Pathophysiology of right ventricular failure:

Refractory cor pulmonale under extracorporeal membrane oxygenation for acute respiratory distress syndrome: the role of conversion to veno-pulmonary arterial assist-a case series

Introduction

Pulmonary vascular dysfunction during severe acute respiratory distress syndrome (ARDS) may lead to right ventricle (RV) dysfunction and acute cor pulmonale (ACP). The occurrence/persistence of ACP despite conventional extracorporeal membrane oxygenation (ECMO) is a challenging situation. We explored the usefulness of a specific dual-lumen cannula that bypasses the RV, and on which a veno-pulmonary arterial assist (V-P ECMO) was mounted, in ARDS patients.

Methods

We report a case-series of ARDS patients put on conventional veno-arterial or veno-venous ECMO and presented refractory ACP as an indication for a reconfiguration to V-P ECMO using the ProtekDuo cannula. The primary endpoint was the mitigation of RV and pulmonary vascular dysfunction as assessed by the change in end-diastolic RV/left ventricle (LV) surface ratio.

Results

Six patients had their conventional ECMO reconfigured to V-P ECMO to treat refractory ACP. There was a decrease in end-diastolic RV/LV surface ratio, as well as end-systolic LV eccentricity index, and lactatemia immediately after V-P ECMO initiation. The resolution of refractory ACP was immediately achieved in four of our six (66%) patients. The V-P ECMO was weaned after a median of 26 [8-93] days after implantation. All but one patient were discharged home. We detected one case of severe hemolysis with V-P ECMO and two suspected cases of right-sided infective endocarditis.

Conclusion

V-P ECMO is useful to mitigate RV overload and to improve hemodynamics in case of refractory ACP despite conventional ECMO.

Medical and Mechanical Circulatory Support of the Failing Right Ventricle

PURPOSE OF REVIEW

To describe medical therapies and mechanical circulatory support devices used in the treatment of acute right ventricular failure.

RECENT FINDINGS

Experts have proposed several algorithms providing a stepwise approach to medical optimization of acute right ventricular failure including tailored volume administration, ideal vasopressor selection to support coronary perfusion, inotropes to restore contractility, and pulmonary vasodilators to improve afterload. Studies have investigated various percutaneous and surgically implanted right ventricular assist devices in several clinical settings. The initial management of acute right ventricular failure is often guided by invasive hemodynamic data tracking parameters of circulatory function with the use of pharmacologic therapies. Percutaneous microaxial and centrifugal extracorporeal pumps bypass the failing RV and support circulatory function in severe cases of right ventricular failure.

Right to Left Cardiac Power Output- New Prognosticator in STEMI Patients With Cardiogenic Shock (R-Shock)

ST elevation myocardial infarction (STEMI) is a leading cause of cardiogenic shock (CS) and carries substantial mortality. Cardiac power output (CPO) is the strongest predictor of clinical outcome in CS, and worse outcomes result from concomitant right and left ventricular failure. Right ventricular performance is calculated using right sided CPO. Our aim was to measure the right sided CPO and compute their ratio to predict in-hospital mortality in STEMI patients with cardiogenic shock. This was a retrospective observational study of consecutive STEMI patients with CS that developed within the first 24hours of admission requiring left and right cardiac catheterization at a large tertiary care center from January 2014-December 2018. One hundred sixty-four patients identified with STEMI; 46% (75) excluded due to incomplete data. 88 remaining patients, 52.8% (47) developed CS. 98.9% within 24 hours. Mean left & right CPO 0.62 (SD 0.3) and 0.22 (SD 0.13), PAPi score 1.81. Logistic regression analysis indicated odds ratio of in-hospital mortality lower for low left CPO, high right CPO and low ratio of left to right CPO (95% CI; 0.69, 0.34, 1.20; 1.38, 0.87, 2.20; 0.52, 0.28, 1.00 respectively). This is the first study to assess right sided CPO and ratio of right and left side CPO and mortality. Our study indicates that there is trend towards higher in-hospital mortality in patients with high right sided CPO and lower ratio of left to right CPO. The exploratory results of this study need to be confirmed in a larger population.

CILP-1 Is a Biomarker for Backward Failure and Right Ventricular Dysfunction in HFrEF

BACKGROUND

CILP-1 regulates myocardial fibrotic response and remodeling and was reported to indicate right ventricular dysfunction (RVD) in pulmonary hypertension (PH) and heart failure (HF). This study examines CILP-1 as a potential biomarker for RVD and prognosis in heart failure with reduced ejection fraction (HFrEF) patients on guideline-directed medical therapy.

METHODS

CILP-1 levels were measured in 610 HFrEF patients from a prospective registry with biobanking (2016-2022). Correlations with echocardiographic and hemodynamic data and its association with RVD and prognosis were analyzed.

RESULTS

The median age was 62 years (Q1-Q3: 52-72), 77.7% of patients were male, and the median NT-proBNP was 1810 pg/mL (Q1-Q3: 712-3962). CILP-1 levels increased with HF severity, as indicated by NT-proBNP and NYHA class (p < 0.0001, for both). CILP-1 showed a weak-moderate direct association with increased left ventricular filling pressures and its sequalae, i.e., backward failure (LA diameter rs = 0.15, p = 0.001; sPAP rs = 0.28, p = 0.010; RVF rs = 0.218, p < 0.0001), but not with cardiac index (CI) and systemic vascular resistance (SVR). CILP-1 trended as a risk factor for all-cause mortality (crude HR for 500 pg/mL increase: 1.03 (95%CI: 1.00-1.06), p = 0.053) but lost significance when it was adjusted for NT-proBNP (adj. HR: 1.00 (95%CI: 1.00-1.00), p = 0.770). No association with cardiovascular hospitalization was observed.

CONCLUSIONS

CILP-1 correlates with HFrEF severity and may indicate an elevated risk for all-cause mortality, though it is not independent from NT-proBNP. Increased CILP-1 is associated with backward failure and RVD rather than forward failure. Whether CILP-1 release in this context is based on elevated pulmonary pressures or is specific to RVD needs to be further investigated.

The hemodynamic interplay between pulmonary ischemia-reperfusion injury and right ventricular function in lung transplantation: a translational porcine model

Lung transplantation (LTx) is a challenging procedure. Following the process of ischemia-reperfusion injury, the transplanted pulmonary graft might become severely damaged, resulting in primary graft dysfunction. In addition, during the intraoperative window, the right ventricle (RV) is at risk of acute failure. The interaction of right ventricular function with lung injury is, however, poorly understood. We aimed to address this interaction in a translational porcine model of pulmonary ischemia-reperfusion injury. Advanced pulmonary and hemodynamic assessment was used, including right ventricular pressure-volume loop analysis. The acute model was based on clamping and unclamping of the left lung hilus, respecting the different hemodynamic phases of a clinical lung transplantation. We found that forcing entire right ventricular cardiac output through a lung suffering from ischemia-reperfusion injury increased afterload (pulmonary vascular resistance from baseline to end experiment P < 0.0001) and induced right ventricular failure (RVF) in 5/9 animals. Notably, we identified different compensation patterns in failing versus nonfailing ventricles (arterial elastance P = 0.0008; stroke volume P < 0.0001). Furthermore, increased vascular pressure and flow produced by the right ventricle resulted in higher pulmonary injury, as measured by ex vivo CT density (correlation: pressure r = 0.8; flow r = 0.85). Finally, RV ischemia as measured by troponin-T was negatively correlated with pulmonary injury (r = -0.76); however, troponin-T values did not determine RVF in all animals. In conclusion, we demonstrate a delicate balance between development of pulmonary ischemia-reperfusion injury and right ventricular function during lung transplantation. Furthermore, we provide a physiological basis for potential benefit of extracorporeal life support technology.NEW & NOTEWORTHY In contrast to the abundant literature of mechanical pulmonary artery clamping to increase right ventricular afterload, we developed a model adding a biological factor of pulmonary ischemia-reperfusion injury. We did not only focus on the right ventricular behavior, but also on the interaction with the injured lung. We are the first to describe this interaction while addressing the hemodynamic intraoperative phases of clinical lung transplantation.

Magnetic Resonance Imaging of Cardiovascular Manifestations Following COVID-19

Globally, over 650 million people have had COVID-19 due to infection with the SARS-Cov-2 virus. Cardiac complications in the acute infectious and early recovery phase were recognized early in the pandemic, including myocardial injury and inflammation. With a decrease in the number of acute COVID-19 related deaths, there has been increased interest in postacute sequela of COVID-19 (PASC) and other longer-term cardiovascular complications. A proportion of patients recovered from COVID-19 have persistent cardiac symptoms and are at risk of cardiovascular disease. Cardiovascular imaging, including MRI, plays an important role in the detection of cardiovascular manifestations of COVID-19 in both the acute and longer-term phases after COVID-19. The purpose of this review is to highlight the role of cardiovascular imaging in the diagnosis and risk stratification of patients with acute and chronic cardiovascular manifestations of COVID-19 with a focus on cardiac MRI. EVIDENCE LEVEL: 4. TECHNICAL EFFICACY: Stage 3.

Keep the Right in Mind-A Focused Approach to Right Ventricle-Predominant Cardiogenic Shock

Cardiogenic shock (CS) remains a highly lethal condition despite many efforts and new interventions. Patients presenting with a rapid onset of hemodynamic instability and subsequent collapse require prompt and appropriate multimodality treatment. Multiple etiologies can lead to heart failure and subsequent shock. As the case prevalence of heart failure increases worldwide, it is of great importance to explore all manners and protocols of presentation and treatment present. With research primarily focusing on CS due to cardiac left-sided pathology, few assessments of right-sided pathology and the subsequent clinical state and treatment have been conducted. This review aims to present an in-depth assessment of the currently available literature, assessing the pathophysiology, presentation and management of CS patients due to right heart failure.

Central versus Peripheral CTEPH-Clinical and Hemodynamic Specifications

Background and Objectives: Chronic thromboembolic pulmonary hypertension (CTEPH) is a chronic progressive disease, resulting from persistent arterial obstruction combined with small-vessel remodeling. Central and peripheral CTEPH are distinguished, according to the dominant lesion's location. This is important for surgical or percutaneous interventional assessment or for medical treatment. Material and Methods: Eighty-one patients (51 male/30 female) with confirmed CTEPH were analyzed, while the CENTRAL type included 51 patients (63%) and the PERIPHERAL type 30 patients (37%). Results: A significant difference in CENTRAL type vs. PERIPHERAL type was determined in gender (male 72.5% vs. 46.7%; p = 0.0198). No difference was found in age, functional status, or echocardiographic parameters. Invasive hemodynamic parameters showed a significant difference in mean pulmonary arterial pressure (46 vs. 58 mmHg; p = 0.0002), transpulmonary gradient (34 vs. 47 mmHg; p = 0.0005), and cardiac index (2.04 vs. 2.5 L.min.m²; p = 0.02) but not in pulmonary vascular resistance. Risk factors showed a significant difference only in acute pulmonary embolism (93.8% vs. 60%; p = 0.0002) and malignancy (2% vs. 13.3%; p = 0.0426). Conclusions: Our study showed hemodynamic differences between CENTRAL type vs. PERIPHERAL type CTEPH with a worse hemodynamic picture in CENTRAL form. This may indicate a different pathophysiological response and/or possible additional influences contributing especially to the peripheral pulmonary bed affection.

Blunted hypoxic pulmonary vasoconstriction in apnoea divers

NEW FINDINGS

What is new and noteworthy? What is the central question of this study? Does the hyperbaric, hypercapnic, acidotic, hypoxic stress of apnoea diving lead to greater pulmonary vasoreactivity and increased right-heart work in apnoea divers? What is the main finding and its importance? Compared to sex- and age-matched controls, Divers had a significantly lower change in total pulmonary resistance in response to short duration isocapnic hypoxia. With oral sildenafil (50 mg), there were no differences in total pulmonary resistance between groups, suggesting Divers can maintain normal pulmonary artery tone in hypoxic conditions. Blunted hypoxic pulmonary vasoconstriction may be beneficial during apnoea diving.

ABSTRACT

Competitive apnoea divers repetitively dive to depths beyond 50 m. During the final portions of ascent, Divers experience significant hypoxaemia. Additionally, hyperbaria during diving increases thoracic blood volume while simultaneously reducing lung volume, increasing pulmonary artery pressure. We hypothesized that Divers would have exaggerated hypoxic pulmonary vasoconstriction leading to increased right-heart work due to their repetitive hypoxaemia and hyperbaria, and that the administration of sildenafil would have a greater effect in reducing pulmonary resistance in Divers. We recruited 16 Divers and 16 age and sex matched non-diving controls (Controls). Using a double-blinded, placebo-controlled, cross-over design, participants were evaluated for normal cardiac and lung function, then their cardiopulmonary responses to 20-30 minutes of isocapnic hypoxia (end-tidal PO₂  = 50 mm Hg) were measured one hour following ingestion of 50 mg sildenafil or placebo. Cardiac structure and cardiopulmonary function were similar at baseline. With placebo, Divers had a significantly smaller increase in total pulmonary resistance than controls after 20-30 minutes isocapnic hypoxia (Δ -3.85 ± 72.85 vs 73.74 ± 91.06 dynes/sec/cm^-5 , p = .0222). With sildenafil, Divers and Controls had similarly blunted increases in total pulmonary resistance after 20-30 minutes of hypoxia. Divers also had a significantly lower systemic vascular resistance following sildenafil in normoxia. These data indicate that repetitive apnoea diving leads to a blunted hypoxic pulmonary vasoconstriction. We suggest this is a beneficial adaption allowing for increased cardiac output with reduced right heart work and thus reducing cardiac oxygen utilization under hypoxemic conditions. This article is protected by copyright. All rights reserved.

Effects of transthoracic echocardiography on the prognosis of patients with acute respiratory distress syndrome: a propensity score matched analysis of the MIMIC-III database

Background

Acute respiratory distress syndrome (ARDS) has high mortality and is mainly related to the circulatory failure.Therefore, real-time monitoring of cardiac function and structural changes has important clinical significance.Transthoracic echocardiography (TTE) is a simple and noninvasive real-time cardiac examination which is widely used in intensive care unit (ICU) patients.The purpose of this study was to analyze the effect of TTE on the prognosis of ICU patients with ARDS.

Methods

The data of ARDS patients were retrieved from the MIMIC-III v1.4 database and patients were divided into the TTE group and non-TTE group. The baseline data were compared between the two groups. The effect of TTE on the prognosis of ARDS patients was analyzed through multivariate logistic analysis and the propensity score (PS). The primary outcome was the 28-d mortality rate. The secondary outcomes included pulmonary artery catheter (PAC) and Pulse index continuous cardiac output (PiCCO) administration, the ventilator-free and vasopressor-free days and total intravenous infusion volume on days 1, 2 and 3 of the mechanical ventilation. To illuminate the effect of echocardiography on the outcomes of ARDS patients,a sensitivity analysis was conducted by excluding those patients receiving either PiCCO or PAC. We also performed a subgroup analysis to assess the impact of TTE timing on the prognosis of patients with ARDS.

Results

A total of 1,346 ARDS patients were enrolled, including 519 (38.6%) cases in the TTE group and 827 (61.4%) cases in the non-TTE group. In the multivariate logistic regression, the 28-day mortality of patients in the TTE group was greatly improved (OR 0.71, 95%CI 0.55–0.92, P = 0.008). More patients in the TTE group received PAC (2% vs. 10%, P < 0.001) and the length of ICU stay in the TTE group was significantly shorter than that in the non-TTE group (17d vs.14d, P = 0.0001). The infusion volume in the TTE group was significantly less than that of the non-TTE group (6.2L vs.5.5L on day 1, P = 0.0012). Importantly, the patients in the TTE group were weaned ventilators earlier than those in the non-TTE group (ventilator-free days within 28 d: 21 d vs. 19.8 d, respectively, P = 0.071). The Kaplan–Meier survival curves showed that TTE patients had significant lower 28-day mortality than non-TTE patients (log-rank = 0.004). Subgroup analysis showed that TTE after hemodynamic disorders can not improve prognosis (OR 1.02, 95%CI 0.79–1.34, P = 0.844).

Conclusion

TTE was associated with improved 28-day outcomes in patients with ARDS.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12890-022-02028-5.

Comprehensive evaluation of Impella RP® in right ventricular failure

Right ventricular failure has a high morbidity and mortality in patients suffering from advanced heart failure, pulmonary hypertension, acute myocardial infarction after cardiac surgery and in left ventricular assist device patients. The Impella RP^® catheter is a mechanical circulatory device, positioned from a venous femoral percutaneous access and passing through the tricuspid and pulmonary valves, reaches the pulmonary artery. Impella RP (Abiomed Inc., MA, USA) acts as a direct right ventricle bypass and it provides a flow up to 4.4 liters per minute, unloading the right ventricle. The main contraindications are: thrombi in the vena cava, right atrium and ventricle and pulmonary artery; mechanical tricuspid or pulmonary prostheses. In this review, the principles of operations, clinical applications and results of Impella RP are summarized and evaluated.

In vivo evaluation of bioprinted cardiac patches composed of cardiac-specific extracellular matrix and progenitor cells in a model of pediatric heart failure

Pediatric patients with congenital heart defects (CHD) often present with heart failure from increased load on the right ventricle (RV) due to both surgical methods to treat CHD and the disease itself. Patients with RV failure often require transplantation, which is limited due to lack of donor availability and rejection. Previous studies investigating the development and in vitro assessment of a bioprinted cardiac patch composed of cardiac extracellular matrix (cECM) and human c-kit + progenitor cells (hCPCs) showed that the construct has promise in treating cardiac dysfunction. The current study investigates in vivo cardiac outcomes of patch implantation in a rat model of RV failure. Patch parameters including cECM-inclusion and hCPC-inclusion are investigated. Assessments include hCPC retention, RV function, and tissue remodeling (vascularization, hypertrophy, and fibrosis). Animal model evaluation shows that both cell-free and neonatal hCPC-laden cECM-gelatin methacrylate (GelMA) patches improve RV function and tissue remodeling compared to other patch groups and controls. Inclusion of cECM is the most influential parameter driving therapeutic improvements, with or without cell inclusion. This study paves the way for clinical translation in treating pediatric heart failure using bioprinted GelMA-cECM and hCPC-GelMA-cECM patches.

Impact of Right Heart Failure on Clinical Outcome of Left Ventricular Assist Devices (LVAD) Implantation: Single Center Experience

The aim of this study was to examine the incidence and significance of right heart failure (RHF) in the early and late phase of left ventricular assist device (LVAD) implantation with the identification of predictive factors for the development of RHF. This was a prospective observational analytical cohort study. The study included 92 patients who underwent LVAD implantation and for whom all necessary clinical data from the follow-up period were available, as well as unambiguous conclusions by the heart team regarding pathologies, adverse events, and complications. Of the total number of patients, 43.5% died. The median overall survival of patients after LVAD implantation was 22 months. In the entire study population, survival rates were 88.04% at one month, 80.43% at six months, 70.65% at one year, and 61.96% at two years. Preoperative RHF was present in 24 patients, 12 of whom died and 12 survived LVAD implantation. Only two survivors developed early RHF (ERHF) and two late RHF (LRHF). The most significant predictors of ERHF development are brain natriuretic peptide (BNP), pre-surgery RHF, FAC < 20%, prior renal insufficiency, and total duration of ICU stay (HR: 1.002, 0.901, 0.858, 23.554, and 1.005, respectively). RHF following LVAD implantation is an unwanted complication with a negative impact on treatment outcome. The increased risk of fatal outcome in patients with ERHF and LRHF after LVAD implantation results in a need to identify patients at risk of RHF, in order to administer the available preventive and therapeutic methods.

Right ventricular failure: a comorbidity or a clinical emergency?

There has been ample data providing a convincing perception about the underlying mechanism pertaining to left ventricle (LV) hypertrophy progressing towards LV failure. In comparison, data available on the feedback of right ventricle (RV) due to volume or pressure overload is minimal. Advanced imaging techniques have aided the study of physiology, anatomy, and diseased state of RV. However, the treatment scenario of right ventricular failure (RVF) demands more attention. It is a critical clinical risk in patients with carcinoid syndrome, pulmonary hypertension, atrial septal defect, and several other concomitant diseases. Although the remodeling responses of both ventricles on an increase of end-diastolic pressure are mostly identical, the stressed RV becomes more prone to oxidative stress activating the apoptotic mechanism with diminished angiogenesis. This instigates the advancement of RV towards failure in contrast to LV. Empirical heart failure (HF) therapies have been ineffective in improving the mortality rate and cardiac function in patients, which prompted a difference between the underlying pathophysiology of RVF and LV failure. Treatment strategies should be devised, taking into consideration the anatomical and physiological characteristics of RV. This review would emphasize on the pathophysiology of the RVF and the differences between two ventricles in molecular response to stress. A proper insight into the underlying pathophysiology is required to develop optimized therapeutic management in RV-specific HF.

High Central Venous Pressure and Right Ventricle Size Are Related to Non-decreased Left Ventricle Stroke Volume After Negative Fluid Balance in Critically Ill Patients: A Single Prospective Observational Study

Background: Optimal adjustment of cardiac preload is essential for improving left ventricle stroke volume (LVSV) and tissue perfusion. Changes in LVSV caused by central venous pressure (CVP) are the most important concerns in the treatment of critically ill patients. Objectives: This study aimed to clarify the changes in LVSV after negative fluid balance in patients with elevated CVP, and to elucidate the relationship between the parameters of right ventricle (RV) filling state and LVSV changes. Methods: This prospective cohort study included patients with high central venous pressure (CVP) (≥8 mmHg) within 24 h of ICU admission in the Critical Medicine Department of Peking Union Medical College Hospital. Patients were classified into two groups based on the LVSV changes after negative fluid balance. The cutoff value was 10%. The hemodynamic and echo parameters of the two groups were recorded at baseline and after negative fluid balance. Results: A total of 71 patients included in this study. Forty in VI Group (LVOT VTI increased ≥10%) and 31 in VNI Group (LVOT VTI increased <10%). Of all patients, 56.3% showed increased LVSV after negative fluid balance. In terms of hemodynamic parameters at T0, patients in VI Group had a higher CVP (p < 0.001) and P(v-a)CO₂ (p < 0.001) and lower ScVO₂ (p < 0.001) relative to VNI Group, regarding the echo parameters at T0, the RV_D/LV_D ratio (p < 0.001), DIVC _{end-expiratory} (p < 0.001), and ΔLVOT VTI (p < 0.001) were higher, while T0 LVOT VTI (p < 0.001) was lower, in VI Group patients. The multifactor logistic regression analysis suggested that a high CVP and RV_D/LV_D ratio ≥0.6 were significant associated with LVSV increase after negative fluid balance in critically patients. The AUC of CVP was 0.894. A CVP >10.5 mmHg provided a sensitivity of 87.5% and a specificity of 77.4%. The AUC of CVP combined with the RV_D/LV_D ratio ≥0.6 was 0.926, which provided a sensitivity of 92.6% and a specificity of 80.4%. Conclusion: High CVP and RV_D/LV_D ratio ≥0.6 were significant associated with RV stressed in critically patients. Negative fluid balance will not always lead to a decrease, even an increase, in LVSV in these patients.

Role of Echocardiography for the Perioperative Assessment of the Right Ventricle

Purpose of Review

This review aims to highlight the perioperative echocardiographic evaluation of right ventricular (RV) function with strengths and limitations of commonly used and evolving techniques. It explains the value of transthoracic echocardiography (TTE) and transesophageal echocardiography (TEE) and describes the perioperative changes of RV function echocardiographers should be aware of.

Recent Findings

RV dysfunction is an entity with strong influence on outcome. However, its definition and assessment in the perioperative interval are not well-defined. Moreover, values assessed by TTE and TEE are not interchangeable; while some parameters seem to correlate well, others do not. Myocardial strain analysis and three-dimensional echocardiography may overcome the limitations of conventional echocardiographic measures and provide further insight into perioperative cardiac mechanics.

Summary

Echocardiography has become an essential part of modern anesthesiology in patients with RV dysfunction. It offers the opportunity to evaluate not only global but also regional RV function and distinguish alterations of RV contraction.

Critical Care Management of the Patient with Pulmonary Hypertension

Pulmonary hypertension patients admitted to the intensive care unit have high mortality, and right ventricular failure typically is implicated as cause of or contributor to death. Initial care of critically ill pulmonary hypertension patients includes recognition of right ventricular failure, appropriate monitoring, and identification and treatment of any inciting cause. Management centers around optimization of cardiac function, with a multipronged approach aimed at reversing the pathophysiology of right ventricular failure. For patients who remain critically ill or in shock despite medical optimization, mechanical circulatory support can be used as a bridge to recovery or lung transplantation.

Time interval between E and E' waves can predict complicated clinical course in patients with acute pulmonary embolism

PURPOSE

Acute pulmonary embolism is a life-threatening cardiothoracic emergency leading to right ventricle systolic and diastolic dysfunction. In the present study, we investigated the right ventricle diastolic function and its predictive value in patients with acute pulmonary embolism.

MATERIAL AND METHODS

Were prospectively recruited in this study 621 patients diagnosed with acute pulmonary embolism between December 2015 and June 2019. Among them, 173 were excluded, leaving 448 patients for follow-up. Transthoracic echocardiography was performed for the evaluation of the right ventricle systolic and diastolic indices. At 30-day follow-up, the patients were allocated either into the benign or in the complicated clinical course group.

RESULTS

The group with complicated clinical course had higher value of pulmonary artery systolic pressure (PASP), right/left ventricle diameter ratio, E-wave velocity, E/A ratio, A' wave velocity, E/E' ratio, and time interval between E and E' waves (P < .05), but lower values of tricuspid annular plane systolic excursion, A-wave velocity, isovolumetric relaxation time, deceleration time, E', and E'/A' (P < .05). Complicated clinical course was associated with shorter isovolumetric relaxation time (r = .564, P < .001), E/E' (r = .495, P < .001), and TE-E' (r = .596, P < .001). Receiver operator characteristic curve analysis showed that TE-E' had the largest area under curve (TE-E' 0.82, IVRT 0.77, E/E' 0.72). A cut-off value of TE-E' = 70 milliseconds had an 81.1% sensitivity and 71.4% specificity for the prediction of the complicated clinical course.

CONCLUSION

The assessment of the right ventricle diastolic function could predict the complicated clinical course in patients with acute pulmonary embolism.

Mortality of right ventricular dysfunction in patients with acute respiratory distress syndrome subjected to lung protective ventilation: A systematic review and meta-analysis

BACKGROUND

The impact of right ventricular dysfunction(RVD) on the prognosis of acute respiratory distress syndrome(ARDS) patients is controversial.

OBJECTIVES

The objectives of this systematic review and meta-analysis was to investigate whether RVD or pulmonary vascular dysfunction are associated with increased mortality in patients with ARDS.

METHODS

We searched Pubmed, Embase, Cochrane Library, Wanfang Data, CNKI, and the WHO Clinical Trial Registry for studies of RVD or pulmonary vascular dysfunction in patients with ARDS.

RESULTS

The presence of RVD or pulmonary vascular dysfunction in patients with ARDS was associated with an increase in mortality (OR = 1.68, 95% CI = 1.21-2.32, P = 0.069, I² = 40.8%). Subgroup analyses obtained similar results. Funnel plots and the Egger's test indicated no publication bias, and sensitivity analyses determined that the results were stable.

CONCLUSION

The prognosis of patients with ARDS and RVD or pulmonary vascular dysfunction is worse than that of ARDS patients without RVD or pulmonary vascular dysfunction.

Hemodynamic clinical phenotyping in septic shock

PURPOSE OF REVIEW

Recent studies have failed to show significant benefit from a uniform strategy, suggesting that hemodynamic management must be individually adapted in septic shock depending on different phenotypes. Different approaches that may be used to this end will be discussed.

RECENT FINDINGS

Fluid management is a cornerstone of resuscitation, as the positive fluid balance has been associated with higher mortality and right ventricular failure. Myocardial evaluation is mandatory, as sepsis patients may present with a hyperkinetic state, left ventricular (systolic and diastolic) and/or right ventricular dysfunction, the latter being associated with higher mortality. Statistical approaches with the identification of hemodynamic clusters based on echocardiographic and clinical parameters might be integrated into daily practice to develop precision medicine. Such approaches may also predict the progression of septic shock.

SUMMARY

Different hemodynamic phenotypes can occur at any stage of sepsis and be associated with one another. The clinician must regularly assess dynamic changes in phenotypes in septic shock patients. Statistical approaches based on machine learning need to be validated by prospective studies.

Cyanidin‑3‑O‑β‑glucoside protects against pulmonary artery hypertension induced by monocrotaline via the TGF‑β1/p38 MAPK/CREB signaling pathway

Pulmonary artery hypertension (PAH) is a disease with high morbidity and mortality. Cyanidin‑3‑O‑β‑glucoside (Cy‑3‑g), a classical anthocyanin, has a variety of biological effects. The present study evaluated whether Cy‑3‑g attenuated PAH, and explored the potential mechanism of action. Rats were injected with monocrotaline (MCT; 60 mg per kg of body weight) and then treated with Cy‑3‑g (200 or 400 mg per kg of body weight) for 4 weeks. Protein expression was determined in vitro in transforming growth factor‑β1 (TGF‑β1)‑mediated human pulmonary arterial smooth muscle cells (SMCs). The results indicated that Cy‑3‑g significantly inhibited the mean pulmonary artery pressure, right ventricular systolic pressure and right ventricular hypertrophy index, as well as vascular remodeling induced by MCT in PAH rats. Further experiments showed that Cy‑3‑g suppressed the expression of pro‑-inflammatory factors and enhanced the levels of anti‑inflammatory factors. Cy‑3‑g blocked oxidative stress and improved vascular endothelial injury. Cy‑3‑g also reduced the proliferation of SMCs. Furthermore, the MCT‑ and TGF‑β1‑induced increase in TGF‑β1, phosphorylated (p)‑p38 mitogen‑activated protein kinase (MAPK) and p‑cAMP‑response element binding protein (CREB) expression was blocked by Cy‑3‑g treatment in vivo and in vitro. These results indicated that Cy‑3‑g could prevent vascular remodeling in PAH via inhibition of the TGF‑β1/p38 MAPK/CREB axis.

Cardiogenic shock in thyroid storm: A biventricular impella (Bi-Pella) approach

The use of biventricular impella support in patients with acute, reversible causes of biventricular cardiogenic shock may play a role in shortening the time to recovery and preventing significant negative outcomes such as renal or hepatic failure.

Evaluation and Management of the Physiologically Difficult Airway: Consensus Recommendations From Society for Airway Management

Multiple international airway societies have created guidelines for the management of the difficult airway. In critically ill patients, there are physiologic derangements beyond inadequate airway protection or hypoxemia. These risk factors contribute to the "physiologically difficult airway" and are associated with complications including cardiac arrest and death. Importantly, they are largely absent from international guidelines. Thus, we created management recommendations for the physiologically difficult airway to provide practical guidance for intubation in the critically ill. Through multiple rounds of in-person and telephone conferences, a multidisciplinary working group of 12 airway specialists (Society for Airway Management's Special Projects Committee) over a time period of 3 years (2016-2019) reviewed airway physiology topics in a modified Delphi fashion. Consensus agreement with the following recommendations among working group members was generally high with 80% of statements showing agreement within a 10% range on a sliding scale from 0% to 100%. We limited the scope of this analysis to reflect the resources and systems of care available to out-of-operating room adult airway providers. These recommendations reflect the practical application of physiologic principles to airway management available during the analysis time period.

Right ventricular failure after left ventricular assist device implantation: a review of the literature

Right ventricular failure (RVF) following left ventricular assist device (LVAD) implantation remains a major complication which may significantly impair patient outcome. The genesis of RVF is, however, multifactorial, and the mechanisms underlying such a condition have not been fully elucidated, making its prevention challenging and the course not always predictable. Although preoperative risks factors can be associated with RV impairment, the physiologic changes after the LV support, can still hamper the function of the RV. Current medical treatment options are limited and sometimes, patients with a severe post-LVAD RVF may be unresponsive to pharmacological therapy and require more aggressive treatment, such as temporary RV support. We retrieved 11 publications which we assessed and divided in groups based on the RV support [extracorporeal membrane oxygenation (ECMO), right ventricular assist device (RVAD), TandemHeart with ProtekDuo cannula]. The current review comprehensively summarizes the main studies of the literature with particular attention to the RV physiology and its changes after the LVAD implantation, the predictors and prognostic score as well as the different modalities of temporary mechanical cardio-circulatory support, and its effects on patient prognosis for RVF in such a setting. In addition, it provides a decision making of the pre-, intra and post-operative management in high- and moderate- risk patients.

[Right ventricular systolic dysfunction as a predictor of adverse outcome in patients with COVID-19]

Aim To analyze survival of patients with COVID-19 based on echocardiographic (EchoCG) criteria for evaluation of the right ventricular (RV) systolic function.Material and methods Data of patients were retrospectively evaluated at the Center for Medical Care of Patients with Coronavirus Infection. Among 142 primarily evaluated patients with documented COVID-19, 110 patients (men/women, 63/47; mean age, 62.3 ± 15.3 years) met inclusion/exclusion criteria. More than 30 EchoCG parameters were analyzed, and baseline data (comorbidities, oxygen saturation, laboratory data, complications, outcomes, etc.) were evaluated. ROC-analysis was used for evaluating the diagnostic significance of different EchoCG parameters for prediction of a specific outcome and its probability. Dependence of the overall survival of patients on different EchoCG parameters was analyzed with the Cox proportional hazards model. For assessing the predictive value of EchoCG parameters for patient stratification by risk of an adverse outcome, a predictive model was developed using the CHAID method.Results The in-hospital death rate of patients included into the study was 15.5 %, and the death rate for this period of in-hospital observation was 12 %. Based on the single-factor analysis of EchoCG parameters, a multifactor model was developed using the method of Cox regression. The model included two predictors for an unfavorable outcome, estimated pulmonary artery systolic pressure (EPASP) and maximal indexed right atrial volume (RAi), and a preventive factor, right ventricular global longitudinal strain (LS RV). Base risks for fatal outcome were determined with an account of the follow-up time. According to the obtained values, an increase in EPASP by 1 mm Hg was associated with increases in the risk of fatal outcome by 8.6 % and in the RA(i) volume by 1 ml/5.8 %. LS RV demonstrated an inverse correlation; a 1% increase in LS RV was associated with a 13.4% decrease in the risk for an unfavorable outcome. According to the ROC analysis, the most significant determinants of the outcome were the tricuspid annular plane systolic excursion (TAPSE) (AUC, 0.84 ± 0.06; cut-off, 18 mm) and EPASP (AUC, 0.86 ± 0.05; cut-off, 42 mm Hg). Evaluating the effects of different EchoCG predictors, that characterized the condition of the right heart, provided a classification tree. Six final decisions were determined in the model, two of which were assigned to the category of reduced risk for fatal outcome and four were assigned to the category of increased risk. Sensitivity of the classification tree model was 94.1 % and specificity was 89.2 %. Overall diagnostic significance was 90.0±2.9 %.Conclusion The presented models for statistical treatment of EchoCG parameters reflect the requirement for a comprehensive analysis of EchoCG parameters based on a combination of standard methods for EchoCG evaluation and current technologies of noninvasive visualization. According to the study results, the new EchoCG marker, LS RV, allows identifying the signs of right ventricular dysfunction (particularly in combination with pulmonary hemodynamic indexes), may enhance the early risk stratification in patients with COVID-19, and help making clinical decisions for patients with different acute cardiorespiratory diseases.

Fluctuations of driving pressure during mechanical ventilation indicates elevated central venous pressure and poor outcomes

Inappropriate mechanical ventilation may induce hemodynamic alterations through cardiopulmonary interactions. The aim of this study was to explore the relationship between airway pressure and central venous pressure during the first 72 h of mechanical ventilation and its relevance to patient outcomes. We conducted a retrospective study of the Department of Critical Care Medicine of Peking Union Medical College Hospital and a secondary analysis of the MIMIC-III clinical database. The relationship between the ranges of driving pressure and central venous pressure during the first 72 h and their associations with prognosis were investigated. Data from 2790 patients were analyzed. Wide range of driving airway pressure (odds ratio, 1.0681; 95% CI, 1.0415-1.0953; p < 0.0001) were independently associated with mortality, ventilator-free time, intensive care unit and hospital length of stay. Furthermore, wide range of driving pressure and elevated central venous pressure exhibited a close correlation. The area under receiver operating characteristic demonstrated that range of driving pressure and central venous pressure were measured at 0.689 (95% CI, 0.670-0.707) and 0.681 (95% CI, 0.662-0.699), respectively. Patients with high ranges of driving pressure and elevated central venous pressure had worse outcomes. Post hoc tests showed significant differences in 28-day survival rates (log-rank (Mantel-Cox), 184.7; p < 0.001). In conclusion, during the first 72 h of mechanical ventilation, patients with hypoxia with fluctuating driving airway pressure have elevated central venous pressure and worse outcomes.

Assessment of Right Heart Function during Extracorporeal Therapy by Modified Thermodilution in a Porcine Model

BACKGROUND

Veno-arterial extracorporeal membrane oxygenation therapy is a growing treatment modality for acute cardiorespiratory failure. Cardiac output monitoring during veno-arterial extracorporeal membrane oxygenation therapy remains challenging. This study aims to validate a new thermodilution technique during veno-arterial extracorporeal membrane oxygenation therapy using a pig model.

METHODS

Sixteen healthy pigs were centrally cannulated for veno-arterial extracorporeal membrane oxygenation, and precision flow probes for blood flow assessment were placed on the pulmonary artery. After chest closure, cold boluses of 0.9% saline solution were injected into the extracorporeal membrane oxygenation circuit, right atrium, and right ventricle at different extracorporeal membrane oxygenation flows (4, 3, 2, 1 l/min). Rapid response thermistors in the extracorporeal membrane oxygenation circuit and pulmonary artery recorded the temperature change. After calculating catheter constants, the distributions of injection volumes passing each circuit were assessed and enabled calculation of pulmonary blood flow. Analysis of the exponential temperature decay allowed assessment of right ventricular function.

RESULTS

Calculated blood flow correlated well with measured blood flow (r2 = 0.74, P < 0.001). Bias was -6 ml/min [95% CI ± 48 ml/min] with clinically acceptable limits of agreement (668 ml/min [95% CI ± 166 ml/min]). Percentage error varied with extracorporeal membrane oxygenation blood flow reductions, yielding an overall percentage error of 32.1% and a percentage error of 24.3% at low extracorporeal membrane oxygenation blood flows. Right ventricular ejection fraction was 17 [14 to 20.0]%. Extracorporeal membrane oxygenation flow reductions increased end-diastolic and end-systolic volumes with reductions in pulmonary vascular resistance. Central venous pressure and right ventricular ejection fractions remained unchanged. End-diastolic and end-systolic volumes correlated highly (r2 = 0.98, P < 0.001).

CONCLUSIONS

Adapted thermodilution allows reliable assessment of cardiac output and right ventricular behavior. During veno-arterial extracorporeal membrane oxygenation weaning, the right ventricle dilates even with stable function, possibly because of increased venous return.

EDITOR’S PERSPECTIVE

Plasma catestatin level predicts sPESI score and mortality in acute pulmonary embolism

INTRODUCTION

Acute pulmonary embolism (APE) is an emergent cardiothoracic disorder. The PESI score is used to estimate 30-day mortality in patients diagnosed with non-high-risk APE. Also, there are biomarkers for predicting prognosis and mortality in APE. Catestatin (CST) is accepted as a marker ofsympathetic nervous system activity which has been shown that the sympathetic nervous system activation can contribute pathogenesis in APE. So, we attempt herein to investigate the correlation of PE diagnosis and prognostic determination with plasma CST levels in PE patients.

MATERIAL AND METHODS

Blood samples were drawn at admission for laboratory assays and CST measurements. Plasma levels of CST were measured by ELISA according to the manufacturer's instruction. Transthoracic echocardiography was performed for the assessment of RV dysfunction using a Toshiba Applio 500 echocardiographic system within 24 h of the admission.

RESULTS

Plasma CST levels were higher in patients with APE than in the control group (17.5 ±6.1 ng/ml vs. 27.3 ±5.7 ng/ml, p < 0.001). Plasma CST levels were higher in the sPESI ≥ 1 (n = 72) than in the patients with sPESI < 1 (37.3 ±6.1 vs. 24.2 ±5.3 ng/ml, p < 0.001). There was a positive correlation between CST level and sPESI score (±0.581, p < 0.001). Mortality occurred in 20 patients with sPESI ≥ 1 (27.7%) and in 9 patients with sPESI < 1 (10.2%) (p = 0.010). Receiver operating characteristic (ROC) curve analysis using a cut-off level of 31.2 ng/ml, and the CST level predicted mortality with a sensitivity of 100% and specificity of 52.6% (AUC = 0.883, 95% CI: 0.689-0.921). Furthermore, the CST level was correlated with right ventricular dysfunction.

CONCLUSIONS

CST can predict sPESI score and mortality in patients with APE.

Novel Echocardiographic Approach to Hemodynamic Phenotypes Predicts Outcome of Patients Hospitalized With Heart Failure

BACKGROUND

Although in clinical practice heart failure (HF) patients are classified using left ventricular ejection fraction (LVEF), this categorization is insufficient for prognosis, especially when LVEF is preserved or there is a concomitant right ventricular (RV) dysfunction. We hypothesized that a combined noninvasive evaluation of LV forward flow, filling pressure, and RV function would be better than LVEF in predicting all-cause mortality of hospitalized patients with HF.

METHODS

Transthoracic echocardiographic examinations of 603 patients hospitalized with HF were analyzed. In a subsample of 200 patients with HF, LV stroke volume index, LV filling pressure estimation, tricuspid annular plane systolic excursion, and systolic pulmonary artery pressure were combined to determine 4 hemodynamic profiles: normal flow-normal pressure, normal flow-high pressure, low flow without RV dysfunction, and low flow with RV dysfunction profile. This model was then applied in a validation cohort (n=403).

RESULTS

Prognosis worsened from the normal flow-normal pressure profile to the low flow with right ventricular dysfunction profile. At the multivariate survival analysis, the model showed independent high risk-stratification capability (P<0.001), even in subgroups of patients with LVEF < or ≥50% (P=0.011 and P<0.001, respectively) and < or ≥40% (P=0.044 and P<0.001, respectively). LVEF and HF classification based on LVEF did not predict outcome.

CONCLUSIONS

Echocardiographic-derived profiling of LV forward flow, filling pressure, and RV function allowed categorization of patients hospitalized with HF and predicted all-cause mortality independently of LVEF. This model is based on conventional echocardiography, is easy to apply, and is, therefore, suggested for clinical practice.

Pterostilbene improves cardiac function in a rat model of right heart failure through modulation of calcium handling proteins and oxidative stress

This study explored the effect of pterostilbene (PTS) complexed with hydroxypropyl-β-cyclodextrin (HPβCD) on right heart function, glutathione and glutaredoxin systems, and the expression of redox-sensitive proteins involved with regulation calcium levels in the experimental model of pulmonary arterial hypertension (PAH) induced by monocrotaline (MCT). After 7 days of PAH induction, rats received daily doses of the PTS:HPβCD complex (corresponding to 25, 50, or 100 mg·kg^-1 of PTS) or vehicle (control group, CTR0) (an aqueous solution containing HPβCD; CTR0 and MCT0 (MCT group that did not receive PTS treatment)) via oral administration for 2 weeks. The results showed that the PTS:HPβCD complex increased the content of reduced glutathione and the activity of glutathione-S-transferase and glutaredoxin in the right ventricle (RV) of MCT-treated rats in a dose-dependent manner. Additionally, at higher doses, it also prevented the reduction of stroke volume and cardiac output, prevented myocardial performance index (MPI) increase, reduced lipoperoxidation, reduced total phospholamban, and increased the expression of sarcoplasmic reticulum calcium ATPase in the RV of MCT-treated rats. These results demonstrate that the PTS:HPβCD complex has a dose-dependent antioxidant mechanism that results in improved cardiac function in experimental right heart failure. Our results open a field of possibilities to PTS administration as new therapeutic approach to conventional therapy for right ventricular dysfunction. Novelty Pterostilbene complexed with hydroxypropyl-β-cyclodextrin could be a new therapeutic approach. Pterostilbene complexed with hydroxypropyl-β-cyclodextrin reestablishes redox homeostasis through glutathione metabolism modulation, leading to an improved MPI in pulmonary arterial hypertension-provoked right heart failure.

Early Escalation of Mechanical Circulatory Support Stabilizes and Potentially Rescues Patients in Refractory Cardiogenic Shock

Background:

Limited progress has been made in the management of cardiogenic shock (CS). Morbidity and mortality of refractory CS remain high. The effects of mechanical circulatory support (MCS) are promising, although many aspects are elusive. We evaluated efficacy and safety of early combined MCS (Impella microaxial pump + venoarterial extracorporeal membrane oxygenation [VA-ECMO]) in refractory CS and aimed to determine factors for decision-making in combined MCS.

Methods and Results:

We analyzed 69 consecutive patients with refractory CS from our registry requiring combined MCS. In 12 cases, therapy was actively withdrawn according to patient’s will. Patients were severely sick (Survival After Venoarterial ECMO score mean±SD, –8.9±4.4) predicting 30% in-hospital survival; ventilation 94%, dialysis 56%. Impella pumps and VA-ECMO were combined early (duration of combined MCS: median 94 hours; interquartile range, 49–150 hours). Early MCS escalation stabilized patients rapidly, reducing number and doses of catecholamines ( P <0.05 versus baseline) while hemodynamics improved. Reflecting an improved microcirculation, lactate levels normalized within 24 hours ( P <0.05 versus baseline). Despite refractory CS and disease severity, survival was favorable (on MCS 61%, 30 days 49%, 6 months 40%). In multivariate Cox-regression, duration of shock-to-first device (hours, hazard ratio, 1.05 [95% CI, 1.01–1.08]; P =0.007) and lactate levels after 12 hours of MCS (hazard ratio, 1.28 [95% CI, 1.09–1.51]; P =0.002) independently predicted survival. Additional right ventricular failure predisposed to futility (hazard ratio, 8.48 [95% CI, 1.85–38.91]; P =0.006).

Conclusions:

The early and consequent combination of MCS by Impella microaxial pumps and VA-ECMO enables stabilization and may rescue high-risk patients with refractory CS at low overall risk. Independent predictors of survival may guide prognostication, decision-making, and allocation of medical resources.

RNA-sequencing analysis of gene expression in a rat model of acute right heart failure

Background: Acute right heart failure (RHF) is the main cause of death in patients with acute pulmonary embolism and emergent pulmonary hypertension. However, the molecular mechanisms underpinning the acute RHF and the interactions between the right (RV) and left ventricles (LVs) under the diseased condition remain unknown. Methods and results: The Sprague Dawley male rats were randomly divided into the normal control, sham, and pulmonary artery banding (PAB) groups. One hour after the PAB operation, after measuring the haemodynamic and anatomical parameters, the free walls of RV and LV were harvested to detect the differential gene expression profiling by high-throughput RNA sequencing. The results showed that the PAB lead to 50-60% obstruction of the main pulmonary artery, which was accompanied by the significant elevation in the positive rate of rise in RV pressure and the maximum RV pressure as compared to the sham group. Moreover, compared with the counterparts in the sham group, the RV and LV in the PAB group exhibited 2057 differentially expressed genes (DEGs, 1159 upregulated and 898 downregulated) and 1196 DEGs (709 upregulated and 487 downregulated), respectively (DEG criteria: |log₂ fold change| ≥1, q value ≤0.05). In comparison to the sham group, the enriched pathways in the PAB group include nuclear factor-κB signalling pathway, extracellular matrix-receptor interaction, and nucleotide oligomerization domain-like receptor signalling pathway. Conclusions: The PAB rat model exhibited the haemodynamic and gene expression changes in the RV that lead to acute RHF. Further, the acute RHF induced by pressure overload also caused gene expression changes in the LV, suggesting the molecular interactions between the RV and LV under the diseased condition.

Impact of concurrent right ventricular myocardial infarction on outcomes among patients with left ventricular myocardial infarction

To compare in-hospital outcomes between left ventricular myocardial infarction (LVMI) patients with and without right ventricular myocardial infarction (RVMI). Patients with acute ST-segment elevation MI (STEMI) undergoing primary percutaneous coronary intervention (PCI) were enrolled and divided into LVMI with and without RVMI groups. Between-group differences and in-hospital outcomes were compared. Compared to patients without RVMI, patients with RVMI were more likely to be male, have higher body mass index, serum levels of C-reactive protein (8.9 ± 2.4 vs 6.2 ± 2.1 mg/dL), B-type natriuretic peptide (1295 ± 340 vs 872 ± 166 pg/mL) and cardiac troponin-I (8.6 ± 2.9 vs 5.2 ± 2.1 ng/mL), and have diabetes (36.3% vs 3.4%) and dyslipidemia (53.4% vs 48.1%). Patients with RVMI had lower left and right ventricular ejection fraction (50.5 ± 5.6% vs 53.4 ± 3.8% and 33.6 ± 2.9% vs 45.7 ± 2.0%), but had higher mean pulmonary artery pressure (30.6 ± 3.3 vs 23.8 ± 3.1 mm Hg). Compared to patients without RVMI, patients with RVMI had higher odds of in-hospital all-cause mortality (4.1% vs 1.0%) and new onset acute heart failure (3.4% vs 1.0%). After adjusted for confounding factors, LVMI with RVMI remained independently associated with composite outcomes, with odds ratio 1.66 (95% confidence interval 1.39–2.04). Compared to isolated LVMI patients, those with concomitant RVMI have higher odds of in-hospital complications, particularly all-cause mortality and new onset acute heart failure.

Pulmonary Hypertension in an Oncologic Intensive Care Unit

Pulmonary hypertension (PH) is the condition of elevated pressures in the pulmonary circulation. PH can develop acutely in patients with critical illness such as acute respiratory distress syndrome, sepsis, massive pulmonary embolism, left ventricular dysfunction, or after surgery. In a cancer patient, unique etiologies such as myeloproliferative disorders, tyrosine kinase inhibitors, or tumor emboli may result in PH. Early recognition and treatment of the causative condition may reverse acute PH or return chronic PH to its baseline status. Progression of the disease or its decompensation due to infection, a thromboembolic event, or other triggers can lead to admission to an intensive care unit. Regardless of etiology, the development or worsening of PH may precipitate hypoxemia, hemodynamic instability, or right ventricular failure, which can be challenging to manage or even fatal. In select cases, rapid institution of advanced treatment modalities may be warranted. This chapter reviews the etiology, epidemiology, pathophysiology, clinical features, diagnosis, and prognosis of PH and presents a comprehensive analysis of PH and right heart failure management strategies in the critical care setting. In particular, a unique perspective on oncologically relevant PH is provided.

Biomarkers and Right Ventricular Dysfunction

Right ventricular failure is common in critically ill patients, as it frequently results from pulmonary embolism or pulmonary hypertension, and can complicate sepsis and the acute respiratory distress syndrome. Right ventricular dysfunction can be challenging to manage and is associated with poor outcomes in this wide array of disease. Laboratory biomarkers are rapid, noninvasive, accurate, and widely available and thus are useful in the diagnosis and management of right ventricular dysfunction in the critically ill patient. This article discusses the pathophysiology of right ventricular failure and reviews the applications of commonly used biomarkers in right ventricular dysfunction in critical care.

Assessment and treatment of the failing right heart: considerations for transplantation referral

Long considered an insignificant chamber, the right ventricle has been recently under spotlight, especially with emerging data supporting its critical role in disease progression. The right ventricle is a triangular heart chamber with complex physiology and pathophysiology. In this review, we discuss the normal physiology of the right ventricle, right ventricular failure, and recent advances in treatment with emphasis on optimal timing for transplantation referral.

Cardiac Dysfunction in Acute Respiratory Distress Syndrome

Acute respiratory distress syndrome is a heterogenous condition with significant mortality and limited therapeutic options. Although hypoxic respiratory failure tends to be the hallmark of the disease, there can be significant cardiac compromise, particularly in the right ventricle. Echocardiography plays an important role in the early diagnosis and recognition of right ventricular dysfunction. Treatment of said dysfunction with mechanical ventilation strategies and therapies such as inhaled nitric oxide or extracorporeal membrane oxygenation remain poorly studied but offer potential salvage strategies.

Biomarkers in the Diagnosis, Management, and Prognostication of Perioperative Right Ventricular Failure in Cardiac Surgery-Are We There Yet?

Right ventricular failure (RVF) is a major risk factor for end organ morbidity and mortality following cardiac surgery. Perioperative RVF is difficult to predict and detect, and to date, no convenient, accurate, or reproducible measure of right ventricular (RV) function is available. Few studies have examined the use of biomarkers in RVF, and even fewer have examined their utility in the perioperative setting of patients undergoing cardiac surgery. Of the available classes of biomarkers, this review focuses on biomarkers of (1) inflammation and (2) myocyte injury/stress, due to their superior potential in perioperative RV assessment, including Galectin 3, ST2/sST2, CRP, cTN/hs-cTn, and BNP/NT-proBNP. This review was performed to help highlight the importance of perioperative RV function in patients undergoing cardiac surgery, to review the current modalities of RV assessment, and to provide a review of RV specific biomarkers and their potential utilization in the clinical and perioperative setting in cardiac surgery. Based on current evidence, we suggest the potential utility of ST2, sST2, Gal-3, CRP, hs-cTn, and NT-proBNP in predicting and detecting RVF in cardiac surgery patients, as they encompass the multifaceted nature of perioperative RVF and warrant further investigation to establish their clinical utility.

Pathophysiology of right ventricular failure in acute pulmonary embolism and chronic thromboembolic pulmonary hypertension: a pictorial essay for the interventional radiologist

Pulmonary embolus (PE) is the third most common cause of cardiovascular death with more than 600,000 cases occurring in the USA per year. About 45% of patients with acute PE will have acute right ventricular failure, and up to 3.8% of patients will develop chronic thromboembolic pulmonary hypertension (CTEPH) with progressive, severe, chronic heart failure. The right ventricle (RV) is constructed to accommodate a low-resistance afterload. Increases in afterload from acute massive and submassive PE and CTEPH may markedly compromise the RV function leading to hemodynamic collapse and death. The purpose of this educational manuscript is to instruct on the pathophysiology of RV failure in massive and submassive PE and CTEPH. It is important to understand the pathophysiology of these diseases as it provides the rationale for therapeutic intervention by the Interventional Radiologist. We review here the pathophysiology of right ventricular (RV) failure in acute massive and submassive PE and CTEPH.

Update on heart failure management and future directions

Heart failure (HF) is an important cardiovascular disease because of its increasing prevalence, significant morbidity, high mortality, and rapidly expanding health care cost. The number of HF patients is increasing worldwide, and Korea is no exception. There have been marked advances in definition, diagnostic modalities, and treatment of HF over the past four decades. There is continuing effort to improve risk stratification of HF using biomarkers, imaging and genetic testing. Newly developed medications and devices for HF have been widely adopted in clinical practice. Furthermore, definitive treatment for end-stage heart failure including left ventricular assist device and heart transplantation are rapidly evolving as well. This review summarizes the current state-of-the-art management for HF and the emerging diagnostic and therapeutic modalities to improve the outcome of HF patients.

Reversal of right ventricular failure by chronic α1A-subtype adrenergic agonist therapy

Right ventricular (RV) failure (RVF) is a serious disease with no effective treatment available. We recently reported a disease prevention study showing that chronic stimulation of α1A-adrenergic receptors (α1A-ARs), started at the time of RV injury, prevented the development of RVF. The present study used a clinically relevant disease reversal design to test if chronic α1A-AR stimulation, started after RVF was established, could reverse RVF. RVF was induced surgically by pulmonary artery constriction in mice. Two weeks after pulmonary artery constriction, in vivo RV fractional shortening as assessed by MRI was reduced by half relative to sham-operated controls (25 ± 2%, n = 27, vs. 52 ± 2%, n = 13, P < 10-11). Subsequent chronic treatment with the α1A-AR agonist A61603 for a further 2 wk resulted in a substantial recovery of RV fractional shortening (to 41 ± 2%, n = 17, P < 10-7 by a paired t-test) along with recovery of voluntary exercise capacity. Mechanistically, chronic A61603 treatment resulted in increased activation of the prosurvival kinase ERK, increased abundance of the antiapoptosis factor Bcl-2, and decreased myocyte necrosis evidenced by a decreased serum level of cardiac troponin. Moreover, A61603 treatment caused increased abundance of the antioxidant glutathione peroxidase-1, decreased level of reactive oxygen species, and decreased oxidative modification (carbonylation) of myofilament proteins. Consistent with these effects, A61603 treatment resulted in increased force development by cardiac myofilaments, which might have contributed to increased RV function. These findings suggest that the α1A-AR is a therapeutic target to reverse established RVF. NEW & NOTEWORTHY Currently, there are no effective therapies for right ventricular (RV) failure (RVF). This project evaluated a novel therapy for RVF. In a mouse model of RVF, chronic stimulation of α1A-adrenergic receptors with the agonist A61603 resulted in recovery of in vivo RV function, improved exercise capacity, reduced oxidative stress-related carbonylation of contractile proteins, and increased myofilament force generation. These results suggest that the α1A-adrenergic receptor is a therapeutic target to treat RVF.

Roles of apoptosis and inflammation in a rat model of acute lung injury induced right ventricular dysfunction

AIM

The effect of intratracheal lipopolysaccharide (LPS) instillation on right ventricular dysfunction in rats was studied with the aim of exploring underlying mechanisms.

MAIN METHODS

A single dose of LPS (10 mg/kg) or an equal volume of saline was instilled intratracheally and lung injury evaluated using histopathologic scoring and wet/dry (W/D) weight ratio at 6 or 12 h post-administration. Besides, serum atrial natriuretic peptide (ANP) was detected using an enzyme-linked immunosorbent assay (ELISA) and right ventricle β-myosin heavy chain (β-MHC) presence was examined using reverse transcription polymerase chain reaction (RT-PCR). Echocardiography examined pulmonary artery acceleration time (PAAT), right ventricular free wall thickness (RVFWT), tricuspid annular plane systolic excursion (TAPSE), and right ventricular end-diastolic diameter (RVEDD). In addition, right ventricular TUNEL staining and Western blots of Bax and Bcl-2 were performed. Right ventricle and left ventricle caspases-3, -8, and -9 activity were examined using fluorometric assay. Finally, right ventricle myeloperoxidase (MPO) neutrophil staining, and right ventricle and plasma cytokines TNF-α, IL-1β, IL-6 detection was performed.

KEY FINDINGS

Histopathologic lung injury and increased W/D weight ratio was seen at 6 h after LPS intratracheal instillation, along with increased ANP, but not β-MHC. Pulmonary hypertension was indicated by decreased PAAT at 6 h post-exposure. Right ventricular systolic dysfunction and dilation were observed at 12 h post-exposure, as indicated by a significant decrease of TAPSE and increase of RVEDD. Of note, the procedure led to an increased right ventricle TUNEL positive cardiomyocytes, an increased Bax/Bcl-2 ratio, and increased right and left ventricle caspases-3, -8, and -9 activity as early as 6 h post-exposure, which was paralleled by increased right ventricle MPO staining and increased expression of right ventricle and serum cytokines TNF-α, IL-1β, and IL-6.

SIGNIFICANCE

As well as acute lung injury, a single dose of LPS intratracheally instilled can induce pulmonary hypertension at 6 h post-exposure, with obvious right ventricular systolic dysfunction and right ventricular dilation present at 12 h post-exposure, possibly via cardiomyocytes apoptosis and inflammation.

Impaired Myofilament Contraction Drives Right Ventricular Failure Secondary to Pressure Overload: Model Simulations, Experimental Validation, and Treatment Predictions

Introduction: Pulmonary hypertension (PH) causes pressure overload leading to right ventricular failure (RVF). Myocardial structure and myocyte mechanics are altered in RVF but the direct impact of these cellular level factors on organ level function remain unclear. A computational model of the cardiovascular system that integrates cellular function into whole organ function has recently been developed. This model is a useful tool for investigating how changes in myocyte structure and mechanics contribute to organ function. We use this model to determine how measured changes in myocyte and myocardial mechanics contribute to RVF at the organ level and predict the impact of myocyte-targeted therapy. Methods: A multiscale computational framework was tuned to model PH due to bleomycin exposure in mice. Pressure overload was modeled by increasing the pulmonary vascular resistance (PVR) and decreasing pulmonary artery compliance (CPA). Myocardial fibrosis and the impairment of myocyte maximum force generation (Fmax) were simulated by increasing the collagen content (↑PVR + ↓CPA + fibrosis) and decreasing Fmax (↑PVR + ↓CPA + fibrosis + ↓Fmax). A61603 (A6), a selective α1A-subtype adrenergic receptor agonist, shown to improve Fmax was simulated to explore targeting myocyte generated Fmax in PH. Results: Increased afterload (RV systolic pressure and arterial elastance) in simulations matched experimental results for bleomycin exposure. Pressure overload alone (↑PVR + ↓CPA) caused decreased RV ejection fraction (EF) similar to experimental findings but preservation of cardiac output (CO). Myocardial fibrosis in the setting of pressure overload (↑PVR + ↓PAC + fibrosis) had minimal impact compared to pressure overload alone. Including impaired myocyte function (↑PVR + ↓PAC + fibrosis + ↓Fmax) reduced CO, similar to experiment, and impaired EF. Simulations predicted that A6 treatment preserves EF and CO despite maintained RV pressure overload. Conclusion: Multiscale computational modeling enabled prediction of the contribution of cellular level changes to whole organ function. Impaired Fmax is a key feature that directly contributes to RVF. Simulations further demonstrate the therapeutic benefit of targeting Fmax, which warrants additional study. Future work should incorporate growth and remodeling into the computational model to enable prediction of the multiscale drivers of the transition from dysfunction to failure.

Multiscale structure-function relationships in right ventricular failure due to pressure overload

Right ventricular (RV) failure (RVF) is the major cause of death in pulmonary hypertension. Recent studies have characterized changes in RV structure in RVF, including hypertrophy, fibrosis, and abnormalities in mitochondria. Few, if any, studies have explored the relationships between these multiscale structural changes and functional changes in RVF. Pulmonary artery banding (PAB) was used to induce RVF due to pressure overload in male rats. Eight weeks postsurgery, terminal invasive measurements demonstrated RVF with decreased ejection fraction (70 ± 10 vs. 45 ± 15%, sham vs. PAB, P < 0.005) and cardiac output (126 ± 40 vs. 67 ± 32 ml/min, sham vs. PAB, P < 0.05). At the organ level, RV hypertrophy was directly correlated with increased contractility, which was insufficient to maintain ventricular-vascular coupling. At the tissue level, there was a 90% increase in fibrosis that had a direct correlation with diastolic dysfunction measured by reduced chamber compliance ( r² = 0.43, P = 0.008). At the organelle level, transmission electron microscopy demonstrated an abundance of small-sized mitochondria. Increased mitochondria was associated with increased ventricular oxygen consumption and reduced mechanical efficiency ( P < 0.05). These results demonstrate an association between alterations in mitochondria and RV oxygen consumption and mechanical inefficiency in RVF and a link between fibrosis and in vivo diastolic dysfunction. Overall, this work provides key insights into multiscale RV remodeling in RVF due to pressure overload. NEW & NOTEWORTHY This study explores the functional impact of multiscale ventricular remodeling in right ventricular failure (RVF). It demonstrates correlations between hypertrophy and increased contractility as well as fibrosis and diastolic function. This work quantifies mitochondrial ultrastructural remodeling in RVF and demonstrates increased oxygen consumption and mechanical inefficiency as features of RVF. Direct correlation between mitochondrial changes and ventricular energetics provides insight into the impact of organelle remodeling on organ level function.

Cardiogenic shock complicating peripartum cardiomyopathy: Importance of early left ventricular unloading and bromocriptine therapy

INTRODUCTION

Acute peripartum cardiomyopathy complicated by cardiogenic shock is a rare but life-threatening disease. A prolactin fragment is considered causal for the pathogenesis of peripartum cardiomyopathy. This analysis sought to investigate the role of early percutaneous mechanical circulatory support with micro-axial flow-pumps and/or veno-arterial extracorporeal membrane oxygenation in combination with the prolactin inhibitor bromocriptine in refractory cardiogenic shock complicating peripartum cardiomyopathy.

METHODS AND RESULTS

In this single-centre analysis, five peripartum cardiomyopathy patients with refractory cardiogenic shock received mechanical circulatory support with either Impella CP microaxial pump only (n=2) or in combination with veno-arterial extracorporeal membrane oxygenation (n=3) in the setting of biventricular failure. All patients were mechanically ventilated. In all cases mechanical circulatory support was combined with bromocriptine therapy and early administration of levosimendan. All patients survived the acute phase of refractory cardiogenic shock. Mechanical circulatory support using a micro-axial pump allowed to significantly reduce catecholamine dosage. Remarkably, early left ventricular support with micro-axial flow-pumps resulted in myocardial recovery whereas delayed Impella (mechanical circulatory support) implantation was associated with poor left ventricular recovery.

CONCLUSION

Mechanical circulatory support in patients with refractory cardiogenic shock complicating peripartum cardiomyopathy was associated with a 30-day survival of 100% and a favourable outcome. Notably, early left ventricular unloading combined with bromocriptine therapy was associated with left ventricular recovery. Therefore, an immediate transfer to a tertiary hospital experienced in mechanical circulatory support in combination with bromocriptine treatment seems indispensable for successful treatment of peripartum cardiomyopathy complicated by cardiogenic shock.

Trapidil improves hemodynamic, echocardiographic and redox state parameters of right ventricle in monocrotaline-induced pulmonary arterial hypertension model

BACKGROUND

Pulmonary arterial hypertension is a disease characterized by increased pulmonary vascular resistance and redox imbalance, leading to failure of right ventricle. Trapidil has been described to improve the redox balance and cardiac conditions.

HYPOTHESIS

Trapidil can improve the redox balance and contribute to functional improvements of the RV in PAH.

METHODS AND RESULTS

Male, 5week-old Wistar rats were divided into four groups: Control, Control + Trapidil, Monocrotaline and Monocrotaline + Trapidil. PAH was induced by an intraperitoneal injection of monocrotaline 60 mg/kg at day 0. Treatment started at day 7 (5 or 8 mg/kg/day) until day 14, when animals were euthanized after echocardiography and catheterism. Right ventricular systolic pressure and pressure/time derivatives were increased in monocrotaline animals. The increased right ventricular diameters in monocrotaline groups were reduced with trapidil. Monocrotaline groups showed higher lipid peroxidation and glutathione peroxidase activity. Trapidil reduced NADPH oxidases activities and increased the reduced glutathiones/total glutathiones ratio. Protein expression of phospholamban in RV was diminished in monocrotaline groups, whereas expression of RyR and SERCA was enhanced in the groups treated with trapidil.

CONCLUSION

Our data suggest that trapidil induces an improvement in RV remodeling in PAH model, mitigating the progression of the disease.

Optimal right heart filling pressure in acute respiratory distress syndrome determined by strain echocardiography

INTRODUCTION

Right ventricular (RV) systolic dysfunction is common in acute respiratory distress syndrome (ARDS). While preload optimization is crucial in its management, dynamic fluid responsiveness indices lack reliability, and there is no consensus on target central venous pressure (CVP). We analyzed the utility of RV free wall longitudinal strain (RVFWS) in the estimation of optimal RV filling pressure in ARDS.

METHODS

A retrospective cross-sectional analysis of clinical data and echocardiograms of patients with ARDS was performed. Tricuspid annular plane systolic excursion (TAPSE), tricuspid peak systolic velocity (S'), RV fractional area change (RVFAC), RVFWS, CVP, systolic pulmonary artery pressure (SPAP), and left ventricular ejection fraction (LVEF) were measured.

RESULTS

Fifty-one patients with moderate-severe ARDS were included. There were inverse correlations between CVP and TAPSE, S', RVFAC, RVFWS, and LVEF. The most significant was with RVFWS (r:.74, R² :.55, P:.00001). Direct correlations with creatinine and lactate were noted. Receiver operating characteristic analysis showed that RVFWS -21% (normal reference value) was associated with CVP: 13 mm Hg (AUC: 0.92, 95% CI: 0.83-1.00). Regression model analysis of CVP, and RVFWS interactions established an RVFWS range from -18% to -24%. RVFWS -24% corresponded to CVP: 11 mm Hg and RVFWS -18% to CVP: 15 mm Hg. Beyond a CVP of 15 mm Hg, biventricular systolic dysfunction rapidly ensues.

CONCLUSIONS

Our data are the first to show that an RV filling pressure of 13±2 mm Hg-as by CVP-correlates with optimal RV mechanics as evaluated by strain echocardiography in patients with moderate-severe ARDS.