Efficacy and safety of extracorporeal membrane oxygenation for high-risk pulmonary embolism: A systematic review and meta-analysis

Acute Pulmonary Embolism: Evidence, Innovation, and Horizons

PURPOSE OF REVIEW

Pulmonary embolism (PE) is the third most common cause of cardiovascular morbidity and mortality. The goal of this review is to discuss the most up-to-date literature on epidemiology, diagnosis, risk stratification, and management of acute PE.

RECENT FINDINGS

Despite an increase in annual incidence rate of PE in the United States and development of multiple advanced therapies for treatment of acute PE, PE-related mortality is not consistently decreasing across populations. Although multiple risk stratification schemes have been developed, it is still unclear which advanced therapy should be used for the individual patient and optimal timing. Fortunately, multiple randomized clinical trials are underway to answer these questions. Nevertheless, up to 50% of patients have persistent reduced quality of life 6 months after acute PE, termed post-PE syndrome. Despite advances in therapeutic options for management of acute PE, many questions remain unanswered, including optimal risk stratification and management of acute PE.

Overcoming challenges in the treatment of massive pulmonary embolism in the elderly: Role of extracorporeal membrane oxygenation

Population aging represents a paramount medical and socio-demographic challenge globally. As living standards improve and medical technology advances, the elderly population experiences an increasing number of detected and treated pulmonary embolisms (PE). However, rescuing massive pulmonary embolism (MPE) in the elderly remains a difficult task. Conventional thrombolysis or surgical thrombolysis might be contraindicated, leading extracorporeal membrane oxygenation (ECMO) to emerge as a treatment modality for MPE in the elderly. Nevertheless, data are scarce regarding the use of ECMO as a standalone treatment for MPE. In this paper, we present the case of an 85-year-old patient with a prior cerebral infarction, who received a diagnosis of MPE in the main trunks of bilateral pulmonary arteries. Considering the patient's systemic condition, the Pulmonary Embolism Response Team (PERT) opted to administer VA-ECMO as the sole treatment approach. Remarkably, the patient achieved a favorable recovery outcome. Our case report contributes new evidence to the treatment of elderly individuals with MPE and highlights the potential of ECMO-only regimens for addressing such cases.

AngioJet thrombectomy with extracorporeal membrane oxygenation support for an acute large-scale pulmonary embolism with bilateral atrial thrombosis: a case report of catastrophic antiphospholipid syndrome

Background

Catastrophic Antiphospholipid Syndrome (CAPS), a severe systemic autoimmune disorder, predominantly causes life-threatening multi-organ failure, with a high mortality rate. It primarily affects small vessels, seldom impacting large vessels. Notably, acute massive pulmonary embolism (PE) with bilateral atrial thrombosis is an exceptional occurrence in CAPS. Acute pulmonary embolism (PE) is a common cardiovascular disease that progresses rapidly and has a high mortality rate. Acute massive PE combined with bilateral atrial thrombosis has an even higher mortality rate. PE treatments primarily include pharmaceuticals, catheter interventions, and surgical measures, with integrated treatment strategies demonstrating promising outcomes in clinical practice. Extracorporeal membrane oxygenation (ECMO) can provide cardiopulmonary support for the treatment of high-risk PE patients and is a proven therapeutic measure.

Methods

This report presents the case of a 52-year-old male admitted due to fever and sudden onset of impaired consciousness, with cardiac ultrasound and pulmonary artery CT angiography revealing an acute large-scale pulmonary embolism accompanied by bilateral atrial thrombosis, with the condition rapidly worsening and manifesting severe respiratory and circulatory failure. With ECMO support, the patient underwent a thrombectomy using an AngioJet intervention. The diagnosis of CAPS was confirmed through clinical presentation and laboratory examination, and treatment was adjusted accordingly.

Results

The patient made a successful recovery and was subsequently discharged from the hospital.

Conclusion

In CAPS patients, the rare instance of acute massive PE accompanied by bilateral atrial thrombosis significantly risks severe respiratory and circulatory failure, adversely affecting prognosis. Early initiation of ECMO therapy is crucial, offering a vital opportunity to address the root cause. In this case report the patient was successfully treated with an AngioJet thrombectomy supported by ECMO.

Management of high-risk pulmonary embolism in the emergency department: A narrative review

BACKGROUND

High-risk pulmonary embolism (PE) is a complex, life-threatening condition, and emergency clinicians must be ready to resuscitate and rapidly pursue primary reperfusion therapy. The first-line reperfusion therapy for patients with high-risk PE is systemic thrombolytics (ST). Despite consensus guidelines, only a fraction of eligible patients receive ST for high-risk PE.

OBJECTIVE

This review provides emergency clinicians with a comprehensive overview of the current evidence regarding the management of high-risk PE with an emphasis on ST and other reperfusion therapies to address the gap between practice and guideline recommendations.

DISCUSSION

High-risk PE is defined as PE that causes hemodynamic instability. The high mortality rate and dynamic pathophysiology of high-risk PE make it challenging to manage. Initial stabilization of the decompensating patient includes vasopressor administration and supplemental oxygen or high-flow nasal cannula. Primary reperfusion therapy should be pursued for those with high-risk PE, and consensus guidelines recommend the use of ST for high-risk PE based on studies demonstrating benefit. Other options for reperfusion include surgical embolectomy and catheter directed interventions.

CONCLUSIONS

Emergency clinicians must possess an understanding of high-risk PE including the clinical assessment, pathophysiology, management of hemodynamic instability and respiratory failure, and primary reperfusion therapies.

Extracorporeal cardiopulmonary resuscitation for refractory cardiac arrest: an overview of current practice and evidence

Cardiac arrest (CA) is a common and potentially avoidable cause of death, while constituting a substantial public health burden. Although survival rates for out-of-hospital cardiac arrest (OHCA) have improved in recent decades, the prognosis for refractory OHCA remains poor. The use of veno-arterial extracorporeal membrane oxygenation during cardiopulmonary resuscitation (ECPR) is increasingly being considered to support rescue measures when conventional cardiopulmonary resuscitation (CPR) fails. ECPR enables immediate haemodynamic and respiratory stabilisation of patients with CA who are refractory to conventional CPR and thereby reduces the low-flow time, promoting favourable neurological outcomes. In the case of refractory OHCA, multiple studies have shown beneficial effects in specific patient categories. However, ECPR might be more effective if it is implemented in the pre-hospital setting to reduce the low-flow time, thereby limiting permanent brain damage. The ongoing ON-SCENE trial might provide a definitive answer regarding the effectiveness of ECPR. The aim of this narrative review is to present the most recent literature available on ECPR and its current developments.

Risk stratification of acute pulmonary embolism

Approximately 5% of pulmonary embolism (PE) cases present with persistent hypotension, obstructive shock, or cardiac arrest. Given the high short-term mortality, management of high-risk PE cases focuses on immediate reperfusion therapies. Risk stratification of normotensive PE is important to identify patients with an elevated risk of hemodynamic collapse or an elevated risk of major bleeding. Risk stratification for short-term hemodynamic collapse includes assessment of physiological parameters, right heart dysfunction, and identification of comorbidities. Validated tools such as European Society of Cardiology guidelines and Bova score can identify normotensive patients with PE and an elevated risk of subsequent hemodynamic collapse. At present, we lack high-quality evidence to recommend one treatment over another (systemic thrombolysis, catheter-directed therapy, or anticoagulation with close monitoring) for patients at elevated risk of hemodynamic collapse. Newer, less well-validated scores such as BACS and PE-CH may help identify patients at a high risk of major bleeding following systemic thrombolysis. The PE-SARD score may identify those at risk of major anticoagulant-associated bleeding. Patients at low risk of short-term adverse outcomes can be considered for outpatient management. The simplified Pulmonary Embolism Severity Index score or Hestia criteria are safe decision aids when combined with physician global assessment of the need for hospitalization following the diagnosis of PE.

Trends in Treatment Patterns and Outcomes of Patients With Pulmonary Embolism in Japan, 2010 to 2020: A Nationwide Inpatient Database Study

Background The impact of major changes in the treatment practice of pulmonary embolism (PE), such as limited indications for systemic thrombolysis and the introduction of direct oral anticoagulants, is not well documented. This study aimed to describe annual trends in the treatment patterns and outcomes in patients with PE. Methods and Results Using the Japanese Diagnosis Procedure Combination inpatient database from April 2010 to March 2021, we identified hospitalized patients with PE. Patients with high-risk PE were defined as those admitted for out-of-hospital cardiac arrest or who received cardiopulmonary resuscitation, extracorporeal membrane oxygenation, vasopressors, or invasive mechanical ventilation on the day of admission. The remaining patients were defined as patients with non-high-risk PE. The patient characteristics and outcomes were reported with fiscal year trend analyses. Of 88 966 eligible patients, 8116 (9.1%) had high-risk PE, and the remaining 80 850 (90.9%) had non-high-risk PE. Between 2010 and 2020, in patients with high-risk PE, the annual proportion of extracorporeal membrane oxygenation use significantly increased from 11.0% to 21.3%, whereas that of thrombolysis use significantly decreased from 22.5% to 15.5% (P for trend <0.001 for both). In-hospital mortality significantly decreased from 51.0% to 43.7% (P for trend=0.04). In patients with non-high-risk PE, the annual proportion of direct oral anticoagulant use increased from 0.0% to 38.3%, whereas that of thrombolysis use significantly decreased from 13.7% to 3.4% (P for trend <0.001 for both). In-hospital mortality significantly decreased from 7.9% to 5.4% (P for trend <0.001). Conclusions Substantial changes in the PE practice and outcomes occurred in patients with high-risk and non-high-risk PE.

Hemodynamic and respiratory support in pulmonary embolism: a narrative review

Pulmonary embolism is a common and potentially fatal disease, with a significant burden on health and survival. Right ventricular dysfunction and hemodynamic instability are considered two key determinants of mortality in pulmonary embolism, which can reach up to 65% in severe cases. Therefore, timely diagnosis and management are of paramount importance to ensure the best quality of care. However, hemodynamic and respiratory support, both major constituents of management in pulmonary embolism, associated with cardiogenic shock or cardiac arrest, have been given little attention in recent years, in favor of other novel advances such as systemic thrombolysis or direct oral anticoagulants. Moreover, it has been implied that current recommendations regarding this supportive care lack enough robustness, further complicating the problem. In this review, we critically discuss and summarize the current literature concerning the hemodynamic and respiratory support in pulmonary embolism, including fluid therapy, diuretics, pharmacological support with vasopressors, inotropes and vasodilators, oxygen therapy and ventilation, and mechanical circulatory support with veno-arterial extracorporeal membrane oxygenation and right ventricular assist devices, while also providing some insights into contemporary research gaps.

The Challenge of Intermediate-Risk Pulmonary Embolism

BACKGROUND

Intermediate-risk pulmonary embolism is a common disease that is associated with significant morbidity and mortality; however, a standardized treatment protocol is not well-established.

AREAS OF UNCERTAINTY

Treatments available for intermediate-risk pulmonary embolisms include anticoagulation, systemic thrombolytics, catheter-directed therapies, surgical embolectomy, and extracorporeal membrane oxygenation. Despite these options, there is no clear consensus on the optimal indication and timing of these interventions.

THERAPEUTIC ADVANCES

Anticoagulation remains the cornerstone of treatment for pulmonary embolism; however, over the past 2 decades, there have been advances in the safety and efficacy of catheter-directed therapies. For massive pulmonary embolism, systemic thrombolytics and, sometimes, surgical thrombectomy are considered first-line treatments. Patients with intermediate-risk pulmonary embolism are at high risk of clinical deterioration; however, it is unclear whether anticoagulation alone is sufficient. The optimal treatment of intermediate-risk pulmonary embolism in the setting of hemodynamic stability with right heart strain present is not well-defined. Therapies such as catheter-directed thrombolysis and suction thrombectomy are being investigated given their potential to offload right ventricular strain. Several studies have recently evaluated catheter-directed thrombolysis and embolectomies and demonstrated the efficacy and safety of these interventions. Here, we review the literature on the management of intermediate-risk pulmonary embolisms and the evidence behind those interventions.

CONCLUSIONS

There are many treatments available in the management of intermediate-risk pulmonary embolism. Although the current literature does not favor 1 treatment as superior, multiple studies have shown growing data to support catheter-directed therapies as potential options for these patients. Multidisciplinary pulmonary embolism response teams remain a key feature in improving the selection of advanced therapies and optimization of care.

Surgical Management and Mechanical Circulatory Support in High-Risk Pulmonary Embolisms: Historical Context, Current Status, and Future Directions: A Scientific Statement From the American Heart Association

Acute pulmonary embolism is the third leading cause of cardiovascular death, with most pulmonary embolism-related mortality associated with acute right ventricular failure. Although there has recently been increased clinical attention to acute pulmonary embolism with the adoption of multidisciplinary pulmonary embolism response teams, mortality of patients with pulmonary embolism who present with hemodynamic compromise remains high when current guideline-directed therapy is followed. Because historical data and practice patterns affect current consensus treatment recommendations, surgical embolectomy has largely been relegated to patients who have contraindications to other treatments or when other treatment modalities fail. Despite a selection bias toward patients with greater illness, a growing body of literature describes the safety and efficacy of the surgical management of acute pulmonary embolism, especially in the hemodynamically compromised population. The purpose of this document is to describe modern techniques, strategies, and outcomes of surgical embolectomy and venoarterial extracorporeal membrane oxygenation and to suggest strategies to better understand the role of surgery in the management of pulmonary embolisms.

Effectiveness of systemic thrombolysis on clinical outcomes in high-risk pulmonary embolism patients with venoarterial extracorporeal membrane oxygenation: a nationwide inpatient database study

BACKGROUND

Current guidelines recommend systemic thrombolysis as the first-line reperfusion treatment for patients with high-risk pulmonary embolism (PE) who present with cardiogenic shock but do not require venoarterial extracorporeal membrane oxygenation (VA-ECMO). However, little is known about the optimal reperfusion treatment in high-risk PE patients requiring VA-ECMO. We aimed to evaluate whether systemic thrombolysis improved high-risk PE patients' outcomes who received VA-ECMO.

METHODS

This was a retrospective cohort study using the Japanese Diagnosis Procedure Combination inpatient database from July 2010 to March 2021. We identified patients who were diagnosed with PE and received VA-ECMO on the day of admission. Patients who received systemic thrombolysis with monteplase or urokinase within two days of initiating VA-ECMO were defined as the thrombolysis group and the remaining patients as the control group. The primary outcome was in-hospital mortality and secondary outcomes were favorable neurological outcomes, length of hospital stay, VA-ECMO duration, total hospitalization cost, major bleeding, and blood transfusion volume. Propensity-score inverse probability of treatment weighting (IPTW) was performed to compare the outcomes between the groups.

RESULTS

Of 1220 eligible patients, 432 (35%) received systemic thrombolysis within two days of initiating VA-ECMO. Among the unweighted cohort, patients in the thrombolysis group were less likely to have poor consciousness at admission, out-of-hospital cardiac arrest, and left heart catheterization. After IPTW, the patient characteristics were well-balanced between the two groups The crude in-hospital mortality was 52% in the thrombolysis group and 61% in the control group. After IPTW, in-hospital mortality did not differ significantly between the two groups (risk difference: - 3.0%, 95% confidence interval: - 9.6% to 3.5%). There were also no significant differences in the secondary outcomes. Sensitivity analyses showed a significant difference in major bleeding between the monteplase and control groups (risk difference: 6.9%, 95% confidence interval: 1.7% to 12.1%), excluding patients who received urokinase. There were no significant differences in the other sensitivity and subgroup analyses except for the total hospitalization cost.

CONCLUSIONS

Systemic thrombolysis was not associated with reduced in-hospital mortality or increased major bleeding in the high-risk PE patients receiving VA-ECMO. However, systemic thrombolysis with monteplase was associated with increased major bleeding.

Outcomes with use of extra-corporeal membrane oxygenation in high-risk pulmonary embolism: a national database perspective

High-risk pulmonary embolism (PE) patients can be managed with systemic lysis, catheter-based therapies, or surgical embolectomy. Despite the advent of newer therapies, patients with high-risk PE remain with a 50-60% short-term mortality risk. In such patients, extracorporeal membrane oxygenation (ECMO) is increasingly utilized for hemodynamic support. To evaluate the outcomes of the use of ECMO in patients with high-risk PE. Using the National Inpatient Sample (NIS) database, we identified patients with high-risk PE using ICD 10 codes and compared in-hospital outcomes of patients with and without ECMO support. We identified 38,035 patients with high-risk PE, of whom 820 had undergone ECMO placement. Most patients who underwent ECMO were male (54%), white (65%), and with a mean age of 53.7 years. ECMO use was not associated with a meaningful difference in patient mortality when comparing treatment groups (OR, 1.32 ± 0.39; 0.74-2.35; p = 0.35). Rather, ECMO use was associated with a higher frequency of inpatient complications. ECMO use was not associated with a significant difference in patient mortality in patients with high-risk PE.

Efficacy and Safety of Veno-Arterial Extracorporeal Membrane Oxygenation in the Treatment of High-Risk Pulmonary Embolism: A Retrospective Cohort Study

Objectives

Veno-arterial extracorporeal membrane oxygenation (ECMO) is increasingly used to treat high-risk pulmonary embolism (PE). However, its efficacy and safety remain uncertain. This retrospective cohort study aimed to determine whether ECMO could improve the clinical outcomes of patients with high-risk PE.

Methods

Forty patients with high-risk PE, who were admitted to Kaohsiung Chang Gung Memorial Hospital between January 2012 and December 2019, were included in this study. Demographic data and clinical outcomes were compared between patients treated without ECMO (non-ECMO group) and those treated with ECMO (ECMO group). Appropriate statistical tools were used to compare variables between groups and the survival was analyzed using the Kaplan-Meier method.

Results

The overall in-hospital mortality rate was 55%, in which 65% (26/40) of patients presented with cardiac arrest with a mortality rate of 77%, which was higher than that of patients without cardiac arrest (14%). There was no significant difference in major complications and in-hospital mortality between the non-ECMO and ECMO groups. However, in subgroup analysis, compared with patients treated without ECMO, earlier ECMO treatment was associated with a reduced risk of cardiac arrest (P = 0.023) and lower in-hospital mortality (P = 0.036). A log-rank test showed a significantly higher cumulative overall survival in the earlier ECMO treatment group (P = 0.033).

Conclusions

In this retrospective cohort study, earlier ECMO treatment was associated with lower in-hospital mortality among unstable patients without cardiac arrest. Our findings suggest that ECMO can be considered as an initial treatment option for patients with high-risk PE in higher-volume hospitals.

Clinical use and outcome of extracorporeal membrane oxygenation in patients with pulmonary embolism

AIM OF THE STUDY

Extracorporeal membrane oxygenation (ECMO) is considered a life-saving treatment option for patients in cardiogenic shock or cardiac arrest undergoing cardiopulmonary resuscitation (CPR) due to acute pulmonary embolism (PE). We sought to analyze use and outcome of ECMO with or without adjunctive treatment strategies in patients with acute PE.

METHODS

We retrospectively analyzed data on patient characteristics, treatments, and in-hospital outcomes for all PE patients (ICD-code I26) undergoing ECMO in Germany between 2005 and 2018.

RESULTS

At total of 1,172,354 patients were hospitalized with PE; of those, 2,197 (0.2%) were treated with ECMO support. Cardiac arrest requiring cardiopulmonary resuscitation was present in 77,196 (6.5%) patients. While more than one fourth of those patients were treated with systemic thrombolysis alone (n = 20,839 patients; 27.0%), a minority of patients received thrombolysis and VA-ECMO (n = 165; 0.2%), embolectomy and VA-ECMO (n = 385; 0.5%) or VA-ECMOalone (n = 588; 0.8%). A multivariable logistic regression analysis indicated the lowest risk for in-hospital death in patients who received embolectomy in combination with VA-ECMO (OR, 0.50 [95% CI, 0.41-0.61], p < 0.001), thrombolysis and VA-ECMO (0.60 [0.43-0.85], p = 0.003) or VA-ECMO alone (0.68 [0.57-0.82], p < 0.001) compared to thrombolysis alone (1.04 [0.99-1.01], p = 0.116).

CONCLUSION

Our findings suggest that the use of VA-ECMO alone or as part of a multi-pronged reperfusion approach including embolectomy or thrombolysis might offer survival advantages compared to thrombolysis alone in patients with PE deteriorating to cardiac arrest.

Venoarterial Extracorporeal Membrane Oxygenation for Acute Massive Pulmonary Embolism: a Meta-Analysis and Call to Action

Venoarterial extracorporeal membrane oxygenation (ECMO) has been used to treat acute massive pulmonary embolism (PE) patients. However, the incremental benefit of ECMO to standard therapy remains unclear. Our meta-analysis objective is to compare in-hospital mortality in patients treated for acute massive PE with and without ECMO. The National Library of Medicine MEDLINE (USA), Web of Science, and PubMed databases from inception through October 2020 were searched. Screening identified 1002 published articles. Eleven eligible studies were identified, and 791 patients with acute massive PE were included, of whom 270 received ECMO and 521 did not. In-hospital mortality was not significantly different between patients treated with vs. without ECMO (OR = 1.24 [95% CI, 0.63–2.44], p = 0.54). However, these findings were limited by significant study heterogeneity. Additional research will be needed to clarify the role of ECMO in massive PE treatment.

Contemporary management of acute pulmonary embolism

This review examines the recent progress in the initial management of pulmonary embolism (PE). Diagnostic strategies allowing the safe decrease of imaging testing have been proposed. New modalities of catheter-based interventions have emerged for hemodynamically unstable PE patients. For normotensive PE patients, direct oral anticoagulant treatment has become the new norm and a large proportion of patients are eligible for home treatment.