Venoarterial Extracorporeal Membrane Oxygenation in Massive Pulmonary Embolism-Related Cardiac Arrest: A Systematic Review

Venoarterial extracorporeal membrane oxygenation for "protected" catheter-based embolectomy in high-risk/massive pulmonary embolism

High-risk/massive pulmonary embolism (PE) has a high mortality rate, especially when cardiac arrest occurs. Venoarterial (V-A) extracorporeal membrane oxygenation (ECMO) can rapidly restore and maintain circulation while a decision regarding further care or performance of other interventions takes place. Catheter-based embolectomy (CBE) is a technology that allows for percutaneous access, clot removal, and potential resolution of shock while avoiding sternotomy required for traditional pulmonary embolectomy. Rapid placement of V-A ECMO in patients with high-risk/massive PE prior to CBE may confer circulatory protection before, during, and after the procedure.

Management Strategies for Acute Pulmonary Embolism in the ICU

TOPIC IMPORTANCE

Acute pulmonary embolism (PE) is a common disease encountered by pulmonologists, cardiologists, and critical care physicians throughout the world. For patients with high-risk acute PE (defined by systemic hypotension) and intermediate high-risk acute PE (defined by the absence of systemic hypotension, but the presence of numerous other concerning clinical and imaging features), intensive care often is necessary. Initial management strategies should focus on optimization of right ventricle (RV) function while decisions about advanced interventions are being considered.

REVIEW FINDINGS

We reviewed the existing literature of various vasoactive agents, IV fluids and diuretics, and pulmonary vasodilators in both animal models and human trials of acute PE. We also reviewed the potential complications of endotracheal intubation and positive pressure ventilation in acute PE. Finally, we reviewed the data of venoarterial extracorporeal membrane oxygenation use in acute PE. The above interventions are discussed in the context of the underlying pathophysiologic features of acute RV failure in acute PE with corresponding illustrations.

SUMMARY

Norepinephrine is a reasonable first choice for hemodynamic support with vasopressin as an adjunct. IV loop diuretics may be useful if evidence of RV dysfunction or volume overload is present. Fluids should be given only if concern exists for hypovolemia and absence of RV dilatation. Supplemental oxygen administration should be considered even without hypoxemia. Positive pressure ventilation should be avoided if possible. Venoarterial extracorporeal membrane oxygenation cannulation should be implemented early if ongoing deterioration occurs despite these interventions.

Hybrid Thrombectomy and Central Extracorporeal Membrane Oxygenation for Massive Pulmonary Embolism in a Child

We describe a hybrid thrombectomy and central extracorporeal membrane oxygenation for a child in cardiogenic shock due to a massive pulmonary embolism.

Venoarterial Extracorporeal Membrane Oxygenation With or Without Advanced Intervention for Massive Pulmonary Embolism

INTRODUCTION

Massive pulmonary embolism (MPE) is a rare but highly fatal condition. Our study's objective was to evaluate the association between advanced interventions and survival among patients with MPE treated with venoarterial extracorporeal membrane oxygenation (VA-ECMO).

METHODS

This is a retrospective review of the Extracorporeal Life Support Organization (ELSO) registry data. We included adult patients with MPE who were treated with VA-ECMO during 2010-2020. Our Primary outcome was survival to hospital discharge; secondary outcomes were ECMO duration among survivors and rates of ECMO-related complications. Clinical variables were compared using the Pearson chi-square and Kruskal-Wallis H tests.

RESULTS

We included 802 patients; 80 (10%) received SPE and 18 (2%) received CDT. Overall, 426 (53%) survived to discharge; survival was not significantly different among those treated with SPE or CDT on VA-ECMO (70%) versus VA-ECMO alone (52%) or SPE or CDT before VA-ECMO (52%). Multivariable regression found a trend towards increased survival among those treated with SPE or CDT while on ECMO (AOR 1.8, 95% CI 0.9-3.6), but no significant correlation. There was no association between advanced interventions and ECMO duration among survivors, or rates of ECMO-related complications.

CONCLUSION

Our study found no difference in survival in patients with MPE who received advanced interventions prior to ECMO, and a slight non-significant benefit in those who received advanced interventions while on ECMO.

Intermediate-Risk and High-Risk Pulmonary Embolism: Recognition and Management: Cardiology Clinics: Cardiac Emergencies

Pulmonary embolism (PE) is the third most common cause of cardiovascular death. Every specialty of medical practitioner will encounter PE in their patients, and should be prepared to employ contemporary strategies for diagnosis and initial risk-stratification. Treatment of PE is based on risk-stratification, with anticoagulation for all patients, and advanced modalities including systemic thrombolysis, catheter-directed therapies, and mechanical circulatory supports utilized in a manner paralleling PE severity and clinical context.

Extracorporeal Membrane Oxygenation for Pulmonary Embolism: A Systematic Review and Meta-Analysis

BACKGROUND

The use of extracorporeal membrane oxygenation (ECMO) for high-risk pulmonary embolism (HRPE) with haemodynamic instability or profound cardiogenic shock has been reported. Guidelines currently support the use of ECMO only in patients with cardiac arrest or circulatory collapse and in conjunction with other curative therapies. We aimed to characterise the mortality of adults with HRPE treated with ECMO, identify factors associated with mortality, and compare different adjunct curative therapies.

METHODS

We conducted a systematic review and meta-analysis, searching four international databases from their inception until 25 June 2023 for studies reporting on more than five patients receiving ECMO for HRPE. Random-effects meta-analyses were conducted. The primary outcome was in-hospital mortality. A subgroup analysis investigating the outcomes with curative treatment for HRPE was also performed. The intra-study risk of bias and the certainty of evidence were also assessed. This study was registered with PROSPERO (CRD42022297518).

RESULTS

A total of 39 observational studies involving 6409 patients receiving ECMO for HRPE were included in the meta-analysis. The pooled mortality was 42.8% (95% confidence interval [CI]: 37.2% to 48.7%, moderate certainty). Patients treated with ECMO and catheter-directed therapy (28.6%) had significantly lower mortality (p < 0.0001) compared to those treated with ECMO and systemic thrombolysis (57.0%). Cardiac arrest prior to ECMO initiation (regression coefficient [B]: 1.77, 95%-CI: 0.29 to 3.25, p = 0.018) and pre-ECMO heart rate (B: -0.076, 95%-CI: -0.12 to 0.035, p = 0.0003) were significantly associated with mortality. The pooled risk ratio when comparing mortality between patients on ECMO and those not on ECMO was 1.51 (95%-CI: 1.07 to 2.14, p < 0.01) in favour of ECMO. The pooled mortality was 55.2% (95%-CI: 47.7% to 62.6%), using trim-and-fill analysis to account for the significant publication bias.

CONCLUSIONS

More than 50% of patients receiving ECMO for HRPE survive. While outcomes may vary based on the curative therapy used, early ECMO should be considered as a stabilising measure when treating patients with HRPE. Patients treated concurrently with systemic thrombolysis have higher mortality than those receiving ECMO alone or with other curative therapies, particularly catheter-directed therapies. Further studies are required to explore ECMO vs. non-ECMO therapies in view of currently heterogenous datasets.

Current status of ECMO for massive pulmonary embolism

Massive pulmonary embolism (MPE) carries significant 30-day mortality and is characterized by acute right ventricular failure, hypotension, and hypoxia, leading to cardiovascular collapse and cardiac arrest. Given the continued high mortality associated with MPE, there has been ongoing interest in utilizing extracorporeal membrane oxygenation (ECMO) to provide oxygenation support to improve hypoxia and offload the right ventricular (RV) pressure in the belief that rapid reduction of hypoxia and RV pressure will improve outcomes. Two modalities can be employed: Veno-arterial-ECMO is a reliable process to decrease RV overload and improve RV function, thus allowing for hemodynamic stability and restoration of tissue oxygenation. Veno-venous ECMO can support oxygenation but is not designed to help circulation. Several societal guidelines now suggest using ECMO in MPE with interventional therapy. There are three strategies for ECMO utilization in MPE: bridge to definitive interventional therapy, sole therapy, and recovery after interventional treatment. The use of ECMO in MPE has been associated with lower mortality in registry reviews, but there has been no significant difference in outcomes between patients treated with and without ECMO in meta-analyses. Considerable heterogeneity in studies is a significant weakness of the available literature. Applying ECMO is also associated with substantial multisystem morbidity due to a systemic inflammatory response, hemorrhagic stroke, renal dysfunction, and bleeding, which must be factored into the outcomes. The application of ECMO in MPE should be combined with an aggressive pulmonary interventional program and should strictly adhere to the current selection criteria.

High-Risk Pulmonary Embolism: Management for the Intensivist

High-risk pulmonary embolism (PE) also known as massive PE carries a high rate of morbidity and mortality. The incidence of high-risk PE continues to increase, yet the outcomes of high-risk PE continue to remain poor. Patients with high-risk PE are often critically ill, with complex underlying physiology, and treatment for the high-risk PE patient almost always requires care and management from an intensivist. Treatment options for high-risk PE continue to evolve rapidly with multiple options for definitive reperfusion therapy and supportive care. A thorough understanding of the physiology, risk stratification, treatment, and support options for the high-risk PE patient is necessary for all intensivists in order to improve outcomes. This article aims to provide a review from an intensivist's perspective highlighting the physiological consequences, risk stratification, and treatment options for these patients as well as providing a proposed algorithm to the risk stratification and acute management of high-risk PE.

Advanced Treatment of Hemodynamically Unstable Acute Pulmonary Embolism and Clinical Follow-up

High-risk acute pulmonary embolism (PE), defined as acute PE associated with hemodynamic instability, remains a significant contributor to cardiovascular morbidity and mortality in the United States and worldwide. Historically, anticoagulant therapy in addition to systemic thrombolysis has been the mainstays of medical therapy for the majority of patients with high-risk PE. In efforts to reduce the morbidity and mortality, a wide array of interventional and surgical therapies has been developed and employed in the management of these patients. However, the most recent guidelines for the management of PE have reserved the use of these advanced therapies in scenarios where thrombolytic therapy plus anticoagulation are unsuccessful. This is due largely to the lack of prospective, randomized studies in this population. Stemming from this, the approach to treatment of these patients varies widely depending on institutional experience and resources. Furthermore, morbidity and mortality remain unacceptably high in this population, with estimated 30-day mortality of at least 30%. As such, development of a standardized approach to treatment of these patients is paramount to improving outcomes. Early and accurate risk stratification in conjunction with a multidisciplinary team approach in the form of a PE response team is crucial. With the advent of novel therapies for the treatment of acute PE, in addition to the growing availability of and familiarity with mechanical circulatory support systems, such a standardized approach may now be within reach.

Large ovarian tumor-caused failure of VA-ECMO in a patient with cardiac arrest related to massive pulmonary embolism

Venoarterial extracorporeal membrane oxygenation (VA-ECMO) plays an important role in patients with massive pulmonary embolism (PE)-related cardiac arrest. A 47-year-old healthy Japanese woman was brought to the emergency department because of shock. The patient suddenly collapsed due to cardiac arrest in an ambulance. The patient was diagnosed with PE on transthoracic echocardiography during cardiopulmonary resuscitation (CPR). Emergency VA-ECMO cannulation was performed percutaneously. Although VA-ECMO support was initiated, the return cannula flow could not be pumped because of the high resistance. Circulation support with VA-ECMO was discontinued. Subsequently, pulmonary angiography under CPR revealed numerous thrombi in the bilateral pulmonary arteries, and aspiration thrombectomy and catheter fragmentation were performed. The patient achieved spontaneous recovery of circulation after successful catheter fragmentation. After the procedure to investigate the cause of VA-ECMO failure, whole-body computed tomography showed a large ovarian tumor and compression of the femoral artery and abdominal aorta. The patient died of multiple organ failure due to hypoxic encephalopathy. Undiagnosed gynecological tumors often cause fulminant PE and may also cause the failure of VA-ECMO due to vascular compression. Alternative cannulation sites and prior thrombolysis should be immediately considered. The complexity of PE management necessitates a well-trained PE response team.

Learning objective

Large gynecological tumors may cause pulmonary embolism-related cardiac arrest and consequent failure of venoarterial extracorporeal membrane oxygenation using the femoral artery approach due to vascular compression by the tumor. An adequate strategy should be considered to achieve immediate recovery of spontaneous circulation and circulation support as simultaneous systematic thrombolysis and an alternative central cannulation approach to protect against hypoxic organ damage. The complexity of pulmonary embolism (PE) management necessitates a well-trained PE response team.

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.

Surgical Science and the Evolution of Critical Care Medicine

Surgical science has driven innovation and inquiry across adult and pediatric disciplines that provide critical care regardless of location. Surgically originated but broadly applicable knowledge has been globally shared within the pages Critical Care Medicine over the last 50 years.

Percutaneous treatment options for acute pulmonary embolism: a clinical consensus statement by the ESC Working Group on Pulmonary Circulation and Right Ventricular Function and the European Association of Percutaneous Cardiovascular Interventions

There is a growing clinical and scientific interest in catheter-directed therapy (CDT) of acute pulmonary embolism (PE). Currently, CDT should be considered for patients with high-risk PE, in whom thrombolysis is contraindicated or has failed. Also, CDT is a treatment option for initially stable patients in whom anticoagulant treatment fails, i.e., those who experience haemodynamic deterioration despite adequately dosed anticoagulation. However, the definition of treatment failure (primary reperfusion therapy or anticoagulation alone) remains an important area of uncertainty. Moreover, several techniques for CDT are available without evidence supporting one over the other, and variation in practice with regard to periprocedural anticoagulation is considerable. The aim of this position paper is to describe the currently available CDT approaches in PE patients and to standardise patient selection, the timing and technique of the procedure itself as well as anticoagulation regimens during CDT. We discuss several clinical scenarios of the clinical evaluation of the "efficacy" of thrombolysis and anticoagulation, including treatment failure with haemodynamic deterioration and treatment failure based on a lack of improvement. This clinical consensus statement serves as a practical guide for CDT, complementary to the formal guidelines.

Contemporary Practice Patterns and Outcomes of Systemic Thrombolysis in Acute Pulmonary Embolism

OBJECTIVE

While systemic thrombolysis (ST) is standard of care in treatment of high-risk pulmonary embolism, large variation in real world usage exists, including use in intermediate-risk pulmonary embolism. There is a paucity of data defining the outcomes, practice patterns of ST dose, duration, and treatment in presumed or imaging confirmed pulmonary embolism.

METHODS

We performed a multicenter retrospective study evaluating real world practice patterns of systemic thrombolysis use in the setting of acute pulmonary embolism (presumed versus imaging confirmed intermediate- and high-risk). Patients who received tissue plasminogen activator for pulmonary embolism between 2017 and 2019 were included. We compared baseline clinical characteristics, tissue plasminogen activator practice patterns, and outcomes in those with confirmed versus presumed pulmonary embolism.

RESULTS

104 patients received systemic thrombolysis for pulmonary embolism; 52 patients had confirmed pulmonary embolism and 52 patients had presumed pulmonary embolism. Significantly more patients treated for presumed pulmonary embolism experienced cardiac arrest (n=47, 90%) than those with confirmed pulmonary embolism (n=23, 44%, p<0.01). Survival to hospital discharge was 65% in patients with confirmed pulmonary embolism versus 6% for those with presumed pulmonary embolism (p<0.01). Systemic thrombolysis was contraindicated in 56% of patients with confirmed pulmonary embolism, with major bleeding in 26% but no intracranial hemorrhage.

CONCLUSIONS

The in-hospital mortality of confirmed acute pulmonary embolism remains high (35%) in contemporary practice in those treated with systemic thrombolysis. A large proportion of these patients had contraindications to systemic thrombolysis and major bleeding rates were significant. Confirmed pulmonary embolism had higher survival rate compared to presumed, including those with cardiac arrest. This observation suggests a limited role of empiric thrombolysis in cardiac arrest situations.

Thrombolytic therapy in cardiac arrest caused by cardiac etiologies or presumed pulmonary embolism: An updated systematic review and meta-analysis

Background

Many cardiac arrest cases are encountered annually worldwide, with poor survival. The use of systemic thrombolysis during cardiopulmonary resuscitation for the treatment of cardiac arrest remains controversial.

Objectives

Evaluate the safety and efficacy of systemic thrombolysis in patients with cardiac arrest due to presumed or confirmed pulmonary embolism or cardiac etiology.

Methods

We searched the PubMed and Cochrane databases from inception through April 2021 to identify relevant randomized controlled trials and observational studies. The primary efficacy and safety outcomes were survival to hospital discharge and reported bleeding, respectively. Sensitivity analysis was performed on the basis of study design and etiology of cardiac arrest.

Results

Eleven studies were included, with 4696 patients (1178 patients received systemic thrombolysis, and 3518 patients received traditional therapy). There was a higher rate of survival to hospital discharge in patients who received systemic thrombolysis versus no systemic thrombolysis (risk ratio [RR], 1.35; 95% confidence interval [CI], 0.95-1.91). There were also higher rates of survival at 24 hours (RR, 1.24; 95% CI, 0.97-1.59) and hospital admission (RR, 1.53; 95% CI, 1.04-2.24), and return of spontaneous circulation (ROSC) (RR, 1.34; 95% CI, 1.05-1.71) with the use of systemic thrombolysis. Impacts on survival to discharge and survival at 24 hours were not statistically significant. Patients receiving systemic thrombolysis had a 65% increase in bleeding events compared with no systemic thrombolysis (RR, 1.65; 95% CI, 1.20-2.27).

Conclusion

Systemic thrombolysis in cardiac arrest did not improve survival to hospital discharge and led to more bleeding events. However, it increased the rates of hospital admission and ROSC achievement.

Extrakorporale Reanimation – Kriterien, Bedingungen, Outcome

Für ausgewählte Patienten, in denen die konventionelle kardiopulmonale Reanimation (cCPR) erfolglos bleibt, sprechen die europäischen Leitlinien zur Reanimation 2021 erstmals eine Empfehlung zur extrakorporalen Reanimation (eCPR) als mögliche Rettungstherapie aus. Die eCPR wird im therapierefraktären Kreislaufstillstand etabliert, um Diagnostik und Therapie reversibler Ursachen, wie Herzinfarkt, Lungenembolie, akzidentielle Hypothermie, Intoxikationen mit herzwirksamen Substanzen und akute Hypoxie, zu ermöglichen. Selektionskriterien für eCPR umfassen prognostische Reanimationsfaktoren, wie beobachteter Kreislaufstillstand, Start von Reanimationsmaßnahmen in < 5 min, schockbarer Erstrhythmus, Zeichen effektiver cCPR wie Lebenszeichen während der Reanimation, anhaltendes Kammerflimmern, intermittierende Phasen von Spontankreislauf oder anhaltendes endtidales CO₂ > 10 mm Hg, Patientenalter und Gesundheitszustand. Die Zeitspanne vom Kreislaufstillstand bis zur eCPR ist eine der wichtigsten Determinanten für neurologisch gutes Überleben und sollte < 60 min liegen. Für die Einhaltung dieser Zielvorgabe muss eine entschlossene „Load-and-Go“-Strategie mit frühzeitiger Patientenselektion und raschem Transport unter mechanischer cCPR in ein eCPR-Zentrum verfolgt werden, oder es wird versucht, die eCPR präklinisch zum Einsatz zu bringen. Zwei randomisierte kontrollierte eCPR-Studien demonstrierten Überlebensraten von 43 % bzw. 31,5 % bei Patienten mit anhaltendem Kammerflimmern bzw. kardialem Kreislaufstillstand. Ob diese Ergebnisse außerhalb einzelner hochspezialisierter Zentren anwendbar sind, ist wie die Frage nach der besten präklinischen und innerklinischen Strategie Gegenstand zukünftiger Studien.

Acute Management of High-Risk and Intermediate-Risk Pulmonary Embolism in Children: A Review

Severe forms of pulmonary embolism (PE) in children, althought rare, cause significant morbidity and mortality. We review the pathophysiologic features of severe (high-risk and intermediate-risk) PE and suggest novel pediatric-specific risk stratifications and an acute treatment algorithm to expedite emergent decision-making. We defined pediatric high-risk PE as causing cardiopulmonary arrest, sustained hypotension, or normotension with signs or symptoms of shock. Rapid primary reperfusion should be pursued with either surgical embolectomy or systemic thrombolysis in conjunction with a heparin infusion and supportive care as appropriate. We defined pediatric intermediate-risk PE as a lack of systemic hypotension or compensated shock, but with evidence of right ventricular strain by imaging, myocardial necrosis by elevated cardiac troponin levels, or both. The decision to pursue primary reperfusion in this group is complex and should be reserved for patients with more severe disease; anticoagulation alone also may be appropriate in these patients. If primary reperfusion is pursued, catheter-based therapies may be beneficial. Acute management of severe PE in children may include systemic thrombolysis, surgical embolectomy, catheter-based therapies, or anticoagulation alone and may depend on patient and institutional factors. Pediatric emergency and intensive care physicians should be familiar with the risks and benefits of each therapy to expedite care. PE response teams also may have added benefit in streamlining care during these critical events.

Can VA-ECMO Be Used as an Adequate Treatment in Massive Pulmonary Embolism?

Introduction: Massive acute pulmonary embolism (MAPE) with obstructive cardiogenic shock is associated with a mortality rate of more than 50%. Venoarterial extracorporeal membrane oxygenation (VA-ECMO) has been increasingly used in refractory cardiogenic shock with very good results. In MAPE, although it is currently recommended as part of initial resuscitation, it is not yet considered a stand-alone therapy. Material and Methods: All patients with MAPE requiring the establishment of VA-ECMO and admitted to our tertiary intensive care unit were analysed over a period of 10 years. The characteristics of these patients, before, during and after ECMO were extracted and analysed. Results: A total of 36 patients were included in the present retrospective study. Overall survival was 64%. In the majority of cases, the haemodynamic and respiratory status of the patient improved significantly within the first 24 h on ECMO. The 30-day survival significantly increased when ECMO was used as stand-alone therapy (odds ratio (OR) 15.58, 95% confidence interval (CI) 2.65–91.57, p = 0.002). Nevertheless, when ECMO was implanted following the failure of thrombolysis, the bleeding complications were major (17 (100%) vs. 1 (5.3%) patients, p < 0.001) and the 30-day mortality increased significantly (OR 0.11, 95% CI 0.022–0.520, p = 0.006). Conclusions: The present retrospective study is certainly one of the most important in terms of the number of patients with MAPE and shock treated with VA-ECMO. This short-term mechanical circulatory support, used as a stand-alone therapy in MAPE, allows for the optimal stabilisation of patients.