculated as the difference between RV stroke volume and forward stroke volume, i.e. pulmonary artery (PA) stroke volume. Survival was estimated from the time of the CMR scan to cardiopulmonary death or lung transplantation. In a subgroup, pressure-volume loop analysis including two-parallel elastances was applied to evaluate effective elastances, including net afterload (effective arterial elastance (E a)), forward afterload (effective pulmonary arterial elastance (E pa)) and backward afterload (effective tricuspid regurgitant elastance (E TR)). The effects of tricuspid valve repair were simulated using the online software package Harvi.

RESULTS

26% of PAH patients had a TR volume ≥30 mL. Greater TR volume was associated with increased N-terminal pro-brain natriuretic peptide (p=0.018), mean right atrial pressure (p<0.001) and RV end-systolic and -diastolic volume (both p<0.001). TR volume ≥30 mL was associated with a poor event-free survival (p=0.008). In comparison to E a, E pa correlated better with indices of RV dysfunction. Lower end-systolic elastance (E es) (p=0.002) and E TR (p=0.030), higher E pa (p=0.001) and reduced E es/E pa (p<0.001) were found in patients with a greater TR volume. Simulations predicted that tricuspid valve repair increases RV myocardial oxygen consumption in PAH patients with severe TR and low E es unless aggressive volume reduction is accomplished.

CONCLUSIONS

In PAH, TR has prognostic significance and is associated with low RV contractility and RV-PA uncoupling. However, haemodynamic simulations showed detrimental consequences of tricuspid valve repair in PAH patients with low RV contractility.

Right Ventricle-Pulmonary Artery Coupling in Patients Undergoing Cardiac Interventions

PURPOSE OF REVIEW

This review aims to summarize the fundamentals of RV-PA coupling, its non-invasive means of measurement, and contemporary understanding of RV-PA coupling in cardiac surgery, cardiac interventions, and congenital heart disease.

RECENT FINDINGS

The need for more accessible clinical means of evaluation of RV-PA coupling has driven researchers to investigate surrogates using cardiac MRI, echocardiography, and right-sided pressure measurements in patients undergoing cardiac surgery/interventions, as well as patients with congenital heart disease. Recent research has aimed to validate these alternative means against the gold standard, as well as establish cut-off values predictive of morbidity and/or mortality. This emerging evidence lays the groundwork for identifying appropriate RV-PA coupling surrogates and integrating them into perioperative clinical practice.

Physiological mechanisms behind respiratory variations in right atrial pressure in pulmonary hypertension

Impaired respiratory variation of right atrial pressure (RAP) in severe pulmonary hypertension (PH) suggests difficulty tolerating increased preload during inspiration. Our study explores whether this impairment links to specific factors: right ventricular (RV) diastolic function, elevated RV afterload, systolic RV function, or RV-pulmonary arterial (PA) coupling. We retrospectively evaluated respiratory RAP variation in all participants enrolled in the EXERTION study. Impaired respiratory variation was defined as end-expiratory RAP - end-inspiratory RAP ≤ 2 mm Hg. RV function and afterload were evaluated using conductance catheterization. Impaired diastolic RV function was defined as end-diastolic elastance (Eed) ≥ median (0.19 mm Hg/mL). Seventy-five patients were included; PH was diagnosed in 57 patients and invasively excluded in 18 patients. Of the 75 patients, 31 (41%) had impaired RAP variation, which was linked with impaired RV systolic function and RV-PA coupling and increased tricuspid regurgitation and Eed as compared to patients with preserved RAP variation. In backward regression, RAP variation associated only with Eed. RAP variation but not simple RAP identified impaired diastolic RV function (area under the receiver operating characteristic curve [95% confidence interval]: 0.712 [0.592, 0.832] and 0.496 [0.358, 0.634], respectively). During exercise, patients with impaired RAP variation experienced greater RV dilatation and reduced diastolic reserve and cardiac output/index compared with patients with preserved RAP variation. Preserved RAP variation was associated with a better prognosis than impaired RAP variation based on the 2022 European Society of Cardiology/European Respiratory Society risk score (chi-square P = 0.025) and survival free from clinical worsening (91% vs 71% at 1 year and 79% vs 50% at 2 years [log-rank P = 0.020]; hazard ratio: 0.397 [95% confidence interval: 0.178, 0.884]). Subgroup analyses in patients with group 1 and group 4 PH demonstrated consistent findings with those observed in the overall study cohort. Respiratory RAP variations reflect RV diastolic function, are independent of RV-PA coupling or tricuspid regurgitation, are associated with exercise-induced haemodynamic changes, and are prognostic in PH.Trial registration. NCT04663217.

Mechanisms maintaining right ventricular contractility-to-pulmonary arterial elastance ratio in VA ECMO: a retrospective animal data analysis of RV-PA coupling

BACKGROUND

To optimize right ventricular-pulmonary coupling during veno-arterial (VA) ECMO weaning, inotropes, vasopressors and/or vasodilators are used to change right ventricular (RV) function (contractility) and pulmonary artery (PA) elastance (afterload). RV-PA coupling is the ratio between right ventricular contractility and pulmonary vascular elastance and as such, is a measure of optimized crosstalk between ventricle and vasculature. Little is known about the physiology of RV-PA coupling during VA ECMO. This study describes adaptive mechanisms for maintaining RV-PA coupling resulting from changing pre- and afterload conditions in VA ECMO.

METHODS

In 13 pigs, extracorporeal flow was reduced from 4 to 1 L/min at baseline and increased afterload (pulmonary embolism and hypoxic vasoconstriction). Pressure and flow signals estimated right ventricular end-systolic elastance and pulmonary arterial elastance. Linear mixed-effect models estimated the association between conditions and elastance.

RESULTS

At no extracorporeal flow, end-systolic elastance increased from 0.83 [0.66 to 1.00] mmHg/mL at baseline by 0.44 [0.29 to 0.59] mmHg/mL with pulmonary embolism and by 1.36 [1.21 to 1.51] mmHg/mL with hypoxic pulmonary vasoconstriction (p < 0.001). Pulmonary arterial elastance increased from 0.39 [0.30 to 0.49] mmHg/mL at baseline by 0.36 [0.27 to 0.44] mmHg/mL with pulmonary embolism and by 0.75 [0.67 to 0.84] mmHg/mL with hypoxic pulmonary vasoconstriction (p < 0.001). Coupling remained unchanged (2.1 [1.8 to 2.3] mmHg/mL at baseline; - 0.1 [- 0.3 to 0.1] mmHg/mL increase with pulmonary embolism; - 0.2 [- 0.4 to 0.0] mmHg/mL with hypoxic pulmonary vasoconstriction, p > 0.05). Extracorporeal flow did not change coupling (0.0 [- 0.0 to 0.1] per change of 1 L/min, p > 0.05). End-diastolic volume increased with decreasing extracorporeal flow (7.2 [6.6 to 7.8] ml change per 1 L/min, p < 0.001).

CONCLUSIONS

The right ventricle dilates with increased preload and increases its contractility in response to afterload changes to maintain ventricular-arterial coupling during VA extracorporeal membrane oxygenation.

Echocardiographic estimation of right ventricular diastolic stiffness based on pulmonary regurgitant velocity waveform analysis in precapillary pulmonary hypertension

Right ventricular (RV) diastolic stiffness is an independent predictor of survival and is strongly associated with disease severity in patients with precapillary pulmonary hypertension (PH). Therefore, a fully validated echocardiographic method for assessing RV diastolic stiffness needs to be established. This study aimed to compare echocardiography-derived RV diastolic stiffness and invasively measured pressure-volume loop-derived RV diastolic stiffness in patients with precapillary PH. We studied 50 consecutive patients with suspected or confirmed precapillary PH who underwent cardiac catheterization, magnetic resonance imaging, and echocardiography within a 1-week interval. Single-beat RV pressure-volume analysis was performed to determine the gold standard for RV diastolic stiffness. Elevated RV end-diastolic pressure (RVEDP) was defined as RVEDP ≥ 8 mmHg. Using continuous-wave Doppler and M-mode echocardiography, an echocardiographic index of RV diastolic stiffness was calculated as the ratio of the atrial-systolic descent of the pulmonary artery-RV pressure gradient derived from pulmonary regurgitant velocity (PRPGDAC) to the tricuspid annular plane movement during atrial contraction (TAPMAC). PRPGDAC/TAPMAC showed significant correlation with β (r = 0.54, p < 0.001) and RVEDP (r = 0.61, p < 0.001). A cut-off value of 0.74 mmHg/mm for PRPGDAC/TAPMAC showed 83% sensitivity and 93% specificity for identifying elevated RVEDP. Multivariate analyses indicated that PRPGDAC/TAPMAC was independently associated with disease severity in patients with precapillary PH, including substantial PH symptoms, stroke volume index, right atrial size, and pressure. PRPGDAC/TAPMAC, based on pulmonary regurgitation velocity waveform analysis, is useful for the noninvasive assessment of RV diastolic stiffness and is associated with prognostic risk factors in precapillary PH.

Traditional and Advanced Echocardiographic Evaluation in Chronic Obstructive Pulmonary Disease: The Forgotten Relation

Chronic obstructive pulmonary disease (COPD) is a significant preventable and treatable clinical disorder defined by a persistent, typically progressive airflow obstruction. This disease has a significant negative impact on mortality and morbidity worldwide. However, the complex interaction between the heart and lungs is usually underestimated, necessitating more attention to improve clinical outcomes and prognosis. Indeed, COPD significantly impacts ventricular function, right and left chamber architecture, tricuspid valve functionality, and pulmonary blood vessels. Accordingly, more emphasis should be paid to their diagnosis since cardiac alterations may occur very early before COPD progresses and generate pulmonary hypertension (PH). Echocardiography enables a quick, noninvasive, portable, and accurate assessment of such changes. Indeed, recent advancements in imaging technology have improved the characterization of the heart chambers and made it possible to investigate the association between a few cardiac function indexes and clinical and functional aspects of COPD. This review aims to describe the intricate relation between COPD and heart changes and provide basic and advanced echocardiographic methods to detect early right ventricular and left ventricular morphologic alterations and early systolic and diastolic dysfunction. In addition, it is crucial to comprehend the clinical and prognostic significance of functional tricuspid regurgitation in COPD and PH and the currently available transcatheter therapeutic approaches for its treatment. Moreover, it is also essential to assess noninvasively PH and pulmonary resistance in patients with COPD by applying new echocardiographic parameters. In conclusion, echocardiography should be used more frequently in assessing patients with COPD because it may aid in discovering previously unrecognized heart abnormalities and selecting the most appropriate treatment to improve the patient's symptoms, quality of life, and survival.

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

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

How Would I Treat My Own Chronic Thromboembolic Pulmonary Hypertension in the Perioperative Period?

Chronic thromboembolic pulmonary hypertension (CTEPH) results from an incomplete resolution of acute pulmonary embolism, leading to occlusive organized thrombi, vascular remodeling, and associated microvasculopathy with pulmonary hypertension (PH). A definitive CTEPH diagnosis requires PH confirmation by right-heart catheterization and evidence of chronic thromboembolic pulmonary disease on imaging studies. Surgical removal of the organized fibrotic material by pulmonary endarterectomy (PEA) under deep hypothermic circulatory arrest represents the treatment of choice. One-third of patients with CTEPH are not deemed suitable for surgical treatment, and medical therapy or interventional balloon pulmonary angioplasty presents alternative treatment options. Pulmonary endarterectomy in patients with technically operable disease significantly improves symptoms, functional capacity, hemodynamics, and quality of life. Perioperative mortality is <2.5% in expert centers where a CTEPH multidisciplinary team optimizes patient selection and ensures the best preoperative optimization according to individualized risk assessment. Despite adequate pulmonary artery clearance, patients might be prone to perioperative complications, such as right ventricular maladaptation, airway bleeding, or pulmonary reperfusion injury. These complications can be treated conventionally, but extracorporeal membrane oxygenation has been included in their management recently. Patients with residual PH post-PEA should be considered for medical or percutaneous interventional therapy.

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

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

Cardiac effort and 6-min walk distance correlate with stroke volume measured by cardiac magnetic resonance imaging

Right ventricular (RV) dysfunction in pulmonary arterial hypertension (PAH) is associated with poor outcomes. Cardiac magnetic resonance imaging (cMRI) is the gold standard for volumetric assessment, and few reports have correlated 6-min walk distance (6MWD) and cMRI parameters in PAH. Cardiac Effort, (the number of heart beats used during 6-min walk test)/(6MWD), incorporates physiologic changes into walk distance and has been associated with stroke volume (SV) measured by nuclear imaging and indirect Fick. Here, we aimed to interrogate the relationship of Cardiac Effort and 6MWD with SV measured by the gold standard, cMRI. This was a single-center, observational, prospective study in Group 1 PAH patients. Subjects completed 6-min walk with heart rate monitoring (Cardiac Effort) and cMRI within 24 h. cMRI was correlated to Cardiac Effort and 6MWD using Spearman Correlation Coefficient. Twenty-five participants with a wide range of RV function completed both cMRI and Cardiac Effort. There was a strong correlation between left ventricle SV index and both Cardiac Effort (r = -0.70, p = 0.0001) and 6MWD (r = 0.67, p = 0.0002). Cardiac Effort and 6MWD were statistically separated in patients at prognostically significant thresholds of left ventricle SV index (>31 ml/m2), RV Ejection Fraction (>35%), and SV/End Systolic Volume ( > 0.53). Cardiac Effort and 6MWD are noninvasive ways to gain insight into those with impaired SV. 6MWD may correlate better with SV than previously thought and heart rate monitoring provides physiologic context to the walk distance obtained.

Right ventricular dilatation: echocardiographic differential diagnosis

The initial means of detecting right ventricular (RV) dilatation is often transthoracic echocardiography (TTE), and once the presence of RV dilatation is suspected, there is the possibility of RV volume overload, RV pressure overload, RV myocardial disease, and even nonpathological RV dilatation. With respect to congenital heart disease with RV volume overload, defects or valvular abnormalities can be easily detected with TTE, with the exception of some diseases. Volumetric assessment using three-dimensional echocardiography may be useful in determining the intervention timing in these diseases. When the disease progresses in patients with pulmonary hypertension as a result of RV pressure overload, RV dilatation becomes more prominent than hypertrophy, and RV functional parameters predict the prognosis at this stage of maladaptive remodeling. The differential diagnosis of cardiomyopathy or comparison with nonpathological RV dilatation may be difficult in the setting of RV myocardial disease. The characteristics of RV functional parameters such as two-dimensional speckle tracking may help differentiate RV cardiomyopathy from other conditions. We review the diseases presenting with RV dilatation, their characteristics, and echocardiographic findings and parameters that are significant in assessing their status or intervention timing.

In vivo pharmacokinetic study of vanillic acid in monocrotaline-induced pulmonary arterial hypertension rats and its tissue distribution

Vanillic acid (VA) is a bioactive chemical present in many food plants and fruits. It has been shown to have a protective effect on pulmonary tissues in monocrotaline-induced pulmonary arterial hypertension, as well as an intervention effect on right ventricular remodeling. The purpose of this study was to develop and test a reliable method for assessing VA utilizing ultra-performance liquid chromatography-high resolution mass spectrometry using caffeic acid as the internal standard. Across diverse substrates, the correlation coefficient for VA ranged from 0.9992 to 0.9995. The method's intraday precision was <13.53% (RSD), and its accuracy (RE) ranged from -9.88 to 4.35%. The precision across days was <13.69% (RSD), while the accuracy ranged from 2.16 to 10.94% (RE). The extraction recoveries ranged from 80.30 to 118.81%, with a lower limit of quantification of 20 ng/mL. The approach was successfully applied to pharmacokinetic and tissue distribution studies of VA in rat plasma after gavage administration, and the pharmacokinetic parameters of VA in the plasma of the monocrotaline-induced pulmonary arterial hypertension were significantly different from those of the control group.

Characterization of pulmonary arterial stiffness using cardiac MRI

Pulmonary arterial stiffness (PAS) is a pathologic hallmark of all types of pulmonary hypertension (PH). Cardiac MRI (CMR), a gold-standard imaging modality for the evaluation of pulmonary flow, biventricular morphology and function has been historically reserved for the longitudinal clinical follow-up, PH phenotyping purposes, right ventricular evaluation, and research purposes. Over the last two decades, numerous indices combining invasive catheterization and non-invasive CMR have been utilized to phenotype the character and severity of PAS in different types of PH and to assess its clinically prognostic potential with encouraging results. Many recent studies have demonstrated a strong role of CMR derived PAS markers in predicting long-term clinical outcomes and improving currently gold standard risk assessment provided by the REVEAL calculator. With the utilization of a machine learning strategies, strong diagnostic and prognostic performance of CMR reported in multicenter studies, and ability to detect PH at early stages, the non-invasive assessment of PAS is on verge of routine clinical utilization. In this review, we focus on appraising important CMR studies interrogating PAS over the last 20 years, describing the benefits and limitations of different PAS indices, and their pathophysiologic relevance to pulmonary vascular remodeling. We also discuss the role of CMR and PAS in clinical surveillance and phenotyping of PH, and the long-term future goal to utilize PAS as a biomarker to aid with more targeted therapeutic management.

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

BACKGROUND

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

Ultrasound-Assisted, Catheter-Directed Thrombolysis for Acute Intermediate/High-Risk Pulmonary Embolism: Design of the Multicenter USAT IH-PE Registry and Preliminary Results

Catheter-based revascularization procedures were developed as an alternative to systemic thrombolysis for patients with intermediate-high- and high-risk pulmonary embolisms. USAT IH-PE is a retrospective and prospective multicenter registry of such patients treated with ultrasound-facilitated, catheter-directed thrombolysis, whose preliminary results are presented in this study. The primary endpoint was the incidence of pulmonary hypertension (PH) at follow-up. Secondary endpoints were short- and mid-term changes in the echocardiographic parameters of right ventricle (RV) function, in-hospital and all-cause mortality, and procedure-related bleeding events. Between March 2018 and July 2023, 102 patients were included. The majority were at intermediate-high-risk PE (86%), were mostly female (57%), and had a mean age of 63.7 ± 14.5 years, and 28.4% had active cancer. Echocardiographic follow-up was available for 70 patients, and in only one, the diagnosis of PH was confirmed by right heart catheterization, resulting in an incidence of 1.43% (CI 95%, 0.036-7.7). RV echocardiographic parameters improved both at 24 h and at follow-up. In-hospital mortality was 3.9% (CI 95%, 1.08-9.74), while all-cause mortality was 11% (CI 95%, 5.4-19.2). Only 12% had bleeding complications, of whom 4.9% were BARC ≥ 3. Preliminary results from the USAT IH-PE registry showed a low incidence of PH, improvement in RV function, and a safe profile.

Echocardiography assessment of right ventricular-pulmonary artery coupling: Validation of surrogates and clinical utilities

Right ventricular-pulmonary artery (RV-PA) coupling indicates efficiency of energy transfer from the right ventricle to the pulmonary circulation. The gold standard measurement, end-systolic elastance/arterial elastance ratio (Ees/Ea), is derived from invasive pressure-volume loop, which is technically demanding, expensive and limited in clinical practice. Recent studies have proposed various non-invasive surrogates of Ees/Ea based on echocardiography assessment, of which TAPSE/PASP ratio is an easily-obtained and validated parameter in severe pulmonary hypertension and rapidly applicated in the diagnosis and risk evaluation of various diseases and cardiac intervention. In this review, we summarized principles and validations of echocardiographic surrogates, and their clinical utilities and also limitations. The goal is to systematically review the research advances of echocardiography assessment of RV-PA coupling and help to guide clinical practice.

Tricuspid Regurgitation and Right Heart Failure: The Role of Imaging in Defining Pathophysiology, Presentation, and Novel Management Strategies

During the last few years, there has been a substantial shift in efforts to understand and manage secondary or functional tricuspid regurgitation (TR) given its prevalence, adverse prognostic impact, and symptom burden associated with progressive right heart failure. Understanding the pathophysiology of TR and right heart failure is crucial for determining the best treatment strategy and improving outcomes. In this article, we review the complex relationship between right heart structural and hemodynamic changes that drive the pathophysiology of secondary TR and discuss the role of multimodality imaging in the diagnosis, management, and determination of outcomes.

Comparison of prognostic value among echocardiographic surrogates of right ventricular-pulmonary arterial coupling: A three-dimensional echocardiographic study

OBJECTIVES

Right ventricular (RV)-pulmonary arterial (PA) coupling is important in various cardiac diseases. Recently, several echocardiographic surrogates for RV-PA coupling have been proposed and reported to be useful in predicting outcomes. However, it remains unclear which surrogate is the most clinically relevant. This study aimed to comprehensively compare the prognostic value of different echocardiographic RV-PA coupling surrogates.

METHODS

We retrospectively reviewed 242 patients with various cardiac conditions who underwent comprehensive transthoracic echocardiography with three-dimensional RV data. In addition to conventional parameters including tricuspid annular plane systolic excursion (TAPSE), fractional area change (FAC), and PA systolic pressure (PASP), we analyzed RV free wall and global longitudinal strain (FWLS and GLS). We also obtained RV ejection fraction (RVEF), stroke volume (SV), and end-systolic volume (ESV) using three-dimensional RV analysis. RV-PA coupling surrogates were calculated as TAPSE/PASP, FAC/PASP, FWLS/PASP, GLS/PASP, RVEF/PASP, and SV/ESV. The study endpoint was a composite outcome of all-cause death or cardiovascular hospitalization within 1 year.

RESULTS

In multivariable analysis, all the RV-PA coupling surrogates were independent predictors of the outcome. Among the surrogates, the model with TAPSE/PASP showed the lowest prognostic value in model fit and discrimination ability, whereas the model with RVEF/PASP exhibited the highest prognostic value. The partial likelihood ratio test indicated that the model with RVEF/PASP was significantly better than the model with TAPSE/PASP (p < .024).

CONCLUSION

All the RV-PA coupling surrogates were independent predictors of the outcome. Notably, RVEF/PASP had the highest prognostic value among the surrogates.

Assessment of Right Ventricular-Arterial Coupling by Echocardiography in Patients with Right Ventricular Pressure and Volume Overload

Background

Right ventricle-pulmonary arterial (RV-PA) coupling is considered the gold standard for assessing right ventricular (RV) function and can be evaluated noninvasively by echocardiography. The ratios of tricuspid annular plane systolic excursion/pulmonary artery systolic pressure (TAPSE/PASP), RV global longitudinal strain (G-RVLS)/PASP, and stroke volume/end-systolic volume (SV/ESV) have been proposed as surrogates of RV-PA coupling. The relationship of these parameters remains incompletely understood in patients with volume and pressure loading conditions. We aimed to compare these parameters and evaluate their relationship with 3D RV data in patients with RV pressure and volume overload.

Methods

This study was performed on 110 individuals who underwent 2D and 3D echocardiography. Fifty-four patients had RV volume overload (atrial septal defect (ASD) group), 34 patients had RV pressure overload (pulmonary hypertension (PH) group), and 22 were controls. TAPSE/PASP, G-RVLS/PASP and SV/ESV ratios were calculated. Correlations between parameters of RV-PA coupling and 3D data were assessed using general linear mixed models.

Results

Compared with the ASD group, the PH group had lower TAPSE/PASP and G-RVLS/PASP ratios. The SV/ESV ratio had a strong correlation with right ventricle ejection fraction (RVEF) in both ASD and PH patients (r = 0.8703, p < 0.001 and r = 0.9388, p < 0.001, respectively). The G-RVLS/PASP ratio showed a strong or moderately negative relationship with end-diastolic volume (EDV), ESV and SV (r = -0.7768, p = 0.001; r = -0.7327, p = 0.0005 and r = -0.6816, p = 0.0018, respectively) in PH patients. The TAPSE/PASP ratio showed moderately negative correlations with EDV and ESV (r = -0.5712, p = 0.0012 and r = -0.5594, p = 0.0016, respectively) in PH patients.

Conclusions

Non-invasive RV-PA coupling parameters derived from echocardiography appear similar, but not identical to profiles in pressure-overloaded and volume-overloaded patients. The correlations between non-invasive RV-PA coupling parameters and 3D data displayed various degrees of correlation.

MRI pulmonary artery flow detects lung vascular pathology in preterms with lung disease

BACKGROUND

Pulmonary vascular disease (PVD) affects the majority of preterm neonates with bronchopulmonary dysplasia (BPD) and significantly determines long-term mortality through undetected progression into pulmonary hypertension. Our objectives were to associate characteristics of pulmonary artery (PA) flow and cardiac function with BPD-associated PVD near term using advanced magnetic resonance imaging (MRI) for improved risk stratification.

METHODS

Preterms <32 weeks postmenstrual age (PMA) with/without BPD were clinically monitored including standard echocardiography and prospectively enrolled for 3 T MRI in spontaneous sleep near term (AIRR (Attention to Infants at Respiratory Risks) study). Semi-manual PA flow quantification (phase-contrast MRI; no BPD n=28, mild BPD n=35 and moderate/severe BPD n=25) was complemented by cardiac function assessment (cine MRI).

RESULTS

We identified abnormalities in PA flow and cardiac function, i.e. increased net forward volume right/left ratio, decreased mean relative area change and pathological right end-diastolic volume, to sensitively detect BPD-associated PVD while correcting for PMA (leave-one-out area under the curve 0.88, sensitivity 0.80 and specificity 0.81). We linked these changes to increased right ventricular (RV) afterload (RV-arterial coupling (p=0.02), PA mid-systolic notching (t2; p=0.015) and cardiac index (p=1.67×10-8)) and correlated echocardiographic findings. Identified in moderate/severe BPD, we successfully applied the PA flow model in heterogeneous mild BPD cases, demonstrating strong correlation of PVD probability with indicators of BPD severity, i.e. duration of mechanical ventilation (rs=0.63, p=2.20×10-4) and oxygen supplementation (rs=0.60, p=6.00×10-4).

CONCLUSIONS

Abnormalities in MRI PA flow and cardiac function exhibit significant, synergistic potential to detect BPD-associated PVD, advancing the possibilities of risk-adapted monitoring.

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.

Impact of right ventricular-pulmonary arterial coupling on clinical outcomes in patients undergoing transcatheter aortic valve implantation

AIMS

The interplay between pulmonary hypertension (PH) and right ventricular (RV) function is reflected in an index of RV function to pulmonary artery (PA) systolic pressure (PASP). The present study aimed to assess the importance of RV-PA coupling on clinical outcomes after transcatheter aortic valve implantation (TAVI).

METHODS AND RESULTS

In a prospective TAVI registry, clinical outcomes of TAVI patients with RV dysfunction or PH were stratified according to coupling or uncoupling of tricuspid annular plane systolic excursion (TAPSE) to PASP, and compared to those of patients with normal RV function and absence of PH. The median TAPSE/PASP ratio was used to differentiate uncoupling (>0.39) from coupling (<0.39). Among 404 TAVI patients, 201 patients (49.8 %) had RVD or PH at baseline: 174 patients had RV-PA uncoupling, and 27 had coupling at baseline. RV-PA hemodynamics normalized in 55.6 % of patients with RV-PA coupling and in 28.2 % of patients with RV-PA uncoupling, and deteriorated in 33.3 % of patients with RV-PA coupling and in 17.8 % of patients with no RVD, respectively, at discharge. Patients with RV-PA uncoupling after TAVI showed a trend towards an increased risk of cardiovascular death at 1 year as compared to patients with normal RV-function (HRadjusted 2.06, 95 % CI 0.97-4.37).

CONCLUSION

After TAVI, RV-PA coupling changed in a significant proportion of patients and is a potentially important metric for risk stratification of TAVI patients with RVD or PH. TWEET: "Patients with right ventricular dysfunction and pulmonary hypertension are at increased risk of death after TAVI. Integrated right ventricular to pulmonary artery hemodynamics change after TAVI in a significant proportion of patients and is instrumental to refine risk stratification."

CLINICAL TRIAL REGISTRATION

https://www.

CLINICALTRIALS

gov: NCT01368250.

Clinical Value of a Novel Three-Dimensional Echocardiography-Derived Index of Right Ventricle-Pulmonary Artery Coupling in Tricuspid Regurgitation

BACKGROUND

Echocardiographic surrogates of right ventricle-to-pulmonary artery (RV-PA) coupling have been reported to be associated with outcomes in patients with secondary tricuspid regurgitation (STR). However, pulmonary artery systolic pressure (PASP) is difficult to estimate using echocardiography in patients with severe STR. The aim of the present study was to evaluate the predictive power of a surrogate of RV-PA coupling obtained using right ventricular (RV) volumes measured on three-dimensional echocardiography.

METHODS

One hundred eight patients (mean age, 73 ± 13 years; 61% women) with moderate or severe STR were included.

RESULTS

At a median follow-up of 24 months (interquartile range, 2-48 months), 72 patients (40%) had reached the composite end point of death of any cause and heart failure hospitalization. RV-PA coupling was computed as the ratio between RV forward stroke volume (SV) (i.e., RV SV - regurgitant volume) and RV end-systolic volume (ESV). RV forward SV/ESV was significantly more related to the composite end point than RV ejection fraction (area under the curve, 0.85 [95% CI, 0.78-0.93] vs 0.73 [95% CI, 0.64-0.83], respectively; P = .03). A value of 0.40 was found to best correlate with outcome. On multivariate Cox regression, RV forward SV/ESV, tricuspid annular plane systolic excursion/PASP, and RV free wall longitudinal strain/PASP were all independently associated with the occurrence of the composite end point when added to a group of parameters including STR severity (severe vs moderate), atrial fibrillation, pulmonary arterial hypertension, right atrial volume, RV end-diastolic volume, and RV free wall longitudinal strain. RV forward SV/ESV < 0.40 (HR, 3.36; 95% CI, 1.49-7.56; P < .01) carried higher related risk than RV free wall longitudinal strain/PASP < -0.42%/mm Hg (HR, 3.1; 95% CI, 1.26-7.84; P = .01) and tricuspid annular plane systolic excursion/PASP < 0.36 mm/mm Hg (HR, 2.69; 95% CI, 1.29-5.58; P = .01). RV ejection fraction did not correlate independently with prognosis when added to the same group of variables.

CONCLUSIONS

RV forward SV/ESV is associated with the risk for death and heart failure hospitalization in patients with STR.

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

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

4D-Flow MRI intracardiac flow analysis considering different subtypes of pulmonary hypertension

Intracardiac flow hemodynamic patterns have been considered to be an early sign of diastolic dysfunction. In this study we investigated right ventricular (RV) diastolic dysfunction between patients with pulmonary arterial hypertension (PAH) and pulmonary hypertension with chronic lung disease (PH-CLD) via 4D-Flow cardiac MRI (CMR). Patients underwent prospective, comprehensive CMR for function and size including 4D-Flow CMR protocol for intracardiac flow visualization and analysis. RV early filling phase and peak atrial phase vorticity (E-vorticity and A-vorticity) values were calculated in all patients. Patients further underwent comprehensive Doppler and tissue Doppler evaluation for the RV diastolic dysfunction. In total 13 patients with PAH, 15 patients with PH-CLD, and 10 control subjects underwent the 4D-Flow CMR and echocardiography evaluation for RV diastolic dysfunction. Reduced E-vorticity differentiated PAH and PH-CLD from healthy controls (both p < 0.01) despite the same Doppler E values. E-vorticity was further decreased in PAH patients when compared to PH-CLD group (p < 0.05) with similar Doppler and tissue Doppler markers of diastolic dysfunction. A-vorticity was decreased in both PAH and PH-CLD groups compared to controls but with no difference between the disease groups. E-vorticity correlated with ejection fraction (R = 0.60, p < 0.001), end-systolic volume (R = 0.50, p = 0.001), stroke volume (R = 0.42, p = 0.007), and cardiac output (R = 0.30, p = 0.027). Intracardiac flow analysis using 4D-Flow CMR derived vorticity is a sensitive method to differentiate diastolic dysfunction in patients with different PH etiology and similar Doppler echocardiography profile.

Tricuspid Regurgitation and Right Heart Failure: The Role of Imaging in Defining Pathophysiology, Presentation, and Novel Management Strategies

During the last few years, there has been a substantial shift in efforts to understand and manage secondary or functional tricuspid regurgitation (TR) given its prevalence, adverse prognostic impact, and symptom burden associated with progressive right heart failure. Understanding the pathophysiology of TR and right heart failure is crucial for determining the best treatment strategy and improving outcomes. In this article, we review the complex relationship between right heart structural and hemodynamic changes that drive the pathophysiology of secondary TR and discuss the role of multimodality imaging in the diagnosis, management, and determination of outcomes.

Persistence of pulmonary hypertension in patients undergoing ventricular assist devices and orthotopic heart transplantation

Pulmonary hypertension (PH) is common in advanced heart failure and often improves quickly after left ventricular assist device (VAD) implantation or orthotopic heart transplantation (OHT), but long-term effects and outcomes are not well-described. This study evaluated PH persistence after VAD as destination therapy (VAD-DT), bridge to transplant (VAD-OHT), or OHT-alone. The study constituted a retrospective review of patients who underwent VAD-DT (n = 164), VAD-OHT (n = 111), or OHT-alone (n = 138) at a single tertiary-care center. Right heart catheterization (RHC) data was collected pre-, post-intervention (VAD and/or OHT), and 1-year from final intervention (latest-RHC) to evaluate the longitudinal hemodynamic course of right ventricular function and pulmonary vasculature. PH (Group II and Group I) definitions were adapted from expert guidelines. All groups showed significant improvements in mean pulmonary artery pressure (mPAP), pulmonary artery wedge pressure (PAWP), cardiac output, and pulmonary vascular resistance (PVR) at each RHC with greatest improvement at post-intervention RHC (post-VAD or post-OHT). PH was reduced from 98% to 26% in VAD-OHT, 92%-49% in VAD-DT, and 76%-28% in OHT-alone from preintervention to latest-RHC. At latest-RHC mPAP remained elevated in all groups despite normalization of PAWP and PVR. VAD-supported patients exhibited suppressed pulmonary artery pulsatility index (PaPi < 3.7) with improvement only posttransplant at latest-RHC. Posttransplant patients with PH at latest-RHC (n = 60) exhibited lower survival (HR: 2.1 [95% CI: 1.3-3.4], p < 0.001). Despite an overall significant improvement in pulmonary pressures and PH proportion, a notable subset of patients exhibited PH post-intervention. Post-intervention PH was associated with lower posttransplant survival.

Diagnosing post-capillary hypertension in patients with left heart disease: impact of new guidelines

BACKGROUND

In 2022, the definition of pulmonary hypertension (PH) in the presence of left heart disease was updated according to the new joint guidelines of the European Society of Cardiology (ESC) and the European Respiratory Society (ERS). The impact of the new ESC/ERS definition on the prevalence of post-capillary PH (pc-PH) and its subgroups of isolated post-capillary (Ipc-PH) and combined pre- and post-capillary PH (Cpc-PH) in patients with left heart disease is unclear.

METHODS

We retrospectively identified N = 242 patients with left heart disease with available data on right heart catheterisation (RHC) and cardiac magnetic resonance imaging (CMR). The proportion of pc-PH and its subgroups was calculated according to the old and new ESC/ERS PH definition. As the old definition did not allow the exact allocation of all patients with pc-PH into a respective subgroup, unclassifiable patients (Upc-PH) were regarded separately.

RESULTS

Seventy-six out of 242 patients had pc-PH according to the new ESC/ERS definitions, with 72 of these patients also meeting the criteria of the old definition. Using the old definition, 50 patients were diagnosed with Ipc-PH, 4 with Cpc-PH, and 18 with Upc-PH. Applying the new definition, Ipc-PH was diagnosed in 35 patients (4 newly), and Cpc-PH in 41 patients. No CMR parameter allowed differentiating between Ipc-PH and Cpc-PH, regardless of which guideline version was used.

CONCLUSION

Applying the new ESC/ERS 2022 guideline definitions mildly increased the proportion of patients diagnosed with pc-PH (+ 5.5%) but markedly increased Cpc-PH diagnoses. This effect was driven by the allocation of patients with formerly unclassifiable forms of post-capillary PH to the Cpc-PH subgroup and a significant shift of patients from the Ipc-PH to the Cpc-PH subgroup. Distribution of post-capillary pulmonary hypertension (pc-PH) subgroups according to the European Society of Cardiology/European Respiratory Society (ESC/ERS) PH guidelines from 2015 and 2022 in N = 242 patients with left heart disease.

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

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

Prognostic role of tricuspid annular plane systolic excursion/pulmonary artery systolic pressure ratio in patients hospitalized for acute heart failure

BACKGROUND

The role of TAPSE/PASP, a measurement of right ventricular to pulmonary artery coupling, in patients hospitalized for acute heart failure (AHF) is poorly described.

OBJECTIVES

To evaluate the prognostic impact of TAPSE/PASP in AHF.

METHODS

This retrospective single-center study included patients hospitalized for AHF between January 2004 and May 2017. TAPSE/PASP was evaluated as a continuous variable and as tertiles according to its value on admission. The main outcome was the composite of 1-year all-cause death or heart failure hospitalization.

RESULTS

A total of 340 patients were included [mean age 68.8 ± 11.8 years; 76.2% men, mean left ventricular ejection fraction (LVEF) 30.4 ± 13.3%]. Patients with lower TAPSE/PASP had more comorbidities and a more advanced clinical profile, and received higher doses of intravenous furosemide in the first 24 h. There was a significant, linear, inverse relationship between TAPSE/PASP values and the incidence of the main outcome (P = 0.003). In two multivariable analyses including clinical (model 1), biochemical and imaging parameters (model 2) TAPSE/PASP ratio was independently associated with the primary end point [model 1: hazard ratio 0.813, 95% confidence interval (CI) 0.708-0.932, P = 0.003; model 2: hazard ratio 0.879, 95% CI 0.775-0.996, P = 0.043]. Patients with TAPSE/PASP greater than 0.47 mm/mmHg had a significantly lower risk of the primary end point (model 1: hazard ratio 0.473, 95% CI 0.277-0.808, P = 0.006; model 2: hazard ratio 0.582, 95% CI 0.355-0.955, P = 0.032; both compared with TAPSE/PASP <0.34 mm/mmHg). Similar findings were observed for 1-year all-cause mortality.

CONCLUSION

TAPSE/PASP on admission demonstrated a prognostic value among patients with AHF.

Heart Failure with Preserved Left Ventricular Ejection Fraction: A Complex Conundrum Simply Not Limited to Diastolic Dysfunction

Over the last two decades, the changing paradigm of heart failure with preserved ejection fraction (HFpEF) has transformed our understanding not only of the pathophysiology of this clinical entity but also the diagnostic and therapeutic approaches aimed at treating this complex patient population. No longer HFpEF should be seen as simply left ventricular diastolic dysfunction but as a group of that in addition of having small and thick left ventricles with abnormal diastolic filling patterns as their main pathophysiologic abnormality; they also have whole host of different abnormalities. In fact, this heterogeneous clinical entity embodies numerous mechanisms and is linked to multiorgan dysfunction, with hypertension and obesity playing a major role. Although we have gained an enormous amount of understanding not only on the causes but also the downstream effects of HFpEF, there is still much to be learned before we can fully comprehend this complex clinical entity. It is the main intention of this review to synthesize the most recent attributes, mechanism, diagnostic tools, and most useful therapeutic alternatives to be considered when evaluating patients either complaining of dyspnea on exertion as well as exercise intolerance or those recently admitted with HF symptoms but with normal LVEF in the absence of any other valvular abnormalities.

Pressure Overload and Right Ventricular Failure: From Pathophysiology to Treatment

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

A new assessment method for right ventricular diastolic function using right heart catheterization by pressure-volume loop

Diastolic stiffness coefficient (β) and end-diastolic elastance (Eed) are ventricular-specific diastolic parameters. However, the diastolic function of right ventricle had not been investigated sufficiently due to the lack of established evaluation method. We evaluated the validity of these parameters calculated using only data of right heart catheterization (RHC) and assessed it in patients with restrictive cardiomyopathy (RCM) and cardiac amyloidosis. We retrospectively analyzed 46 patients with heart failure who underwent RHC within 10 days of cardiac magnetic resonance (CMR). Right ventricular end-diastolic volume and end-systolic volume were calculated using only RHC data, which were found to be finely correlated with those obtained from CMR. β and Eed calculated by this method were also significantly correlated with those derived from conventional method using CMR. By this method, β and Eed were significantly higher in RCM with amyloidosis group than dilated cardiomyopathy group. In addition, the β and Eed calculated by our method were finely correlated with E/A ratio on echocardiography. We established an easy method to estimate β and Eed of right ventricle from only RHC. The method finely demonstrated right ventricular diastolic dysfunction in patients with RCM and amyloidosis.

Acute Changes in Right Ventricular Function in Pediatric Patients with Pulmonary Valve Stenosis Undergoing Percutaneous Valvuloplasty: A Speckle-Tracking Study

INTRODUCTION

Pulmonary valve stenosis determines multiple effects on the right ventricular dimension and function. Percutaneous balloon valvuloplasty is the treatment of choice in severe pulmonary valve stenosis in patients of all ages. However, little is known regarding right ventricular function immediate changes after percutaneous balloon dilation. Pediatric patients with isolated pulmonary valve stenosis represent a pure clinical model of chronic RV pressure overload not affected by other confounders or comorbidities.

AIM OF THE STUDY

This study seeks to explore right ventricle (RV) mechanics in pediatric patients early after percutaneous balloon pulmonary valvuloplasty (BPV) for valvar pulmonary stenosis (PS).

MATERIALS AND METHODS

Forty-three pediatric patients (19 males), mean age 3.2 ± 4.9 years old, with severe pulmonary valve stenosis and indication for percutaneous balloon valvuloplasty were recruited. All patients underwent standard transthoracic echocardiography (TTE), and speckle-tracking echocardiography (STE) with an analysis of right ventricle free-wall longitudinal strain (RVFWLS) one day before and one day after the procedure. For each patient, we collected invasive parameters during the interventional procedure before and after BPV.

RESULTS

After the procedure, there was an immediate significant reduction in both peak-to-peak transpulmonary gradient (peak-to-peak PG) and ratio between the right ventricle and aortic systolic pressure (RV/AoP) with a drop of ∆29.3 ± 14.67 mmHg and ∆0.43 ± 0.03, respectively. Post-procedural echocardiography showed peak and mean transvalvar pressure gradient drop (∆50 ± 32.23 and ∆31 ± 17.97, respectively). The degree of pulmonary valve regurgitation was mild in 8% of patients before the procedure, affecting 29% of our patients post-BPV (p = 0.007). The analysis of right ventricular mechanics showed a significant improvement of fractional area change (FAC) immediately after BPV (40.11% vs. 44.42%, p = 0.01). On the other hand, right ventricular longitudinal systolic function parameters, TAPSE and global RVFWLS, did not improve significantly after intervention. The segmental analysis of the RVFWLS showed a significant regional increase in the myocardial deformation of the apical segments.

CONCLUSIONS

Percutaneous BPV represents an efficient and safe procedure to relieve severe pulmonary valve stenosis. The analysis of the right ventricular function on echocardiography demonstrated an immediate global systolic function improvement, while longitudinal systolic function was persistently impaired 24 h after intervention, possibly due to the necessity of a longer recovery time.

Pulmonary Hypertension in Left Heart Diseases: Pathophysiology, Hemodynamic Assessment and Therapeutic Management

Pulmonary hypertension (PH) associated with left heart diseases (PH-LHD), also termed group 2 PH, represents the most common form of PH. It develops through the passive backward transmission of elevated left heart pressures in the setting of heart failure, either with preserved (HFpEF) or reduced (HFrEF) ejection fraction, which increases the pulsatile afterload of the right ventricle (RV) by reducing pulmonary artery (PA) compliance. In a subset of patients, progressive remodeling of the pulmonary circulation resulted in a pre-capillary phenotype of PH, with elevated pulmonary vascular resistance (PVR) further increasing the RV afterload, eventually leading to RV-PA uncoupling and RV failure. The primary therapeutic objective in PH-LHD is to reduce left-sided pressures through the appropriate use of diuretics and guideline-directed medical therapies for heart failure. When pulmonary vascular remodeling is established, targeted therapies aiming to reduce PVR are theoretically appealing. So far, such targeted therapies have mostly failed to show significant positive effects in patients with PH-LHD, in contrast to their proven efficacy in other forms of pre-capillary PH. Whether such therapies may benefit some specific subgroups of patients (HFrEF, HFpEF) with specific hemodynamic phenotypes (post- or pre-capillary PH) and various degrees of RV dysfunction still needs to be addressed.

Assessment of Right Ventricular Function-a State of the Art

PURPOSE OF REVIEW

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

RECENT FINDINGS

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

Right ventricular dysfunction in patients with acute respiratory distress syndrome receiving venovenous extracorporeal membrane oxygenation

Acute respiratory distress syndrome is characterized by non-cardiogenic pulmonary edema, decreased pulmonary compliance, and abnormalities in gas exchange, especially hypoxemia. Patients with acute respiratory distress syndrome (ARDS) who receive support with venovenous (V-V) extracorporeal membrane oxygenation (ECMO) usually have severe lung disease. Many patients with ARDS have associated pulmonary vascular injury which can result in elevated pulmonary vascular resistance and right heart dysfunction. Since V-V ECMO relies upon preserved cardiac function, right heart failure has important implications for patient evaluation, management, and outcomes. Worsening right heart function complicates ARDS and disease processes. Given the increasing use of ECMO to support patients with ARDS, an understanding of right ventricular-ECMO and cardiopulmonary interactions is essential for the clinician. A narrative review of the manifestations of right heart dysfunction, as well as diagnosis and management strategies for the patient with ARDS on ECMO, is provided.

Predicting hospitalization by TAPSE/SPAP and the role of spironolactone in asymptomatic heart failure patients

Aim: To appraise the prediction of tricuspid annular plane systolic excursion (TAPSE)/systolic pulmonary artery pressure (SPAP) with regard to hospitalization and the effect of spironolactone use. Materials & methods: A total of 245 patients were evaluated for the study. Patients were followed for 1 year and cardiovascular outcomes were determined. Results: It was determined that TAPSE/SPAP was an independent predictor of hospitalization. A 0.1-mmHg decrease in TAPSE/SPAP was associated with a 9% increase in relative risk. No event was observed above the 0.47 level. Negative correlation with TAPSE (uncoupling) began in the spironolactone group when SPAP was ≥43 and in nonusers when SPAP was 38 (Pearson's correlation coefficient: -,731 vs -,383; p < 0.001 vs p = 0.037). Conclusion: TAPSE/SPAP measurement may be useful in predicting 1-year hospitalization in asymptomatic heart failure patients. This ratio was also found to be higher in patients who used spironolactone.

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.

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.

Potential Prognostic Value of Native T1 in Pulmonary Hypertension Patients

Native T1, extracellular volume fraction (ECV), and late gadolinium enhancement (LGE) characterize myocardial tissue and relate to patient prognosis in a variety of diseases, including pulmonary hypertension. The purpose of this study was to evaluate if left ventricle (LV) fibrosis measurements have prognostic value for cardiac outcomes in pulmonary hypertension subgroups. 54 patients with suspected pulmonary hypertension underwent right-heart catheterization and were classified into pulmonary hypertension subgroups: pre-capillary component (PreCompPH) and isolated post-capillary (IpcPH). Cardiac magnetic resonance imaging (MRI) scans were performed with the acquisition of balanced cine steady-state free precession, native T1, and LGE pulse sequences to measure cardiac volumes and myocardial fibrosis. Associations between cardiac events and cardiac MRI measurements were analyzed within PreCompPH and IpcPH patients. IpcPH: LV native T1 was higher in patients who experienced a cardiac event within two years vs. those who did not. In patients with LV native T1 > 1050 ms, the rate of cardiac events was higher. ECV and quantitative LGE did not differ between groups. PreCompPH: native T1, ECV, and quantitative/qualitative LGE did not differ between patients who experienced a cardiac event within two years vs. those who did not. LV native T1 may have potential value for forecasting cardiac events in IpcPH, but not in PreCompPH, patients.

Longitudinal Validation of Right Ventricular Pressure Monitoring for the Assessment of Right Ventricular Systolic Dysfunction in a Large Animal Ischemic Model

Right ventricular (RV) dysfunction is a major cause of morbidity and mortality in intensive care and cardiac surgery. Early detection of RV dysfunction may be facilitated by continuous monitoring of RV waveform obtained from a pulmonary artery catheter. The objective is to evaluate the extent to which RV pressure monitoring can detect changes in RV systolic performance assess by RV end-systolic elastance (E_es) following the development of an acute RV ischemic in a porcine model.

HYPOTHESIS

RV pressure monitoring can detect changes in RV systolic performance assess by RV E_es following the development of an acute RV ischemic model.

METHODS AND MODELS

Acute ischemic RV dysfunction was induced by progressive embolization of microsphere in the right coronary artery to mimic RV dysfunction clinically experienced during cardiopulmonary bypass separation caused by air microemboli. RV hemodynamic performance was assessed using RV pressure waveform-derived parameters and RV E_es obtained using a conductance catheter during inferior vena cava occlusions.

RESULTS

Acute ischemia resulted in a significant reduction in RV E_es from 0.26 mm Hg/mL (interquartile range, 0.16-0.32 mm Hg/mL) to 0.14 mm Hg/mL (0.11-0.19 mm Hg/mL; p < 0.010), cardiac output from 6.3 L/min (5.7-7 L/min) to 4.5 (3.9-5.2 L/min; p = 0.007), mean systemic arterial pressure from 72 mm Hg (66-74 mm Hg) to 51 mm Hg (46-56 mm Hg; p < 0.001), and mixed venous oxygen saturation from 65% (57-72%) to 41% (35-45%; p < 0.001). Linear mixed-effect model analysis was used to assess the relationship between E_es and RV pressure-derived parameters. The reduction in RV E_es best correlated with a reduction in RV maximum first derivative of pressure during isovolumetric contraction (dP/dt_max) and single-beat RV E_es. Adjusting RV dP/dt_max for heart rate resulted in an improved surrogate of RV E_es.

INTERPRETATION AND CONCLUSIONS

Stepwise decreases in RV E_es during acute ischemic RV dysfunction were accurately tracked by RV dP/dt_max derived from the RV pressure waveform.

Right ventricular failure: Current strategies and future development

Right heart failure can be defined as a clinical syndrome consisting of signs and symptoms of heart failure resulting from right ventricular dysfunction. Function is normally altered due to three mechanisms: (1) pressure overload (2) volume overload, or (3) a decrease in contractility due to ischaemia, cardiomyopathy or arrythmias. Diagnosis is based upon a combination of clinical assessment plus echocardiographic, laboratory and haemodynamic parameters, and clinical risk assessment. Treatment includes medical management, mechanical assist devices and transplantation if recovery is not observed. Distinct attention to special circumstances such as left ventricular assist device implantation should be sought. The future is moving towards new therapies, both pharmacological and device centered. Immediate diagnosis and management of RV failure, including mechanical circulatory support where needed, alongside a protocolized approach to weaning is important in successfully managing right ventricular failure.

Utility of cardiac magnetic resonance feature tracking strain assessment in chronic thromboembolic pulmonary hypertension for prediction of REVEAL 2.0 high risk status

Chronic thromboembolic pulmonary hypertension may be cured by pulmonary endarterectomy (PEA). Thromboembolic disease distribution/PEA success primarily determines prognosis but risk scoring criteria may be adjunctive. Right ventriculoarterial (RV-PA) and ventriculoatrial (RV-right atrium [RA]) coupling may be evaluated by cardiac MRI (CMR) feature tracking deformation/strain assessment. We characterized biatrial and biventricular CMR feature tracking (FT) strain parameters following PEA and tested the ability of CMR FT to identify REVEAL 2.0 high-risk status. We undertook a retrospective single-center cross-sectional study of patients (n = 57) who underwent PEA (2015-2020). All underwent pre and postoperative catheterization and CMR. Pulmonary arterial hypertension validated risk scores were calculated. Significant postoperative improvements were observed in mean pulmonary artery pressure (mPAP) (pre-op 45 ± 11 mmHg vs. post-op 26 ± 11 mmHg; p < 0.001) and PVR however a large proportion had residual pulmonary hypertension (45%; mPAP ≥25 mmHg). PEA augmented left heart filling with left ventricular end diastolic volume index and left atrial volume index increment. Left ventricular ejection fraction was unchanged postoperatively but LV global longitudinal strain improved (pre-op median -14.2% vs. post-op -16.0%; p < 0.001). Right ventricular (RV) geometry and function also improved with reduction in RV mass. Most had uncoupled RV-PA relationships which recovered (pre-op right ventricular free wall longitudinal strain -13.2 ± 4.8%, RV stroke volume/right ventricular end systolic volume ratio 0.78 ± 0.53 vs. post-op -16.8 ± 4.2%, 1.32 ± 0.55; both p < 0.001). Postoperatively, there were six REVEAL 2.0 high-risk patients, best predicted by impaired RA strain which was superior to traditional volumetric parameters (area under the curve [AUC] 0.99 vs. RVEF AUC 0.88). CMR deformation/strain evaluation can offer insights into coupling recovery; RA strain may be an expeditious surrogate for the more laborious REVEAL 2.0 score.