Venoarterial extracorporeal membrane oxygenation is an effective management strategy for massive pulmonary embolism patients

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.

Veno-arterial extracorporeal membrane oxygenation versus standard medical management for massive pulmonary embolism

PURPOSE

There is limited research on the use and outcomes of veno-arterial extracorporeal membrane oxygenation (VA-ECMO) treatment for massive pulmonary embolism (PE). This study compared VA-ECMO treatment for massive PE versus patients treated medically.

MATERIALS AND METHODS

Patients diagnosed with massive PE at one hospital system were reviewed. VA-ECMO and non-ECMO groups were compared by t test and Chi-square. Mortality risk factors were identified by logistic regression. Survival was assessed by Kaplan Meier and propensity matching of groups.

RESULTS

Ninety-two patients were included (22 VA-ECMO and 70 non-ECMO). Age (OR 1.08, 95% CI 1.03-1.13), arterial SBP (OR 0.97, 95% CI 0.94-0.99), albumin (OR 0.3, 95% CI 0.1-0.8), and phosphorus (OR 2.0, 95% CI 1.4-3.17) were independently associated with 30-day mortality. Alkaline phosphate (OR 1.03, 95% CI 1.01-1.05) and SOFA score (OR 1.3, 95% CI 1.06-1.51) were associated with 1-year mortality. Propensity matching showed no difference in 30-day (59% VA-ECMO versus 72% non-ECMO, p = 0.363) or 1-year survival (50% VA-ECMO versus 64% non-ECMO, p = 0.355).

CONCLUSIONS

Patients treated with VA-ECMO for massive PE and medically treated patients have similar short- and long-term survival. Further research is needed to define clinical recommendations and benefits of intensive therapy such as VA-ECMO in this critically ill population.

Availability in ECMO Reduces the Failure to Rescue in Patients With Pulmonary Embolism After Major Surgery: A Nationwide Analysis of 2.4 Million Cases

Objective

Postoperative pulmonary embolism (PE) is a rare but potentially life-threatening complication, which can be treated with extracorporeal membrane oxygenation (ECMO) therapy, a novel therapy option for acute cardiorespiratory failure. We postulate that hospitals with ECMO availability have more experienced staff, technical capabilities, and expertise in treating cardiorespiratory failure.

Design

A retrospective analysis of surgical procedures in Germany between 2012 and 2019 was performed using hospital billing data. High-risk surgical procedures for postoperative PE were analyzed according to the availability of and expertise in ECMO therapy and its effect on outcome, regardless of whether ECMO was used in patients with PE.

Methods

Descriptive, univariate, and multivariate analyses were applied to identify possible associations and correct for confounding factors (complications, complication management, and mortality).

Results

A total of 13,976,606 surgical procedures were analyzed, of which 2,407,805 were defined as high-risk surgeries. The overall failure to rescue (FtR) rate was 24.4% and increased significantly with patient age, as well as type of surgery. The availability of and experience in ECMO therapy (defined as at least 20 ECMO applications per year; ECMO centers) are associated with a significantly reduced FtR in patients with PE after high-risk surgical procedures. In a multivariate analysis, the odds ratio (OR) for FtR after postoperative PE was significantly lower in ECMO centers (OR, 0.75 [0.70-0.81], P < 0.001).

Conclusions

The availability of and expertise in ECMO therapy lead to a significantly reduced FtR rate of postoperative PE. This improved outcome is independent of the use of ECMO in these patients.

ECMO management for severe pulmonary embolism with concurrent cerebral hemorrhage: a case report

Background

Acute pulmonary embolism (APE) is a common and potentially fatal cardiovascular disease that can lead to sudden cardiac arrest in severe cases. When conventional cardiopulmonary resuscitation measures fail to achieve the return of spontaneous circulation (ROSC) in patients with APE, venoarterial extracorporeal membrane oxygenation (ECMO) becomes a viable therapeutic option. As an advanced life support treatment, ECMO ensures the perfusion of critical organs, providing sufficient time for interventions necessary for ROSC.

Case introduction

We report the case of a patient who experienced cardiac arrest due to pulmonary embolism. During the treatment, the patient received two sessions of external cardiopulmonary resuscitation (ECPR) as supportive care and experienced cerebral hemorrhage. Ultimately, the patient improved and was discharged following support from extracorporeal membrane oxygenation (ECMO), careful anticoagulation strategies, and intervention with balloon pulmonary angioplasty.

Conclusion

ECMO can serve as an important life support technology for patients with severe APE. Through a cautious anticoagulation therapy, not only was the ECMO support successfully maintained but also was further deterioration of cerebral hemorrhage effectively prevented. For patients with concurrent main pulmonary artery embolism and bleeding, balloon pulmonary angioplasty may be an option.

Outcomes of heparinized adult veno-arterial extracorporeal membrane oxygenation patients managed with low and high activated partial thromboplastin time targets: A systematic review and meta-analysis

INTRODUCTION

There are no randomized controlled trials comparing low and high activated partial thromboplastin time (aPTT) targets in heparinized adult veno-arterial (VA) extracorporeal membrane oxygenation (ECMO) patients. Our systematic review and meta-analysis summarized complication rates in adult VA ECMO patients treated with low and high aPTT targets.

METHODS

Studies published from January 2000 to May 2022 were identified using Pubmed, Embase, Cochrane Library, and LILACS (Latin American and Caribbean Health Sciences Literature). Studies were included if aPTT was primarily used to guide heparin anticoagulation. For the low aPTT group, we included studies where aPTT goal was ≤60 seconds and for the high aPTT group, we included studies where aPTT goal was ≥60 seconds. Proportional meta-analysis with a random effects model was used to calculate pooled complication rates for patients in the two aPTT groups.

RESULTS

Twelve studies met inclusion criteria (5 in the low aPTT group and 7 in the high aPTT group). The pooled bleeding complication incidence for low aPTT studies was 53.6% (95% CI = 37.4%-69.4%, I2 = 60.8%) and for high aPTT studies was 43.8% (95% CI = 21.7%-67.1%, I2 = 91.8%). No studies in the low aPTT group reported overall thrombosis incidence, while three studies in the high aPTT group reported overall thrombosis incidence. The pooled thrombosis incidence for high aPTT studies was 16.1% (95% CI = 9.0%-24.5%, I2 = 13.1%).

CONCLUSIONS

Adult ECMO patients managed with low and high aPTT goals appeared to have similar bleeding and other complication rates further highlighting the need for a randomized controlled trial.

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.

Medical and Mechanical Circulatory Support of the Failing Right Ventricle

PURPOSE OF REVIEW

To describe medical therapies and mechanical circulatory support devices used in the treatment of acute right ventricular failure.

RECENT FINDINGS

Experts have proposed several algorithms providing a stepwise approach to medical optimization of acute right ventricular failure including tailored volume administration, ideal vasopressor selection to support coronary perfusion, inotropes to restore contractility, and pulmonary vasodilators to improve afterload. Studies have investigated various percutaneous and surgically implanted right ventricular assist devices in several clinical settings. The initial management of acute right ventricular failure is often guided by invasive hemodynamic data tracking parameters of circulatory function with the use of pharmacologic therapies. Percutaneous microaxial and centrifugal extracorporeal pumps bypass the failing RV and support circulatory function in severe cases of right ventricular failure.

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.

Extracorporeal membrane oxygenation for acute pulmonary embolism after postoperative craniocerebral trauma: a case report

Introduction

Massive pulmonary embolism (PE) is a life-threatening complication of major surgery with a mortality rate of up to 50%. Extracorporeal membrane oxygenation (ECMO) is primarily used for respiratory and circulatory support. Venoarterial extracorporeal membrane oxygenation (VA-ECMO) is used to stabilize patients with acute massive PE. Acute brain injury, vascular disease, and immunosuppression are contraindications to ECMO, as stated in the 2021 Extracorporeal Life Support Organization guidelines.

Case summary

We report a case of a patient with craniocerebral trauma whose postoperative course was complicated by massive PE and subsequent cardiac arrest that required urgent VA-ECMO, followed by anticoagulation with heparin. The patient showed hemodynamic improvement and was discharged 68 days after hospitalization.

Discussion

ECMO has gradually been accepted for patients with craniocerebral injuries. The safety and effectiveness of ECMO in patients with craniocerebral injury, along with the optimal duration of ECMO and anticoagulation strategies, require further study.

An Intensivist-Led Extracorporeal Membrane Oxygenation Program: Design, Implementation, and Outcomes of the First Five Years

We describe the development, implementation, and outcomes of an intensivist-led adult extracorporeal life support (ECLS) program using intensivists both to perform venovenous (V-V), venoarterial (V-A), and extracorporeal cardiopulmonary resuscitation (ECPR) cannulations, and to manage patients on ECLS throughout their ICU course. All adults supported with ECLS at the University of New Mexico Hospital (UNMH) from February 1, 2017 to December 31, 2021 were retrospectively analyzed. A total of 203 ECLS cannulations were performed in 198 patients, including 116 V-A cannulations (including 65 during ECPR) and 87 V-V cannulations (including 38 in patients with COVID-19). UNMH intensivists performed 195 cannulations, with 9 cannulation complications. Cardiothoracic surgeons performed 8 cannulations. Overall survival to hospital discharge or transfer was 46.5%. Survival was 32.3% in the ECPR group and 56% in the non-ECPR V-A group. In the V-V cohort, survival was 66.7% in the COVID-19-negative patients and 34.2% in the COVID-19-positive patients. This large series of intensivist-performed ECLS cannulations-including V-A, V-V, and ECPR modalities-demonstrates the successful implementation of a comprehensive intensivist-led ECLS program. With outcomes comparable to those in the literature, our program serves as a model for the initiation and development of ECLS programs in settings with limited access to local subspecialty cardiothoracic surgical services.

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.

VA-ECMO-assisted aspiration thrombectomy in a patient presenting with acute massive PE with absolute contraindications to thrombolytics

Massive pulmonary embolism (PE) is a life-threatening complication of major surgery with a mortality rate up to 50%. First-line therapy for massive PE is systemic thrombolytics, but surgical patients are at high bleeding risk with absolute contraindications. As surgical thrombectomy carries a high burden of morbidity and mortality, endovascular interventions are becoming more common in these clinical scenarios. We report a case of a neurosurgical patient whose postoperative course was complicated by massive PE and subsequent cardiac arrest that required emergent venoarterial extracorporeal membrane oxygenation, followed by aspiration thrombectomy with the Inari FlowTriever Device (Inari Medical). The patient had immediate hemodynamic improvement with eventual recovery to baseline functional status.

Extracorporeal Membrane Oxygenation—First Strategy for Acute Life-Threatening Pulmonary Embolism

Background

Both venoarterial extracorporeal membrane oxygenation (VA-ECMO) and percutaneous mechanical thrombectomy (PMT) are increasingly used to treat acute life-threatening pulmonary embolism (PE). However, there are little data regarding their effectiveness. This study aimed to present the short-term outcomes after managing nine patients with acute life-threatening massive or submassive PE by VA-ECMO with or without complemented PMT and propose a preliminary treatment algorithm.

Methods

This study was a single-center retrospective review of a prospectively maintained registry. It included nine consecutive patients with massive or submassive pulmonary embolism who underwent VA-ECMO for initial hemodynamic stabilization, with or without PMT, from August 2018 to November 2021.

Results

Mean patient age was 54.7 years. Four of nine patients (44.4%) required cardiopulmonary resuscitation before or during VA-ECMO cannulation. All cannulations (100%) were successfully performed percutaneously. Overall survival was 88.9% (8 of 9 patients). One patient died from a hemorrhagic stroke. Of the survivors, the median ECMO duration was 8 days in patients treated with ECMO alone and 4 days in those treated with EMCO and PMT. Five of nine patients (55.6%) required concomitant PMT to address persistent right heart dysfunction, with the remaining survivors (44.4%) receiving VA-ECMO and anticoagulation alone. For survivors receiving VA-ECMO plus PMT, median hospital lengths of stay were 7 and 13 days, respectively.

Conclusions

An ECMO-first strategy complemented with PMT can be performed effectively and safely for acute life-threatening massive or submassive PE. VA-ECMO is feasible for initial stabilization, serving as a bridge to therapy primarily in inoperable patients with massive PE. Further evaluation in a larger cohort of patients is warranted to assess whether VA-ECMO plus PMT may offer an alternative or complementary therapy to thrombolysis or surgical thrombectomy.

Type of Research

Single-center retrospective review of a prospectively maintained registry.

Clinical experiences of high-risk pulmonary thromboembolism receiving extracorporeal membrane oxygenation in single institution

Background

The main cause of death in pulmonary embolism (PE) is right-heart failure due to acute pressure overload. In this sense, extracorporeal membrane oxygenation (ECMO) might be useful in maintaining hemodynamic stability and improving organ perfusion. Some previous studies have reported ECMO as a bridge to reperfusion therapy of PE. However, little is known about the patients that benefit from ECMO.

Methods

Patients who underwent ECMO due to pulmonary thromboembolism at a single university-affiliated hospital between January 2010 and December 2018 were retrospectively reviewed.

Results

During the study period, nine patients received ECMO in high-risk PE. The median age of the patients was 60 years (range, 22–76 years), and six (66.7%) were male. All nine patients had cardiac arrests, of which three occurred outside the hospital. All the patients received mechanical support with veno-arterial ECMO, and the median ECMO duration was 1.1 days (range, 0.2–14.0 days). ECMO with anticoagulation alone was performed in six (66.7%), and ECMO with reperfusion therapy was done in three (33.3%). The 30-day mortality rate was 77.8%. The median time taken from the first cardiac arrest to initiation of ECMO was 31 minutes (range, 30–32 minutes) in survivors (n=2) and 65 minutes (range, 33–482 minutes) in non-survivors (n=7).

Conclusion

High-risk PE with cardiac arrest has a high mortality rate despite aggressive management with ECMO and reperfusion therapy. Early decision to start ECMO and its rapid initiation might help save those with cardiac arrest in high-risk PE.

Mobility Levels With Physical Rehabilitation Delivered During and After Extracorporeal Membrane Oxygenation: A Marker of Illness Severity or an Indication of Recovery?

OBJECTIVE

The aims of this study were to determine whether physical rehabilitation intervention for individuals who required extracorporeal membrane oxygenation (ECMO) is associated with clinical outcomes and to assess whether the patient mobility response over initial rehabilitation sessions early in the intensive care unit (ICU) course predicts or is associated with survival, lengths of stay, discharge disposition, and 30-day readmissions.

METHODS

This study was a 10-year retrospective practice analysis of adults who were critically ill and required ECMO for >72 hours in the cardiothoracic ICU at an academic medical center. Physical rehabilitation implemented during or following the initiation of ECMO was quantified on the basis of timing, frequency, and change in mobility level in response to the intervention over the first 4 consecutive sessions. The primary dependent outcome was in-hospital mortality. Secondary outcomes included 30-day readmission and discharge disposition ranked on an ordinal scale.

RESULTS

Three hundred fifteen individuals (mean age = 50 years [SD = 15 years]; 63% men; mean Sequential Organ Failure Assessment score = 11.6 [SD = 3.3]) met the inclusion criteria. Two hundred eighteen individuals (69%) received at least 1 physical rehabilitation session while requiring ECMO, 70 (22%) received rehabilitation after ECMO was discontinued, and 27 (9%) never received rehabilitation. Individuals discharged alive achieved higher mobility levels and had a steeper, more positive rate of change in mobility over the first 4 sessions than individuals who died in the hospital (2.8 vs 0.38; degrees of freedom = 199, t = 8.24). Those who received rehabilitation and achieved the milestones of sitting on the edge of the bed and walking for >45 m were more likely to survive (47% vs 13%; χ2 = 156) than those who did not (26% vs 3.5%; χ2 = 80).

CONCLUSION

A positive rate of change in mobility and the ability to achieve mobility milestones with rehabilitation were associated with improved clinical outcomes.

IMPACT

An individual's mobility response to physical rehabilitation early in the ICU course is an important indicator of illness and should be used with clinical presentation to guide clinical decision-making and predict outcomes.

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.