Medical and surgical treatment of acute right ventricular failure

Pathophysiology, diagnosis and management of right ventricular failure: A state of the art review of mechanical support devices

The function of the right ventricle (RV) is to drive the forward flow of blood to the pulmonary system for oxygenation before returning to the left ventricle. Due to the thin myocardium of the RV, its function is easily affected by decreased preload, contractile motion abnormalities, or increased afterload. While various etiologies can lead to changes in RV structure and function, sudden changes in RV afterload can cause acute RV failure which is associated with high mortality. Early detection and diagnosis of RV failure is imperative for guiding initial medical management. Echocardiographic findings of reduced tricuspid annular plane systolic excursion (<1.7) and RV wall motion (RV S' <10 cm/s) are quantitatively supportive of RV systolic dysfunction. Medical management commonly involves utilizing diuretics or fluids to optimize RV preload, while correcting the underlying insult to RV function. When medical management alone is insufficient, mechanical circulatory support (MCS) may be necessary. However, the utility of MCS for isolated RV failure remains poorly understood. This review outlines the differences in flow rates, effects on hemodynamics, and advantages/disadvantages of MCS devices such as intra-aortic balloon pump, Impella, centrifugal-flow right ventricular assist devices, extracorporeal membrane oxygenation, and includes a detailed review of the latest clinical trials and studies analyzing the effects of MCS devices in acute RV failure.

Characteristics and Outcomes of Critically Ill Patients With Pulmonary Hypertension Who Undergo Endotracheal Intubation and Mechanical Ventilation

Background: Patients with pulmonary hypertension (PH) who undergo endotracheal intubation have an increased risk of adverse outcomes, but little is known regarding prognostic factors and there is limited evidence to guide management. We sought to define characteristics, prognostic factors, and outcomes of critically ill patients with PH who underwent intubation. Study Design: We performed a single-center retrospective cohort study of critically ill patients with group 1, 3 or 4 PH who underwent intubation. Results: Eighty-one patients were included. Patients had a median age of 56 years (interquartile range 44-65) and were predominantly female (n = 53, 65%) and Caucasian (n = 71, 88%). Forty-five (56%) had group 1 PH while 25 (31%) had group 3 PH and 11 (14%) had group 4 PH. Patients were admitted to the hospital for right ventricular failure (n = 21, 25.6%), sepsis (n = 18, 22.2%), and respiratory failure (n = 19, 23.1%). Hypoxemic respiratory failure (n = 54, 66.7%) was the most common indication for intubation. In-hospital mortality was 30.9% and 1-year mortality was 48.2%. All patients (11 of 11, 100%) intubated electively for intensive care unit procedures survived to hospital discharge while only 1 of 6 (16.7%) intubated in the setting of a cardiac arrest survived. After adjusting for right ventricular systolic pressure, pre-intubation PaO2 (odds ratio [OR] = 0.99, 95% confidence interval [CI] 0.97-1.00, P = .02) and postintubation PaO2 (OR = 0.97 per 1mm Hg, 95% CI 0.95 to 0.99, P = .003), pH (OR = 0.49 per 0.1 increase, 95% CI 0.29 to 0.80, P = .005) and PaCO2 (OR = 1.08 per 1mm Hg, 95% CI 1.02 to 1.14, P = .005) were significantly associated with in-hospital mortality. Results were similar when we excluded patients intubated electively or in the setting of cardiac arrest. Conclusions: Intubation in critically ill patients with PH is associated with significant in-hospital mortality and nearly 50% 1-year mortality. Potentially modifiable factors, such as peri-intubation gas exchange, are associated with an increased risk of death while other demographic and hemodynamic variables are not.

Prognostic Value of Respiratory Variation in Right Atrial Pressure in Patients With Precapillary Pulmonary Hypertension

BACKGROUND

Precapillary pulmonary hypertension is characterized by elevated mean pulmonary artery pressure from increased pulmonary vascular resistance. Lack of respiratory variation in right atrial pressure can be viewed as a surrogate for severe pulmonary hypertension and inability of the right ventricle to tolerate preload augmentation during inspiration.

RESEARCH QUESTION

Is the lack of respiratory variation in right atrial pressure predictive of right ventricular dysfunction and worse clinical outcomes in precapillary pulmonary hypertension?

STUDY DESIGN AND METHODS

We retrospectively reviewed right atrial pressure tracings of patients with precapillary pulmonary hypertension who underwent right heart catheterization. Patients with respiratory variation in right atrial pressure (end expiratory-end inspiratory) ≤ 2 mm Hg were considered to have effectively no meaningful variation in right atrial pressure.

RESULTS

Lack of respiratory variation in right atrial pressure was associated with lower cardiac index by indirect Fick (2.34 ± 0.09 vs 2.76 ± 0.1 L/min/m2; P = .001), lower pulmonary artery saturation (60% ± 1.02% vs 64% ± 1.15%; P = .007), higher pulmonary vascular resistance (8.9 ± 0.44 vs 6.1 ± 0.49 Wood units, P < .0001), right ventricular dysfunction on echocardiography (87.3% vs 38.8%; P < .0001), higher pro brain natriuretic peptide (2,163 ± 2,997 vs 633 ± 402 ng/mL; P < .0001), and more hospitalizations within 1 year for right ventricular failure (65.4% vs 29.6%; P < .0001). There was also a trend toward higher mortality at 1 year in patients with no respiratory variation in right atrial pressure (25.4% vs 11.1%; P = .06).

INTERPRETATION

Lack of respiratory variation in right atrial pressure is associated with poor clinical outcomes, adverse hemodynamic parameters, and right ventricular dysfunction in patients with precapillary pulmonary hypertension. Larger studies are needed to further evaluate its utility in prognosis and potential risk stratification in patients with precapillary pulmonary hypertension.

Mechanical Circulatory Support and Critical Care Management of High-Risk Acute Pulmonary Embolism

Hemodynamically significant pulmonary embolism (PE) remains a widely prevalent, underdiagnosed condition associated with mortality rates as high as 30%. The main driver of poor outcomes is acute right ventricular failure that remains clinically challenging to diagnose and requires critical care management. Treatment of high-risk (or massive) acute PE has traditionally included systemic anticoagulation and thrombolysis. Mechanical circulatory support, including both percutaneous and surgical approaches, are emerging as treatment options for refractory shock due to acute right ventricular failure in the setting of high-risk acute pulmonary embolism.

Acute Right Ventricular Failure: Pathophysiology, Diagnostic Approach with Emphasis on the Role of Echocardiography

Right ventricular function is one of the important predictors of survival in heart failure patients. In the past, there has been only limited knowledge regarding right-sided heart failure when compared to left-sided failure. However, there are more emerging data in recent years, and several studies have emphasized the unique features of the right ventricle regarding its anatomy, pathophysiology, clinical consequences, diagnostic modalities, and treatment options. Despite that, management of acute right ventricular failure is still challenging. This article summarizes an overview of acute right heart failure including pathophysiology, causes, clinical features, and diagnostic work-up with emphasis on the role of echocardiography.

IGFBP7 as a preoperative predictor of congestive acute kidney injury after cardiac surgery

Objective

Congestive acute kidney injury (c-AKI) refers to AKI in the presence of right ventricular failure (RVF) and is a highly morbid complication of cardiac surgery. However, treatment has traditionally been reactive rather than proactive due to limited modalities to predict this complication. The objective of this study was to investigate the ability of insulin-like growth-factor binding protein 7 (IGFBP7), to predict c-AKI, AKI and RVF in patients undergoing cardiac surgery, as compared to N-terminal prohormone B-type natriuretic peptide (NT-pro-BNP) and pulmonary artery pulsatility index (PAPi).

Methods

This prospective nested case–control study consisted of 350 adult patients who underwent elective cardiac surgery. The outcomes were c-AKI, AKI and RVF. Unadjusted and adjusted conditional logistic regression models and areas under the receiver operating characteristic curve (AUC) were used to assess the predictive performance of each marker.

Results

For the prediction of c-AKI, the unadjusted IGPBP7 model had an AUC of 0.81, as compared with 0.51 for NT-pro-BNP and 0.61 for PAPi. The adjusted c-AKI models had AUCs of 0.90 for IGFBP7, 0.87 for NT-pro-BNP and 0.77 for PAPi. For AKI and RVF, the predictive performance of IGFBP7 was moderate and exceeded that of NT-pro-BNP and PAPi in univariable analysis. IGFBP7 remained a robust independent predictor of all outcomes in multivariable analysis, whereas the other markers did not.

Conclusions

IGFBP7 is a promising biomarker for prediction of AKI, RVF and c-AKI and could have value for preoperative optimisation and risk stratification of patients undergoing cardiac surgery.

[Adults with congenital heart disease presenting to the emergency department : Potential pitfalls]

The number of adults with congenital heart disease (ACHD) already exceeds the number of children with congenital heart disease in the industrialized world. ACHD patients often show complex pathophysiology and anatomy even after reparative cardiac surgery. In case of complications patients may rapidly deteriorate and become unstable, even when they were asymptomatic or had only mild symptoms before the onset of the complication. Compared to all patients seen by emergency physicians, emergencies in ACHD patients are still rare. This review is aimed to guide management in ACHD emergency situations. Approximately two-thirds of all emergency admissions are caused by arrhythmias or acute heart failure. Sustained arrhythmias may rapidly lead to acute cardiac decompensation in ACHD patients. If medical treatment fails or patients present in hemodynamically unstable conditions, prompt electrical cardioversion is mandatory. Symptomatic bradycardia may require urgent pacemaker implantation. Depending on the underlying heart defect, placement of temporary transvenous pacemaker leads may be impossible. Acute heart failure in ACHD patients is often caused by acute right heart failure. Other more frequent emergencies are infections, syncope, thromboembolic events, and aortic dissection. It is highly recommended to contact the tertiary care center that follows the patient regularly early in case of patient presentation to the emergency room.

The effect of levosimendan on right ventricular function in patients with heart dysfunction: a systematic review and meta-analysis

Levosimendan exerts positive inotropic and vasodilatory effects. Currently, its effects on right heart function remain uncertain. This systematic review and meta-analysis is intended to illustrate the impacts of levosimendan on systolic function of the right heart in patients with heart dysfunction. We systematically searched electronic databases (PubMed, the Cochrane Library, Embase and Web of Science) up to November 30, 2020, and filtered eligible studies that reported the impacts of levosimendan on right heart function. Of these, only studies whose patients suffered from heart dysfunction or pulmonary hypertension were included. Additionally, patients were divided into two groups (given levosimendan or not) in the initial research. Then, RevMan5.3 was used to conduct further analysis. A total of 8 studies comprising 390 patients were included. The results showed that after 24 h of levosimendan, patients' right ventricular fractional area change [3.17, 95% CI (2.03, 4.32), P < 0.00001], tricuspid annular plane systolic excursion [1.26, 95% CI (0.35, 2.16), P = 0.007] and tricuspid annular peak systolic velocity [0.86, 95% CI (0.41, 1.32), P = 0.0002] were significantly increased compared to the control group. And there is an increasing trend of cardiac output in levosimendan group [1.06, 95% CI (- 0.16, 2.29), P = 0.09 ] .Furthermore, patients' systolic pulmonary arterial pressure [- 5.57, 95% CI (- 7.60, - 3.54), P < 0.00001] and mean pulmonary arterial pressure [- 1.01, 95% CI (- 1.64, - 0.37), P = 0.002] were both significantly decreased, whereas changes in pulmonary vascular resistance [- 55.88, 95% CI (- 206.57, 94.82), P = 0.47] were not significant. Our study shows that in patients with heart dysfunction, levosimendan improves systolic function of the right heart and decreases the pressure of the pulmonary artery.

Evaluation of Inhaled Alprostadil in Hospitalized Adult Patients

BACKGROUND

Intermittent inhaled alprostadil (iPGE₁) may be a viable alternative to inhaled nitric oxide or epoprostenol for management of right ventricular failure, pulmonary hypertension (pHTN) or acute respiratory distress syndrome (ARDS). However, limited evidence exists regarding iPGE₁ use in adults, ideal dosing strategies, or optimal use cases.

OBJECTIVE

To describe the clinical characteristics of patients receiving iPGE₁ and identify specific sub-populations warranting further research.

METHODS

This was a single-center, retrospective, descriptive analysis of inpatients who received at least one dose of iPGE₁. The primary outcome was to describe patient characteristics and alprostadil dosing strategies. Secondary outcomes included changes in respiratory support requirements, hemodynamics, and inotropic/vasoactive use. Outcomes were stratified and compared based on primary therapeutic indication (cardiac or pulmonary).

RESULTS

Fifty-four patients received iPGE₁ 40 (75%) for pulmonary (pHTN or ARDS) and 14 (25%) for cardiac indications. There was no difference between indications in the number of patients de-escalated from level of respiratory (53% vs 57%, P = 0.76), inotropic (70% vs 57%, P = 0.39), or vasopressor support (78% vs 57%, P = 0.17). Furthermore, there was no significant improvement in cardiopulmonary parameters at multiple time intervals after iPGE₁ initiation.

CONCLUSION AND RELEVANCE

This is the largest study to date on the use of intermittent iPGE₁ in adults. Alprostadil was safely utilized in novel populations; however, efficacy as evaluated by clinical or surrogate endpoints could not be demonstrated and further investigation is needed to determine its potential and optimal place in therapy.

Hemodynamic Instability during Acute Kidney Injury and Acute Renal Replacement Therapy: Pathophysiology and Clinical Implications

Hemodynamic instability associated with acute renal replacement therapy (aRRT, HIRRT) and/or with acute kidney injury (AKI) is frequently observed in the intensive care unit; it affects patients' renal recovery, and negatively impacts short- and long-term mortality. A thorough understanding of mechanisms underlying HIRRT and AKI-related hemodynamic instability may allow the physician in adopting adequate strategies to prevent their occurrence and reduce their negative consequences. The aim of this review is to summarize the main alterations occurring in patients with AKI and/or requiring aRRT of those homeostatic mechanisms which regulate hemodynamics and oxygen delivery. In particular, a pathophysiological approach has been used to describe the maladaptive interactions between cardiac output and systemic vascular resistance occurring in these patients and leading to hemodynamic instability. Finally, the potential positive effects of aRRT on these pathophysiological mechanisms and on restoring hemodynamic stability have been described.

Anesthetic protocol for right ventricular dysfunction management in heart transplantation: systematic review, development and validation

BACKGROUND

Right Ventricular Dysfunction (RVD) is the most frequent intraoperative hemodynamic complication in Heart Transplantation (HTx). RVD occurs in 0.04-1.0% of cardiac surgeries with cardiotomy and in 20-50% of HTx, with mortality up to 75%. No consensus has been established for how anesthesiologists should manage RVD, with management methods many times remaining unvalidated.

METHODS

We conducted a systematic review, following PRISMA guidelines, to create an anesthetic protocol to manage RVD in HTx, using databases that include PubMed and Embase, until September 2018 based on inclusion and exclusion criteria. The articles screening for the systematic review were done two independent reviewers, in case of discrepancy, we consulted a third independent reviewer. Based on the systematic review, the anesthetic protocol was developed. The instrument selected to perform the validation of the protocol was AGREE II, for this purpose expert anesthetists were recruited to do this process. The minimum arbitration score for domains validation cutoff of AGREE II is arbitered to 70%. This study was registered at PROSPERO (115600).

RESULTS

In the systematic review, 152 articles were included. We present the protocol in a flowchart with six steps based on goal-directed therapy, invasive monitoring, and transesophageal echocardiogram. Six experts judged the protocol and validated it.

CONCLUSION

The protocol has been validated by experts and new studies are needed to assess its applicability and potential benefits on major endpoints.

Preoperative Assessment and Perioperative Management of the Patient with Pulmonary Vascular Disease

The incidence of pulmonary hypertension (PH) in patients undergoing noncardiac surgery has increased steadily over the past decade. Patients with known PH have significantly higher perioperative morbidity and mortality than those without PH. Moreover, a substantial number of patients may have occult disease. It, therefore, is of paramount importance for perioperative providers to recognize high-risk patients and treat them appropriately. This review first provides an overview of PH pathophysiology, then estimates the perioperative incidence of PH and its impact on surgical outcomes, and finally outlines a perioperative management strategy.

Treatment of right ventricular dysfunction and heart failure in pulmonary arterial hypertension

Right heart dysfunction and failure is the principal determinant of adverse outcomes in patients with pulmonary arterial hypertension (PAH). In addition to right ventricular (RV) dysfunction, systemic congestion, increased afterload and impaired myocardial contractility play an important role in the pathophysiology of RV failure. The behavior of the RV in response to the hemodynamic overload is primarily modulated by the ventricular interaction and its coupling to the pulmonary circulation. The presentation can be acute with hemodynamic instability and shock or chronic producing symptoms of systemic venous congestion and low cardiac output. The prognostic factors associated with poor outcomes in hospitalized patients include systemic hypotension, hyponatremia, severe tricuspid insufficiency, inotropic support use and the presence of pericardial effusion. Effective therapeutic management strategies involve identification and effective treatment of the triggering factors, improving cardiopulmonary hemodynamics by optimization of volume to improve diastolic ventricular interactions, improving contractility by use of inotropes, and reducing afterload by use of drugs targeting pulmonary circulation. The medical therapies approved for PAH act primarily on the pulmonary vasculature with secondary effects on the right ventricle. Mechanical circulatory support as a bridge to transplantation has also gained traction in medically refractory cases. The current review was undertaken to summarize recent insights into the evaluation and treatment of RV dysfunction and failure attributable to PAH.

Acute myopericarditis as a cause of isolated right ventricular failure

Myopericarditis is characterized by pericardial and myocardial inflammation and is a known cause of chest pain and heart failure. It is primarily associated with biventricular or left ventricular dysfunction. We describe an unusual case of a 57-year-old woman with myopericarditis causing isolated right ventricular (RV) failure. She initially presented with chest pain and cardiogenic shock and was found to have acute RV dysfunction with a normally functioning left ventricle. After excluding more common causes of RV failure, she was diagnosed with acute myopericarditis. In this report, we discuss the differential diagnoses and work-up of acute RV failure, as well as review prior cases of RV-predominant myocarditis/myopericarditis. We highlight the importance of recognizing isolated RV failure as a possible, but rare, presentation of myopericarditis.

Use and costs of inhaled nitric oxide and inhaled epoprostenol in adult critically ill patients: A quality improvement project

PURPOSE

Inhaled epoprostenol and inhaled nitric oxide are pulmonary vasodilators commonly used in the management of acute respiratory distress syndrome and right ventricular failure; however, they have vastly different cost profiles. The purpose of the project was to transition from nitric oxide to epoprostenol as the inhaled pulmonary vasodilator (IPV) of choice in adult critically ill patients and evaluate the effect of the transition on associated usage and costs.

METHODS

A single-center, prospective, before and after quality improvement project including adult patients receiving inhaled nitric oxide, inhaled epoprostenol, or both was conducted in 7 adult intensive care units, operating rooms, and postanesthesia care units of a tertiary care academic medical center. The total number of patients, hours of therapy, and costs for each agent were compared between stages of protocol implementation and annually.

RESULTS

Seven hundred twenty-nine patients received inhaled nitric oxide, inhaled epoprostenol, or both during the study period. The monthly inhaled nitric oxide use in number of patients, hours, and cost decreased during all stages of the project (p < 0.01). The monthly inhaled epoprostenol use in number of patients, hours, and cost increased during all stages (p < 0.01). Overall, total IPV use increased during the study. However, despite this increase in usage, there was a 47% reduction in total IPV cost.

CONCLUSION

Implementation of a staged protocol to introduce and expand inhaled epoprostenol use in adult critically ill patients resulted in decreased use and cost of inhaled nitric oxide. The total cost of all IPV was decreased by 47% despite increased IPV use.

Levosimendan or milrinone for right ventricular inotropic treatment?-A secondary analysis of a randomized trial

BACKGROUND

The aim of the present study was to compare the effects of milrinone and levosimendan on right ventricular (RV) inotropy and lusitropy in patients after aortic valve replacement (AVR) for aortic stenosis, a procedure in which an abnormal postoperative RV function may be seen.

METHODS

In a prospective, blinded trial, 31 patients were randomized to receive either milrinone (0.4 and 0.8 µg/kg/min, n = 16) or levosimendan (0.1 and 0.2 µg/kg/min, n = 15) after AVR for aortic stenosis. RV performance, afterload (pulmonary arterial elastance), RV strain, systolic (SR-S) and early diastolic (SR-E) strain rate were measured by pulmonary artery thermodilution catheterization and transoesophageal two-dimensional speckle tracking echocardiography. To circumvent the indirect effects of inodilator-induced hemodynamic changes on RV systolic and diastolic deformation, pulmonary arterial elastance, central venous pressure and heart rate were maintained constant by atrial pacing, plasma volume expansion with colloids and phenylephrine-induced vasoconstriction during treatment with the inotropes.

RESULTS

A dose-dependent increase in stroke volume index and cardiac index by approximately 20% were seen with both agents at the highest doses, with no difference between groups (P = .792 and 0.744, respectively). In both groups, RV strain and SR-S dose-dependently increased by 20% and 15%-19%, respectively, at the highest doses (P = .742 and 0.259, respectively) with no difference between groups. SR-E improved by both agents 20%-24% at the highest dose with no difference between groups (P = .714).

CONCLUSIONS

The direct RV inotropic and lusitropic effects of levosimendan and milrinone were comparable at clinically relevant infusion rates.

Use of Levosimendan in Intensive Care Unit Settings: An Opinion Paper

Levosimendan is an inodilator that promotes cardiac contractility primarily through calcium sensitization of cardiac troponin C and vasodilatation via opening of adenosine triphosphate–sensitive potassium (K_ATP) channels in vascular smooth muscle cells; the drug also exerts organ-protective effects through a similar effect on mitochondrial K_ATP channels. This pharmacological profile identifies levosimendan as a drug that may have applications in a wide range of critical illness situations encountered in intensive care unit medicine: hemodynamic support in cardiogenic or septic shock; weaning from mechanical ventilation or from extracorporeal membrane oxygenation; and in the context of cardiorenal syndrome. This review, authored by experts from 9 European countries (Austria, Belgium, Czech republic, Finland, France, Germany, Italy, Sweden, and Switzerland), examines the clinical and experimental data for levosimendan in these situations and concludes that, in most instances, the evidence is encouraging, which is not the case with other cardioactive and vasoactive drugs routinely used in the intensive care unit. The size of the available studies is, however, limited and the data are in need of verification in larger controlled trials. Some proposals are offered for the aims and designs of these additional studies.

Amniotic fluid embolism: principles of early clinical management

Amniotic fluid embolism is an uncommon, but potentially lethal, complication of pregnancy. Because amniotic fluid embolism usually is seen with cardiac arrest, the initial immediate response should be to provide high-quality cardiopulmonary resuscitation. We describe key features of initial treatment of patients with amniotic fluid embolism. Where available, we recommend performing transthoracic or transesophageal echocardiography as soon as possible because this is an easy and reliable method of identifying a failing right ventricle. If such failure is identified, treatment that is tailored at improving right ventricular performance should be initiated with the use of inotropic agents and pulmonary vasodilators. Blood pressure support with vasopressors is preferred over fluid infusion in the setting of severe right ventricular compromise. Amniotic fluid embolism-related coagulopathy should be managed with hemostatic resuscitation with the use of a 1:1:1 ratio of packed red cells, fresh frozen plasma, and platelets (with cryoprecipitate as needed to maintain a serum fibrinogen of >150-200 mg/dL). In cases that require prolonged cardiopulmonary resuscitation or, after arrest, severe ventricular dysfunction refractory to medical management, consideration for venoarterial extracorporeal membrane oxygenation should be given.

Can Biomarkers Provide Right Ventricular-Specific Prognostication in the Perioperative Setting?

Since the introduction of biomarkers in the late 1980s, considerable research has been dedicated to their validation and application. As a result, many biomarkers are now commonly used in clinical practice. However, the role of biomarkers in the prediction of right ventricular failure (RVF) and in the prognostication for patients with RVF remains underexplored. Barriers include a lack of awareness of the importance of right ventricular function, especially in the perioperative setting, as well as a lack of reproducible means to assess right ventricular function in this setting. We provide an overview of biomarkers with right ventricular prognostic capabilities that could be further explored in patients expecting cardiac surgery, who are notoriously susceptible to developing RVF. We discuss biomarkers' mechanistic pathways and highlight their potential strengths and weaknesses in use in research and clinical care.

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

BACKGROUND

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

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.

Prognostic implications of small left atria on hospitalized patients

Aims

To demonstrate the association between small left atria (LA) and outcome in a relatively large heterogeneous population of hospitalized patients.

Methods and results

In a single-centre retrospective study, all inpatients that underwent an echocardiographic assessment between 2011 and 2016 and had an available left atrial volume index (LAVI) measurement were included. The cohort consisted of 17 343 inpatients who had an available LAVI measurement, 288 with small LA (LAVI <16 mL/m2), 7531 patients had LAVI within normal limits (16–34 mL/m2) divided into low normal (16–24.9 mL/m2; n = 2636) and high normal (25–34 mL/m2; n = 4895), 4720 patients had large LAVI (34.1–45 mL/m2) and 4804 had very large LAVI (>45 mL/m2). Median follow-up time was 2.4 years. After adjustments for age, gender, and baseline characteristics with a P-value <0.2 in univariable analyses (body mass index, haemoglobin, ischaemic heart disease, valvulopathy, atrial fibrillation, diabetes mellitus, hypertension, hyperlipidaemia, smoking, renal dysfunction, lung disease, and malignancy) small LA was associated with a higher risk for in-hospital mortality (odds ratio 2.9, 95% confidence interval (CI) 1.4–5.7; P = 0.002] and all-cause mortality [hazard ratio (HR) 2.1, 95% CI 1.6–2.8; P < 0.001] compared with high normal LA. For every mL/m2 decrease below high normal LA size the risk for in-hospital and long-term all-cause mortality increased by 10% (HR 1.1, 95% CI 1.02–1.18; P = 0.005) and 8% (HR 1.08, 95% CI 1.05–1.12; P < 0.001), respectively.

Conclusion

Small LA are independently associated poorer short- and long-term mortality. LA volume should be referred to as J-shaped in terms of mortality.

Helsinki committee approval number

0170-17-TLV.

Chronic Right Heart Failure: Expanding Prevalence and Challenges in Outpatient Management

Right heart failure is caused by right heart dysfunction resulting in suboptimal stroke volume to supply the pulmonary circulation. Therapeutic developments mean that patients with acute right heart failure survive to hospital discharge and live with chronic right heart failure. Chronic right heart failure management aims to reduce afterload, optimize preload, and support contractility, with the best evidence available in vascular targeted therapy for pulmonary arterial hypertension. However, the management of chronic right heart failure relies on adapting therapies for left ventricular heart failure to the right. We review right heart failure management in the ambulatory setting and its challenges.

Right heart dysfunction: from pathophysiologic insights to therapeutic options: a translational overview

: The right ventricle has become increasingly studied in cardiovascular research. In this article, we describe specific pathophysiological characteristics of the right ventricle, with special focus on functional and molecular modifications as well as therapeutic strategies in right ventricular dysfunction, underlining the differences with the left ventricle. Then we analyze the main imaging modalities to assess right ventricular function in different clinical settings. Finally, we acknowledge main therapeutic advances for treatment of right heart diseases.

Acute right ventricular myocardial infarction

INTRODUCTION

Acute right ventricular myocardial infarction (RVMI) is observed in 30-50% of patients presenting with inferior wall myocardial infarction (MI) and, occasionally, with anterior wall MI. The clinical consequences vary from no hemodynamic compromise to severe hypotension and cardiogenic shock depending on the extent of RV ischemia. Areas covered: The pathophysiological mechanisms, diagnostic steps, and novel therapeutic approaches of acute RVMI are described. Expert commentary: Diagnosis of acute RVMI is based on physical examination, cardiac biomarkers, electrocardiography, and coronary angiography, whereas noninvasive imaging modalities (echocardiography, cardiac magnetic resonance imaging) play a complementary role. Early revascularization, percutaneous or pharmacological, represents key step in the management of RMVI. Maintenance of reasonable heart rate and atrioventricular synchrony is essential to sustain adequate cardiac output in these patients. When conventional treatment is not successful, mechanical circulatory support, including right ventricle assist devices, percutaneous cardiopulmonary support, and intra-aortic balloon pump, might be considered. The prognosis associated with RVMI is worse in the short term, compared to non-RVMI, but those patients who survive hospitalization have a relatively good long-term prognosis.

Left ventricular assist device (LVAD) program in Chile: first successful experience in South America

Background

The need to have a variety of tools to deal with end-stage heart failure (ES-HF), along with the limited heart transplantation availability encouraged us to create a pilot Left ventricular assist device (LVAD) program in a public health care system hospital in Chile.

Methods

A retrospective analysis of the first nine patients of an ongoing LVAD program initiated on August 2013 was performed, completing an average of 30 months of follow-up. The most important events regarding to morbidity and mortality are described.

Results

Nine patients with ES-HF underwent LVAD implantation surgery; one of them died 23 days after surgery and another died after 11 months. One patient successfully underwent heart transplantation after 16 months of HeartWare ventricular assist device (HVAD) support; the other six patients remain in the program and have an average follow-up of 846 days at the time of this study (range, 23-1,481 days). The survival rate at 6, 12 and 18 months follow-up was 89%, 78% and 78% respectively.

Conclusions

This new pioneering LVAD program in Chile has been successful and now constitutes a vital adjunct to all who work in heart transplantation and ES-HF programs. It offers an effective therapeutic alternative when there is a severe donor shortage, in cases of atypical blood types, emergencies, exceptional cases with contraindication for heart transplantation or when there is important donor-receiver size mismatch.

Hospital and intensive care unit management of decompensated pulmonary hypertension and right ventricular failure

Pulmonary hypertension and concomitant right ventricular failure present a diagnostic and therapeutic challenge in the intensive care unit and have been associated with a high mortality. Significant co-morbidities and hemodynamic instability are often present, and routine critical care unit resuscitation may worsen hemodynamics and limit the chances of survival in patients with an already underlying poor prognosis. Right ventricular failure results from structural or functional processes that limit the right ventricle’s ability to maintain adequate cardiac output. It is commonly seen as the result of left heart failure, acute pulmonary embolism, progression or decompensation of pulmonary hypertension, sepsis, acute lung injury, or in the perioperative setting. Prompt recognition of the underlying cause and institution of treatment with a thorough understanding of the elements necessary to optimize preload, cardiac contractility, enhance systemic arterial perfusion, and reduce right ventricular afterload are of paramount importance. Moreover, the emergence of previously uncommon entities in patients with pulmonary hypertension (pregnancy, sepsis, liver disease, etc.) and the availability of modern devices to provide support pose additional challenges that must be addressed with an in-depth knowledge of this disease.

Focused Review of Perioperative Care of Patients with Pulmonary Hypertension and Proposal of a Perioperative Pathway

Morbidity and mortality risk increase considerably for patients with pulmonary hypertension (PH) undergoing non-cardiac surgery. Unfortunately, there are no comprehensive, evidence-based guidelines for perioperative evaluation and management of these patients. We present a brief review of the literature on perioperative outcomes for patients with PH and describe the implementation of a collaborative perioperative management program for these high-risk patients at a tertiary academic center.

Perioperative Management of the Adult Patient on Venovenous Extracorporeal Membrane Oxygenation Requiring Noncardiac Surgery

The use of venovenous extracorporeal membrane oxygenation is increasing worldwide. These patients often require noncardiac surgery. In the perioperative period, preoperative assessment, patient transport, choice of anesthetic type, drug dosing, patient monitoring, and intraoperative and postoperative management of common patient problems will be impacted. Furthermore, common monitoring techniques will have unique limitations. Importantly, patients on venovenous extracorporeal membrane oxygenation remain subject to hypoxemia, hypercarbia, and acidemia in the perioperative setting despite extracorporeal support. Treatments of these conditions often require both manipulation of extracorporeal membrane oxygenation settings and physiologic interventions. Perioperative management of anticoagulation, as well as thresholds to transfuse blood products, remain highly controversial and must take into account the specific procedure, extracorporeal membrane oxygenation circuit function, and patient comorbidities. We will review the physiologic management of the patient requiring surgery while on venovenous extracorporeal membrane oxygenation.

Acute Right Heart Failure

Heart failure is defined as a life-threatening complex clinical syndrome with exacerbation of symptoms signifying decompensation and requires emergent treatment. In its acute state it presents within 24 hours with symptoms such as shortness of breath, volume overload including pulmonary edema, sometimes forward failure and even cardiogenic shock. Two forms of acute heart failure exist: newly diagnosed “de novo” or acutely decompensated chronic heart failure. This chapter summarizes the clinical and prognostic classification of acute right heart failure, epidemiology, diagnostic work-up and the principles behind treatment and management options that focus on preload optimization, afterload reduction and improvement of contractility.

Very Small Left Atrial Volume as a Marker for Mortality in Patients Undergoing Nongated Computed Tomography Pulmonary Angiography

Objectives: To evaluate the association between very small left atria (VSLA) on nongated computed tomography pulmonary angiography (CTPA) and mortality in patients without pulmonary embolism (PE). Methods: Patients who underwent nongated CTPA between 2011 and 2015 in order to rule out PE, and had an echocardiogram within 24 h of the CTPA, were retrospectively identified. The left atrial volume of nongated CTPA was calculated using automatic 4-chamber volumetric analysis software. The association between the lowest 5th percentile of the left atrial volume index, referred to as the VSLA group, and mortality was investigated after adjustment for age, gender, background diseases, and laboratory values. Results: The study cohort included 241 patients. Patients with VSLA had a left atrial volume index <24 mL/m2 (n = 11). Demographics and background diseases did not differ between the study groups. The median follow-up was 22.7 months (IQR 0.03-54.3). VSLA was an independent predictor of mortality (HRadj = 3.6; 95% CI 1.46-8.87; p = 0.005), along with malignancy (HRadj = 2.28; 95% CI 1.32-3.93; p = 0.003) and lower hemoglobin (HRadj = 0.86; 95% CI 0.76-0.99; p = 0.032). Conclusions: Our findings suggest that VSLA on nongated CTPA may serve as a marker for mortality. The use of CTPA volumetric analysis can help risk stratification in patients with dyspnea and no PE.

Medical Management of Pulmonary Embolism: Beyond Anticoagulation

Pulmonary embolism (PE) is a common medical condition that carries significant morbidity and mortality. Although diagnosis, anticoagulation, and interventional clot-burden reduction strategies represent the focus of clinical research and care in PE, appropriate risk stratification and supportive care are crucial to ensure good outcomes. In this chapter, we will discuss the medical management of PE from the time of presentation to discharge, focusing on the critical care of acute right ventricular failure, anticoagulation of special patient populations, and appropriate follow-up testing after acute PE.

Circulating Histone Concentrations Differentially Affect the Predominance of Left or Right Ventricular Dysfunction in Critical Illness

OBJECTIVES

Cardiac complications are common in critical illness and associated with grave consequences. In this setting, elevated circulating histone levels have been linked to cardiac injury and dysfunction in experimental models and patients with sepsis. The mechanisms underlying histone-induced cardiotoxicity and the functional consequences on left ventricle and right ventricle remain unclear. This study aims to examine dose-dependent effects of circulating histones on left ventricle and right ventricle function at clinically relevant concentrations.

DESIGN

Prospective laboratory study with in vitro and in vivo investigations.

SETTING

University research laboratory.

SUBJECTS

Twelve-week old male C57BL/6N mice.

INTERVENTIONS

Cultured cardiomyocytes were incubated with clinically relevant histone concentrations, and a histone infusion mouse model was also used with hemodynamic changes characterized by echocardiography and left ventricle/right ventricle catheter-derived variables. Circulating histones and cardiac troponin levels were obtained from serial blood samples.

MEASUREMENTS AND MAIN RESULTS

IV histone infusion caused time-dependent cardiac troponin elevation to indicate cardiac injury. At moderate sublethal histone doses (30 mg/kg), left ventricular contractile dysfunction was the prominent abnormality with reduced ejection fraction and prolonged relaxation time. At high doses (≥ 60 mg/kg), pulmonary vascular obstruction induced right ventricular pressure increase and dilatation, but left ventricular end-diastolic volume improved because of reduced blood return from the lungs. Mechanistically, histones induced profound calcium influx and overload in cultured cardiomyocytes with dose-dependent detrimental effects on intracellular calcium transient amplitude, contractility, and rhythm, suggesting that histones directly affect cardiomyocyte function adversely. However, increasing histone-induced neutrophil congestion, neutrophil extracellular trap formation, and thrombosis in the pulmonary microvasculature culminated in right ventricular dysfunction. Antihistone antibody treatment abrogated histone cardiotoxicity.

CONCLUSIONS

Circulating histones significantly compromise left ventricular and right ventricular function through different mechanisms that are dependent on histone concentrations. This provides a translational basis to explain and target the spectral manifestations of cardiac dysfunction in critical illness.

Isolated right ventricular infarction: a diagnostic challenge

A 73-year-old woman was admitted to the emergency room due to sudden-onset dyspnoea, altered mental status and haemodynamic instability. ECG showed a junctional rhythm, T-wave inversion in I, aVL and V2-V6 (present in a previous ECG), and no ST/T changes in the right precordial leads. Transthoracic echocardiography, however, revealed a severe depression of global systolic function of right ventricle with akinesia of free wall and a normal left ventricular function. Coronary angiography showed an occlusion of the proximal segment of the right coronary artery, which was treated with balloon angioplasty, and a chronic lesion of the anterior descending artery. The patient had a good recovery and was discharged on the 14th day. Myocardial perfusion scintigraphy (stress and rest) was performed a month later, showing a fixed perfusion defect in the apex and anterior wall (medium-apical), with no signs of ischaemia.

2015 SCAI/ACC/HFSA/STS Clinical Expert Consensus Statement on the Use of Percutaneous Mechanical Circulatory Support Devices in Cardiovascular Care (Endorsed by the American Heart Association, the Cardiological Society of India, and Sociedad Latino Americana de Cardiologia Intervencion; Affirmation of Value by the Canadian Association of Interventional Cardiology-Association Canadienne de Cardiologie d'intervention)

Although historically the intra-aortic balloon pump has been the only mechanical circulatory support device available to clinicians, a number of new devices have become commercially available and have entered clinical practice. These include axial flow pumps, such as Impella(®); left atrial to femoral artery bypass pumps, specifically the TandemHeart; and new devices for institution of extracorporeal membrane oxygenation. These devices differ significantly in their hemodynamic effects, insertion, monitoring, and clinical applicability. This document reviews the physiologic impact on the circulation of these devices and their use in specific clinical situations. These situations include patients undergoing high-risk percutaneous coronary intervention, those presenting with cardiogenic shock, and acute decompensated heart failure. Specialized uses for right-sided support and in pediatric populations are discussed and the clinical utility of mechanical circulatory support devices is reviewed, as are the American College of Cardiology/American Heart Association clinical practice guidelines.

Sevoflurane anesthesia during acute right ventricular ischemia in pigs preserves cardiac function better than propofol anesthesia

BACKGROUND

The intention of the present study was to evaluate possible cardioprotective properties of inhalation anesthesia with sevoflurane.

METHODS AND MATERIALS

A porcine, open-chest model of right ventricular ischemia was used in 7 pigs receiving inhalation anesthesia with sevoflurane. The model was earlier developed and published by our group, using pigs receiving intravenous anesthesia with propofol. They served as controls. The animals were observed for three hours after the induction of right ventricular ischemia by ligation of the main branches supplying the right ventricular free wall.

RESULTS

In the sevoflurane group, the cardiac output recovered 2 hours after the induction of ischemia and intact right ventricular stroke work was observed. In the propofol group, no such recovery occurred. The release of troponin T was significantly lower than in the sevoflurane group.

CONCLUSIONS

Inhalation anesthesia with sevoflurane seems superior to intravenous anesthesia with propofol in acute right ventricular ischemic dysfunction.

Right atrial pressure/pulmonary artery wedge pressure ratio: A more specific predictor of survival in pulmonary arterial hypertension

BACKGROUND

Pulmonary arterial hypertension (PAH) is a progressive, fatal disease. Current prognostic models are not ideal, and identifying more accurate prognostic variables is needed. The objective of this study was to evaluate the relative prognostic value of the right atrial pressure/pulmonary artery wedge pressure (RAP/PAWP) ratio in PAH patients. We hypothesized that the RAP/PAWP ratio is more predictive of survival than any of the other measured or calculated hemodynamic variables.

METHODS

We performed a secondary analysis of a PAH cohort (Cohort 1) and validated our results in a separate cohort (Cohort 2). Cohort 1 included primarily patients enrolled in prospective, short-term, randomized clinical trials and subsequently followed long term. Cohort 2 included patients prospectively enrolled in a PAH registry at a tertiary PAH referral center.

RESULTS

Cohort 1 (n = 847) and Cohort 2 (n = 697) had a mean age of 47 and 54 years, respectively. Most were female (78% and 73%, respectively), Caucasian (83% and 82%), with advanced functional class disease status (New York Heart Association Functional Class III/IV 85% and 68%) and with significantly elevated hemodynamics (mean RAP/PAWP ratio: 1.2 and 1.0; pulmonary vascular resistance: 13.5 and 9.4 Wood units). RAP/PAWP ratio indicated a 1-year hazard ratio of 1.44 (p = 0.0001) and 1.35, respectively (p < 0.0001), and was the most consistently predictive hemodynamic variable across the 2 cohorts. These results remain valid even when adjusted for other covariables in multivariable regression models.

CONCLUSIONS

The RAP/PAWP ratio is a more specific predictor of survival than any other hemodynamic variable, and we recommend that it be used in clinical prognostication and PAH predictive models.