Extra-corporeal membrane oxygenation and outcomes in massive pulmonary embolism: Two eras at an urban tertiary care hospital

Evidence-Based Update on Transcatheter Therapies for Pulmonary Embolism

PURPOSE OF REVIEW

Pulmonary embolism (PE) remains a leading cause of cardiovascular morbidity and mortality. Multiple new therapies are in development and under study to improve our contemporary care of patients with PE. We review and compare here these novel therapeutics and technologies.

RECENT FINDINGS

Multiple novel therapeutic devices have been developed and are under active study. This work has advanced the care of patients with intermediate and high-risk PE. Novel therapies are improving care of complex PE patients. These have inspired large multicenter international randomized controlled trials that are actively recruiting patients to advance the care of PE. These studies will work towards advancing guidelines for clinical care of patients with PE.

Mechanical Support in High-Risk Pulmonary Embolism: Review Article

Acute pulmonary embolism (PE) may manifest with mild nonspecific symptoms or progress to a more severe hemodynamic collapse and sudden cardiac arrest. A substantial thrombotic burden can precipitate sudden right ventricular strain and failure. Traditionally, systemic thrombolytics have been employed in such scenarios; however, patients often present with contraindications, or these interventions may prove ineffective. Outcomes for this medically complex patient population are unfavorable, necessitating a compelling argument for advanced therapeutic modalities or alternative approaches. Moreover, patients frequently experience complications beyond hemodynamic instability, such as profound hypoxia and multiorgan failure, necessitating assertive early interventions to avert catastrophic consequences. The existing data on the utilization of mechanical circulatory support (MCS) devices are not exhaustive. Various options for percutaneous MCS devices exist, each possessing distinct advantages and disadvantages. There is an imminent imperative to develop a tailored approach for this high-risk patient cohort to enhance their overall outcomes.

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.

Unmet Needs and Future Direction for Pulmonary Embolism Interventions

Venous thromboembolism (VTE) usually develops in the deep veins of the extremities. Pulmonary embolism (PE) is a type of VTE that is most commonly (∼90%) caused by a thrombus that originates from the deep veins of the lower extremities. PE is the third most common cause of death after myocardial infarction and stroke. In this review, the authors investigate and discuss the risk stratification and definitions of the aforementioned categories of PE and further explore the management of acute PE along with the types of catheter-based treatment options and their efficacy.

Percutaneous Management of High-Risk Pulmonary Embolism

Acute pulmonary embolism (PE) leads to an abrupt increase in pulmonary vascular resistance and right ventricular afterload, and when significant enough, can result in hemodynamic instability. High-risk PE is a dire cardiovascular emergency and portends a poor prognosis. Traditional therapeutic options to rapidly reduce thrombus burden like systemic thrombolysis and surgical pulmonary endarterectomy have limitations, both with regards to appropriate candidates and efficacy, and have limited data demonstrating their benefit in high-risk PE. There are growing percutaneous treatment options for acute PE that include both localized thrombolysis and mechanical embolectomy. Data for such therapies with high-risk PE are currently limited. However, given the limitations, there is an opportunity to improve outcomes, with percutaneous treatments options offering new mechanisms for clot reduction with a possible improved safety profile compared with systemic thrombolysis. Additionally, mechanical circulatory support options allow for complementary treatment for patients with persistent instability, allowing for a bridge to more definitive treatment options. As more data develop, a shift toward a percutaneous approach with mechanical circulatory support may become a preferred option for the management of high-risk PE at tertiary care centers.

The Role of Echocardiography in Extracorporeal Membrane Oxygenation

PURPOSE OF REVIEW

Extracorporeal membrane oxygenation (ECMO) is increasingly used to temporarily support patients in severe circulatory and/or respiratory failure. Echocardiography is a core component of successful ECMO deployment. Herein, we review the role of echocardiography at different phases on extracorporeal support including candidate identification, cannulation, maintenance, complication vigilance, and decannulation.

RECENT FINDINGS

During cannulation, ultrasound is used to confirm intended vascular access and appropriate inflow cannula positioning. While on ECMO, echocardiographic evaluation of ventricular loading conditions and hemodynamics, cannula positioning, and surveillance for intracardiac or aortic thrombi is needed for complication mitigation. Echocardiography is crucial during all phases of ECMO use. Specific echocardiographic queries depend on the ECMO type, V-V, or V-A, and the specific cannula configuration strategy employed.

Current interventional therapies in acute pulmonary embolism

Pulmonary embolism (PE) is the third leading cause of cardiovascular mortality. The management of PE is currently evolving given the development of new technologies and team-based approaches. This document will focus on risk stratification of PEs, review of the current interventional therapies, the role of clinical endpoints to assess the effectiveness of different interventional therapies, and the role for mechanical circulatory support in the complex management of this disease.

Catheter-based therapies in acute and chronic pulmonary embolism

PURPOSE OF REVIEW

The aim of this study is to summarize currently available catheter-based therapies in acute and chronic pulmonary embolic disease.

RECENT FINDINGS

Catheter-based therapies to treat acute pulmonary embolism and its sequelae such as chronic thromboembolic pulmonary hypertension (CTEPH) are emerging as the next frontier within interventional cardiology. However, the true benefit of these catheter-based therapies in intermediate-risk and high-risk pulmonary embolism and CTEPH remains unclear. The current evidence supporting such interventions comes primarily from small single-arm studies in acute pulmonary embolism and case series in CTEPH.

SUMMARY

Appropriately powered randomized controlled trials with meaningful clinical outcomes as endpoints are needed to elucidate the true benefit of catheter-based therapies in pulmonary embolism compared with other treatment modalities such as anticoagulation and systemic thrombolysis in acute pulmonary embolism and riociguat and pulmonary endarterectomy in CTEPH.

Comparison of Surgical Embolectomy and Veno-arterial Extracorporeal Membrane Oxygenation for Massive Pulmonary Embolism

Massive pulmonary embolism (MPE) is associated with a 20-50% mortality rate with guideline directed therapy. MPE treatment with surgical embolectomy (SE) or venoarterial extracorporeal membrane oxygenation (VA-ECMO) have shown promising results. In the context of a surgical management strategy for MPE, a comparison of outcomes associated with VA-ECMO or SE was performed. A retrospective review of a single institution cardiac surgery database was performed, identifying MPE treated with SE or VA-ECMO between 2005-2020. Primary outcome was in-hospital survival. 59 MPE [27 (46.8%) VA-ECMO vs 32 (54.2%) SE] were identified. All presented with elevated cardiac biomarkers, tachycardia (mean heart rate 113 ± 20 beats/minute), hypotension (mean systolic blood pressure 85 ± 22 mm Hg) and vasopressors requirement, without significant differences between cohorts. Preoperative CPR was performed in 37.3% (22/59), without a significant difference between cohorts. More VA-ECMO presented with questionable neurologic status (GCS ≤ 4) [9/27 (33.3%) vs 2/32 (6.2%), P = 0.008] and more VA-ECMO failed thrombolysis [8/27 (29.6) vs 2/32 (6.3), P = 0.014]. All presented with severe RV dysfunction, by discharge all had normalization of echocardiographic RV function. Overall mortality was 10.2%, with a trend toward higher mortality among VA-ECMO [14.9% (4/27) vs 6.3% (2/32) P = 0.14]. CPR was independently associated with death (OR 10.8, P = 0.02) whereas treatment modality was not (OR 0.24). In an extremely unstable MPE population VA-ECMO and SE were safely performed with low mortality while achieving RV recovery. Adverse outcomes were more closely associated with preoperative CPR than with treatment modality.

Current Endovascular Treatment Options in Acute Pulmonary Embolism

Acute pulmonary embolism (PE) is a significant cause of mortality and morbidity across the globe. Over the last few decades, there have been major therapeutic advances in acute PE management, including catheter-based therapy. However, the effectiveness of catheter-based therapy in acute PE is not supported by Level I evidence, making the use of this promising treatment rather controversial and ambiguous. In this paper, we discuss the risk stratification of acute PE and review the medical and endovascular treatment options. We also summarize and review the data supporting the use of endovascular treatment options in acute PE and describe the potential role of the PE response team.

Mid-term outcomes with the use of extracorporeal membrane oxygenation for cardiopulmonary failure secondary to massive pulmonary embolism

OBJECTIVES

There has been increasing interest in using extracorporeal membrane oxygenation (ECMO) to rescue patients with pulmonary embolism (PE) in the advanced stages of respiratory or haemodynamic decompensation. We examined mid-term outcomes and risk factors for in-hospital mortality.

METHODS

We conducted a retrospective study of 36 patients who required ECMO placement (32 veno-arterial ECMO, 4 veno-venous) following acute PE. Survival curves were estimated using the Kaplan-Meier method. Risk factors for in-hospital mortality were assessed by logistic regression analysis. Functional status and quality of life were assessed by phone questionnaire.

RESULTS

Overall survival to hospital discharge was 44.4% (16/36). Two-year survival conditional to discharge was 94% (15/16). Two-year survival after veno-arterial ECMO was 39% (13/32). In patients supported with veno-venous ECMO, survival to discharge was 50%, and both patients were alive at follow-up. In univariable analysis, a history of recent surgery (P = 0.064), low left ventricular ejection fraction (P = 0.029), right ventricular dysfunction ≥ moderate at weaning (P = 0.083), on-going cardiopulmonary resuscitation at ECMO placement (P = 0.053) and elevated lactate at weaning (P = 0.002) were risk factors for in-hospital mortality. In multivariable analysis, recent surgery (P = 0.018) and low left ventricular ejection fraction at weaning (P = 0.013) were independent factors associated with in-hospital mortality. At a median follow-up of 23 months, 10 patients responded to our phone survey; all had acceptable functional status and quality of life.

CONCLUSIONS

Massive acute PE requiring ECMO support is associated with high early mortality, but patients surviving to hospital discharge have excellent mid-term outcomes with acceptable functional status and quality of life. ECMO can provide a stable platform to administer other intervention with the potential to improve outcomes. Risk factors for in-hospital mortality after PE and veno-arterial ECMO support were identified.

Management of Acute Pulmonary Embolism

Purpose of the Review

Over 100,000 cardiovascular-related deaths annually are caused by acute pulmonary embolism (PE). While anticoagulation has historically been the foundation for treatment of PE, this review highlights the recent rapid expansion in the interventional strategies for this condition.

Recent Findings

At the time of diagnosis, appropriate risk stratification helps to accurately identify patients who may be candidates for advanced therapeutic interventions. While systemic thrombolytics (ST) is the mostly commonly utilized intervention for high-risk PE, the risk profile of ST for intermediate-risk PE limits its use. Assessment of an individualized patient risk profile, often via a multidisciplinary pulmonary response team (PERT) model, there are various interventional strategies to consider for PE management. Novel therapeutic options include catheter-directed thrombolysis, catheter-based embolectomy, or mechanical circulatory support for certain high-risk PE patients. Current data has established safety and efficacy for catheter-based treatment of PE based on surrogate outcome measures. However, there is limited long-term data or prospective comparisons between treatment modalities and ST. While PE diagnosis has improved with modern cross-sectional imaging, there is interest in improved diagnostic models for PE that incorporate artificial intelligence and machine learning techniques.

Summary

In patients with acute pulmonary embolism, after appropriate risk stratification, some intermediate and high-risk patients should be considered for interventional-based treatment for PE.

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

High-risk pulmonary embolism (PE) requires hemodynamic and respiratory support along with reperfusion strategies. Recently updated European guidelines assign a low class of recommendation to extracorporeal membrane oxygenation (ECMO) for high-risk PE. This systematic review assessed clinical outcomes after ECMO in high-risk PE. We searched electronic databases including PubMed, Embase and Web of Science from January 2000 to April 2020. Efficacy outcomes included in-hospital survival with good neurological outcome and survival at follow-up. Safety outcomes included lower limb ischemia and hemorrhagic and ischemic stroke. Where possible (absence of high heterogeneity), meta-analyses of outcomes were undertaken using a random-effects model. We included 16 uncontrolled case-series (533 participants). In-hospital survival with good neurological outcome ranged between 50% and 95% while overall survival at follow-up ranged from 35% to 95%, both with a major degree of heterogeneity (I² > 70%). The prevalence of lower limb ischemia was 8% (95% CI 3% to 15%). The prevalence of stroke (either hemorrhagic or ischemic) was 11% (95% CI 3% to 23%), with notable heterogeneity (I² = 63.35%). Based on currently available literature, it is not possible to draw definite conclusions on the usefulness of ECMO for high-risk PE. Prospective, multicenter, large-scale studies or nationwide registries are needed to best define the role of ECMO for high-risk PE. PROSPERO registration ID: CRD42019136282.

COVID-19 and Thrombotic or Thromboembolic Disease: Implications for Prevention, Antithrombotic Therapy, and Follow-Up: JACC State-of-the-Art Review

Coronavirus disease-2019 (COVID-19), a viral respiratory illness caused by the severe acute respiratory syndrome-coronavirus-2 (SARS-CoV-2), may predispose patients to thrombotic disease, both in the venous and arterial circulations, because of excessive inflammation, platelet activation, endothelial dysfunction, and stasis. In addition, many patients receiving antithrombotic therapy for thrombotic disease may develop COVID-19, which can have implications for choice, dosing, and laboratory monitoring of antithrombotic therapy. Moreover, during a time with much focus on COVID-19, it is critical to consider how to optimize the available technology to care for patients without COVID-19 who have thrombotic disease. Herein, the authors review the current understanding of the pathogenesis, epidemiology, management, and outcomes of patients with COVID-19 who develop venous or arterial thrombosis, of those with pre-existing thrombotic disease who develop COVID-19, or those who need prevention or care for their thrombotic disease during the COVID-19 pandemic.

Contemporary Management of Acute Pulmonary Embolism

Multiple treatment options beyond anticoagulation exist for massive and submassive pulmonary embolism to reduce mortality. For some patients, systemic thrombolytics and catheter-directed thrombolysis are appropriate interventions. For others, surgical pulmonary embolectomy can be life-saving. Extracorporeal life support and right ventricular assist devices can provide hemodynamic support in challenging cases. We propose a management algorithm for the treatment of massive and submassive pulmonary embolism, in conjunction with a multidisciplinary pulmonary embolism response team, to guide clinicians in individualizing treatment for patients in a timely manner.

Interventional Therapies in Acute Pulmonary Embolism

Treatment of acute pulmonary embolism (PE) historically included anticoagulation and systemic thrombolytic therapy. More recently, catheter guided interventions provided promise of mitigating bleeding risks usually associated with systemic thrombolysis in intermediate to high risk PE patients. Catheter based interventions can broadly be divided into catheter directed thrombolysis and catheter based embolectomy. Both modalities are currently undergoing active research and each has their respective risks and benefits. The decision to administer these advanced therapies for acute PE can be challenging but can be accomplished via a multi-disciplinary PE response team.

Diagnosis, Treatment and Follow Up of Acute Pulmonary Embolism: Consensus Practice from the PERT Consortium

Pulmonary embolism (PE) is a life-threatening condition and a leading cause of morbidity and mortality. There have been many advances in the field of PE in the last few years, requiring a careful assessment of their impact on patient care. However, variations in recommendations by different clinical guidelines, as well as lack of robust clinical trials, make clinical decisions challenging. The Pulmonary Embolism Response Team Consortium is an international association created to advance the diagnosis, treatment, and outcomes of patients with PE. In this consensus practice document, we provide a comprehensive review of the diagnosis, treatment, and follow-up of acute PE, including both clinical data and consensus opinion to provide guidance for clinicians caring for these patients.

Interventional Therapies for Acute Pulmonary Embolism: Current Status and Principles for the Development of Novel Evidence: A Scientific Statement From the American Heart Association

Pulmonary embolism (PE) represents the third leading cause of cardiovascular mortality. The technological landscape for management of acute intermediate- and high-risk PE is rapidly evolving. Two interventional devices using pharmacomechanical means to recanalize the pulmonary arteries have recently been cleared by the US Food and Drug Administration for marketing, and several others are in various stages of development. The purpose of this document is to clarify the current state of endovascular interventional therapy for acute PE and to provide considerations for evidence development for new devices that will define which patients with PE would derive the greatest net benefit from their use in various clinical settings. First, definitions and limitations of commonly used risk stratification tools for PE are reviewed. An adjudication of risks and benefits of available interventional therapies for PE follows. Next, considerations for optimal future evidence development in this field are presented in the context of the current US regulatory framework. Finally, the document concludes with a discussion of the pros and cons of the rapidly expanding PE response team model of care delivery.

National trends and outcomes for extra-corporeal membrane oxygenation use in high-risk pulmonary embolism

Little is known about the temporal trends and outcomes for extra-corporeal membrane oxygenation (ECMO) in patients with high-risk pulmonary embolism (PE) in the United States. We queried the National Inpatient Sample (NIS) database from 2005 to 2013 to identify patients admitted with high-risk PE. Our objective was to determine trends for ECMO use in patients with high-risk PE. We also assessed in-hospital outcomes among patients with high-risk PE receiving ECMO. We evaluated 77,809 hospitalizations for high-risk PE. There was an upward trend in the utilization of ECMO from 0.07% in 2005 to 1.1% in 2013 ( p = 0.015). ECMO was utilized more in urban teaching hospitals and large hospitals. ECMO use was associated with lower mortality in patients with massive PE ( p < 0.001). In-hospital mortality for patients receiving ECMO was 61.6%, with no change over the observational period ( p = 0.68). Our investigation revealed several independent predictors of increased mortality in patients with high-risk PE using ECMO as hemodynamic support, including: age, female sex, obesity, congestive heart failure, and chronic pulmonary disease. ECMO, therefore, as a rescue strategy or bridge to definitive treatment, may be effective in the management of high-risk PE when selecting patients with favorable clinical characteristics.

Decompressive laparotomy for a patient on VA-ECMO for massive pulmonary embolism that suffered traumatic liver laceration after mechanical CPR

Massive pulmonary embolism (PE) is an embolus sufficiently obstructing pulmonary blood flow to cause right ventricular (RV) failure and hemodynamic instability. We have utilized veno-arterial extracorporeal membrane oxygenation (VA-ECMO) for early and aggressive intervention for massive PE patients. We present a case of a 61-year-old female placed on VA-ECMO for a massive PE while presenting in cardiac arrest and receiving mechanical cardiopulmonary resuscitation (CPR) via the LUCAS 2.0 device (Physio-Control Inc., Lund, Sweden). The patient suffered a severe liver laceration secondary to mechanical CPR and required a decompressive laparotomy. This case highlights that mechanical CPR during other interventions can lead to malposition of the device and could result in solid organ injury.