Assessment of right ventricular adaptability to loading conditions can improve the timing of listing to transplantation in patients with pulmonary arterial hypertension

Cardiological Challenges Related to Long-Term Mechanical Circulatory Support for Advanced Heart Failure in Patients with Chronic Non-Ischemic Cardiomyopathy

Long-term mechanical circulatory support by a left ventricular assist device (LVAD), with or without an additional temporary or long-term right ventricular (RV) support, is a life-saving therapy for advanced heart failure (HF) refractory to pharmacological treatment, as well as for both device and surgical optimization therapies. In patients with chronic non-ischemic cardiomyopathy (NICM), timely prediction of HF's transition into its end stage, necessitating life-saving heart transplantation or long-term VAD support (as a bridge-to-transplantation or destination therapy), remains particularly challenging, given the wide range of possible etiologies, pathophysiological features, and clinical presentations of NICM. Decision-making between the necessity of an LVAD or a biventricular assist device (BVAD) is crucial because both unnecessary use of a BVAD and irreversible right ventricular (RV) failure after LVAD implantation can seriously impair patient outcomes. The pre-operative or, at the latest, intraoperative prediction of RV function after LVAD implantation is reliably possible, but necessitates integrative evaluations of many different echocardiographic, hemodynamic, clinical, and laboratory parameters. VADs create favorable conditions for the reversal of structural and functional cardiac alterations not only in acute forms of HF, but also in chronic HF. Although full cardiac recovery is rather unusual in VAD recipients with pre-implant chronic HF, the search for myocardial reverse remodelling and functional improvement is worthwhile because, for sufficiently recovered patients, weaning from VADs has proved to be feasible and capable of providing survival benefits and better quality of life even if recovery remains incomplete. This review article aimed to provide an updated theoretical and practical background for those engaged in this highly demanding and still current topic due to the continuous technical progress in the optimization of long-term VADs, as well as due to the new challenges which have emerged in conjunction with the proof of a possible myocardial recovery during long-term ventricular support up to levels which allow successful device explantation.

Tricuspid Regurgitation Velocity/Tricuspid Annular Plane Systolic Excursion (TRV/TAPSE) Ratio as a Novel Indicator of Disease Severity and Prognosis in Patients with Precapillary Pulmonary Hypertension

BACKGROUND

Tricuspid annular plane systolic excursion (TAPSE) and tricuspid regurgitation velocity (TRV) are two echocardiographic parameters with prognostic value in patients with pulmonary hypertension (PH). When analyzed concurrently as the TRV/TAPSE ratio, they allow the ventricular-pulmonary artery coupling (RVPAC) to be assessed. This could better predict disease severity in patients with PH.

OBJECTIVE

Our study aimed to evaluate the prognostic value of the TRV/TAPSE ratio echocardiographic parameter in adults with precapillary PH.

METHODS

This study included 39 patients (74% women; average age, 63 years) with precapillary PH (pulmonary arterial hypertension and chronic thromboembolic PH) The mean follow-up period was 16.6 ± 13.3 months. Twelve patients (31%) died during the observation time. We measured TAPSE as a surrogate of RV contractility and TRV reflecting RV afterload, while ventricular-arterial coupling was evaluated by the ratio between these two parameters (TRV/TAPSE). To assess disease progression and the patient's functional capacity, the World Health Organization functional class (WHO FC) was determined. Patient physical capacity was also evaluated using the 6 min walk test (6MWT). The analysis included values of N-terminal prohormone brain natriuretic peptide (NT-proBNP), which were taken routinely during the follow-up visit.

RESULTS

The mean calculated TRV/TAPSE ratio was 0.26 ± 0.08 m/s/mm. Upon comparison of the TRV/TAPSE ratio to the disease prognostic indicators, we observed a statistically significant correlation between TRV/TAPSE and the results of the WHO FC, 6MWT, and NT-proBNP. The TRV/TAPSE ratio is thus a good predictor of mortality in PH patients (AUC, 0.781). Patients with a TRV/TAPSE ratio > 0.30 m/s/mm had a shorter survival time, with log-rank test p < 0.0001. Additionally, ROC analysis revealed higher AUC for TRV/TAPSE than for TAPSE and TRV alone.

CONCLUSIONS

TRV/TAPSE is a promising practicable echocardiographic parameter reflecting RVPAC. Moreover, TRV/TAPSE could be viable risk stratification parameter and could have prognostic value in patients with PH.

Thoracic Spinal Cord Neuroinflammation as a Novel Therapeutic Target in Pulmonary Hypertension

BACKGROUND

Pulmonary hypertension (PH) is associated with aberrant sympathoexcitation leading to right ventricular failure (RVF), arrhythmias, and death. Microglial activation and neuroinflammation have been implicated in sympathoexcitation in experimental PH. We recently reported the first evidence of thoracic spinal cord (TSC) neuroinflammation in PH rats. Here, we hypothesize that PH is associated with increased cardiopulmonary afferent signaling leading to TSC-specific neuroinflammation and sympathoexcitation. Furthermore, inhibition of TSC neuroinflammation rescues experimental PH and RVF.

METHODS

We performed transcriptomic analysis and its validation on the TSC of monocrotaline (n=8) and Sugen hypoxia (n=8) rat models of severe PH-RVF. A group of monocrotaline rats received either daily intrathecal microglial activation inhibitor minocycline (200 μg/kg per day, n=5) or PBS (n=5) from day 14 through 28. Echocardiography and right ventricle-catheterization were performed terminally. Real-time quantitative reverse transcription PCR, immunolocalization, microglia+astrocyte quantification, and terminal deoxynucleotidyl transferase dUTP nick end labeling were assessed. Plasma catecholamines were measured by ELISA. Human spinal cord autopsy samples (Control n=3; pulmonary arterial hypertension n=3) were assessed to validate preclinical findings.

RESULTS

Increased cardiopulmonary afferent signaling was demonstrated in preclinical and clinical PH. Our findings delineated common dysregulated genes and pathways highlighting neuroinflammation and apoptosis in the remodeled TSC and highlighted increased sympathoexcitation in both rat models. Moreover, we validated significantly increased microglial and astrocytic activation and CX3CL1 expression in TSC of human pulmonary arterial hypertension. Finally, amelioration of TSC neuroinflammation by minocycline in monocrotaline rats inhibited microglial activation, decreased proinflammatory cytokines, sympathetic nervous system activation and significantly attenuated PH and RVF.

CONCLUSIONS

Targeting neuroinflammation and associated molecular pathways and genes in the TSC may yield novel therapeutic strategies for PH and RVF.

The ratio of TAPSE to PASP predicts prognosis in lung transplant candidates with pulmonary arterial hypertension

Lung transplantation (LT) is the only option for patients with pulmonary arterial hypertension (PAH) refractory to maximal medical therapy. However, some patients referred for LT could survive without LT, and its determinants remain unclear. This study aimed to elucidate prognostic factors of severe PAH at the referral time. We retrospectively analyzed 34 patients referred for LT evaluation. The primary outcome was a composite of death or LT. Over a median follow-up period of 2.56 years, eight patients received LT and eight died. Compared with LT-free survival group, pulmonary arterial systolic pressure (PASP) was higher (p = 0.042), and the ratio of tricuspid annular plane systolic excursion (TAPSE) to PASP (TAPSE/PASP) was lower (p = 0.01) in LT or death group. In receiver operating characteristic analysis, the area under the curve was 0.759 (95% confidence interval 0.589-0.929) for TAPSE/PASP to predict primary outcome, and the optimal cut-off value was 0.30 mm/mmHg (sensitivity 0.875 and specificity 0.667). In a multivariate analysis, TAPSE/PASP was independently associated with death or LT. Kaplan-Meier analysis showed a better LT-free survival in patients with TAPSE/PASP ≧0.30 mm/mmHg than in those with < 0.30 mm/mmHg (p = 0.001). Low-level TAPSE/PASP could be a poor prognostic factor in PAH patients referred for LT evaluation.

Prevalence and risk prediction value of tricuspid regurgitation by echocardiography in precapillary pulmonary hypertension

Background

In precapillary pulmonary hypertension (PH), the incidence of different tricuspid regurgitation (TR) degree is poorly defined. The impact of TR severity on pulmonary artery pressure (PAP) assessment and clinical risk stratification in precapillary PH remains unclear.

Methods

A total of 207 patients diagnosed precapillary PH who underwent right heart catheterization (RHC) and echocardiography within 3 days were included. The severity of TR was graded as trace, mild, moderate and severe. Pearson correlation analysis was performed to evaluate the correlation between systolic PAP by echocardiography (sPAP_ECHO) and mean PAP by RHC (mPAP_RHC) in different TR degree groups. The impact factors on risk stratification of precapillary PH were analyzed by logistic regression analysis.

Results

The proportion of None, Trace, Mild, Moderate and Severe TR group was 2.4%, 23.7%, 39.1%, 28.5% and 6.3% respectively. Right atrium (RA) area increased gradually with TR aggravation (p < 0.001). Moderate and Severe TR group had higher N-terminal pro-B-type natriuretic peptide (p < 0.001), right atrial pressure (RAP) (p = 0.018), right ventricular basal diameter (RVD)/left ventricular basal diameter (LVD) ratio (p < 0.001), larger right ventricle (RV) (p < 0.001) and lower tricuspid annular plane systolic excursion (p = 0.006) compared with Trace and Mild group. TR-sPAP_ECHO in Moderate TR group had the greatest correlation coefficient with mPAP_RHC (0.742, p < 0.001) followed by Mild (0.635, p < 0.001) and severe group (0.592, p = 0.033), while there was no correlation in Trace TR group (0.308, p = 0.076). Multivariate logistic regression showed three significant independent echocardiography predictors of high-risk precapillary PH: RVD/LVD ratio (OR = 5.734; 95%CI1.502–21.889, p = 0.011), RA area (OR 1.054; 95% CI 1.004–1.107, p = 0.035) and systolic annular tissue velocity of the lateral tricuspid annulus (S’) (OR 0.735, 95% CI 0.569–0.949, p = 0.018).

Conclusions

Precapillary PH was not necessarily accompanied by significant TR. None or Trace TRaccounted for 26% in our population and TR-sPAP_ECHO was not applicable to estimate PAP in these patients. RVD/LVD ratio, RA area and S’ can independently predict the high-risk patients with precapillary PH. TR may play an indirect role in risk stratification by affecting these indicators.

Comparative analysis of right ventricular metabolic reprogramming in pre-clinical rat models of severe pulmonary hypertension-induced right ventricular failure

Background

Pulmonary hypertension (PH) leads to right ventricular (RV) hypertrophy and failure (RVF). The precise mechanisms of the metabolic basis of maladaptive PH-induced RVF (PH-RVF) are yet to be fully elucidated. Here we performed a comparative analysis of RV-metabolic reprogramming in MCT and Su/Hx rat models of severe PH-RVF using targeted metabolomics and multi-omics.

Methods

Male Sprague Dawley rats (250–300 gm; n = 15) were used. Rats received subcutaneous monocrotaline (60 mg/kg; MCT; n = 5) and followed for ~30-days or Sugen (20 mg/kg; Su/Hx; n = 5) followed by hypoxia (10% O₂; 3-weeks) and normoxia (2-weeks). Controls received saline (Control; n = 5). Serial echocardiography was performed to assess cardiopulmonary hemodynamics. Terminal RV-catheterization was performed to assess PH. Targeted metabolomics was performed on RV tissue using UPLC-MS. RV multi-omics analysis was performed integrating metabolomic and transcriptomic datasets using Joint Pathway Analysis (JPA).

Results

MCT and Su/Hx rats developed severe PH, RV-hypertrophy and decompensated RVF. Targeted metabolomics of RV of MCT and Su/Hx rats detected 126 and 125 metabolites, respectively. There were 28 and 24 metabolites significantly altered in RV of MCT and Su/Hx rats, respectively, including 11 common metabolites. Common significantly upregulated metabolites included aspartate and GSH, whereas downregulated metabolites included phosphate, α-ketoglutarate, inositol, glutamine, 5-Oxoproline, hexose phosphate, creatine, pantothenic acid and acetylcarnitine. JPA highlighted common genes and metabolites from key pathways such as glycolysis, fatty acid metabolism, oxidative phosphorylation, TCA cycle, etc.

Conclusions

Comparative analysis of metabolic reprogramming of RV from MCT and Su/Hx rats reveals common and distinct metabolic signatures which may serve as RV-specific novel therapeutic targets for PH-RVF.

Heart-lung interactions in COVID-19: prognostic impact and usefulness of bedside echocardiography for monitoring of the right ventricle involvement

Due to the SARS-CoV-2 infection–related severe pulmonary tissue damages associated with a relative specific widespread thrombotic microangiopathy, the pathophysiologic role of heart–lung interactions becomes crucial for the development and progression of right ventricular (RV) dysfunction. The high resistance in the pulmonary circulation, as a result of small vessel thrombosis and hypoxemia, is the major cause of right heart failure associated with a particularly high mortality in severe COVID-19. Timely identification of patients at high risk for RV failure, optimization of mechanical ventilation to limit its adverse effects on RV preload and afterload, avoidance of medication-related increase in the pulmonary vascular resistance, and the use of extracorporeal membrane oxygenation in refractory respiratory failure with hemodynamic instability, before RV failure develops, can improve patient survival. Since it was confirmed that the right-sided heart is particularly involved in the clinical deterioration of patients with COVID-19 and pressure overload-induced RV dysfunction plays a key role for patient outcome, transthoracic echocardiography (TTE) received increasing attention. Limited TTE focused on the right heart appears highly useful in hospitalized COVID-19 patients and particularly beneficial for monitoring of critically ill patients. In addition to detection of right-sided heart dilation and RV dysfunction, it enables assessment of RV-pulmonary arterial coupling and evaluation of RV adaptability to pressure loading which facilitate useful prognostic statements to be made. The increased use of bedside TTE focused on the right heart could facilitate more personalized management and treatment of hospitalized patients and can contribute towards reducing the high mortality associated with SARS-CoV-2 infection.

Preoperative echocardiographic parameters predict primary graft dysfunction following pediatric lung transplantation

The importance of preoperative cardiac function in pediatric lung transplantation is unknown. We hypothesized that worse preoperative right ventricular (RV) systolic and worse left ventricular (LV) diastolic function would be associated with a higher risk of primary graft dysfunction grade 3 (PGD 3) between 48 and 72 hours. We performed a single center, retrospective pilot study of children (<18 years) who had echocardiograms <1 year prior to lung transplantation between 2006 and 2019. Conventional and strain echocardiography parameters were measured, and PGD was graded. Area under the receiver operating characteristic (AUROC) curves and logistic regression were performed. Forty-one patients were included; 14 (34%) developed PGD 3 and were more likely to have pulmonary hypertension (PH) as the indication for transplant (P = .005). PGD 3 patients had worse RV global longitudinal strain (P = .01), RV free wall strain (FWS) (P = .003), RV fractional area change (P = .005), E/e' (P = .01) and lateral e' velocity (P = .004) but not tricuspid annular plane systolic excursion (P = .61). RV FWS (AUROC 0.79, 95% CI 0.62-0.95) and lateral e' velocity (AUROC 0.87, 95% CI 0.68-1.00) best discriminated PGD 3 development and showed the strongest association with PGD 3 (RV FWS OR 3.87 [95% CI 1.59-9.43], P = .003; lateral e' velocity OR 0.10 [95% CI 0.01-0.70], P = .02). These associations remained when separately adjusting for age, weight, primary PH diagnosis, ischemic time, and bypass time. In this pilot study, worse preoperative RV systolic and worse LV diastolic function were associated with PGD 3 and may be modifiable recipient risk factors in pediatric lung transplantation.

Weaning from ventricular assist device support after recovery from left ventricular failure with or without secondary right ventricular failure

Although complete myocardial recovery after ventricular assist device (VAD) implantation is rather seldom, systematic search for recovery is worthwhile because for recovered patients weaning from VADs is feasible and can provide survival benefits with long-term freedom from heart failure (HF) recurrence, even if a chronic cardiomyopathy was the primary cause for the drug-refractory HF necessitating left ventricular (LVAD) or biventricular support (as bridge-to-transplantation or definitive therapy) and even if recovery remains incomplete. LVAD patients explanted for myoacardial recovery compared to those transplanted from LVAD support showed similar survival rates and a significant proportion of explanted patients can achieve cardiac and physical functional capacities that are within the normal range of healthy controls. In apparently sufficiently recovered patients, a major challenge remains still the pre-explant prediction of the weaning success which is meanwhile reliably possible for experienced clinicians. In weaning candidates, the combined use of certain echocardiography and right heart catheterization parameters recorded before VAD explantation can predict post-weaning cardiac stability with good accuracy. However, in the absence of standardization or binding recommendations, the protocols for assessment of native cardiac improvement and also the weaning criteria differ widely among centers. Currently there are still only few larger studies on myocardial recovery assessment after VAD implantation. Therefore, the weaning practice relies mostly on small case series, local practice patterns, and case reports, and the existing knowledge, as well as the partially differing recommendations which are based mainly on expert opinions, need to be periodically systematised. Addressing these shortcomings, our review aims to summarize the evidence and expert opinion on the evaluation of cardiac recovery during mechanical ventricular support by paying special attention to the reliability of the methods and parameters used for assessment of myocardial recovery and the challenges met in both evaluation of recovery and weaning decision making.

Right Ventricular Failure Post-Implantation of Left Ventricular Assist Device: Prevalence, Pathophysiology, and Predictors

Despite advances in left ventricular assist device (LVAD) technology, right ventricular failure (RVF) continues to be a complication after implantation. Most patients undergoing LVAD implantation have underlying right ventricular (RV) dysfunction (either as a result of prolonged LV failure or systemic disorders) that becomes decompensated post-implantation. Additional insults include intra-operative factors or a sudden increase in preload in the setting of increased cardiac output. The current literature estimates post-LVAD RVF from 3.9% to 53% using a diverse set of definitions. A few of the risk factors that have been identified include markers of cardiogenic shock (e.g., dependence on inotropes and Interagency Registry for Mechanically Assisted Circulatory Support profiles) as well as evidence of cardiorenal or cardiohepatic syndromes. Several studies have devised multivariable risk scores; however, their performance has been limited. A new functional assessment of RVF and a novel hepatic marker that describe cholestatic properties of congestive hepatopathy may provide additional predictive value. Furthermore, future studies can help better understand the relationship between pulmonary hypertension and post-LVAD RVF. To achieve our ultimate goal-to prevent and effectively manage RVF post-LVAD-we must start with a better understanding of the risk factors and pathophysiology. Future research on the different etiologies of RVF-ranging from acute post-surgical complication to late-onset RV cardiomyopathy-will help standardize definitions and tailor therapies appropriately.

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.

Temporary assist device support for the right ventricle: pre-implant and post-implant challenges

Severe right ventricular (RV) failure is more likely reversible than similar magnitudes of left ventricular (LV) failure and, because reversal of both adaptive remodeling and impaired contractility require most often only short periods of support, the use of temporary RV assist devices (t-RVADs) can be a life-saving therapy option for many patients. Although increased experience with t-RVADs and progresses made in the development of safer devices with lower risk for complications has improved both recovery rate of RV function and patient survival, the mortality of t-RVAD recipients can still be high but it depends mainly on the primary cause of RV failure (RVF), the severity of end-organ dysfunction, and the timing of RVAD implantation, and much less on adverse events and complications related to RVAD implantation, support, or removal. Reduced survival of RVAD recipients should therefore not discourage appropriate application of RVADs because their underuse further reduces the chances for RV recovery and patient survival. The article reviews and discusses the challenges related to the pre-implant and post-implant decision-making processes aiming to get best possible therapeutic results. Special attention is focused on pre-implant RV assessment and prediction of RV improvement during mechanical unloading, patient selection for t-RVAD therapy, assessment of unloading-promoted RV recovery, and prediction of its stability after RVAD removal. Particular consideration is also given to prediction of RVF after LVAD implantation which is usually hampered by the complex interactions between the different risk factors related indirectly or directly to the RV potential for reverse remodeling and functional recovery.

Evaluation of Cardiac Recovery in Ventricular Assist Device Recipients: Particularities, Reliability, and Practical Challenges

In carefully selected patients with ventricular assist devices (VADs), good long-term results after device weaning and explantation can be achieved when reverse remodelling and improvement of native cardiac function occur. Monitoring of cardiac size, geometry, and function after initial VAD implantation is necessary to identify such patients. Formal guidelines for recovery assessment in patients with VADs do not exist, and protocols for recovery assessment and criteria for device weaning and explantation vary among centres. Barriers to evaluation of cardiac recovery include technical problems in obtaining echo images in patients with VADs, time restrictions for necessary VAD reductions/interruptions during assessment, and regurgitant flow patterns that occur with interruption of continuous flow VADs. The few larger studies addressing cardiac recovery after VAD implantation employed varied study designs, limiting interpretation. Current clinical practice is guided largely by local practice patterns, case reports, and small case series, and the available body of research-consisting mostly of expert opinions-has not been systematically addressed. This summary reviews evidence and expert opinion on VAD-promoted cardiac recovery assessment, its reliability, and associated challenges.

Tricuspid annular plane systolic excursion (TAPSE) in pediatric pulmonary hypertension: Integrating right ventricular ejection efficiency (RVEe) into advanced multi-parametric imaging

The tricuspid annular plane systolic excursion (TAPSE) has evolved into one of the major echocardiographic indicators of systolic right ventricular (RV) longitudinal function in pediatric pulmonary hypertension (PH). Current RV function research in children with PH focusses on multi-parametric approaches that include TAPSE. The RV ejection efficiency (RVEe) is one of the new variables that reflects the relationship of TAPSE divided by the indexed pulmonary vascular resistance (PVRi) measured by cardiac catheterization. Here, we investigated not only RVEe, but also the ratio of TAPSE divided by pulmonary systolic arterial pressure (PASP; TAPSE/PASP ratio), and a possible association of these indices with NYHA functional class (FC) or the modified ROSS score in 42 children with PH. Both, the RVEe (TAPSE/PVRi) and the TAPSE/PASP ratio were inversely related to NYHA FC and the modified ROSS score in the pediatric PH compared. Compared to TAPSE as single measure, in both multiparametric variables (RVEe, TAPSE/PASP) more pronounced differences in subjects with different NYHA FC/modified ROSS score values were observed. Taken together, the RVEe (TAPSE/PVRi) and TAPSE/PASP ratio distinguish between NYHA FC/modified ROSS score compared to the single echocardiographic variable TAPSE, highlighting the usefulness of a multiparametric approach.

Non-invasive right ventricular load adaptability indices in patients with scleroderma-associated pulmonary arterial hypertension

Scleroderma-associated pulmonary arterial hypertension (SSc-PAH) is associated with worse outcome than idiopathic pulmonary arterial hypertension (IPAH), potentially due to worse right ventricular adaptation to load as suggested by pressure–volume loop analysis. The value of non-invasive load-adaptability metrics has not been fully explored in SSc-PAH. This study sought to assess whether patients with incident SSc-PAH have worse echocardiographic load-adaptability metrics than patients with IPAH. Twenty-two patients with incident SSc-PAH were matched 1:1 with IPAH based on pulmonary vascular resistance. Echocardiographic load-adaptability indices were divided into: surrogates of ventriculo-arterial coupling (e.g. right ventricular area change/end-systolic area), indices reflecting the proportionality of load adaptation (e.g. tricuspid regurgitation velocity-time integral normalized for average right ventricular radius), and simple ratios (e.g. tricuspid annular plane systolic excursion/right ventricular systolic pressure). The prognostic value of these indices for clinical worsening (i.e. death, transplant, or hospitalization for heart failure) at one year was explored. The two groups were comprised of patients of similar age, with similar cardiac index, pulmonary resistance, capacitance and NT-proBNP levels (p > 0.10). There was no difference in baseline right ventricular dimension, function or load-adaptability indices. At one year, eight (36.4%) SSc-PAH patients had experienced clinical worsening (eight hospitalizations and two deaths) versus one hospitalization in the IPAH group. Load adaptation at one year in survivors was not worse in SSc-PAH (p > 0.33). Patients with IPAH responded better to therapy than SSc-PAH in terms of reduction of right ventricular areas at one year (p < 0.05). Right ventricular load-adaptability echocardiographic indices do not appear to capture the increased risk of negative outcomes at one year associated with SSc-PAH.

Evaluation of the right ventricle by echocardiography: particularities and major challenges

INTRODUCTION

Compared with the left ventricle (LV), the right ventricle (RV) is less suited for evaluation by echocardiography (ECHO). Nevertheless, RV ECHO-assessment has currently emerged as an important diagnostic tool with meaningful prognostic value and essential contribution to therapeutic decisions. Although significant progress has been made, including generation of higher-quality normative data, validation of several two-dimensional measurements and improvements in three-dimensional ECHO-techniques, many challenges in RV ECHO-assessment still persist. Areas covered: This review discusses the particular challenges and limits in obtaining accurate measurements of RV anatomical and functional parameters and focuses primarily on the difficulties in proper interpretation of the highly load dependent RV ECHO-parameters which complicates the use of this valuable diagnostic and surveillance technique. Expert commentary: There is increasing evidence that RV assessment in relation with its actual loading conditions by ECHO-derived composite variables, which either incorporate a certain functional parameter and load, or incorporate measures which reflect the relationship between RV dilation and RV load, considering also the right atrial pressure (i.e. 'load adaptation index'), is particularly suited for clinical decision-making. Load dependency of RV ECHO-parameters must be taken into consideration especially in patients with advanced RV dysfunction scheduled for LV assist device implantation or lung transplantation.

Tricuspid flow and regurgitation in congenital heart disease and pulmonary hypertension: comparison of 4D flow cardiovascular magnetic resonance and echocardiography

BACKGROUND

Tricuspid valve (TV) regurgitation (TR) is a common complication of pulmonary hypertension and right-sided congenital heart disease, associated with increased morbidity and mortality. Estimation of TR severity by echocardiography and conventional cardiovasvular magnetic resonance (CMR) is not well validated and has high variability. 4D velocity-encoded (4D-flow) CMR was used to measure tricuspid flow in patients with complex right ventricular (RV) geometry and varying degrees of TR. The aims of the present study were: 1) to assess accuracy of 4D-flow CMR across the TV by comparing 4D-flow CMR derived TV effective flow to 2D-flow derived effective flow across the pulmonary valve (PV); 2) to assess TV 4D-flow CMR reproducibility, and 3) to compare TR grade by 4D-flow CMR to TR grade by echocardiography.

METHODS

TR was assessed by both 4D-flow CMR and echocardiography in 21 healthy subjects (41.2 ± 10.5 yrs., female 7 (33%)) and 67 RV pressure-load patients (42.7 ± 17.0 yrs., female 32 (48%)). The CMR protocol included 4D-flow CMR measurement across the TV, 2D-flow measurement across the PV and conventional planimetric measurements. TR grading on echocardiographic images was performed based on the international recommendations. Bland-Altman analysis and intra-class correlation coefficients (ICC) were used to asses correlations and agreement.

RESULTS

TV effective flow measured by 4D-flow CMR showed good correlation and agreement with PV effective flow measured by 2D-flow CMR with ICC = 0.899 (p < 0.001) and mean difference of -1.79 ml [limits of agreement -20.39 to 16.81] (p = 0.084). Intra-observer agreement for effective flow (ICC = 0.981; mean difference - 1.51 ml [-12.88 to 9.86]) and regurgitant fraction (ICC = 0.910; mean difference 1.08% [-7.90; 10.06]) was good. Inter-observer agreement for effective flow (ICC = 0.935; mean difference 2.12 ml [-15.24 to 19.48]) and regurgitant fraction (ICC = 0.968; mean difference 1.10% [-7.96 to 5.76]) were comparable. In 25/65 (38.5%) TR grade differed by at least 1 grade using 4D-flow CMR compared to echocardiography.

CONCLUSION

TV effective flow derived from 4D-flow CMR showed excellent correlation to PV effective flow derived from 2D-flow CMR, and was reproducible to measure TV flow and regurgitation. Twenty-five out of 65 patients (38.5%) were classified differently by at least one TR grade using 4D-flow CMR compared to echocardiography.

Pulmonary Hypertension in Heart Failure Patients: Pathophysiology and Prognostic Implications

Pulmonary hypertension (PH) due to left heart disease (LHD), i.e., group 2 PH, is the most common reason for increased pressures in the pulmonary circuit. Although recent guidelines incorporate congenital heart disease in this classification, left-sided heart diseases of diastolic and systolic origin including valvular etiology are the vast majority. In these patients, an increased left-sided filling pressure triggers a multistage hemodynamic evolution that ends into right ventricular failure through an initial passive increase in pulmonary artery pressure complicated over time by pulmonary vasoconstriction, endothelial dysfunction, and remodeling of the small-resistance pulmonary arteries. Regardless of the underlying left heart pathology, when present, PH-LHD is associated with more severe symptoms, worse exercise tolerance, and outcome, especially when right ventricular dysfunction and failure are part of the picture. Compared with group 1 and other forms of pulmonary arterial hypertension, PH-LHD is more often seen in elderly patients with a higher prevalence of cardiovascular comorbidities and most, if not all, of the features of metabolic syndrome, especially in case of HF preserved ejection fraction. In this review, we provide an update on current knowledge and some potential challenges about the pathophysiology and established prognostic implications of group 2 PH in patients with HF of either preserved or reduced ejection fraction.

Impact of Left Ventricular Diastolic Dysfunction on Lung Transplantation Outcome in Patients With Pulmonary Arterial Hypertension

Diastolic dysfunction may influence perioperative outcome, early graft function, and long-term survival. We compared the outcomes of double lung transplantation (DLTx) for patients with pulmonary arterial hypertension (PAH) with preoperative left ventricular (LV) diastolic dysfunction with the outcomes of patients without diastolic dysfunction. Of 116 consecutive patients with PAH (who underwent transplantation between January 1995 and December 2013), 44 met our inclusion and exclusion criteria. Fourteen (31.8%) patients with diastolic dysfunction pretransplantation had a higher body mass index (29 [IQR 21.5-32.6] vs 22.4 [IQR 19.9-25.3] kg/m² ) and mean pulmonary arterial pressure (54.6 ± 10 mmHg vs 47 ± 11.3 mmHg) and right atrial pressure (16.5 ± 5.2 mmHg vs 10.6 ± 5.2 mmHg). The patients received extracorporeal life support more frequently (33% vs 7% [p = 0.02]), had worse APACHE II scores (21.7 ± 7.4 vs 15.3 ± 5.3 [p = 0.02]), and a trend toward worse ventilator-free days (2.5 [IQR 6.5-32.5] vs 17 [IQR 3-23] [p = 0.08]). There was no effect on development of primary graft dysfunction or intensive care unit/hospital survival. One-year survival was worse (hazard ratio [HR] 4.45, 95% confidence interval [CI] 1.3-22, p = 0.02). Diastolic dysfunction was the only variable that correlated with overall survival (HR 5.4, 95% CI 1.3-22, p = 0.02). Diastolic dysfunction leads to early postoperative morbidity and worse survival in patients with PAH after DLTx.

Load Adaptability in Patients With Pulmonary Arterial Hypertension

Right ventricular (RV) adaptation to pressure overload is a major prognostic factor in patients with pulmonary arterial hypertension (PAH). The objectives were first to define the relation between RV adaptation and load using allometric modeling, then to compare the prognostic value of different indices of load adaptability in PAH. Both a derivation (n = 85) and a validation cohort (n = 200) were included. Load adaptability was assessed using 3 approaches: (1) surrogates of ventriculo-arterial coupling (e.g., RV area change/end-systolic area), (2) simple ratio of function and load (e.g., tricuspid annular plane systolic excursion/right ventricular systolic pressure), and (3) indices assessing the proportionality of adaptation using allometric pressure-function or size modeling. Proportional hazard modeling was used to compare the hazard ratio for the outcome of death or lung transplantation. The mean age of the derivation cohort was 44 ± 11 years, with 80% female and 74% in New York Heart Association class III or IV. Mean pulmonary vascular resistance index (PVRI) was 24 ± 11 with a wide distribution (1.6 to 57.5 WU/m²). Allometric relations were observed between PVRI and RV fractional area change (R² = 0.53, p < 0.001) and RV end-systolic area indexed to body surface area right ventricular end-systolic area index (RVESAI) (R² = 0.29, p < 0.001), allowing the derivation of simple ratiometric load-specific indices of RV adaptation. In right heart parameters, RVESAI was the strongest predictor of outcomes (hazard ratio per SD = 1.93, 95% confidence interval 1.37 to 2.75, p < 0.001). Although RVESAI/PVRI^0.35 provided small incremental discrimination on multivariate modeling, none of the load-adaptability indices provided stronger discrimination of outcome than simple RV adaptation metrics in either the derivation or the validation cohort. In conclusion, allometric modeling enables quantification of the proportionality of RV load adaptation but offers small incremental prognostic value to RV end-systolic dimension in PAH.

Right heart imaging in patients with heart failure: a tale of two ventricles

PURPOSE OF REVIEW

The purpose is to describe the recent advances made in imaging of the right heart, including deformation imaging, tissue, and flow characterization by MRI, and molecular imaging.

RECENT FINDINGS

Recent developments have been made in the field of deformation imaging of the right heart, which may improve risk stratification of patients with heart failure and pulmonary hypertension. In addition, more attention has been given to load adaptability metrics of the right heart; these simplified indices, however, still face challenges from a conceptual point of view. The emergence of novel MRI sequences, such as native T1 mapping, allows better detection and quantification of myocardial fibrosis and could allow better prediction of postsurgical recovery of the right heart. Other advances in MRI include four-dimensional flow imaging, which may be particularly useful in congenital heart disease or for the detection of early stages of pulmonary vascular disease.

SUMMARY

The review will place the recent developments in right heart imaging in the context of clinical care and research.

Echocardiographic assessment of the right ventricle: Impact of the distinctly load dependency of its size, geometry and performance

Right ventricular (RV) size, shape and function are distinctly load-dependent and pulmonary load is an important determinant of RV function in patients with congestive heart failure (CHF) due to primary impaired left ventricular function and in those with pre-capillary pulmonary hypertension (PH). In a pressure overloaded RV, not only dilation and aggravation of tricuspid regurgitation, but also systolic dysfunction leading to RV failure (RVF) can occur already before the development of irreversible alterations in RV myocardial contractility. This explains RV ability for reverse remodeling and functional improvement in patients with post-capillary and pre-capillary PH of a different etiology, after normalization of loading conditions. There is increasing evidence that RV evaluation by echocardiography in relation with its loading conditions can improve the decision-making process and prognosis assessments in clinical praxis. Recent approaches to evaluate the RV in relation with its actual loading conditions by echo-derived composite variables which either incorporate a certain functional parameter (i.e. tricuspid annulus peak systolic excursion, stroke volume, RV end-systolic volume index, velocity of myocardial shortening) and load, or incorporate measures which reflect the relationship between RV load and RV dilation, also taking the right atrial pressure into account (i.e. "load adaptation index"), appeared particularly suited and therefore also potentially useful for evaluation of RV contractile function. Special attention is focused on the usefulness of RV echo-evaluation in relation to load for proper decision making before ventricular assist-device implantation in patients with CHF and for optimal timing of listing procedures to transplantation in patients with end-stage pre-capillary PH.

Echocardiographic findings associated with mortality ortransplant in patients with pulmonary arterial hypertension:A systematic review and meta-analysis

Background

Identification of patients at risk of deterioration is essential to guide clinical management in pulmonary arterial hypertension (PAH). This study aims to provide a comprehensive overview of well-investigated echocardiographic findings that are associated with clinical deterioration in PAH.

Methods

MEDLINE and EMBASE databases were systematically searched for longitudinal studies published by April 2015 that reported associations between echocardiographic findings and mortality, transplant or clinical worsening. Meta-analysis using random effect models was performed for echocardiographic findings investigated by four or more studies. In case of statistical heterogeneity a sensitivity analysis was conducted.

Results

Thirty-seven papers investigating 51 echocardiographic findings were included. Meta-analysis of univariable hazard ratios (HRs) and sensitivity analysis showed that presence of pericardial effusion (pooled HR 1.70; 95 % CI 1.44–1.99), right atrial area (pooled HR 1.71; 95 % CI 1.38–2.13) and tricuspid annular plane systolic excursion (TAPSE; pooled HR 1.72; 95 % CI 1.34–2.20) were the most well-investigated and robust predictors of mortality or transplant.

Conclusions

This meta-analysis substantiates the clinical yield of specific echocardiographic findings in the prognostication of PAH patients in day-to-day practice. In particular, pericardial effusion, right atrial area and TAPSE are of prognostic value.

Electronic supplementary material

The online version of this article (doi: 10.1007/s12471-016-0845-3) contains supplementary material, which is available to authorized users.