Percutaneous balloon atrial septostomy on top of venoarterial extracorporeal membrane oxygenation results in safe and effective left heart decompression

Effect of Atrial Septostomy on Left Ventricular Function in Pediatric Dilated Cardiomyopathy Requiring ECMO

Balloon atrial septostomy (BAS) reduces left ventricular (LV) hypertension during extracorporeal membrane oxygenation (ECMO). However, the acute effect of BAS on LV function as measured by echocardiography is unknown. This was a Retrospective analysis of clinical outcome, LV dimensions, and LV function in dilated cardiomyopathy patients 0-18 years old who underwent BAS on ECMO. In 13 patients with median (IQR) age of 2.3 (0.6-10.9) years, there were no differences in clinical markers of cardiac output at intervals between 12 h before and 6 days after BAS. In addition, BAS was associated with a low rate of periprocedural complications (0.0%), acute kidney injury (7.7%), and worsening radiographic pulmonary vascular congestion (30.7%). There was a significant worsening in LV end systolic diameter (LVIDs; 3.6 [2.9-4.8] cm vs 4.2 [3.2-5.6] cm vs 3.3 [2.6-4.6] cm, p = 0.025), LV end systolic posterior wall thickness (LVPWs; 0.7 [0.5-0.9] cm vs 0.6 [0.5-0.9] cm vs 0.8 [0.6-1.2] cm, p = 0.038), fractional shortening (FS; 17.6% [8.4-20.4%] vs 6.3% [2.0-9.9%] vs 13.2% [3.6-23.4%], p = 0.013), and ejection fraction (EF; 13.1% [8.7-18.9%] vs 5.3% [2.5-11.1%] vs 9.2% [6.0-16.3%], p = 0.039) following BAS that improved in approximately 1 week. There were no differences in LV global longitudinal strain following BAS. We conclude that BAS was associated with low procedural and clinical adverse event rates in our cohort. The worsening LVIDs, LVPWs, FS, and EF seen immediately after the procedure suggests that BAS causes altered loading conditions affecting LV function in pediatric patients with dilated cardiomyopathy requiring ECMO.

Temporary mechanical circulatory support as a bridge to durable left ventricular assist device as destination therapy in fulminant giant cell myocarditis：A case report

Fulminant giant cell myocarditis is a fatal form of acute myocarditis leading to a rapid-onset clinical presentation with lethal arrhythmias, acute heart failure, or cardiogenic shock requiring mechanical circulatory support. We report the case of a 52-year-old female diagnosed with fulminant myocarditis requiring veno-arterial extracorporeal membrane oxygenation (V-A ECMO) and intra-aortic balloon pump(IABP) support. Due to hemodynamic instability, she was transferred to our hospital by helicopter on day 4. On arrival at our hospital, she underwent percutaneous balloon atrial septostomy to decompress the left ventricle. Although the left ventricular distension and pulmonary edema improved after atrial septostomy, no signs of biventricular function recovery were identified on day 14. On day 23, V-A ECMO and IABP were switched to a durable left ventricular assist device(LVAD) system and a right ventricular assist device(RVAD) with ECMO (RVAD-ECMO) under median sternotomy. On day 37, RVAD-ECMO was eventually removed and rehabilitation was started with the remaining LVAD support as destination therapy. On day 78, the patient was finally discharged with LVAD support to follow-up as an outpatient. This case underscores the importance of a multidisciplinary approach and rigorous monitoring to optimize outcomes in the treatment of fulminant giant cell myocarditis.

Scrutinizing the Role of Venoarterial Extracorporeal Membrane Oxygenation: Has Clinical Practice Outpaced the Evidence?

The use of venoarterial extracorporeal membrane oxygenation (VA-ECMO) for temporary mechanical circulatory support in various clinical scenarios has been increasing consistently, despite the lack of sufficient evidence regarding its benefit and safety from adequately powered randomized controlled trials. Although the ARREST trial (Advanced Reperfusion Strategies for Patients with Out-of-Hospital Cardiac Arrest and Refractory Ventricular Fibrillation) and a secondary analysis of the PRAGUE OHCA trial (Prague Out-of-Hospital Cardiac Arrest) provided some evidence in favor of VA-ECMO in the setting of out-of-hospital cardiac arrest, the INCEPTION trial (Early Initiation of Extracorporeal Life Support in Refractory Out-of-Hospital Cardiac Arrest) has not found a relevant improvement of short-term mortality with extracorporeal cardiopulmonary resuscitation. In addition, the results of the recently published ECLS-SHOCK trial (Extracorporeal Life Support in Cardiogenic Shock) and ECMO-CS trial (Extracorporeal Membrane Oxygenation in the Therapy of Cardiogenic Shock) discourage the routine use of VA-ECMO in patients with infarct-related cardiogenic shock. Ongoing clinical trials (ANCHOR [Assessment of ECMO in Acute Myocardial Infarction Cardiogenic Shock, NCT04184635], REVERSE [Impella CP With VA ECMO for Cardiogenic Shock, NCT03431467], UNLOAD ECMO [Left Ventricular Unloading to Improve Outcome in Cardiogenic Shock Patients on VA-ECMO, NCT05577195], PIONEER [Hemodynamic Support With ECMO and IABP in Elective Complex High-risk PCI, NCT04045873]) may clarify the usefulness of VA-ECMO in specific patient subpopulations and the efficacy of combined mechanical circulatory support strategies. Pending further data to refine patient selection and management recommendations for VA-ECMO, it remains uncertain whether the present usage of this device improves outcomes.

Interatrial Shunt Devices

Elevated left atrial pressure during exercise is a hallmark of heart failure (HF) and is associated with adverse left atrial remodeling and poor outcomes. To decompress the pressure-overloaded left atrium in patients with HF, several device-based approaches have been developed to create a permanent, pressure-dependent, left-to-right interatrial shunt. Such approaches are currently in various stages of investigations in both HF with reduced ejection fraction (EF) and HF with preserved EF. This review discusses the evolution of the concept of left atrial decompression and summarizes the current landscape of device-based approaches used for left atrial decompression.

Postcardiotomy Shock Syndrome: A Narrative Review of Perioperative Diagnosis and Management

Postcardiotomy shock (PCS) is generally described as the inability to separate from cardiopulmonary bypass due to ineffective cardiac output after cardiotomy, which is caused by a primary cardiac disorder, resulting in inadequate tissue perfusion. Postcardiotomy shock occurs in 0.5% to 1.5% of contemporary cardiac surgery cases, and is accompanied by an in-hospital mortality of approximately 67%. In the last 2 decades, the incidence of PCS has increased, likely due to the increased age and baseline morbidity of patients requiring cardiac surgery. In this narrative review, the authors discuss the epidemiology and pathophysiology of PCS, the rationale and evidence behind the initiation, continuation, escalation, and discontinuation of mechanical support devices in PCS, and the anesthetic implications.

Left Atrial Decompression in Pediatric Patients Supported With Extracorporeal Membrane Oxygenation for Failure to Wean From Cardiopulmonary Bypass: A Propensity-Weighted Analysis

Background Left atrial (LA) decompression on extracorporeal membrane oxygenation (ECMO) can reduce left ventricular distension, allowing myocardial rest and recovery, and protect from lung injury secondary to cardiogenic pulmonary edema. However, clinical benefits remain unknown. We sought to evaluate the association between LA decompression and in-hospital adverse outcome (mortality, transplant on ECMO, or conversion to ventricular assist device) in patients who failed to wean from cardiopulmonary bypass using a propensity score to adjust for baseline differences. Methods and Results Children (aged <18 years) with biventricular physiology supported with ECMO for failure to wean from cardiopulmonary bypass after cardiac surgery from 2000 through 2016, reported to the ELSO (Extracorporeal Life Support Organization) Registry, were included. Inverse probability of treatment weighted logistic regression was used to test the association between LA decompression and in-hospital adverse outcomes. Of the 2915 patients supported with venoarterial ECMO for failure to wean from cardiopulmonary bypass, 1508 had biventricular physiology and 279 (18%) underwent LA decompression (LA+). Genetic and congenital abnormalities (P=0.001) and pulmonary hypertension (P=0.010) were less frequent and baseline arrhythmias (P=0.022) were more frequent in LA+ patients. LA+ patients had longer pre-ECMO mechanical ventilation and CBP time (P<0.001), and used aortic cross-clamp (P=0.001) more frequently. Covariates were well balanced between the propensity-weighted cohorts. In-hospital adverse outcomes occurred in 47% of LA+ patients and 51% of the others. Weighted multivariate logistic regression showed LA decompression to be protective for in-hospital adverse outcomes (adjusted odds ratio, 0.775 [95% CI, 0.644-0.932]). Conclusions LA decompression independently decreased the risk of in-hospital adverse outcome in pediatric venoarterial ECMO patients who failed to wean from cardiopulmonary bypass, suggesting that these patients may benefit from LA decompression.

Is combined use of radiofrequency ablation and balloon dilation the future of interatrial communications?

INTRODUCTION

Personalized and stable interatrial communication is an important palliative therapy for patients with heart failure. However, this remains a technically challenging task.

AREAS COVERED

In the past decades, substantial advancements in atrial septostomy for the creation of controllable and durable interatrial communication have been made, and numerous novel devices and techniques are in various stages of development. In this review, we discuss the evolving indications for atrial septostomy, current approaches with or without device implantation, and indicators for optimal interatrial communication. The combined use of radiofrequency ablation and balloon dilation (CURB) is an individualized management approach based on underlying hemodynamics, which demonstrates unique advantages in creating a sufficient interatrial communication with satisfactory stability. The advantages and disadvantages of this implant-free procedure are analyzed and its clinical prospects are assessed.

EXPERT OPINION

With ready availability, high safety, and efficacy, CURB is a promising procedure for creating personalized and stable interatrial communication without device implantation. Further research is required to simplify the procedure, screen optimal reference parameters for personalized therapy, and evaluate the long-term outcome in a large population of patients.

Use of Percutaneous Atrioseptotosmy for Left Heart Decompression During Veno-Arterial Extracorporeal Membrane Oxygenation Support: An Observational Study

Background

Left ventricular overload is frequent under veno‐arterial extracorporeal membrane oxygenation, which is associated with a worsening of the prognosis of these patients. Several left heart decompression (LHD) techniques exist. However, there is no consensus on their timing and type. We aimed to describe characteristics and outcomes of patients undergoing LHD and to compare percutaneous atrioseptostomy (PA) to other LHD techniques.

Methods and Results

Retrospective analysis was conducted of consecutive and prospectively collected patients supported by veno‐arterial extracorporeal membrane oxygenation for refractory cardiac arrest or cardiogenic shock between January 2015 and April 2018, with a 90‐day follow‐up in our tertiary center. Patients were divided according to the presence of LHD, and then according to its type (PA versus others). Thirty‐nine percent (n=63) of our patients (n=163) required an LHD. Patients with LHD had lower left ventricular ejection fraction, more ischemic cardiomyopathy, and no drug intoxication‐associated cardiogenic shock. PA was frequently used for LHD (41% of first‐line and 57% of second‐line LHD). PA appears safe and fast to realize (6.3 [interquartile range, 5.8–10] minutes) under fluoroscopic and echocardiographic guidance, with no acute complications. PA was associated with fewer neurological complications (12% versus 38%, P=0.02), no need to insert a second LHD (0% versus 19%, P=0.04), and higher 90‐day survival compared with other techniques (42% versus 19%, log‐rank test P=0.02), despite more sepsis (96% versus 73%, P=0.02) and blood transfusions (13.5% versus 7%, P=0.01). Multivariate analysis confirms the association between PA and 90‐day survival (hazard ratio, 2.53 [1.18–5.45], P=0.019).

Conclusions

LHD was frequently used for patients supported with veno‐arterial extracorporeal membrane oxygenation, especially in cases of ischemic cardiomyopathy and low left ventricular ejection fraction. PA seems to be a safe and efficient LHD technique associated with greater mid‐term survival justifying the pursuit of research on this topic.

Venting during venoarterial extracorporeal membrane oxygenation

Cardiogenic shock and cardiac arrest contribute pre-dominantly to mortality in acute cardiovascular care. Here, veno-arterial extracorporeal membrane oxygenation (VA-ECMO) has emerged as an established therapeutic option for patients suffering from these life-threatening entities. VA-ECMO provides temporary circulatory support until causative treatments are effective and enables recovery or serves as a bridging strategy to surgical ventricular assist devices, heart transplantation or decision-making. However, in-hospital mortality rate in this treatment population is still around 60%. In the recently published ARREST trial, VA-ECMO treatment lowered mortality rate in patients with ongoing cardiac arrest due to therapy refractory ventricular fibrillation compared to standard advanced cardiac life support in selected patients. Whether VA-ECMO can reduce mortality compared to standard of care in cardiogenic shock has to be evaluated in the ongoing prospective randomized studies EURO-SHOCK (NCT03813134) and ECLS-SHOCK (NCT03637205). As an innate drawback of VA-ECMO treatment, the retrograde aortic flow could lead to an elevation of left ventricular (LV) afterload, increase in LV filling pressure, mitral regurgitation, and elevated left atrial pressure. This may compromise myocardial function and recovery, pulmonary hemodynamics—possibly with concomitant pulmonary congestion and even lung failure—and contribute to poor outcomes in a relevant proportion of treated patients. To overcome these detrimental effects, a multitude of venting strategies are currently engaged for both preventive and emergent unloading. This review aims to provide a comprehensive and structured synopsis of existing venting modalities and their specific hemodynamic characteristics. We discuss in detail the available data on outcome categories and complication rates related to the respective venting option.

Graphical abstract

Influence of left ventricular unloading on pediatric post-cardiotomy veno-arterial extracorporeal life support outcomes

Background

The effectiveness of veno-arterial extracorporeal life support (V-A ECLS) in treating neonatal and pediatric patients with complex congenital heart disease (CHD) and requiring cardio-circulatory assistance is well-known. Nevertheless, the influence of left ventricle (LV) distension and its countermeasure, namely LV unloading, on survival and clinical outcomes in neonates and children treated with V-A ECLS needs still to be addressed. Therefore, the aim of this study was to determine the effects of LV unloading on in-hospital survival and complications in neonates and children treated with V-A ECLS.

Methods

The clinical outcomes of 90 pediatric patients with CHD under 16 years of age supported with V-A ECLS for post-cardiotomy cardiogenic shock (CS) were retrospectively reviewed in relationship with the presence or absence of an active LV unloading strategy.

Results

The patient cohort included 90 patients (age 19.6 ± 31.54 months, 64.4% males), 42 of whom were vented with different techniques (38 with atrial septostomy (AS) or left atria cannula, two with cannula from LV apex, 1 with intra-aortic balloon pump (IABP), and one with pigtail across the aortic valve). The LV unloading strategy significantly increased the in-hospital survival (odds ratio [OR] = 2.74, 95% CI 1.06–7.08; p = 0.037). On the contrary, extracorporeal cardiopulmonary resuscitation decreased the related survival (OR = 0.32, 95% CI 1.09–0.96; p = 0.041). The most common complications were infections (28.8%), neurological injury (26%), and bleeding (25.6%). However, these did not differently occur in venting and no-venting groups.

Conclusion

In pediatric patients with CHD supported with V-A ECLS for post-cardiotomy CS, the LV unloading strategy was associated with increased survival.

Left ventricular venting in veno-arterial extracorporeal membrane oxygenation: A computer simulation study

INTRODUCTION

Veno-arterial extracorporeal membrane oxygenation (V-A ECMO) is the fastest way to restore circulation in refractory cardiogenic shock, however it cannot unload the failing left ventricle. There is a lack of consensus regarding optimal approach to left ventricular venting in V-A ECMO patients with severely depressed or absent left ventricular function.

METHODS

A computer model was developed in Matlab Simulink R20016b (MathWorks, Inc., Natick, MA, USA) to analyze different venting options as well as atrial septostomy in the setting of cardiogenic shock and V-A ECMO.

RESULTS

The model has shown an inverse linear relationship between left atrial pressure and either vent, Impella or atrial septum defect flow rate. The minimum vent flow required to prevent pulmonary edema in complete loss of left ventricular function needed to be higher than the bronchial blood flow. Atrial septostomy restored normal pulmonary blood flow with low left atrial pressure but induced stasis in the left ventricle. Venting the pulmonary artery induced stasis in the entire pulmonary circulation as well as left atrium and left ventricle. Venting the left ventricle directly with a cannula or Impella device avoided blood stasis.

CONCLUSION

Our data suggest that reduction of left atrial pressure is linearly related to the vent, Impella or atrial septal defect flow rate. The preferred vent location is the left ventricle as it avoids stasis in the pulmonary circulation and cardiac chambers.

Transatrial balloon atrial septostomy to facilitate weaning off venoarterial ECMO after pulmonary endarterectomy

Atrial septostomy has been the last resort in the management of patients with the right ventricular failure related to pulmonary hypertension before lung transplantation. In this paper, we present a simple and safe technique (transatrial approach) for balloon atrial septostomy in a patient who required central venoarterial extracorporeal membrane oxygenation after pulmonary endarterectomy.

Atrial Septostomy for Left Ventricular Unloading During Extracorporeal Membrane Oxygenation for Cardiogenic Shock: Animal Model

OBJECTIVES

The aim of this study was to quantify and understand the unloading effect of percutaneous balloon atrial septostomy (BAS) in acute cardiogenic shock (CS) treated with venoarterial (VA) extracorporeal membranous oxygenation (ECMO).

BACKGROUND

In CS treated with VA ECMO, increased left ventricular (LV) afterload is observed that commonly interferes with myocardial recovery or even promotes further LV deterioration. Several techniques for LV unloading exist, but the optimal strategy and the actual extent of such procedures have not been fully disclosed.

METHODS

In a porcine model (n = 11; weight 56 kg [53-58 kg]), CS was induced by coronary artery balloon occlusion (57 minutes [53-64 minutes]). Then, a step-up VA ECMO protocol (40-80 mL/kg/min) was run before and after percutaneous BAS was performed. LV pressure-volume loops and multiple hemoglobin saturation data were evaluated. The Wilcoxon rank sum test was used to assess individual variable differences.

RESULTS

Immediately after BAS while on VA ECMO support, LV work decreased significantly: pressure-volume area, end-diastolic pressure, and stroke volume to ∼78% and end-systolic pressure to ∼86%, while superior vena cava and tissue oximetry did not change. During elevating VA ECMO support (40-80 mL/kg/min) with BAS vs without BAS, we observed 1) significantly less mechanical work increase (122% vs 172%); 2) no end-diastolic volume increase (100% vs 111%); and 3) a considerable increase in end-systolic pressure (134% vs 144%).

CONCLUSIONS

In acute CS supported by VA ECMO, atrial septostomy is an effective LV unloading tool. LV pressure is a key component of LV work load, so whenever LV work reduction is a priority, arterial pressure should carefully be titrated low while maintaining organ perfusion.

Left Ventricular Unloading during Extracorporeal Life Support: Current Practice

Veno-arterial extracorporeal life support (VA-ECLS) is a powerful tool that can provide complete cardiopulmonary support for patients with refractory cardiogenic shock. However, VA-ECLS increases left ventricular afterload resulting in greater myocardial oxygen demand, which can impair myocardial recovery and worsen pulmonary edema. These complications can be ameliorated by various LV venting strategies to unload the LV. Evidence suggests that LV venting improves outcomes in VA-ECLS, but there is a paucity of randomized trials to help guide optimal strategy and the timing of venting. In this review, we discuss the available evidence regarding LV venting in VA-ECLS, explain important hemodynamic principles involved, and propose a practical approach to LV venting in VA-ECLS.

Left Heart Decompression on Veno-Arterial Extracorporeal Membrane Oxygenation in Children With Dilated Cardiomyopathy and Myocarditis: An Extracorporeal Life Support Organization Registry Review

OBJECTIVES

To describe the association between left heart decompression on veno-arterial extracorporeal membrane oxygenation and survival in patients with myocarditis and dilated cardiomyopathy. The secondary outcome is to study association of left heart decompression with survival in children with myocarditis compared with those with dilated cardiomyopathy.

DESIGN

Retrospective study of a multicenter registry database.

SETTING

Data reported to Extracorporeal Life Support Organization from international extracorporeal membrane oxygenation centers.

PATIENTS

Patients less than or equal to 18 years old with a diagnosis of myocarditis or dilated cardiomyopathy receiving extracorporeal membrane oxygenation.

INTERVENTIONS

None.

MEASUREMENTS AND MAIN RESULTS

A total of 1,438 pediatric extracorporeal membrane oxygenation runs were identified. Thirty-seven percent of the patients had myocarditis (n = 532), whereas the rest had dilated cardiomyopathy. Survival to hospital discharge was 63%. Median extracorporeal membrane oxygenation duration was 148 hours with interquartile range (84-248 hr). Nineteen percent of patients (n = 274) had left heart decompression. Multivariable analysis revealed using left heart decompression (adjusted odds ratio, 1.42; 95% CI, 1.06-1.89; p = 0.02), e-cardiopulmonary resuscitation (adjusted odds ratio, 0.63; 95% CI, 0.51-0.79; p < 0.001), higher pH (adjusted odds ratio, 3.69; 95% CI, 1.80-7.53; p < 0.001), and diagnosis of myocarditis (adjusted odds ratio, 1.69; 95% CI, 1.35-2.08; p < 0.001) were associated with greater odds of survival. In the multivariable analysis for patients with dilated cardiomyopathy, left heart decompression failed to reveal a significant association with survival (20% among survivors vs 17% among nonsurvivors, 95% CI, -2.2% to 8.0%). Meanwhile in patients with myocarditis, the multivariable analysis failed to exclude the possibility that left heart decompression was associated with up to a three-fold greater odds of survival (adjusted odds ratio, 1.77; 95% CI, 0.99-.15).

CONCLUSIONS

Retrospective review of the Extracorporeal Life Support Organization registry revealed an association between left heart decompression and greater odds of survival in children with myocarditis and dilated cardiomyopathy on extracorporeal membrane oxygenation. When comparing patients with dilated cardiomyopathy against those with myocarditis, we could not exclude a three-fold greater odds of survival associated with the use of left heart decompression. This finding warrants further prospective evaluation.

The Atrial Flow Regulator: A Novel Device for Left Ventricular Unloading in Patients Receiving Venoarterial Extracorporeal Membrane Oxygenation Support?

Severe pulmonary edema, secondary to left ventricular afterload increment, is a common problem occurring in patients receiving venoarterial extracorporeal membrane oxygenation. No consensus is currently available for its management, but several devices/procedures have been described, including an Impella device (Abiomed), balloon atrial septostomy, intraaortic balloon counterpulsation, or an additional venous cannula, as possible adjuncts. We report the feasibility and efficacy of the atrial flow regulator device (Occlutech) for left ventricular unloading in a 58-year-old patient receiving extracorporeal membrane oxygenation. However, the benefits of this device relative to simple balloon atrial septostomy need to be further investigated.

Comparison of Circulatory Unloading Techniques for Venoarterial Extracorporeal Membrane Oxygenation

Left ventricular (LV) distention and pulmonary congestion are major complications inherent to venoarterial extracorporeal membrane oxygenation (ECMO). This study aimed to quantitatively compare the hemodynamic differences between common circulatory unloading methods for ECMO. Ten circulatory unloading techniques were evaluated on a mock circulatory loop simulating acute LV failure supported by ECMO. Simulated unloading techniques included: surgical and percutaneous pulmonary artery (PA) venting, surgical left atrial venting, surgical and percutaneous LV venting, atrial septal defect, partial support ventricular assist device, intraaortic balloon pump, and temporary VAD with inline oxygenator (tVAD). The most LV unloading occurred with the surgically placed LV vent and tVAD, which reduced LV end-diastolic volume from 295 to 167 ml and 82 ml, respectively. Meanwhile, the PA surgical vent was the most effective at reducing mean PA pressure from 21.0 to 10.6 mm Hg, and the tVAD was most effective at reducing left atrial pressure from 13.3 to 4.4 mm Hg. The major limitation of this study was the use of a mock circulatory loop, which simulated lower left atrial pressure than is typically seen clinically. This study identified clinically significant hemodynamic variability between the different circulatory unloading techniques evaluated. However, the applicability of these techniques will vary with different patient disease etiology. Further studies on ECMO unloading will help to quantify hemodynamic benefits and establish treatment guidelines.

The mechanical support of cardiogenic shock

PURPOSE OF REVIEW

Cardiogenic shock (CS) therapy involving catecholamines, inotropes, fluids and revascularization is often insufficient, and short-term mortality remains 50%. Different treatment algorithms and mechanical circulatory support devices (MCS) have been increasingly used in the treatment of CS. Coronavirus disease 2019 (COVID-19) pandemic is a major challenge faced by intensive care medicine providers inevitably influencing also CS management.

RECENT FINDINGS

There is a lack of prospective data as well as international consensus regarding CS classification, patient risk stratification, and MCS use. Veno-arterial extracorporeal membrane oxygenation is considered the first line MCS in refractory CS and Impella the MCS of choice for the left ventricle unloading. Several ongoing randomized trials will provide much-needed evidence for MCS use in the coming years. COVID-19 infection is associated with several cardiovascular disorders complicated by CS and more data regarding the prevalence and mortality of CS during COVID-19 infection are needed.

SUMMARY

This review summarizes current trends in the use of MCS in CS and discusses differences in CS management during the COVID-19 pandemic. Careful patient selection, early MCS initiation, and comprehensive intensive care by experienced team is key to successful outcome in patients with refractory CS.

[Refractory pulmonary edema under ECMO: Is there a place for Rashkind atrioseptotomy?]

Hydrostatic pulmonary edema is a well-known complication of veinoarterial extracorporeal membrane oxygenation (VA-ECMO) caused by increased left ventricle afterload due to reverse blood flow in the aorta. Several techniques are commonly used for left ventricle venting such as intra-aortic balloon pump, Impella® (Abiomed, Danvers, MA), central surgical cannulation or Rahskind atrial septostomy. We reported two cases of hydrostatic pulmonary edema in patients under VA-ECMO for whom it was decided to perform Rashkind technique. The first is a late anterior myocardial infarction complicated with cardiac arrest and cardiogenic shock. Refractory hypoxemia due to hydrostatic pulmonary edema conducted us to perform atrial septostomy. The second case is a refractory cardiogenic shock due to left main stent thrombosis myocardial infarction. Procedural transesophageal echocardiography revealed a large left atrial thrombus extended to pulmonary veins preventing the procedure. These two cases illustrate the importance and gravity of pulmonary edema induced by VA-ECMO. The first shows that this technique is feasible, allows great left ventricle unloading and improves hypoxemia. The second underlines the interest of performing transesophageal echocardiography to look for pulmonary veins thrombosis that can take part in the elevation of hydrostatic pressure and forbid Rashkind manoeuver.

Successful combination treatment with transcatheter balloon atrioseptostomy and bilateral pulmonary artery banding in a collapsed preterm neonate

There has been an increase in the use of extracorporeal membrane oxygenation for severe neonatal cardiac failure. However, the frequency of complications is high, particularly in preterm and low-birth-weight neonates. Herein, we present combination treatment with transcatheter balloon atrioseptostomy and bilateral pulmonary artery banding in a collapsed preterm neonate. This strategy can be an alternative to circulatory support using extracorporeal membrane oxygenation.

Comparison of left ventricular unloading strategies on venoarterial extracorporeal life support

OBJECTIVES

Our goal was to compare the haemodynamic effects of different mechanical left ventricular (LV) unloading strategies and clinical outcomes in patients with refractory cardiogenic shock supported with venoarterial extracorporeal membrane oxygenation (VA-ECMO).

METHODS

A total of 448 patients supported with VA-ECMO for refractory cardiogenic shock between 1 March 2015 and 31 January 2020 were included and analysed in a single-centre, retrospective case-control study. Fifty-three patients (11.8%) on VA-ECMO required LV unloading. Percutaneous balloon atrial septostomy (PBAS), intra-aortic balloon pump (IABP) and transapical LV vent (TALVV) strategies were compared with regards to the composite rate of death, procedure-related complications and neurological complications. The secondary outcomes were reduced pulmonary capillary wedge pressure, pulmonary artery pressure, central venous pressure, left atrial diameter and resolution of pulmonary oedema on a chest X-ray within 48 h.

RESULTS

No death related to the LV unloading procedure was detected. Reduction in pulmonary capillary wedge pressure was highest with the TALVV technique (17.2 ± 2.1 mmHg; P < 0.001) and was higher in the PBAS than in the IABP group; the difference was significant (9.6 ± 2.5 and 3.9 ± 1.3, respectively; P = 0.001). Reduction in central venous pressure with TALVV was highest with the other procedures (7.4 ± 1.1 mmHg; P < 0.001). However, procedure-related complications were significantly higher with TALVV compared to the PBAS and IABP groups (50% vs 17.6% and 10%, respectively; P = 0.015). We observed no significant differences in mortality or neurological complications between the groups.

CONCLUSIONS

Our results suggest that TALVV was the most effective method for LV unloading compared with PBAS and IABP for VA-ECMO support but was associated with complications. Efficient LV unloading may not improve survival.

Basics of extra corporeal membrane oxygenation: a pediatric intensivist's perspective

Extra Corporeal membrane oxygenation (ECMO) is one of the most advanced forms of life support therapy in the Intensive Care Unit. It relies on the principle where an external artificial circuit carries venous blood from the patient to a gas exchange device (oxygenator) within which blood becomes enriched with oxygen and has carbon dioxide removed. The blood is then returned to the patient via a central vein or an artery. The goal of ECMO is to provide a physiologic milieu for recovery in refractory cardiac/respiratory failure. The technology is not a definitive treatment for a disease, but provides valuable time for the body to recover. In that way it can be compared to a bridge, where patients are initiated on ECMO as a bridge to recovery, bridge to decision making, bridge to transplant or bridge to diagnosis. The use of this modality in children is not backed by a lot of randomized controlled trials, but the use has increased dramatically in our country in last 10 years. This article is not intended to provide an in-depth overview of ECMO, but outlines the basic principles that a pediatric intensive care physician should know in order to manage a kid on ECMO support.

Modalities of Left Ventricle Decompression during VA-ECMO Therapy

Veno-arterial extracorporeal membrane oxygenation (VA-ECMO) is used to sustain circulatory and respiratory support in patients with severe cardiogenic shock or refractory cardiac arrest. Although VA-ECMO allows adequate perfusion of end-organs, it may have detrimental effects on myocardial recovery. Hemodynamic consequences on the left ventricle, such as the increase of afterload, end-diastolic pressure and volume, can lead to left ventricular (LV) distention, increase of myocardial oxygen consumption and delayed LV function recovery. LV distention occurs in almost 50% of patients supported with VA-ECMO and is associated with an increase in morbidity and mortality. Thus, recognizing, preventing and treating LV distention is key in the management of these patients. In this review, we aim to discuss the pathophysiology of LV distention and to describe the strategies to unload the LV in patients supported with VA-ECMO.

Right-Left Ventricular Interaction in Left-Sided Heart Failure With and Without Venoarterial Extracorporeal Membrane Oxygenation Support-A Simulation Study

Left ventricular (LV) dilatation is commonly seen with LV failure and is often aggravated during venoarterial extracorporeal membrane oxygenation (VA ECMO). In this context, the intricate interaction between left and right heart function is considered to be of pivotal importance, yet mechanistically not well understood. We hypothesize that a preserved or enhanced right heart contractility causes increased LV loading both with and without VA ECMO. A closed-loop in-silico simulation model containing the cardiac chambers, the pericardium, septal interactions, and the pulmonary and systemic vascular systems with an option to connect a simulated VA ECMO circuit was developed. Right ventricular contractility was modified during simulation of severe LV failure with and without VA ECMO. Left atrial pressures increased from 14.0 to 23.8 mm Hg without VA ECMO and from 18.4 to 27.0 mm Hg under VA ECMO support when right heart contractility was increased between end-systolic elastance 0.1 and 1.0 mm Hg/ml. Left-sided end-diastolic volumes increased from 125 to 169 ml without VA ECMO and from 150 to 180 ml with VA ECMO. Simulations demonstrate that increased diastolic loading of the LV may be driven by increased right ventricular contractility and that left atrial pressures cannot be interpreted as a reflection of the degree of LV dysfunction and overload without considering right ventricular function. Our study illustrates that modelling and computer simulation are important tools to unravel complex cardiovascular mechanisms underlying the right-left heart interdependency both with and without mechanical circulatory support.

Limited Balloon Atrial Septostomy for Left Ventricular Unloading in Peripheral Extracorporeal Membrane Oxygenation

BACKGROUND

This study describes the authors' experience with a limited balloon atrial septostomy technique, using a median balloon size of 15 mm, as a left ventricular (LV) unloading strategy in venoarterial extracorporeal membrane oxygenation (VA-ECMO). There has been increasing use of VA-ECMO in cardiogenic shock. Although LV unloading strategies have been suggested to improve outcomes, it is unclear which strategy is optimal.

METHODS AND RESULTS

We performed a retrospective study of patients who underwent a limited balloon atrial septostomy for LV unloading in peripheral VA-ECMO at a single center. The goal of this study was to define the procedural outcomes and clinical characteristics of these patients. Of the 12 patients identified, none had complications related to the procedure. There was a significant decrease in the mean left atrial pressure and the majority of patients had radiologic improvement in pulmonary vascular congestion. Of the 12 patients, 58.3% survived to discharge.

CONCLUSIONS

Limited BAS is an elegant and safe method for unloading the LV in peripheral VA-ECMO.

Implantation of an Atrial Flow Regulator in a Child on Venoarterial Extracorporeal Membrane Oxygenator as a Bridge to Heart Transplant: A Case Report

BACKGROUND

Balloon dilation and stenting of the atrial septum are techniques used to unload left heart cavities in acute or end-stage heart failure in children. However, they carry significant risks such as tamponade or device embolization.

CASE PRESENTATION

We report the first case of a child with an end-stage mitochondrial cardiomyopathy on a venoarterial extracorporeal membrane oxygenator as a bridge to heart transplant where an atrial flow regulator device has been implanted.

CONCLUSIONS

This case illustrates the feasibility and safety of atrial flow regulator implantation in this setting. This procedure allowed to wean inotropic support while awaiting heart transplantation.

Air in extracorporeal membrane oxygenation: can never be overemphasized

INTRODUCTION

Air in extracorporeal membrane oxygenation circuit may lead to deleterious consequence.

CASE REPORT

Three cases of air in extracorporeal membrane oxygenation were presented. Air was introduced from right jugular venous sheath during percutaneous septal repair, pulmonary artery catheter during intensive care unit, and sewing holes on atrial wall during surgery respectively. Accidents in Case 2 and Case 3 were successfully managed, while Case 1 was suspected of cerebral air embolism through transseptal right-to-left shunt.

DISCUSSION

With extracorporeal membrane oxygenation being widely applied in more clinical settings, especially in catheterization lab, risks of air in extracorporeal membrane oxygenation increase. More attention should be paid to patients with communication between right and left heart system, especially in situations when venous accesses' exposure to air could not be avoided.

CONCLUSION

Air in the extracorporeal membrane oxygenation circuit should never be overemphasized, especially during special procedures.

Interatrial Shunting for Treating Acute and Chronic Left Heart Failure

The creation of an interatrial shunt has emerged as a new therapy to decompress the left atrium in patients with acute and chronic left heart failure (HF). Current data support the safety of this therapy, and promising preliminary efficacy results have been reported in patients who are refractory to optimal medical/device therapy. This article aims to provide an updated overview and clinical perspective on interatrial shunting for treating different HF conditions, and highlights the potential challenges and future directions of this therapy.

The hemodynamic effect of different left ventricular unloading techniques during veno-arterial extracorporeal life support: a systematic review and meta-analysis

Background:

Pulmonary edema and left ventricular thrombosis may arise during veno-arterial extracorporeal life support due to an increase in cardiac load. This mechanical stress can be reduced through different left ventricular unloading techniques. We set out to quantitatively summarize the hemodynamic effects of available methods in patients treated with veno-arterial extracorporeal life support.

Methods:

Literature was systematically searched for studies reporting left ventricular unloading during veno-arterial extracorporeal life support as reflected by changes in left atrial pressure, pulmonary capillary wedge pressure, diastolic pulmonary artery pressure, or left ventricular end-diastolic pressure. For studies including ⩾10 patients per group, changes in these parameters were pooled using (1) standardized mean differences and (2) ratio of means. Assessment of potential bias was performed for all studies.

Results:

Eight studies met the inclusion criteria. Reported techniques included use of intra-aortic balloon pump (n = 1), micro-axial blood pump (Impella®, n = 2), left ventricular venting (n = 1), and atrial septostomy (n = 4). Overall, left ventricular unloading was associated with a statistically significant reduction in preload parameters (standardized mean differences = −1.05 (95% confidence interval = −1.24 to −0.86) and ratio of means = 0.60 (0.47 to 0.76)). Effect sizes were strongest for micro-axial blood pump and atrial septostomy (standardized mean differences = −1.11 (−1.55 to −0.68) and −1.22 (−1.47 to −0.96), and ratio of means = 0.58 (0.39 to 0.86) and 0.54 (0.36 to 0.83), respectively).

Conclusion:

Left ventricular unloading was associated with a significant reduction in left ventricular preload parameters in the setting of veno-arterial extracorporeal life support. This effect may be most pronounced for micro-axial blood pump and atrial septostomy.

Successful multimodality management of severe pulmonary arterial hypertension during pregnancy with VA-ECMO and atrial septostomy using stent

A 30-year-old Thai woman (gravida 1, para 0) at 33 weeks gestation was referred to our hospital due to acute right ventricular failure. Pulmonary vasodilators were gradually administered before delivery. On the verge of sudden postpartum cardiac circulation collapse, she was resuscitated with veno-arterial extracorporeal membrane oxygenation (VA-ECMO). Abdominal compartment syndrome was developed in the early period of the mechanical support. Knowledge of pathophysiology about pulmonary arterial hypertension during pregnancy was applied. Atrial septostomy was the effective procedure for discontinuing mechanical support (VA-ECMO) corresponding to the suitable timing for maximal effect of pulmonary vasodilators. The patient and her child were safe and discharged in 2 months after the admission.

How small is enough for the left heart decompression cannula during extracorporeal membrane oxygenation?

Background

Left ventricular (LV) distension is a recognizable problem accompanied by subsequent complications during venoarterial extracorporeal membrane oxygenation (VA-ECMO). However, no gold standard for LV decompression has been established, and no minimal flow requirement has been designated. Thus, we evaluated the efficacy of the 8-Fr Mullins sheath for left heart decompression during VA-ECMO in adult patients.

Methods

Left heart decompression was performed when severe pulmonary edema was detected on chest radiography or when no generation of pulse pressure followed severe LV dysfunction in patients receiving VA-ECMO. We punctured the interatrial septum and inserted an 8-Fr Mullins sheath into the left atrium via the femoral vein. The sheath was connected to the venous catheter used for ECMO. The catheter was maintained during VA-ECMO.

Results

The left heart decompression procedure was performed in seven of 35 patients who received VA-ECMO between February 2017 and June 2018. Three patients had acute myocardial infarction; three, fulminant myocarditis; and one, dilated cardiomyopathy. Four patients showed noticeable improvement of pulmonary edema within 3 days, and three patients with a pulse pressure of <10 mm Hg showed an increase in pulse pressure of >20 mm Hg within 24 hours from the left heart decompression procedure. All seven patients were successfully weaned from VA-ECMO. No complications related to the left heart decompression procedure occurred.

Conclusions

An 8-Fr sheath may be a possible option for left heart decompression in adult patients with LV distension under VA-ECMO who are expecting recovery of LV function.

Medical Optimization and Liberation of Adult Patients From VA-ECMO

Venoarterial extracorporeal membrane oxygenation (VA-ECMO) can be an efficacious cardiopulmonary support for adults as rescue from refractory cardiogenic shock. It is best employed as a bridging strategy to recovery or alternative support rather than sustained, long-term mechanical circulatory support. The purpose of this paper is to discuss strategies to optimize patient management on VA-ECMO and approaches to promote successful separation from support. Rapid medical optimization will assist in reducing the time on VA-ECMO, thereby improving the likelihood of patient salvage. Suitably trained physicians and personnel, guided by structured protocols, can promote excellence in team care and provision of consistent management. Focusing on anticoagulation, careful neurologic monitoring, prevention of leg ischemia, awareness of differential hypoxemia, optimizing mechanical ventilation, identifying and timely intervention for left-ventricular distension (LVD), along with a strategic weaning algorithm, can prevent significant morbidity and mortality. LVD physiology, diagnosis, and risk factors are reviewed. Indications for LV decompression, along with medical and mechanical management options, are elucidated.

Relationship Between Time to Left Atrial Decompression and Outcomes in Patients Receiving Venoarterial Extracorporeal Membrane Oxygenation Support: A Multicenter Pediatric Interventional Cardiology Early-Career Society Study

OBJECTIVES

To assess the variation in timing of left atrial decompression and its association with clinical outcomes in pediatric patients supported with venoarterial extracorporeal membrane oxygenation across a multicenter cohort.

DESIGN

Multicenter retrospective study.

SETTING

Eleven pediatric hospitals within the United States.

PATIENTS

Patients less than 18 years on venoarterial extracorporeal membrane oxygenation who underwent left atrial decompression from 2004 to 2016.

INTERVENTIONS

None.

MEASUREMENTS AND MAIN RESULTS

A total of 137 patients (median age, 4.7 yr) were included. Cardiomyopathy was the most common diagnosis (47%). Cardiac arrest (39%) and low cardiac output (50%) were the most common extracorporeal membrane oxygenation indications. Median time to left atrial decompression was 6.2 hours (interquartile range, 3.8-17.2 hr) with the optimal cut-point of greater than or equal to 18 hours for late decompression determined by receiver operating characteristic curve. In univariate analysis, late decompression was associated with longer extracorporeal membrane oxygenation duration (median 8.5 vs 5 d; p = 0.02). In multivariable analysis taking into account clinical confounder and center effects, late decompression remained significantly associated with prolonged extracorporeal membrane oxygenation duration (adjusted odds ratio, 4.4; p = 0.002). Late decompression was also associated with longer duration of mechanical ventilation (adjusted odds ratio, 4.8; p = 0.002). Timing of decompression was not associated with in-hospital survival (p = 0.36) or overall survival (p = 0.42) with median follow-up of 3.2 years.

CONCLUSIONS

In this multicenter study of pediatric patients receiving venoarterial extracorporeal membrane oxygenation, late left atrial decompression (≥ 18 hr) was associated with longer duration of extracorporeal membrane oxygenation support and mechanical ventilation. Although no survival benefit was demonstrated, the known morbidities associated with prolonged extracorporeal membrane oxygenation use may justify a recommendation for early left atrial decompression.

Mechanical Circulatory Support in the Cardiac Catheterization Laboratory for Cardiogenic Shock

Despite the development of acute revascularisation, the mortality rate for cardiogenic shock remains around 50%. Mechanical circulatory support devices have long held promise in improving outcomes in shock, but high-quality evidence of benefit has not been forthcoming. In this article we review the currently available devices for treating shock, their physiological effects and the evidence base for their use in practice. We subsequently look ahead within this developing field, including new devices and novel indications for established technology.

Clinical Pearls of Venoarterial Extracorporeal Membrane Oxygenation for Cardiogenic Shock

Extracorporeal membrane oxygenation (ECMO) is a technique that uses a pump to drain blood from a body, circulate blood through a membrane lung, and return the oxygenated blood back into the body. Venoarterial (VA) ECMO is a simplified version of the heart-lung machine that assists native pulmonary and/or cardiac function. VA ECMO is composed of a drainage cannula in the venous system and a return cannula in the arterial system. Because VA ECMO can increase tissue perfusion by increasing the arterial blood flow, it is used to treat medically refractory cardiogenic shock or cardiac arrest. VA ECMO has a distinct physiology that is referred to as differential flows. It can cause several complications such as left ventricular distension with pulmonary edema, distal limb ischemia, bleeding, and thromboembolism. Physicians who are using this technology should be knowledgeable on the prevention and management of these complications. We review the basic physiology of VA ECMO, the mechanism of complications, and the simple management of VA ECMO.

Interatrial Shunting for Heart Failure: Early and Late Results From the First-in-Human Experience With the V-Wave System

OBJECTIVES

This was a first-in-human study to assess the feasibility, safety, and exploratory efficacy of interatrial shunting for treating high-risk heart failure (HF) in patients with reduced and preserved ejection fraction.

METHODS

A single-arm open-label study of patients with New York Heart Association functional class III or IV HF on optimal therapy was performed at 6 centers. The V-Wave shunt, an hourglass-shaped implant containing a 1-way bioprosthetic valve, was implanted by transseptal catheterization. Clinical, functional, echocardiographic, and hemodynamic evaluations were performed at baseline, 3 and 12 months, and annually (clinical follow-up) thereafter (median follow-up 28 months; interquartile range: 21 to 31 months).

RESULTS

A total of 38 patients were enrolled (30 with HF with reduced ejection fraction and 8 with HF with preserved ejection fraction; mean age 66 ± 9 years; 97% and 3% in New York Heart Association functional classes III and IV, respectively), and the shunt device was successfully implanted in all cases without periprocedural mortality. The rate of major device- or procedure-related complications during the first 12 months was 2.6% (periprocedural cardiac tamponade in 1 patient). At 3- and 12-month follow-up, there were improvements in New York Heart Association functional class (classes I and II in 78% and 60% of patients, respectively), quality of life (improvements ≥5 points in 74% and 73% of patients, respectively), and 6-min walk distance (mean increases of 41 ± 63 m and 28 ± 83 m, respectively) (p < 0.02 for all, data available for 36 patients), without changes in objective measures of left- or right-sided function. All shunts were patent at 3 months, but 5 of 36 (14%) had occluded, and another 13 of 36 (36%) were stenotic at the valve by 12 months. Patients with widely patent shunts had lower long-term rates of death, left ventricular assist device placement or heart transplantation (p = 0.001), and HF hospitalization (p = 0.008), along with a reduction of pulmonary capillary wedge pressure (from 23.3 ± 5.4 mm Hg at baseline to 18.0 ± 4.0 mm Hg at 12 months; p = 0.011).

CONCLUSIONS

Interatrial shunting with the V-Wave system was feasible and safe in patients with HF with reduced and preserved ejection fraction. Improvements in clinical and functional status were observed early and at 12 months despite attenuation of shunt patency in one-half of the patients. Patients with preserved shunt patency tended to maintain clinical benefit during longer term follow-up. Device modification that improves the durability of patency is likely worthwhile before confirmation of these findings in a randomized trial.

The Role of Echocardiography in Neonates and Pediatric Patients on Extracorporeal Membrane Oxygenation

Indications for extracorporeal membrane oxygenation (ECMO) and extracorporeal cardiopulmonary resuscitation (ECPR) are expanding, and echocardiography is a tool of utmost importance to assess safety, effectiveness and readiness for circuit initiation and separation. Echocardiography is key to anticipating complications and improving outcomes. Understanding the patient's as well as the ECMO circuit's anatomy and physiology is crucial prior to any ECMO echocardiographic evaluation. It is also vital to acknowledge that the utility of echocardiography in ECMO patients is not limited to the evaluation of cardiac function, and that clinical decisions should not be made exclusively upon echocardiographic findings. Though echocardiography has specific indications and applications, it also has limitations, characterized as: prior to and during cannulation, throughout the ECMO run, upon separation and after separation from the circuit. The use of specific and consistent echocardiographic protocols for patients on ECMO is recommended.

Left ventricular unloading during veno-arterial ECMO: a review of percutaneous and surgical unloading interventions

Short-term mechanical support by veno-arterial extracorporeal membrane oxygenation (VA ECMO) is more and more applied in patients with severe cardiogenic shock. A major shortcoming of VA ECMO is its variable, but inherent increase of left ventricular (LV) mechanical load, which may aggravate pulmonary edema and hamper cardiac recovery. In order to mitigate these negative sequelae of VA ECMO, different adjunct LV unloading interventions have gained a broad interest in recent years. Here, we review the whole spectrum of percutaneous and surgical techniques combined with VA ECMO reported to date.

Mechanical circulatory support in patients with cardiogenic shock in intensive care units: A position paper of the "Unité de Soins Intensifs de Cardiologie" group of the French Society of Cardiology, endorsed by the "Groupe Athérome et Cardiologie Interventionnelle" of the French Society of Cardiology

Cardiogenic shock (CS) is a major challenge in contemporary cardiology. Despite a better understanding of the pathophysiology of CS, its management has only improved slightly. The prevalence of CS has remained stable over the past decade, but its outcome has seen few improvements, with the 1-month mortality rate still in the range of 40-60%. Inotropes and vasopressors are the first-line therapies for CS, but they are associated with significant hazards, and have well-known deleterious effects. Furthermore, a significant number of patients develop refractory CS with haemodynamic instability, causing critical organ hypoperfusion and/or pulmonary congestion, despite increasing doses of catecholamines. A major change has resulted from the recent advent and availability of potent mechanical circulatory support (MCS) devices. These devices, which ensure sustained blood flow, provide a great and long-awaited opportunity to improve the prognosis of CS. Several efficient MCS devices are now available, including left ventricle-to-aorta circulatory support devices and full pulmonary and circulatory support with venoarterial extracorporeal membrane oxygenation. However, evidence to support their indications, the timing of implantation and the selection of patients and devices is scarce. Because these devices are gaining momentum and are becoming readily available, the "Unité de Soins Intensifs de Cardiologie" group of the French Society of Cardiology aims to propose practical algorithms for the use of these devices, to help intensive care unit and cardiac care unit physicians in this complex area, where evidence is limited.