Comprehensive invasive and noninvasive approach to the right ventricle-pulmonary circulation unit: state of the art and clinical and research implications

Left Atrial Phasic Function Impairment in Subacute and Chronic Pulmonary Embolism Patients With Different Degrees of Obstruction: An MRI Feature Tracking Study

BACKGROUND

The alteration of left atrial (LA) phasic function in subacute and chronic pulmonary embolism (PE) patients is unclear.

PURPOSE

To investigate LA phasic strain and LA-right ventricular (RV) interaction in subacute and chronic PE patients with different degrees of obstruction by MRI-feature tracking (MRI-FT).

STUDY TYPE

Retrospective.

POPULATION

One hundred three PE patients (54 subacute [2 weeks to 3 months after initial symptoms], 49 chronic [>3 months after initial symptoms]) and 80 controls.

FIELD STRENGTH/SEQUENCE

3.0 T/balanced steady state free precession sequence.

ASSESSMENT

Patients were divided into mild (pulmonary artery obstruction index [PAOI] < 30%, N = 57), moderate (30% ≤ PAOI < 50%, N = 27), and severe (50% ≥ PAOI, N = 19) PE subgroups. LA reservoir, conduit, and active pump longitudinal strains (εs, εe, and εa) and strain rates (SRs, SRe, and SRa) and biventricular global strains were measured. Determinants of LA strains were investigated.

STATISTICAL TESTS

ANOVA, t-tests, Mann-Whitney U tests, linear regression. P < 0.05 was considered statistically significant.

RESULTS

For both subacute and chronic PE patients, LA reservoir, conduit, and active pump strains and strain rates were significantly lower than in controls. However, there were no significant differences in LA strains between patients with subacute and chronic PE (P = 0.933, 0.625, and 0.630 for εs, εe, and εa). The severe PE subgroup had significantly higher εa and SRa than the mild and moderate PE subgroups. LA strains were significantly correlated with RV diameter and biventricular strains, and RV diameter (β = -6.836, -4.084, and -1.899 for εs, εe, and εa) was independently associated with LA strains after adjustment for other factors (R2 = 0.627, 0.536, and 0.437 for εs, εe, and εa).

DATA CONCLUSION

LA phasic function evaluated by MRI-FT was significantly impaired in subacute and chronic PE patients, and LA active pump function in the severe PE subgroup was higher than that in the mild and moderate PE subgroups. The independent association between RV diameter and LA strains demonstrates that RV diameter may be an important indicator for monitoring LA dysfunction in PE patients.

EVIDENCE LEVEL

3 TECHNICAL EFFICACY: Stage 3.

Useful central mechanical circulatory support system for critical biventricular heart failure associated with high pulmonary vascular resistance

BACKGROUND

Peripheral veno-arterial extracorporeal membrane oxygenation (ECMO) is a powerful life-saving tool; however, it can sometimes induce severe pulmonary edema in patients with critical heart failure. We report favorable outcomes in critically ill patients by using a central ECMO system with an innovative blood perfusion method.

METHODS

We analyzed 10 patients with severe heart failure and pulmonary edema who were treated with the central ECMO system at our institution between April 2022 and October 2023. The system consists of central cannulation with two inflows from the right atrium and left ventricle, and two outflows to the aorta and pulmonary artery, connected by two Y-connectors to a single ECMO circuit (RALV-AOPA ECMO). In this system, blood flow to the pulmonary artery is adjusted and mean pulmonary artery pressure is limited to <20 mm Hg, which reduces right ventricular afterload and prevents the worsening of pulmonary edema and hemorrhage.

RESULTS

Six patients were diagnosed with fulminant lymphocytic myocarditis, and four were diagnosed with coronavirus disease 2019-related myocardial injury. The ejection fraction was 6.5 ± 4.1%. The average intraoperative pulmonary vascular resistance was 4.6 ± 1.3 Wood units. After 24 h, the mean pulmonary arterial pressure was 12.8 ± 4.3 mm Hg, and pulmonary vascular resistance was 1.5 ± 0.3 Wood units. The duration of central RALV-AOPA ECMO was 3.7 ± 2.1 days. Finally, six patients were weaned, three received HeartMate3, and one received heart transplantation. At follow-up, all patients remained alive (428 ± 208 days), and two patients experienced cerebrovascular accidents without any lasting sequelae.

CONCLUSIONS

The central RALV-AOPA ECMO is an innovative system that achieves early improvement in pulmonary vascular resistance and is safe and feasible for patients with acute biventricular failure and pulmonary edema.

Right Heart Failure in the Intensive Care Unit: Etiology, Pathogenesis, Diagnosis, and Treatment

Right heart (RH) failure carries a high rate of morbidity and mortality. Patients who present with RH failure often exhibit complex aberrant cardio-pulmonary physiology with varying presentations. The treatment of RH failure almost always requires care and management from an intensivist. Treatment options for RH failure patients continue to evolve rapidly with multiple options available, including different pharmacotherapies and mechanical circulatory support devices that target various components of the RH circulatory system. An understanding of the normal RH circulatory physiology, treatment, and support options for the RH failure patients is necessary for all intensivists to improve outcomes. The purpose of this review is to provide clinical guidance on the diagnosis and management of RH failure within the intensive care unit setting, and to highlight the different pathophysiological manifestations of RH failure, its hemodynamics, and treatment options available at the disposal of the intensivist.

Clinical parameters of death and heart failure hospitalization in biventricular systolic dysfunction assessed via cardiac magnetic resonance

AIMS

While factors associated with adverse events are well elucidated in setting of isolated left ventricular dysfunction, clinical and imaging-based prognosticators of adverse outcomes are lacking in context of biventricular dysfunction. The purpose of this study was to establish role of clinical variables in prognosis of biventricular heart failure (HF), as assessed by cardiac magnetic resonance imaging.

METHODS

Study cohort consisted of 840 patients enrolled in DERIVATE registry with coexisting CMR-derived right ventricular (RV) and left ventricular (LV) dysfunction, as defined by RV and LV ejection fractions ≤45 % and ≤ 50 %, respectively. The primary objective was to identify factors associated with adverse long-term outcomes, defined as composite of all-cause death and HF hospitalizations (DHFH). Kaplan-Meir curves were plotted for survival analysis. Cox proportional hazard models were constructed to estimate adjusted hazard ratios (aHRs) and associated 95 % confidence intervals for clinical variables and their correlation with adverse events.

RESULTS

Mean age was 61.0 years; 83.1 % were male, 26.6 % had diabetes mellitus (DM), and 45.9 % had non-ischemic cardiomyopathy. At median follow-up of 2 years, DHFH occurred in 32.5 % of the cohort. Kaplan-Meir analysis showed higher rate of DHFH in patients with DM (35.2 % vs. 22.6 %, p < 0.001). Multivariate Cox regression analysis showed that DM was independently associated with DHFH (aHR 1.61 [95 % CI: 1.15-2.25]; p = 0.003). Importantly, ACE-inhibitor/ARB usage in patients with DM was associated with significant reduction in DHFH (aHR 0.53 [95 % CI: 0.31-0.90]; p = 0.02).

CONCLUSION

In patients with biventricular HF, DM was a strong predictor of DHFH, with ACE-inhibitor/ARB usage having cardioprotective effect.

Evolving perspectives on aortic stenosis: the increasing importance of evaluating the right ventricle before aortic valve intervention

Aortic stenosis (AS) was historically considered a disease of the left side of the heart, with the main pathophysiological impact being predominantly on the left ventricle (LV). However, progressive pressure overload in AS can initiate a cascade of extra-valvular myocardial remodeling that could also precipitate maladaptive alterations in the structure and function of the right ventricle (RV). The haemodynamic and clinical importance of these changes in patients with AS have been largely underappreciated in the past. Contemporary data indicates that RV dilatation or impairment identifies the AS patients who are at increased risk of adverse clinical outcomes after aortic valve replacement (AVR). It is now increasingly recognised that effective quantitative assessment of the RV plays a key role in delineating the late clinical stage of AS, which could improve patient risk stratification. Despite the increasing emphasis on the pathological significance of RV changes in AS, it remains to be established if earlier detection of these changes can improve the timing for intervention. This review will summarise the features of normal RV physiology and the mechanisms responsible for RV impairment in AS. In addition, we will discuss the multimodality approach to the comprehensive assessment of RV size, function and mechanics in AS patients. Finally, we will review the emerging evidence reinforcing the negative impact of RV dysfunction on clinical outcomes in AS patients treated with AVR.

The Non-invasive Assessment of the Pulmonary Circulation-Right Ventricular Functional Unit: Diagnostic and Prognostic Implications

The pulmonary circulation and the right ventricle play a pivotal role in the global hemodynamics of human beings, so much so that their close interaction is encapsulated in the concept of a "morpho-functional unit". In this review we aim to pinpoint the strengths and weaknesses of various noninvasive established techniques. The goal is to detect early morphologic and/or functional changes in the pulmonary circulation and right ventricular unit, which is crucial for tailoring treatments and prognostic assessments. The scope of this review includes resting and stress echocardiography, cardiopulmonary exercise testing, computed tomography, and cardiac magnetic resonance in characterizing the pulmonary circulation-right ventricular unit both morphologically and functionally.

An Update on the Diagnosis and Management of Acute Right Heart Failure

Right ventricular (RV) dysfunction and resultant acute right heart failure (ARHF) is a rapidly growing field of interest, driven by increasing appreciation of its contribution to heart failure morbidity and mortality. Understanding of ARHF pathophysiology has advanced dramatically over recent years and can be broadly described as RV dysfunction related to acute changes in RV afterload, contractility, preload, or left ventricular dysfunction. There are several diagnostic clinical signs and symptoms as well as imaging and hemodynamic assessments that can provide insight into the degree of RV dysfunction. Medical management is tailored to the different causative pathologies, and in cases of severe or end-stage dysfunction, mechanical circulatory support can be utilized. In this review, we describe the pathophysiology of ARHF, how its diagnosis is established by clinical signs and symptoms and imaging findings, and provide an overview of treatment options, both medical and mechanical.

Gut microbiota contributes to high-altitude hypoxia acclimatization of human populations

BACKGROUND

The relationship between human gut microbiota and high-altitude hypoxia acclimatization remains highly controversial. This stems primarily from uncertainties regarding both the potential temporal changes in the microbiota under such conditions and the existence of any dominant or core bacteria that may assist in host acclimatization.

RESULTS

To address these issues, and to control for variables commonly present in previous studies which significantly impact the results obtained, namely genetic background, ethnicity, lifestyle, and diet, we conducted a 108-day longitudinal study on the same cohort comprising 45 healthy Han adults who traveled from lowland Chongqing, 243 masl, to high-altitude plateau Lhasa, Xizang, 3658 masl, and back. Using shotgun metagenomic profiling, we study temporal changes in gut microbiota composition at different timepoints. The results show a significant reduction in the species and functional diversity of the gut microbiota, along with a marked increase in functional redundancy. These changes are primarily driven by the overgrowth of Blautia A, a genus that is also abundant in six independent Han cohorts with long-term duration in lower hypoxia environment in Shigatse, Xizang, at 4700 masl. Further animal experiments indicate that Blautia A-fed mice exhibit enhanced intestinal health and a better acclimatization phenotype to sustained hypoxic stress.

CONCLUSIONS

Our study underscores the importance of Blautia A species in the gut microbiota's rapid response to high-altitude hypoxia and its potential role in maintaining intestinal health and aiding host adaptation to extreme environments, likely via anti-inflammation and intestinal barrier protection.

Impact of Pre-Transplant Left Ventricular Diastolic Pressure on Primary Graft Dysfunction after Lung Transplantation: A Narrative Review

Lung transplantation (LT) constitutes the last therapeutic option for selected patients with end-stage respiratory disease. Primary graft dysfunction (PGD) is a form of severe lung injury, occurring in the first 72 h following LT and constitutes the most common cause of early death after LT. The presence of pulmonary hypertension (PH) has been reported to favor PGD development, with a negative impact on patients' outcomes while complicating medical management. Although several studies have suggested a potential association between pre-LT left ventricular diastolic dysfunction (LVDD) and PGD occurrence, the underlying mechanisms of such an association remain elusive. Importantly, the heterogeneity of the study protocols and the various inclusion criteria used to define the diastolic dysfunction in those patients prevents solid conclusions from being drawn. In this review, we aim at summarizing PGD mechanisms, risk factors, and diagnostic criteria, with a further focus on the interplay between LVDD and PGD development. Finally, we explore the predictive value of several diastolic dysfunction diagnostic parameters to predict PGD occurrence and severity.

Application of an echocardiographic index to characterize right ventricular-pulmonary arterial coupling in heart failure

Heart failure (HF), with its high morbidity and mortality, remains a global public health issue. Right ventricular (RV) dysfunction is a sign of deterioration in the natural history of HF, and a thorough evaluation of the relationship between RV contractility and its afterload through RV-pulmonary arterial (RV-PA) coupling can aid in accurately assessing overall RV function. The ratio of RV end-systolic elastance (Ees) to pulmonary arterial elastance (Ea) invasively measured by right heart catheterization served as the gold standard for evaluating RV-PA coupling. An echocardiographic index termed tricuspid annular plane systolic excursion/pulmonary artery systolic pressure (TAPSE/PASP) has been shown to correlate well with Ees/Ea. TAPSE/PASP is recognized as a non-invasive surrogate of RV-PA coupling and has been extensively studied in patients with HF. This review briefly describes the methods of assessing RV-PA coupling, mainly discussing echocardiography, summarizes the clinical utility of TAPSE/PASP in patients with different HF types, and provides an overview of the available literature.

Comparison of admittance and cardiac magnetic resonance generated pressure-volume loops in a porcine model

Objective. Pressure-volume loop analysis, traditionally performed by invasive pressure and volume measurements, is the optimal method for assessing ventricular function, while cardiac magnetic resonance (CMR) imaging is the gold standard for ventricular volume estimation. The aim of this study was to investigate the agreement between the assessment of end-systolic elastance (Ees) assessed with combined CMR and simultaneous pressure catheter measurements compared with admittance catheters in a porcine model.Approach. Seven healthy pigs underwent admittance-based pressure-volume loop evaluation followed by a second assessment with CMR during simultaneous pressure measurements.Main results. Admittance overestimated end-diastolic volume for both the left ventricle (LV) and the right ventricle (RV) compared with CMR. Further, there was an underestimation of RV end-systolic volume with admittance. For the RV, however, Ees was systematically higher when assessed with CMR plus simultaneous pressure measurements compared with admittance whereas there was no systematic difference in Ees but large differences between admittance and CMR-based methods for the LV.Significance. LV and RV Ees can be obtained from both admittance and CMR based techniques. There were discrepancies in volume estimates between admittance and CMR based methods, especially for the RV. RV Ees was higher when estimated by CMR with simultaneous pressure measurements compared with admittance.

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.

Increasing Levels of Positive End-expiratory Pressure Cause Stepwise Biventricular Stroke Work Reduction in a Porcine Model

BACKGROUND

Positive end-expiratory pressure (PEEP) is commonly applied to avoid atelectasis and improve oxygenation in patients during general anesthesia but affects cardiac pressures, volumes, and loading conditions through cardiorespiratory interactions. PEEP may therefore alter stroke work, which is the area enclosed by the pressure-volume loop and corresponds to the external work performed by the ventricles to eject blood. The low-pressure right ventricle may be even more susceptible to PEEP than the left ventricle. The authors hypothesized that increasing levels of PEEP would reduce stroke work in both ventricles.

METHODS

This was a prospective, observational, experimental study. Six healthy female pigs of approximately 60 kg were used. PEEP was stepwise increased from 0 to 5, 7, 9, 11, 13, 15, 17, and 20 cm H2O to cover the clinical spectrum of PEEP. Simultaneous, biventricular invasive pressure-volume loops, invasive blood pressures, and ventilator data were recorded.

RESULTS

Increasing PEEP resulted in stepwise reductions in left (5,740 ± 973 vs. 2,303 ± 1,154 mmHg · ml; P < 0.001) and right (2,064 ± 769 vs. 468 ± 133 mmHg · ml; P < 0.001) ventricular stroke work. The relative stroke work reduction was similar between the two ventricles. Left ventricular ejection fraction, afterload, and coupling were preserved. On the contrary, PEEP increased right ventricular afterload and caused right ventriculo-arterial uncoupling (0.74 ± 0.30 vs. 0.19 ± 0.13; P = 0.01) with right ventricular ejection fraction reduction (64 ± 8% vs. 37 ± 7%, P < 0.001).

CONCLUSIONS

A stepwise increase in PEEP caused stepwise reduction in biventricular stroke work. However, there are important interventricular differences in response to increased PEEP levels. PEEP increased right ventricular afterload leading to uncoupling and right ventricular ejection fraction decline. These findings may support clinical decision-making to further optimize PEEP as a means to balance between improving lung ventilation and preserving right ventricular function.

EDITOR’S PERSPECTIVE

Feasibility of a Composite Measure of Pulmonary Vascular Impedance and Application to Patients with Chronic RV Failure Post LVAD Implant

Pulmonary vascular impedance (PVZ) describes RV afterload in the frequency domain and has not been studied extensively in LVAD patients. We sought to determine (1) feasibility of calculating a composite (c)PVZ using standard of care (SoC), asynchronous, pulmonary artery pressure (PAP) and flow (PAQ) waveforms; and (2) if chronic right ventricular failure (RVF) post-LVAD implant was associated with changes in perioperative cPVZ.PAP and PAQ were obtained via SoC procedures at three landmarks: T(1), Retrospectively, pre-operative with patient conscious; and T(2) and T(3), prospectively with patient anesthetized, and either pre-sternotomy or chest open with LVAD, respectively. Additional PAP's were taken at T(4), following chest closure; and T(5), 4-24 h post chest closure. Harmonics (z) were calculated by Fast Fourier Transform (FFT) with cPVZ(z) = FFT(PAP)/FFT(PAQ). Total pulmonary resistance Z(0); characteristic impedance Zc, mean of cPVZ(2-4); and vascular stiffness PVS, sum of cPVZ(1,2), were compared at T(1,2,3) between +/-RVF groups.Out of 51 patients, nine experienced RVF. Standard hemodynamics and changes in cPVZ-derived parameters were not significant between groups at any T.In conclusion, cPVZ calculated from SoC measures is possible. Although data that could be obtained were limited it suggests no difference in RV afterload for RVF patients post-implant. If confirmed in larger studies, focus should be placed on cardiac function in these subjects.

Right ventricular systolic function and mechanical dyssynchrony in ischemic or non-ischemic dilated cardiomyopathy: A speckle-tracking study

AIM

This study assessed RV dyssynchrony (irrespective to QRS duration) and RV systolic function in non-ischemic dilated cardiomyopathy (NIDCM) versus ischemic dilated cardiomyopathy (IDCM) patients by using different echo-Doppler modalities.

METHODS

Eighty-five cases (48 patients with DCM [whether ischemic or non-ischemic] and 37 age-matched healthy controls) were studied. Conventional echo-Doppler study, tissue Doppler (TDI), and speckle tracking (STE) were carried out to measure LV and RV systolic function. Time-to-peak negative longitudinal strain at the four RV sites were assessed by TDI derived strain and 2D speckle tracking.

RESULTS

Patients with DCM (whether ischemic or non-ischemic) had significantly lower fractional area change, RV tricuspid annular systolic velocity (p < .001 for both), tricuspid annular plane systolic excursion (p = .01), RV-GLS whether TDI or 2D derived (p < .001). Twenty-nine patients (60%) showed right intraventricular delay (RV4SD > 60 ms). The RV-dyssynchrony index was negatively correlated to %FAC (r = -.362, p = .01), RV Sm (r = -.312, p = .04), and 2D-RV GLS (r = -.305, p = .05). Insignificant higher RV-dysynchrony index was detected in NIDCM compared to IDCM group; however, the basal septal segment was significantly delayed in dilated group. More impaired RV systolic function was detected in ischemic group. 2D STE and TDI showed a significant correlation in the assessment of the right-intraventricular delay (p = .001).

CONCLUSION

Right-intraventricular dyssynchrony are detectable in patients with dilated cardiomyopathy (whether ischemic or non-ischemic) with a higher statistically insignificant value in non-ischemic group by using tissue Doppler imaging and 2D speckle tracking. More impairment of the RV systolic function was noticed in the ischemic group. Impaired RV systolic function was associated with right intraventricular delay.

Ventricular interdependence in critically ill patients: from physiology to bedside

The review focuses on the mechanism of ventricular interdependence, a frequently encountered phenomena, especially in critically ill patients. It is explained by the anatomy of the heart, with two ventricles sharing a common wall, the septum, and nested in an acutely inextensible envelope, the pericardium. In pathological situation, it results in abnormal movements of the interventricular septum driven by respiration, leading to abnormal filling of one or the other ventricle. Ventricular interdependence has several clinical applications and explains some situations of hemodynamic impairment, especially in situations of cardiac tamponade, severe acute asthma, right ventricular (RV) overload, or more simply, in case of positive pressure ventilation with underlying acute pulmonary hypertension. Ventricular interdependence can be monitored with pulmonary arterial catheter or echocardiography. Knowledge of this phenomena has very concrete clinical applications in the management of filling or in the prevention or treatment of RV overload.

Role of Exercise Stress Echocardiography in Pulmonary Hypertension

Resting and exercise right heart catheterisation is the gold standard method to diagnose and differentiate types of pulmonary hypertension (PH). As it carries technical challenges, the question arises if non-invasive exercise stress echocardiography may be used as an alternative. Exercise echocardiography can unmask exercise PH, detect the early stages of left ventricular diastolic dysfunction, and, therefore, differentiate between pre- and post-capillary PH. Regardless of the underlying aetiology, a developed PH is associated with increased mortality. Parameters of overt right ventricle (RV) dysfunction, including RV dilation, reduced RV ejection fraction, and elevated right-sided filling pressures, are detectable with resting echocardiography and are associated with worse outcome. However, these measures all fail to identify occult RV dysfunction. Echocardiographic measures of RV contractile reserve during exercise echocardiography are very promising and provide incremental prognostic information on clinical outcome. In this paper, we review pulmonary haemodynamic response to exercise, briefly describe the modalities for assessing pulmonary haemodynamics, and discuss in depth the contemporary key clinical application of exercise stress echocardiography in patients with PH.

Cardiac magnetic resonance for prophylactic implantable-cardioverter defibrillator therapy international study: prognostic value of cardiac magnetic resonance-derived right ventricular parameters substudy

AIMS

Right ventricular systolic dysfunction (RVSD) is an important determinant of outcomes in heart failure (HF) cohorts. While the quantitative assessment of RV function is challenging using 2D-echocardiography, cardiac magnetic resonance (CMR) is the gold standard with its high spatial resolution and precise anatomical definition. We sought to investigate the prognostic value of CMR-derived RV systolic function in a large cohort of HF with reduced ejection fraction (HFrEF).

METHODS AND RESULTS

Study cohort comprised of patients enrolled in the CarDiac MagnEtic Resonance for Primary Prevention Implantable CardioVerter DefibrillAtor ThErapy registry who had HFrEF and had simultaneous baseline CMR and echocardiography (n = 2449). RVSD was defined as RV ejection fraction (RVEF) <45%. Kaplan-Meier curves and cox regression were used to investigate the association between RVSD and all-cause mortality (ACM). Mean age was 59.8 ± 14.0 years, 42.0% were female, and mean left ventricular ejection fraction (LVEF) was 34.0 ± 10.8. Median follow-up was 959 days (interquartile range: 560-1590). RVSD was present in 936 (38.2%) and was an independent predictor of ACM (adjusted hazard ratio = 1.44; 95% CI [1.09-1.91]; P = 0.01). On subgroup analyses, the prognostic value of RVSD was more pronounced in NYHA I/II than in NYHA III/IV, in LVEF <35% than in LVEF ≥35%, and in patients with renal dysfunction when compared to those with normal renal function.

CONCLUSION

RV systolic dysfunction is an independent predictor of ACM in HFrEF, with a more pronounced prognostic value in select subgroups, likely reflecting the importance of RVSD in the early stages of HF progression.

Management of Post-Myocardial Infarction Right Ventricular Failure

Right ventricular failure (RVF) due to an acute myocardial infarction (MI) has been associated with high morbidity and mortality. Initial treatment is guided by early recognition and prompt revascularization. Current management of post-MI RVF is built upon expert consensus and is also informed by RVF from other etiologies, including massive pulmonary embolism, left ventricular assist device-associated right ventricular dysfunction, postcardiotomy shock, etc.; this speaks to the limited data available on the specific management of RVF in acute MI. The goal of this review is to discuss the current literature on the pathophysiology, general management considerations, interventional management, hemodynamic monitoring, medical management, and mechanical circulatory support of MI-induced RVF.

Perioperative cardiovascular pathophysiology in patients undergoing lung resection surgery: a narrative review

Although thoracic surgery is understood to confer a high risk of postoperative respiratory complications, the substantial haemodynamic challenges posed are less well appreciated. This review highlights the influence of cardiovascular comorbidity on outcome, reviews the complex pathophysiological changes inherent in one-lung ventilation and lung resection, and examines their influence on cardiovascular complications and postoperative functional limitation. There is now good evidence for the presence of right ventricular dysfunction postoperatively, a finding that persists to at least 3 months. This dysfunction results from increased right ventricular afterload occurring both intraoperatively and persisting postoperatively. Although many patients adapt well, those with reduced right ventricular contractile reserve and reduced pulmonary vascular flow reserve might struggle. Postoperative right ventricular dysfunction has been implicated in the aetiology of postoperative atrial fibrillation and perioperative myocardial injury, both common cardiovascular complications which are increasingly being appreciated to have impact long into the postoperative period. In response to the physiological demands of critical illness or exercise, contractile reserve, flow reserve, or both can be overwhelmed resulting in acute decompensation or impaired long-term functional capacity. Aiding adaptation to the unique perioperative physiology seen in patients undergoing thoracic surgery could provide a novel therapeutic avenue to prevent cardiovascular complications and improve long-term functional capacity after surgery.

Pulmonary artery wave reflection and right ventricular function after lung resection

BACKGROUND

Lung resection has been shown to impair right ventricular function. Although conventional measures of afterload do not change, surgical ligation of a pulmonary artery branch, as occurs during lobectomy, can create a unilateral proximal reflection site, increasing wave reflection (pulsatile component of afterload) and diverting blood flow through the contralateral pulmonary artery. We present a cardiovascular magnetic resonance imaging (MRI) observational cohort study of changes in wave reflection and right ventricular function after lung resection.

METHODS

Twenty-seven patients scheduled for open lobectomy for suspected lung cancer underwent cardiovascular MRI preoperatively, on postoperative Day 2, and at 2 months. Wave reflection was assessed in the left and right pulmonary arteries (operative and non-operative, as appropriate) by wave intensity analysis and calculation of wave reflection index. Pulmonary artery blood flow distribution was calculated as percentage of total blood flow travelling in the non-operative pulmonary artery. Right ventricular function was assessed by ejection fraction and strain analysis.

RESULTS

Operative pulmonary artery wave reflection increased from 4.3 (2.1-8.8) % preoperatively to 9.5 (4.9-14.9) % on postoperative Day 2 and 8.0 (2.3-11.7) % at 2 months (P<0.001) with an associated redistribution of blood flow towards the nonoperative pulmonary artery (r>0.523; P<0.010). On postoperative Day 2, impaired right ventricular ejection fraction was associated with increased operative pulmonary artery wave reflection (r=-0.480; P=0.028) and pulmonary artery blood flow redistribution (r=-0.545; P=0.011). At 2 months, impaired right ventricular ejection fraction and right ventricular strain were associated with pulmonary artery blood flow redistribution (r=-0.634, P=0.002; r=0.540, P=0.017).

CONCLUSIONS

Pulsatile afterload increased after lung resection. The unilateral increase in operative pulmonary artery wave reflection resulted in redistribution of blood flow through the nonoperative pulmonary artery and was associated with right ventricular dysfunction.

CLINICAL TRIAL REGISTRATION

NCT01892800.

Right ventricular dysfunction predicts outcome after transcatheter mitral valve repair for primary mitral valve regurgitation

AIMS

Right ventricular dysfunction (RVD), as expressed by right ventricular to pulmonary artery coupling, has recently been identified as a strong outcome predictor in patients undergoing mitral valve edge-to-edge repair (M-TEER) for secondary mitral regurgitation (MR). The aim of this study was to define RVD in patients undergoing M-TEER for primary MR (PMR) and to evaluate its impact on procedural MR reduction, symptomatic development and 2-year all-cause mortality.

METHODS AND RESULTS

This multicentre study included patients undergoing M-TEER for symptomatic PMR at nine international centres. The study cohort was divided into a derivation (DC) and validation cohort (VC) for calculation and validation of the best discriminatory value for RVD. A total of 648 PMR patients were included in the study. DC and VC were comparable regarding procedural success and outcomes at follow-up. Sensitivity analysis identified RVD as an independent predictor for 2-year mortality in the DC (hazard ratio [HR] 2.37, 95% confidence interval [CI] 1.47-3.81, p < 0.001), which was confirmed in the VC (HR 2.06, 95% CI 1.36-3.13, p < 0.001). Procedural success (MR ≤2+) and symptomatic improvement at follow-up (New York Heart Association [NYHA] class ≤II) were lower in PMR patients with RVD (MR ≤2+: 82% vs. 93%, p = 0.002; NYHA class ≤II: 57.3% vs. 66.5%, p = 0.09 for with vs. without RVD). In all PMR patients, the presence of RVD significantly impaired 2-year survival after M-TEER (HR 2.23, 95% CI 1.63-3.05, p < 0.001).

CONCLUSIONS

Mitral valve edge-to-edge repair is an effective treatment option for PMR patients. The presence of RVD is associated with less MR reduction, less symptomatic improvement and increased 2-year mortality. Accordingly, RVD might be included into pre-procedural prognostic considerations.

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

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

Relationship between Pulmonary Regurgitation and Ventriculo-Arterial Interactions in Patients with Post-Early Repair of Tetralogy of Fallot: Insights from Wave-Intensity Analysis

This study aimed to investigate the effect of pulmonary regurgitation (PR) on left ventricular ventriculo-arterial (VA) coupling in patients with repaired tetralogy of Fallot (ToF). It was hypothesised that increasing PR severity results in a smaller forward compression wave (FCW) peak in the aortic wave intensity, because of right-to-left ventricular interactions. The use of cardiovascular magnetic resonance (CMR)-derived wave-intensity analysis provided a non-invasive comparison between patients with varying PR degrees. A total of n = 201 patients were studied and both hemodynamic and wave-intensity data were compared. Wave-intensity peaks and areas of the forward compression and forward expansion waves were calculated as surrogates of ventricular function. Any extent of PR resulted in a significant reduction in the FCW peak. A correlation was found between aortic distensibility and the FCW peak, suggesting unfavourable (VA) coupling in patients that also present stiffer ascending aortas. Data suggest that VA coupling is affected by increased impedance.

Right and left ventricular structures and functions in acute HFpEF: comparing the hypertensive pulmonary edema and worsening heart failure phenotypes

BACKGROUND

Limited data are available on right (RV) and left (LV) ventricular structures and functions in acute heart failure with preserved ejection fraction (AHF-pEF) presenting with hypertensive pulmonary edema (APE) versus predominant peripheral edema (peHF).

METHODS AND RESULTS

In a prospective study of consecutive patients with AHF-pEF, 80 patients met inclusion and not exclusion criteria, and underwent echocardiographic and laboratory examination in the emergency ward. The survived (94%) were re-evaluated at the discharge. At admission, systolic, diastolic, pulse blood pressure (BP), and high sensitivity troponin I were higher (all P < 0.05) with APE than with peHF while brain-type natriuretic peptide (BNP), hemoglobin and estimated glomerular filtration rate (eGFR) did not differ between the two phenotypes. LV volumes and EF were comparable between APE and peHF, but APE showed lower relative wall thickness (RWT), smaller left atrial (LA) volume, higher pulse pressure/stroke volume (PP/SV), and higher ratio between the peak velocities of the early diastolic waves sampled by traditional and tissue Doppler modality (mitral E/e', all P < 0.05). Right ventricular and atrial (RA) areas were smaller, tricuspid anular plane systolic excursion (TAPSE) and estimated pulmonary artery peak systolic pressure (sPAP) were higher with APE than with peHF (all P < 0.05) while averaged degree of severity of tricuspid insufficiency was greater with peHF than with APE. At discharge, PP/SV, mitral E/e', sPAP, RV sizes were reduced from admission in both phenotypes (all P < 0.05) and did not differ anymore between phenotypes, whereas LV EF and TAPSE did not show significant changes over time and treatments.

CONCLUSION

In AHF-pEF, at comparable BNP and LV EF, hypertensive APE showed eccentric LV geometry but smaller RV and RA sizes, and higher RV systolic function, increased LV ventricular filling and systemic arterial loads. AHF resolution abolished the differences in PP/SV and LV diastolic load between APE and peHF whereas APE remained associated with more eccentric RV and higher TAPSE.

Evaluation of right ventricular function in patients with pulmonary arterial hypertension by different right ventricular-pulmonary artery coupling methods

To compare the accuracy of end-systolic elasticity (Ees)/arterial elasticity (Ea) ratio measured by single beat estimation, pressure-volume loop and cardiac magnetic resonance (CMR) combined volume method in patients with pulmonary artery hypertension, and to find a feasible and reliable method to quantitatively evaluate the function of right ventricle in patients with pulmonary artery hypertension. Forty-nine pulmonary artery hypertension patients enrolled between May 2017 and May 2018 in our hospital were retrospectively analyzed. Firstly, measure Ees/Ea ratio by single beat estimation, pressure-volume loop and CMR combined volume method, then, compare Ees/Ea ratio with New York Heart Association (NYHA) classification and NT-proBNP value respectively to evaluate the accuracy of the 3 methods. Ees/Ea ratio measured by single beat estimation is 2.07 ± 1.01, correlation analysis is not statistically significant when compare with NYHA classification and NT-proBNP value (P > .05). Ees/Ea ratio measured by pressure-volume loop is 2.64 ± 1.48, correlation analysis is not statistically significant when compare with NYHA classification and NT-proBNP value (P > .05). Ees/Ea ratio measured by CMR combined volume method is 0.72 ± 0.43, correlation analysis is statistically significant when compare with NYHA classification and NT-proBNP with negative correlation (P < .05). Ees/Ea ratio decrease according to the increase of NT-proBNP value and the NYHA classification. There is linear regression equation between Ees/Ea ratio measured by CMR combined volume method and log (NT-proBNP) value: Y = -0.257X + 1.45, and the linear regression equation is statistically significant (P = .001). Ees/Ea ratio measured by CMR combined volume method is a feasible and reliable method to quantitatively evaluate the function of right ventricule in patients with pulmonary artery hypertension, which might be further verified in a larger patient population.

Utility of the tricuspid annular tissue doppler systolic velocity and pulmonary artery systolic pressure relationship in right ventricular systolic function assessment: A pilot study

BACKGROUND

Tricuspid annular plane systolic excursion (TAPSE) to pulmonary artery systolic pressure (PASP) ratio has been validated as a valuable noninvasive measure of right ventricular (RV) elastance and systolic function. However, the more reliable TA systolic (s') velocity measure of RV systolic function compared to TAPSE has not been previously studied.

METHODS

We conducted a pilot study using several variables of RV function in 50 patients with the main aim to determine which numerical expression between TA TDI s'/PASP and TAPSE/PASP ratio was most useful.

RESULTS

In a stepwise multiple regression analysis, TA TDI s'/PASP ratio (p < .0002); LVOT VTI/RVOT VTI ratio (p < .0002); RVOT VTI (p < .0047); TAPSE/PASP ratio (p < .0259) and TA TDI e' (p < .0292) were best in discriminating normal versus abnormal RV systolic function. Using receiver operator curve analysis, cut-off values for both TA TDI s'/PASP (>3.9 mm/c/mmHg) had 82.1% sensitivity and 77.3% specificity while the TAPSE/PASP (>.61 mm/mmHg) had 89.3% sensitivity and 68.2% specificity in identifying normal RV function in our studied population.

CONCLUSION

Our results indicate that TA TDI s'/PASP is a better mathematical expression when examining the relationship between RV contractility and RV resistance relationship. Furthermore, we also found that inclusion of RVOT VTI, RV diastolic properties, and left ventricular systolic function are important determinants of RV systolic function assessments and should be routinely included. Additional prospective studies are now needed to confirm these results using hemodynamic data.

Chitinase 3-like-1 contributes to the development of pulmonary vascular remodeling in pulmonary hypertension

Chitinase 3-like 1 (CHI3L1) is the prototypic chitinase-like protein mediating inflammation, cell proliferation, and tissue remodeling. Limited data suggests CHI3L1 is elevated in human pulmonary arterial hypertension (PAH) and is associated with disease severity. Despite its importance as a regulator of injury/repair responses, the relationship between CHI3L1 and pulmonary vascular remodeling is not well understood. We hypothesize that CHI3L1 and its signaling pathways contribute to the vascular remodeling responses that occur in pulmonary hypertension (PH). We examined the relationship of plasma CHI3L1 levels and severity of PH in patients with various forms of PH, including Group 1 PAH and Group 3 PH, and found that circulating levels of serum CHI3L1 were associated with worse hemodynamics and correlated directly with mean pulmonary artery pressure and pulmonary vascular resistance. We also used transgenic mice with constitutive knockout and inducible overexpression of CHI3L1 to examine its role in hypoxia-, monocrotaline-, and bleomycin-induced models of pulmonary vascular disease. In all 3 mouse models of pulmonary vascular disease, pulmonary hypertensive responses were mitigated in CHI3L1 null mice and accentuated in transgenic mice that overexpress CHI3L1. Finally, CHI3L1 alone was sufficient to induce pulmonary arterial smooth muscle cell proliferation, inhibit pulmonary vascular endothelial cell apoptosis, induce the loss of endothelial barrier function, and induce endothelial-to-mesenchymal transition. These findings demonstrate that CHI3L1 and its receptors play an integral role in pulmonary vascular disease pathobiology and may offer a novel target for the treatment PAH and PH associated with fibrotic lung disease.

Right ventricular strain related to pulmonary artery pressure predicts clinical outcome in patients with pulmonary arterial hypertension

Aims

In pulmonary arterial hypertension (PAH), the right ventricle (RV) is exposed to an increased afterload. In response, RV mechanics are altered. Markers which would relate RV function and afterload could therefore aid to understand this complex response system and could be of prognostic value. The aim of our study was to (i) assess the RV-arterial coupling using ratio between RV strain and systolic pulmonary artery pressure (sPAP), in patients with PAH, and (ii) investigate the prognostic value of this new parameter over other echocardiographic parameters.

Methods and results

Echocardiograms of 65 pre-capillary PAH patients (45 females, age 61 ± 15 years) were retrospectively analysed. Fractional area change (FAC), sPAP, tricuspid annular plane systolic excursion, and RV free-wall (FW) longitudinal strain (LS) were measured. A primary endpoint of death or heart/lung transplantation described clinical endpoint. Patients who reached a clinical endpoint had worse functional capacity (New York Heart Association), reduced RV function, and higher sPAP. Left ventricle function was similar in both groups. Only RVFW LS/sPAP ratio was found as an independent predictor of clinical endpoint in multivariable analysis (hazard ratio 8.3, 95% confidence interval 3.2–21.6, P &lt; 0.001). The RWFW LS/sPAP (cut-off 0.19) demonstrated a good accuracy for the prediction of reaching the clinical endpoint, with a sensitivity of 92% and specificity of 82.5%.

Conclusion

RVFW LS/sPAP ratio significantly predicts all-cause mortality and heart–lung transplantation, and was superior to other well-established parameters, in patients with pre-capillary PAH. We therefore propose RVFW LS/sPAP as a new prognostic echocardiographic marker.

Exploring the failing right ventricle in pulmonary hypertension by cardiac magnetic resonance: An in vivo study utilizing Macitentan

Cardiac magnetic resonance (CMR) imaging is used to assess the right ventricle (RV) of pulmonary hypertensive (PH) patients and more recently to track changes in response to therapy. We wished to investigate if repeat CMRs could be used to assess ventricular changes in the Sugen 5416 hypoxic (Su/Hx) rat model of PH treated with the dual endothelin receptor antagonist Macitentan. Male Sprague Dawley Su/Hx rats were dosed for 3 weeks with either vehicle or Macitentan (30 mg/kg) daily, control rats received only vehicle. All rats underwent three CMR scans; before treatment, 2 weeks into treatment, and end of the study. A separate group of Su/Hx and control rats, treated as above, underwent terminal hemodynamic measurements. Using terminal and CMR measurements, Macitentan was found to lower RV systolic pressure pulmonary artery remodeling and increase RV ejection fraction but not change RV hypertrophy (RVH). Repeat CMRs determined that Su/Hx rats treated with Macitentan had significantly reversed RVH via reducing RV mass as well as reducing elevated left ventricular eccentricity index; reductions in RV mass were also observed in Su/Hx vehicle rats exposed to normoxic conditions. We have demonstrated that repeat CMRs can be used to assess the volume and structural changes in the ventricles of the Su/Hx rat model. Using repeat CMRs has allowed us to build a more complete picture of the response of the RV and the left ventricle to treatment. It is unknown if these effects are a consequence of direct action on the RV or secondary to improvements in the lung vasculature.

Comparison of PCWP and LVEDP Measurements in Patients with Severe Aortic Stenosis Undergoing TAVI-Same Same but Different?

BACKGROUND

Pulmonary capillary wedge pressure (PCWP) and left ventricular end-diastolic pressure (LVEDP) are often used as equivalents for determination of pulmonary hypertension (PH). PH is a comorbidity in patients with severe aortic valve stenosis (AS) and associated with limited prognosis. The aim of the study was to examine the role of differentiated classification basis of PCWP and LVEDP in patients planning for transcatheter aortic valve implantation (TAVI).

METHODS

284 patients with severe AS completed a combined left (LHC) and right heart catheterization (RHC) as part of a TAVI planning procedure. Patients were categorized twice into subtypes of PH according to 2015 European Society of Cardiology (ESC) guidelines-on the one hand with PCWP and on the other hand with LVEDP as classification basis. PCWP-LVEDP relationships were figured out using Kaplan-Meier curves, linear regressions and Bland-Altman analysis.

RESULTS

Regarding 1-year mortality, Kaplan-Meier analyses showed similar curves in spite of different classification bases of PH subtypes according to PCWP or LVEDP with exception of pre-capillary PH subtype. PCWP-LVEDP association in the overall cohort was barely present (R = 0.210, R² = 0.044). When focusing analysis on PH patients only a slightly increased linear regression was noted compared to the overall cohort (R = 0.220, R² = 0.048). The strongest regression was observed in patients with creatinine ≥ 132 µmol/L (R = 0.357, R² = 0.127) and in patients with mitral regurgitation ≥ II° (R = 0.326, R² = 0.106).

CONCLUSIONS

In patients with severe AS, there is a weak association between hemodynamic parameters measured by LHC and RHC. RHC measurements alone are not suitable for risk stratification with respect to one-year mortality. If analysis of hemodynamic parameters is necessary in patients with severe AS scheduled for TAVI, measurement results of LHC and RHC should be combined and LVEDP could serve as a helpful indicator for risk assessment.

Right Ventricular Dyssynchrony in Patients With Chronic Thromboembolic Pulmonary Hypertension and Pulmonary Arterial Hypertension

BACKGROUND

Chronic thromboembolic pulmonary hypertension (CTEPH) and pulmonary arterial hypertension (PAH) are characterized by elevated pulmonary arterial pressure resulting in right heart failure. Right ventricular (RV) dyssynchrony may be associated with early-stage RV dysfunction; however, the differences in RV dyssynchrony between CTEPH and PAH and the factors contributing to RV dyssynchrony remain unclear.

METHODS AND RESULTS

Forty-four patients (CTEPH, 26; PAH, 18) were enrolled in this study. RV dyssynchrony was assessed by determining the standard deviation of the intervals from the peak QRS to peak systolic strain for 6 segments of the RV free and septal wall by using 2-dimensional speckle-tracking echocardiography (RV-6SD). The RV-6SD, pulmonary hemodynamics, echocardiographic findings, and patient demographics in CTEPH and PAH patients were compared and their correlations with RV-6SD were investigated. CTEPH patients were older and had significantly higher pulse pressure of the pulmonary artery (PP), tricuspid valve regurgitation pressure gradient, and RV-6SD, and lower pulmonary arterial compliance (PAC), despite showing comparable pulmonary arterial pressures. Age-adjusted multiple logistic analysis showed that RV-6SD and PAC were predictors of CTEPH rather than PAH. RV-SD6 was positively correlated with PP and RV dimension and negatively correlated with PAC.

CONCLUSIONS

CTEPH patients showed more evident RV dyssynchrony than PAH patients. Low PAC and a widened PP may delay RV free wall motion and cause RV dyssynchrony.

The added value of right ventricular function normalized for afterload to improve risk stratification of patients with pulmonary arterial hypertension

Background

Risk stratification is central to the management of pulmonary arterial hypertension (PAH). For this purpose, multiparametric tools have been developed, including the ESC/ERS risk score and its simplified versions derived from large database analysis such as the COMPERA and the French Pulmonary Hypertension Network (FPHN) registries. However, the distinction between high and intermediate-risk profiles may be difficult as the latter lacks granularity. In addition, neither COMPERA or FPHN strategies included imaging-derived markers. We thus aimed at investigating whether surrogate echocardiographic markers of right ventricular (RV) to pulmonary artery (PA) coupling could improve risk stratification in patients at intermediate-risk.

Material and methods

A single-center retrospective analysis including 102 patients with a diagnosis of PAH was performed. COMPERA and FPHN strategies were applied to stratify clinical risk. The univariate linear regression was used to test the influence of the echo-derived parameters qualifying the right heart (right ventricle basal diameter, right atrial area, and pressure, tricuspid regurgitation velocity, tricuspid annular plane systolic excursion -TAPSE-). Among these, the TAPSE and tricuspid regurgitation velocity ratio (TAPSE/TRV) as well as the TAPSE and systolic pulmonary artery pressure ratio (TAPSE/sPAP) were considered as surrogate of RV-PA coupling.

Results

TAPSE/TRV and TAPSE/sPAP resulted the more powerful markers of prognosis. Once added to COMPERA, TAPSE/TRV or TAPSE/sPAP significantly dichotomized intermediate-risk group in intermediate-to-low-risk (TAPSE/TRV≥3.74 mm∙nm/s)^-1 or TAPSE/sPAP≥0.24 mm/mmHg) and in intermediate-to-high-risk subgroups (TAPSE/TRV<3.74 mm∙(m/s)^-1 or TAPSE/sPAP<0.24 mm/mmHg). In the same way, TAPSE/TRV or TAPSE/sPAP was able to select patients at lower risk among those with 2, 1, and 0 low-risk criteria of both invasive and non-invasive FPHN registries.

Conclusions

Our results suggest that adopting functional-hemodynamic echo-derived parameters may provide a more accurate risk stratification in patients with PAH. In particular, TAPSE/TRV or TAPSE/sPAP improved risk stratification in patients at intermediate-risk, that otherwise would have remained less characterized.

The right ventricular involvement in dilated cardiomyopathy: prevalence and prognostic implications of the often-neglected child

Dilated cardiomyopathy (DCM) is a primary heart muscle disease characterized by left or biventricular systolic impairment. Historically, most of the clinical attention has been devoted to the evaluation of left ventricular function and morphology, while right ventricle (RV) has been for many years the forgotten chamber. Recently, progresses in cardiac imaging gave clinicians precious tools for the evaluation of RV, raising the awareness of the importance of biventricular assessment in DCM. Indeed, RV involvement is far from being uncommon in DCM, and the presence of right ventricular dysfunction (RVD) is one of the major negative prognostic determinants in DCM patients. However, some aspects such as the possible role of specific genetic mutations in determining the biventricular phenotype in DCM, or the lack of specific treatments able to primarily counteract RVD, still need research. In this review, we summarized the current knowledge on RV involvement in DCM, giving an overview on the epidemiology and pathogenetic mechanisms implicated in determining RVD. Furthermore, we discussed the imaging techniques to evaluate RV function and the role of RV failure in advanced heart failure.

The Pulmonary Artery Catheter in the Perioperative Setting: Should It Still Be Used?

The pulmonary artery catheter (PAC) was introduced into clinical practice in the 1970s and was initially used to monitor patients with acute myocardial infarctions. The indications for using the PAC quickly expanded to critically ill patients in the intensive care unit as well as in the perioperative setting in patients undergoing major cardiac and noncardiac surgery. The utilization of the PAC is surrounded by multiple controversies, with literature claiming its benefits in the perioperative setting, and other publications showing no benefit. The right interpretation of the hemodynamic parameters measured by the PAC and its clinical implications are of the utmost essence in order to guide a specific therapy. Even though clinical trials have not shown a reduction in mortality with the use of the PAC, it still remains a valuable tool in a wide variety of clinical settings. In general, the right selection of the patient population (high-risk patients with or without hemodynamic instability undergoing high-risk procedures) as well as the right clinical setting (centers with experience and expertise) are essential in order for the patient to benefit most from PAC use.

The physiologic basis of pulmonary arterial hypertension

Pulmonary arterial hypertension (PAH) is a rare dyspnea-fatigue syndrome caused by a progressive increase in pulmonary vascular resistance (PVR) and eventual right ventricular (RV) failure. In spite of extensive pulmonary vascular remodeling, lung function in PAH is generally well preserved, with hyperventilation and increased physiologic dead space, but minimal changes in lung mechanics and only mild to moderate hypoxemia and hypocapnia. Hypoxemia is mainly caused by a low mixed venous PO₂ from a decreased cardiac output. Hypocapnia is mainly caused by an increased chemosensitivity. Exercise limitation in PAH is cardiovascular rather than ventilatory or muscular. The extent of pulmonary vascular disease in PAH is defined by multipoint pulmonary vascular pressure-flow relationships with a correction for hematocrit. Pulsatile pulmonary vascular pressure-flow relationships in PAH allow for the assessment of RV hydraulic load. This analysis is possible either in the frequency-domain or in the time-domain. The RV in PAH adapts to increased afterload by an increased contractility to preserve its coupling to the pulmonary circulation. When this homeometric mechanism is exhausted, the RV dilates to preserve flow output by an additional heterometric mechanism. Right heart failure is then diagnosed by imaging of increased right heart dimensions and clinical systemic congestion signs and symptoms. The coupling of the RV to the pulmonary circulation is assessed by the ratio of end-systolic to arterial elastances, but these measurements are difficult. Simplified estimates of RV-PA coupling can be obtained by magnetic resonance or echocardiographic imaging of ejection fraction.

A computational model of contributors to pulmonary hypertensive disease: impacts of whole lung and focal disease distributions

Pulmonary hypertension has multiple etiologies and so can be difficult to diagnose, prognose, and treat. Diagnosis is typically made via invasive hemodynamic measurements in the main pulmonary artery and is based on observed elevation of mean pulmonary artery pressure. This static mean pressure enables diagnosis, but does not easily allow assessment of the severity of pulmonary hypertension, nor the etiology of the disease, which may impact treatment. Assessment of the dynamic properties of pressure and flow data obtained from catheterization potentially allows more meaningful assessment of the strain on the right heart and may help to distinguish between disease phenotypes. However, mechanistic understanding of how the distribution of disease in the lung leading to pulmonary hypertension impacts the dynamics of blood flow in the main pulmonary artery and/or the pulmonary capillaries is lacking. We present a computational model of the pulmonary vasculature, parameterized to characteristic features of pulmonary arterial hypertension and chronic thromboembolic pulmonary hypertension to help understand how the two conditions differ in terms of pulmonary vascular response to disease. Our model incorporates key features known to contribute to pulmonary vascular function in health and disease, including anatomical structure and multiple contributions from gravity. The model suggests that dynamic measurements obtained from catheterization potentially distinguish between distal and proximal vasculopathy typical of pulmonary arterial hypertension and chronic thromboembolic pulmonary hypertension. However, the model suggests a non-linear relationship between these data and vascular structural changes typical of pulmonary arterial hypertension and chronic thromboembolic pulmonary hypertension which may impede analysis of these metrics to distinguish between cohorts.

Right Ventricular Myocardial Adaptation Assessed by Two-Dimensional Speckle Tracking Echocardiography in Canine Models of Chronic Pulmonary Hypertension

Background: Pulmonary hypertension (PH) is a life-threatening disease in dogs characterized by an increase in pulmonary arterial pressure (PAP) and/or pulmonary vascular resistance. Right ventricle adapts to its pressure overload through various right ventricular (RV) compensative mechanisms: adaptive and maladaptive remodeling. The former is characterized by concentric hypertrophy and increased compensatory myocardial contractility, whereas the latter is distinguished by eccentric hypertrophy associated with impaired myocardial function. Objectives: To evaluate the RV adaptation associated with the increase of PAP using two-dimensional speckle tracking echocardiography. Animals: Seven experimentally induced PH models. Methods: Dogs were anesthetized and then a pulmonary artery catheter was placed via the right jugular vein. Canine models of PH were induced by the repeated injection of microspheres through the catheter and monitored pulmonary artery pressure. Dogs were performed echocardiography and hemodynamic measurements in a conscious state when baseline and systolic PAP (sPAP) rose to 30, 40, 50 mmHg, and chronic phase. The chronic phase was defined that the sPAP was maintained at 50 mmHg or more for 4 weeks without injection of microspheres. Results: Pulmonary artery to aortic diameter ratio, RV area, end-diastolic RV wall thickness, and RV myocardial performance index were significantly increased in the chronic phase compared with that in the baseline. Tricuspid annular plane systolic excursion was significantly decreased in the chronic phase compared with that in the baseline. The RV longitudinal strain was significantly decreased in the sPAP30 phase, increased in the sPAP40 and sPAP50 phases, and decreased in the chronic phase. Conclusions: Changes in two-dimensional speckle tracking echocardiography-derived RV longitudinal strain might reflect the intrinsic RV myocardial contractility during the PH progression, which could not be detected by conventional echocardiographic parameters.

Right ventricular and cyclic guanosine monophosphate signalling abnormalities in stages B and C of heart failure with preserved ejection fraction

Aims

Identifying early right ventricular (RV) dysfunction and impaired vasodilator reserve is challenging in heart failure with preserved ejection fraction (HFpEF). We hypothesized that cardiac magnetic resonance (CMR)‐based exercise imaging and serial cyclic guanosine monophosphate (cGMP) measurements can identify dynamic RV‐arterial uncoupling and responsiveness to pulmonary vasodilators at early stages of the HFpEF syndrome.

Methods and results

Patients with HFpEF (n = 16), impaired left ventricular relaxation due to concentric remodelling (LVCR, n = 7), and healthy controls (n = 8) underwent CMR at rest and during supine bicycle exercise with simultaneous measurements of central haemodynamics and circulating cGMP levels, before and after oral administration of 50 mg sildenafil. At rest, mean pulmonary artery pressures (mPAP) were higher in HFpEF, compared with LVCR and controls (27 ± 2, 18 ± 1, and 11 ± 1, respectively; P = 0.01), whereas biventricular volumes, heart rate, and stroke volume were similar. During exercise, LVCR and HFpEF had a greater increase in the ratio of mPAP over cardiac output than controls (5.50 ± 0.77 and 6.34 ± 0.86 vs. 2.24 ± 0.55 in controls, P = 0.005). The ratio of peak exercise to rest RV end‐systolic pressure‐volume, a surrogate of RV contractility, was significantly reduced in LVCR and HFpEF (2.32 ± 0.17 and 1.56 ± 0.08 vs. 3.49 ± 0.35 in controls, P < 0.001) and correlated with peak exercise VO₂ (R² = 0.648, P < 0.001). cGMP levels increased with exercise across the HFpEF spectrum (P < 0.05 vs. baseline), except when postcapillary pulmonary hypertension was present at rest (P = 0.73 vs. baseline). A single sildenafil administration failed to increase circulating cGMP levels and did not improve RV performance.

Conclusion

Exercise CMR identifies impaired RV‐arterial coupling at an early stage of HFpEF. Circulating cGMP levels phenocopy the haemodynamic spectrum in HFpEF but fail to increase after phosphodiesterase type 5 inhibition, endorsing the need for alternative interventions to increase cGMP signalling in HFpEF.

The echocardiographic ratio tricuspid annular plane systolic excursion/pulmonary arterial systolic pressure predicts short-term adverse outcomes in acute pulmonary embolism

AIMS

Right ventricular (RV) failure causes death from acute pulmonary embolism (PE), due to a mismatch between RV systolic function and increased RV afterload. We hypothesized that an echocardiographic ratio of this mismatch [RV systolic function by tricuspid annular plane systolic excursion (TAPSE) divided by pulmonary arterial systolic pressure (PASP)] would predict adverse outcomes better than each measurement individually, and would be useful for risk stratification in intermediate-risk PE.

METHODS AND RESULTS

This was a retrospective analysis of a single academic centre Pulmonary Embolism Response Team registry from 2012 to 2019. All patients with confirmed PE and a formal transthoracic echocardiogram performed within 2 days were included. All echocardiograms were analysed by an observer blinded to the outcome. The primary endpoint was a 7-day composite outcome of death or haemodynamic deterioration. Secondary outcomes were 7- and 30-day all-cause mortality. A total of 627 patients were included; 135 met the primary composite outcome. In univariate analysis, the TAPSE/PASP was associated with our primary outcome [odds ratio = 0.028, 95% confidence interval (CI) 0.010-0.087; P < 0.0001], which was significantly better than either TAPSE or PASP alone (P = 0.017 and P < 0.0001, respectively). A TAPSE/PASP cut-off value of 0.4 was identified as the optimal value for predicting adverse outcome in PE. TAPSE/PASP predicted both 7- and 30-day all-cause mortality, while TAPSE and PASP did not.

CONCLUSION

A combined echocardiographic ratio of RV function to afterload is superior in prediction of adverse outcome in acute intermediate-risk PE. This ratio may improve risk stratification and identification of the patients that will suffer short-term deterioration after intermediate-risk PE.

Changes in the Pulmonary Artery Wave Reflection in Dogs with Experimentally-Induced Acute Pulmonary Embolism and the Effect of Vasodilator

Simple Summary

Pulmonary hypertension (PH) remains a fatal disease, despite the advances in disease-specific therapies. This may be because the assessment of pulmonary hemodynamics in PH has not been established. Recently, several studies have reported that the pulmonary arterial wave reflection (PAWR) might influence the right ventricular afterload and could provide additional information regarding the severity and progression of PH. However, the pathophysiology of PAWR has some unclear points particularly in the case of acute pulmonary embolism (APE). The objective of this study was to investigate, for the first time, the characteristics of PAWR in a dog model of APE using dual-tipped sensor wire. From the result of the present study, after dogs developed PH by injections of dextran microsphere, PAWR was increased significantly along with the pulmonary vascular resistance (PVR) and reduced after vasodilator administration. In addition, PAWR was significantly correlated with PVR and right ventricular fractional area of change (FAC). These results indicating that PAWR may be useful as a new evaluation method in PH and may detect changes related to right ventricular afterload earlier than pulmonary artery pressure (PAP).

Abstract

Pulmonary hypertension (PH) is a complex syndrome that has been frequently diagnosed in dogs and humans and can be detected by Doppler echocardiography and invasive catheterization. Recently, PAWR attracts much attention as a noninvasive approach for the early detection of PH. The present study aims to investigate the PAWR changes in acute pulmonary embolism (APE) and highlight the response of PAWR variables to vasodilator therapy in dogs. For this purpose, anesthesia and catheterization were performed in 6 Beagle dogs. After that, APE was experimentally conducted by Dextran microsphere administration, followed by vasodilator (Nitroprusside; 1μg/kg/min/IV) administration. The hemodynamics, echocardiography, PVR and PAWR variables were evaluated at the baseline, after APE and after administration of nitroprusside. The result showed a significant increase in PVR, PAP, tricuspid regurgitation (TR) as well as PAWR variables following APE induction compared with the baseline (p < 0.05). Vasodilation caused by administration of nitroprusside reduced the mean atrial pressure, PVR and PAWR parameters. There were a significant correlation and linear regression between PAWR indices and PVR as well as right ventricular function parameters. In conclusion, PAWR is not only correlated with PVR but also the right ventricular function parameter, which indicates that PAWR may be useful as a new evaluation method in PH, considering that PAWR can assess both right ventricular afterload and right ventricular function.

Morphological Analysis of the Right Ventricular Endocardial Wall in Pulmonary Hypertension

Pulmonary hypertension (PH) is a chronic progressive disease diagnosed when the pressure in the main pulmonary artery, assessed by right heart catheterization (RHC), is greater than 25 mmHg. Changes in the pulmonary vasculature due to the high pressure yield an increase in the right ventricle (RV) afterload. This starts a remodeling process during which the ventricle exhibits changes in shape and eventually fails. RV models were obtained from the segmentation of cardiac magnetic resonance images at baseline and 1-year follow-up for a pilot study that involved 12 PH and 7 control subjects. The models were used to create surface meshes of the geometry and to compute the principal, mean, and Gaussian curvatures. Ten global curvature indices were calculated for each of the RV endocardial wall reconstructions at the end-diastolic volume (EDV) and end-systolic volume (ESV) phases of the cardiac cycle. Statistical analysis of the data was performed to discern if there are significant differences in the curvature indices between controls and the PH group, as well as between the baseline and follow-up phases for the PH subjects. Six curvature indices, namely, the Gaussian curvature at ESV, the mean curvature at EDV and ESV, the L2-norm of the mean curvature at ESV, and the L2-norm of the major principal curvature at EDV and ESV, were found to be significantly different between controls and PH subjects (p < 0.05). We infer that these geometry measures could be used as indicators of RV endocardial wall morphology changes. Two global parameters, the Gaussian and mean curvatures at ESV, showed significant changes at the one-year follow-up for the PH subjects (p < 0.05). The aforementioned geometry measures to assess changes in RV shape could be used as part of a noninvasive computational tool to aid clinicians in PH diagnostic and progression assessment, and to evaluate the effectiveness of treatment.

Right Ventricular Contraction Patterns in Patients Undergoing Transcatheter Tricuspid Valve Repair for Severe Tricuspid Regurgitation

OBJECTIVES

This study investigated patterns of right ventricular (RV) contraction by using cardiac magnetic resonance (CMR) imaging in patients undergoing transcatheter tricuspid valve repair (TTVR).

BACKGROUND

The role of RV function in patients with severe tricuspid regurgitation undergoing TTVR is poorly understood.

METHODS

Global RV dysfunction was defined as CMR-derived RV ejection fraction (RVEF) ≤45% and longitudinal RV dysfunction was defined as tricuspid annular plane systolic excursion (TAPSE) <17 mm on echocardiography. Patients were stratified into 3 types of RV contraction: type I, TAPSE ≥17 and RVEF >45%; type II, TAPSE <17 and RVEF >45%; and type III, TAPSE <17 and RVEF ≤45%. CMR feature tracking was performed to assess longitudinal and circumferential RV strain. The primary outcome was a composite of all-cause mortality or first heart failure hospitalization.

RESULTS

Of 79 patients (median age 79 years, 51% female), 18 (23%) presented with global and 40 (51%) presented with longitudinal RV dysfunction. The composite outcome occurred in 22 patients (median follow-up 362 days). Global RV dysfunction but not longitudinal RV dysfunction (hazard ratio: 6.62; 95% confidence interval: 2.77-15.77; and hazard ratio: 1.30; 95% confidence interval: 0.55-3.08, respectively) was associated with the composite outcome. Compared with type I RV contraction, patients with type II RV contraction exhibited increased circumferential strain, with a preservation of RVEF despite diminished longitudinal strain. Patients with type III RV contraction exhibited both diminished longitudinal and circumferential strain, resulting in an impaired RVEF. Patients with type III RV contraction showed the worst survival (P < 0.001).

CONCLUSIONS

Global RV dysfunction is a predictor of outcomes among TTVR patients. Tricuspid regurgitation patients can be stratified into 3 types of RV contraction, in which a loss of longitudinal function can be compensated by increasing circumferential function, preserving RVEF and favorable outcomes.

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

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

Exercise hemodynamics in heart failure patients with preserved and mid-range ejection fraction: key role of the right heart

OBJECTIVE

We sought to explore whether classification of patients with heart failure and mid-range (HFmrEF) or preserved ejection fraction (HFpEF) according to their left ventricular ejection fraction (LVEF) identifies differences in their exercise hemodynamic profile, and whether classification according to an index of right ventricular (RV) function improves differentiation.

BACKGROUND

Patients with HFmrEF and HFpEF have hemodynamic compromise on exertion. The classification according to LVEF implies a key role of the left ventricle. However, RV involvement in exercise limitation is increasingly recognized. The tricuspid annular plane systolic excursion/systolic pulmonary arterial pressure (TAPSE/PASP) ratio is an index of RV and pulmonary vascular function. Whether exercise hemodynamics differ more between HFmrEF and HFpEF than between TAPSE/PASP tertiles is unknown.

METHODS

We analyzed 166 patients with HFpEF (LVEF ≥ 50%) or HFmrEF (LVEF 40-49%) who underwent basic diagnostics (laboratory testing, echocardiography at rest, and cardiopulmonary exercise testing [CPET]) and exercise with right heart catheterization. Hemodynamics were compared according to echocardiographic left ventricular or RV function.

RESULTS

Exercise hemodynamics (e.g. pulmonary arterial wedge pressure/cardiac output [CO] slope, CO increase during exercise, and maximum total pulmonary resistance) showed no difference between HFpEF and HFmrEF, but significantly differed across TAPSE/PASP tertiles and were associated with CPET results. N-terminal pro-brain natriuretic peptide concentration also differed significantly across TAPSE/PASP tertiles but not between HFpEF and HFmrEF.

CONCLUSION

In patients with HFpEF or HFmrEF, TAPSE/PASP emerged as a more appropriate stratification parameter than LVEF to predict clinically relevant impairment of exercise hemodynamics. Stratification of exercise hemodynamics in patients with HFpEF or HFmrEF according to LVEF or TAPSE/PASP, showing significant distinctions only with the RV-based strategy. All data are shown as median [upper limit of interquartile range] and were calculated using the independent-samples Mann-Whitney U test or Kruskal-Wallis test. PVR pulmonary vascular resistance; max maximum level during exercise.

Multimodal assessment of right ventricle overload-metabolic and clinical consequences in pulmonary arterial hypertension

BACKGROUND

In pulmonary arterial hypertension (PAH) increased afterload leads to adaptive processes of the right ventricle (RV) that help to maintain arterio-ventricular coupling of RV and preserve cardiac output, but with time the adaptive mechanisms fail. In this study, we propose a multimodal approach which allows to estimate prognostic value of RV coupling parameters in PAH patients.

METHODS

Twenty-seven stable PAH patients (49.5 ± 15.5 years) and 12 controls underwent cardiovascular magnetic resonance (CMR). CMR feature tracking analysis was performed for RV global longitudinal strain assessment (RV GLS). RV-arterial coupling was evaluated by combination of RV GLS and three proposed surrogates of RV afterload-pulmonary artery systolic pressure (PASP), pulmonary vascular resistance (PVR) and pulmonary artery compliance (PAC). 18-FDG positron emission tomography (PET) analysis was used to assess RV glucose uptake presented as SUVRV/LV. Follow-up time of this study was 25 months and the clinical end-point was defined as death or clinical deterioration.

RESULTS

Coupling parameters (RV GLS/PASP, RV GLS/PVR and RV GLS*PAC) significantly correlated with RV function and standardized uptake value (SUVRV/LV). Patients who experienced a clinical end-point (n = 18) had a significantly worse coupling parameters at the baseline visit. RV GLS/PASP had the highest area under curve in predicting a clinical end-point and patients with a value higher than (-)0.29%/mmHg had significantly worse prognosis. It was also a statistically significant predictor of clinical end-point in multivariate analysis (adjusted R2 = 0.68; p < 0.001).

CONCLUSIONS

Coupling parameters are linked with RV hemodynamics and glucose metabolism in PAH. Combining CMR and hemodynamic measurements offers more comprehensive assessment of RV function required for prognostication of PAH patients.

TRIAL REGISTRATION

NCT03688698, 09/26/2018, retrospectively registered; Protocol ID: 2017/25/N/NZ5/02689.

High Right Ventricular Afterload during Exercise in Patients with Pulmonary Arterial Hypertension

The right ventricle (RV) is more sensitive to an increase in afterload than the left ventricle (LV), and RV afterload during exercise increases more easily than LV afterload. Pulmonary arterial hypertension (PAH)-specific therapy has improved pulmonary hemodynamics at rest; however, the pulmonary hemodynamic response to exercise is still abnormal in most patients with PAH. In these patients, RV afterload during exercise could be higher, resulting in a greater increase in RV wall stress. Recently, an increasing number of studies have indicated the short-term efficacy of exercise training. However, considering the potential risk of promoting myocardial maladaptive remodeling, even low-intensity repetitive exercise training could lead to long-term clinical deterioration. Further studies investigating the long-term effects on the RV and pulmonary vasculature are warranted. Although the indications for exercise training for patients with PAH have been expanding, exercise training may be associated with various risks. Training programs along with risk stratification based on the pulmonary hemodynamic response to exercise may enhance the safety of patients with PAH.