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

Interventional strategies to unload the right ventricle: a systematic review

INTRODUCTION

The function of the right ventricle (RV) is dependent on preload, end-systolic elastance (afterload) and intrinsic RV contractility. RV dysfunction comprises dilatation and hypertrophy leading to RV failure and commonly death despite advances in medical treatments. This systematic review summarizes current and future interventional treatments to mechanically unload the RV. First, this review focuses on targeting pulmonary vascular afterload by addressing 1. Catheter-directed treatment for acute pulmonary embolism, 2. Balloon Pulmonary Angioplasty for chronic thromboembolic pulmonary hypertension, and 3. Pulmonary Artery Denervation for pulmonary hypertension. Second, mechanical support systems for enhancing RV contractility, and interventions targeting tricuspid regurgitation as a cause of RV failure are discussed.

METHODS

On 2nd December 2024, a systematic search for publications between 2022 and 2025 was performed, using MEDLINE, EMBASE, Cochrane and SCOPUS. The primary outcome was improvement in hemodynamic measurements. Secondary outcomes included In-hospital mortality and complications. Meta-analyses, randomized controlled trials and for newer devices, observational studies and case series were included.

RESULTS

Of 32,852 screened studies, 80 were included. All treatments demonstrated various degrees of RV unloading.

CONCLUSION

Novel treatments directed at mechanical RV unloading may improve survival, but further research is needed to examine long-term effects.

PROSPERO REGISTRATION

;(CRD42024616310).

A prospective, multicenter, randomized controlled trial evaluating anticoagulation alone vs anticoagulation plus computer assisted vacuum thrombectomy for the treatment of intermediate-high-risk acute pulmonary embolism: Rationale and design of the STORM-PE study

BACKGROUND

Therapeutic anticoagulation (AC) is standard care for pulmonary embolism (PE). Endovascular therapy with mechanical thrombectomy (MT) is commonly performed for PE and well-studied in single-arm trials. The efficacy benefit of MT over AC alone in a randomized fashion remains unstudied.

METHODS AND RESULTS

STORM-PE (ClinicalTrials.gov Identifier: NCT05684796) is a post-market, international, open-label trial conducted in partnership with The Pulmonary Embolism Response Team ConsortiumTM. Up to 100 patients with confirmed acute intermediate-high-risk PE demonstrated by right ventricular (RV) dysfunction with a right-to-left ventricular (RV/LV) ratio ≥1.0 and elevated cardiac biomarkers will be randomized 1:1 to receive AC alone or AC plus Computer Assisted Vacuum Thrombectomy (CAVT) with the Indigo Aspiration System (Penumbra Inc.). The primary outcome is a mean change in RV/LV ratio at 48 hours, assessed by computed tomographic pulmonary angiography (CTPA) and adjudicated by a blinded, independent imaging Core Lab. Additional endpoints are composite major adverse events, functional outcomes (6-minute walk test, New York Heart Association classification, post-venous thromboembolism functional status scale, modified Medical Research Council Dyspnea Scale, Borg Scale), quality of life (Pulmonary Embolism Quality of Life Questionnaire and EQ-5D-5L), mortality, and symptomatic PE recurrence through 90 days. A Clinical Events Committee will adjudicate adverse events for causality and attribution and an independent Data Safety Monitoring Board will oversee the study. STORM-PE is funded by Penumbra Inc.

CONCLUSIONS

The STORM-PE trial will help inform future guidelines and standards of care related to frontline treatment using mechanical thrombectomy with CAVT for patients with acute intermediate-high-risk PE.

TRIAL REGISTRATION

STORM-PE, NCT05684796, is registered at https://clinicaltrials.gov/study/NCT05684796.

Management of high-risk acute pulmonary embolism: an emulated target trial analysis

BACKGROUND

High-risk acute pulmonary embolism (PE) is a life-threatening condition necessitating hemodynamic stabilization and rapid restoration of pulmonary perfusion. In this context, evidence regarding the benefit of advanced circulatory support and pulmonary recanalization strategies is still limited.

METHODS

In this observational study, we assessed data of 1060 patients treated for high-risk acute PE with 991 being included in a target trial emulation to investigate all-cause in-hospital mortality estimates with different advanced treatment strategies. The four treatment groups consisted of patients undergoing (I) veno-arterial extracorporeal membrane oxygenation (VA-ECMO) alone (n = 126), (II) intrahospital systemic thrombolysis (SYS) (n = 643), (III) surgical thrombectomy (ST) (n = 49), and (IV) percutaneous catheter-directed treatment (PCDT) (n = 173). VA-ECMO was allowed as bridging to pulmonary recanalization in groups II, III, and IV. Marginal causal contrasts were estimated using the g-formula with logistic regression models as the primary approach. Sensitivity analyses included targeted maximum likelihood estimation (TMLE) with machine learning, inverse probability of treatment weighting (IPTW), as well as variations of estimands, handling of missing values, and a complete target trial emulation excluding the VA-ECMO alone group.

RESULTS

In the overall target trial population, the median age was 62.0 years, and 53.3% of patients were male. The estimated probability of in-hospital mortality from the primary target trial intention-to-treat analysis for VA-ECMO alone was 57% (95% confidence interval [CI] 47%; 67%), compared to 48% (95% CI 44%; 53%) for intrahospital SYS, 34% (95%CI 18%; 50%) for ST, and 43% (95% CI 35%; 51%) for PCDT. The mortality risk ratios were largely in favor of any advanced recanalization strategy over VA-ECMO alone. The robustness of these findings was supported by all sensitivity analyses. In the crude outcome analysis, patients surviving to discharge had a high probability of favorable neurologic outcome in all treatment groups.

CONCLUSION

Advanced recanalization by means of SYS, ST, and several promising catheter-directed systems may have a positive impact on short-term survival of patients presenting with high-risk PE compared to the use of VA-ECMO alone as a bridge to recovery.

Catheter-Directed Aspiration for Right Atrial and Right Ventricular Masses: Trends in Use Over the Years and Comparison Between Percutaneous and Surgical Thrombectomy for Clot in Transit

BACKGROUND

Percutaneous mechanical aspiration thrombectomy is increasingly being employed as a less invasive alternative for managing right heart masses, including clot in transit.

AIMS

We aimed to analyze trends in the use of catheter-directed aspiration (CDA) for right heart masses. Additionally, we analyzed in-hospital outcomes of percutaneous versus surgical approaches for patients with CIT and PE.

METHODS

We performed a retrospective cohort study based on the National Inpatient Sample (NIS) database from 2016 to 2020. Our population included patients who underwent catheter-directed mechanical aspiration of right heart mass and thrombus to analyze trends during the study period. Moreover, we identified patients with acute PE stratified into cohorts: percutaneous catheter-directed thrombectomy (CDT) and surgical embolectomy. The primary outcome was the composite endpoint of in-hospital mortality, major bleeding, and stroke.

RESULTS

A total of 1789 underwent CDA during the study period. There was an increase in usage of CDA for right heart thrombus and mass (203 in 2016 vs. 533 in 2020). Among patients with PE, 400 patients underwent CDT, and 150 patients underwent SE for clot in transit. On multivariate analysis, there was no significant difference in composite endpoints between the two groups (31.2% in percutaneous vs. 40% in the surgical group, p = 0.243). However, patients who underwent CDT had lower in-hospital mortality than surgical thrombectomy (12.5 vs. 26.6%, p = 0.015).

CONCLUSIONS

There is a significant increase in the use of CDA for right heart thrombus and mass. Moreover, our study shows significantly lower in-hospital mortality in PE patients with CIT undergoing CDT compared to surgical thrombectomy.

Clot-in-transit and pulmonary embolism: an urgent call for awareness and action

Patients with acute pulmonary embolism (PE) have a wide spectrum of clinical presentations, from incidental findings to sudden cardiac death. Management and treatment recommendations in currently available guidelines vary according to patient risk and haemodynamic profile. A clot-in-transit (CiT) in the right heart chambers may be occasionally identified and is, therefore, an under-recognised but challenging condition, often preceding an abrupt clinical deterioration, and associated with increased mortality. Data on the detection of a CiT are sparse but consistent in attributing negative prognostic relevance, and therefore the presence of CiT should be systematically investigated and recorded in the setting of PE.In this review, the challenges related to the identification of a CiT are highlighted. Here, we propose an algorithm where the role of the Pulmonary Embolism Response Team (PERT) is reinforced. The PERT should convene once the CiT is suspected, to define the timeline for the diagnostic steps and subsequent management on a case-by-case basis. A patient with PE and CiT requires close bedside monitoring and rapid escalation therapy in case of clinical deterioration. Beyond anticoagulation alone, more aggressive strategies can be considered, including systemic thrombolysis, surgical pulmonary embolectomy and the currently emerging catheter-directed therapies. PROSPERO registration number: CRD42024493303.

Critical Care Management of Acute Pulmonary Embolism

The unprimed right ventricle is exquisitely sensitive to acute elevations in afterload. High pulmonary vascular tone incurred with acute pulmonary embolism has the potential to induce obstructive shock and circulatory collapse. While emergent pulmonary reperfusion is essential in severe circumstances, an important subset of pulmonary embolism patients may exhibit a less extreme presentation posing a management dilemma. As intensive care therapies have the potential to both salvage and harm the failing right ventricle, a keen understanding of the pathophysiology is requisite in the care of the contemporary patient with hemodynamically significant pulmonary embolism. Here, we review right ventricular pathophysiology, an approach to risk stratification, and offer guidance on the medical and mechanical supportive and therapeutic strategies for the critically ill patient with acute pulmonary embolism.

A Practical Clinical Approach to Navigate Pulmonary Embolism Management: A Primer and Narrative Review of the Evolving Landscape

Advances in imaging, pharmacological, and procedural technologies have rapidly expanded the care of pulmonary embolism. Earlier, more accurate identification and quantification has enhanced risk stratification across the spectrum of the disease process, with a number of clinical tools available to prognosticate outcomes and guide treatment. Direct oral anticoagulants have enabled a consistent and more convenient long-term therapeutic option, with a greater shift toward outpatient treatment for a select group of low-risk patients. The array of catheter-directed therapies now available has contributed to a more versatile and nuanced armamentarium of treatment options, including ultrasound-facilitated thrombolysis and mechanical thrombectomy. Research into supportive care for pulmonary embolism have explored the optimal use of vasopressors and volume resuscitation, as well as utilization of various devices, including right ventricular mechanical support and extracorporeal membrane oxygenation. Even in the realm of surgery, outcomes have steadily improved in experienced centers. This rapid expansion in diagnostic and therapeutic data has necessitated implementation of pulmonary embolism response teams to better interpret the available evidence, manage the utilization of advanced therapies, and coordinate multidisciplinary care. We provide a narrative review of the risk stratification and management of pulmonary embolism, with a focus on structuralizing the multidisciplinary approach and organizing the literature on new and emerging therapies.

Venoarterial extracorporeal membrane oxygenation in high-risk pulmonary embolism: A narrative review

Emergent reperfusion, most commonly with the administration of thrombolytic agents, is the recommended management approach for patients presenting with high-risk, or hemodynamically unstable pulmonary embolism. However, a subset of patients with a more catastrophic presentation, including refractory shock and impending or active cardiopulmonary arrest, may require immediate circulatory support. Venoarterial extracorporeal membrane oxygenation (VA-ECMO) can be deployed rapidly by the well-trained team and provide systemic perfusion allowing for hemodynamic stabilization. Subsequent embolectomy or a standalone strategy allowing for thrombus autolysis may be followed with decannulation after several days. Retrospective studies and registry data suggest favorable clinical outcomes with the use of VA-ECMO as an upfront stabilization strategy even among patients presenting with cardiopulmonary arrest. In this review, we discuss the physiologic rationale, evidence base, and an approach to ECMO deployment and subsequent management strategies among select patients with high-risk pulmonary embolism.

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.

Trident-inspired fucoidan-based armor-piercing microcapsule for programmed acute pulmonary embolism treatment

Pulmonary embolism remains the third leading cause of human mortality after malignant tumors and myocardial infarction. Commonly available thrombolytic therapeutic agents suffer from the limitations of very short half-life, inadequate targeting, limited clot penetration, and a propensity for severe bleeding. Inspired by the trident, we developed the armor-piercing microcapsule (MC), fucoidan-urokinase-S-nitrosoglutathione-polydopamine@MC (FUGP@MC), which exhibited a triple combination of photothermal, mechanical and pharmacological thrombolysis for the therapeutic treatment of acute pulmonary embolism (APE). Briefly, the outermost fucoidan layer was utilized for targeting to the APE area. Programmed APE treatment was triggered by near-infrared (NIR) light irradiation. Photothermal thrombolytic therapy was carried out by photothermal conversion of polydopamine. The photothermal conversion broke the S-nitroso bond in S-nitrosoglutathione (GSNO) and produced large amounts of nitric oxide (NO) for mechanical thrombolysis, which subsequently disrupted the interfacial structure of microcapsule to stimulate the release of the urokinase (UK), leading to a triple synergistic thrombolytic effect. The results demonstrated that the embolization residual rate of FUGP@MC (contained ≈ 1452.5 IU/kg UK) group was significantly lower than that of UK (10,000 IU/kg) group (6.35 % VS 16.78 %). Remarkably, FUGP@MC demonstrated a reliable in vivo biosafety proficiency. In summary, trident-inspired armor-piercing microcapsule FUGP@MC reveals a potential avenue for advancing pulmonary embolism therapeutics and promises to be a safer alternative candidate to current drug approaches.

Anticoagulant Therapy in Patients Undergoing Acute Pulmonary Embolism Interventions

Catheter-based interventions and surgical embolectomy represent alternatives to systemic fibrinolysis for patients with high-risk pulmonary embolism (PE) or those with intermediate-high-risk PE who deteriorate hemodynamically. They are indicated when systemic fibrinolysis is contraindicated or ineffective, or if obstructive shock is imminent. Extracorporeal membrane oxygenation can be added to reperfusion therapies or used alone for severe right ventricular dysfunction and cardiogenic shock. These advanced therapies complement but do not replace anticoagulation, which remains the cornerstone in PE management. This review summarizes the evidence and shares practical recommendations for the use of anticoagulant therapy before, during, and after acute PE interventions.

Interventional Therapies and Mechanical Circulatory Support for Acute Pulmonary Embolism

Acute pulmonary embolism (PE) represents the third leading cause of cardiovascular mortality, with most PE-related mortality associated with acute right ventricular (RV) failure. Despite an increase in attention to acute PE with new endovascular devices for therapy and the adoption of multidisciplinary clinical treatment teams, mortality rates remain high in patients who present with PE-related hemodynamic compromise. Currently, the advanced treatment modalities for acute high-risk and intermediate high-risk PE are limited to several interventional modalities-open surgical embolectomy and systemic fibrinolytic agents. The purpose of this state-of-the-art review is to describe modern therapeutic techniques and strategies (both interventional and surgical) and the role of mechanical circulatory support (MCS) for hemodynamic compromise in PE.

Exploration of effective biomarkers for venous thrombosis embolism in Behçet's disease based on comprehensive bioinformatics analysis

Behçet's disease (BD) is a multifaceted autoimmune disorder affecting multiple organ systems. Vascular complications, such as venous thromboembolism (VTE), are highly prevalent, affecting around 50% of individuals diagnosed with BD. This study aimed to identify potential biomarkers for VTE in BD patients. Three microarray datasets (GSE209567, GSE48000, GSE19151) were retrieved for analysis. Differentially expressed genes (DEGs) associated with VTE in BD were identified using the Limma package and weighted gene co-expression network analysis (WGCNA). Subsequently, potential diagnostic genes were explored through protein-protein interaction (PPI) network analysis and machine learning algorithms. A receiver operating characteristic (ROC) curve and a nomogram were constructed to evaluate the diagnostic performance for VTE in BD patients. Furthermore, immune cell infiltration analyses and single-sample gene set enrichment analysis (ssGSEA) were performed to investigate potential underlying mechanisms. Finally, the efficacy of listed drugs was assessed based on the identified signature genes. The limma package and WGCNA identified 117 DEGs related to VTE in BD. A PPI network analysis then selected 23 candidate hub genes. Four DEGs (E2F1, GATA3, HDAC5, and MSH2) were identified by intersecting gene sets from three machine learning algorithms. ROC analysis and nomogram construction demonstrated high diagnostic accuracy for these four genes (AUC: 0.816, 95% CI: 0.723-0.909). Immune cell infiltration analysis revealed a positive correlation between dysregulated immune cells and the four hub genes. ssGSEA provided insights into potential mechanisms underlying VTE development and progression in BD patients. Additionally, therapeutic agent screening identified potential drugs targeting the four hub genes. This study employed a systematic approach to identify four potential hub genes (E2F1, GATA3, HDAC5, and MSH2) and construct a nomogram for VTE diagnosis in BD. Immune cell infiltration analysis revealed dysregulation, suggesting potential macrophage involvement in VTE development. ssGSEA provided insights into potential mechanisms underlying BD-induced VTE, and potential therapeutic agents were identified.

Integration of Extracorporeal Membrane Oxygenation into the Management of High-Risk Pulmonary Embolism: An Overview of Current Evidence

High-risk pulmonary embolism (PE) refers to a large embolic burden causing right ventricular failure and hemodynamic instability. It accounts for approximately 5% of all cases of PE but contributes significantly to overall PE mortality. Systemic thrombolysis is the first-line revascularization therapy in high-risk PE. Surgical embolectomy or catheter-directed therapy is recommended in patients with an absolute contraindication to systemic thrombolysis. Extracorporeal membrane oxygenation (ECMO) provides respiratory and hemodynamic support for the most critically ill PE patients with refractory cardiogenic shock or cardiac arrest. The complex management of these individuals requires urgent yet coordinated multidisciplinary care. In light of existing evidence regarding the utility of ECMO in the management of high-risk PE patients, a number of possible indications for ECMO utilization have been suggested in the literature. Specifically, in patients with refractory cardiac arrest, resuscitated cardiac arrest, or refractory shock, including in cases of failed thrombolysis, venoarterial ECMO (VA-ECMO) should be considered, either as a bridge to percutaneous or surgical embolectomy or as a bridge to recovery after surgical embolectomy. We review here the current evidence on the use of ECMO as part of the management strategy for the highest-risk presentations of PE and summarize the latest data in this indication.

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.

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.

Cutting-Edge Techniques and Drugs for the Treatment of Pulmonary Embolism: Current Knowledge and Future Perspectives

Pulmonary embolism (PE) is a potentially life-threatening condition requiring prompt diagnosis and treatment. Recent advances have led to the development of newer techniques and drugs aimed at improving PE management, reducing its associated morbidity and mortality and the complications related to anticoagulation. This review provides an overview of the current knowledge and future perspectives on PE treatment. Anticoagulation represents the first-line treatment of hemodynamically stable PE, direct oral anticoagulants being a safe and effective alternative to traditional anticoagulation: these drugs have a rapid onset of action, predictable pharmacokinetics, and low bleeding risk. Systemic fibrinolysis is suggested in patients with cardiac arrest, refractory hypotension, or shock due to PE. With this narrative review, we aim to assess the state of the art of newer techniques and drugs that could radically improve PE management in the near future: (i) mechanical thrombectomy and pulmonary embolectomy are promising techniques reserved to patients with massive PE and contraindications or failure to systemic thrombolysis; (ii) catheter-directed thrombolysis is a minimally invasive approach that can be suggested for the treatment of massive or submassive PE, but the lack of large, randomized controlled trials represents a limitation to widespread use; (iii) novel pharmacological approaches, by agents inhibiting thrombin-activatable fibrinolysis inhibitor, factor Xia, and the complement cascade, are currently under investigation to improve PE-related outcomes in specific settings.

Cardiac Catheterization Laboratory Management of the Comatose Adult Patient With an Out-of-Hospital Cardiac Arrest: A Scientific Statement From the American Heart Association

Out-of-hospital cardiac arrest is a leading cause of death, accounting for ≈50% of all cardiovascular deaths. The prognosis of such individuals is poor, with <10% surviving to hospital discharge. Survival with a favorable neurologic outcome is highest among individuals who present with a witnessed shockable rhythm, received bystander cardiopulmonary resuscitation, achieve return of spontaneous circulation within 15 minutes of arrest, and have evidence of ST-segment elevation on initial ECG after return of spontaneous circulation. The cardiac catheterization laboratory plays an important role in the coordinated Chain of Survival for patients with out-of-hospital cardiac arrest. The catheterization laboratory can be used to provide diagnostic, therapeutic, and resuscitative support after sudden cardiac arrest from many different cardiac causes, but it has a unique importance in the treatment of cardiac arrest resulting from underlying coronary artery disease. Over the past few years, numerous trials have clarified the role of the cardiac catheterization laboratory in the management of resuscitated patients or those with ongoing cardiac arrest. This scientific statement provides an update on the contemporary approach to managing resuscitated patients or those with ongoing cardiac arrest.

Contemporary Management and Outcomes of Patients With High-Risk Pulmonary Embolism

BACKGROUND

Contemporary care patterns/outcomes in high-risk pulmonary embolism (PE) patients are unknown.

OBJECTIVES

This study sought to characterize the management of high-risk PE patients and identify factors associated with poor outcomes.

METHODS

A retrospective analysis of the PERT (Pulmonary Embolism Response Team) Consortium Registry was performed. Patients presenting with intermediate-risk PE, high-risk PE, and catastrophic PE (those with hemodynamic collapse) were identified. Patient characteristics were compared with chi-square testing for categorical covariates and Student's t-test for continuous covariates. Multivariable logistic regression was used to assess associations between clinical characteristics and outcomes in the high-risk population.

RESULTS

Of 5,790 registry patients, 2,976 presented with intermediate-risk PE and 1,442 with high-risk PE. High-risk PE patients were more frequently treated with advanced therapies than intermediate-risk PE patients (41.9% vs 30.2%; P < 0.001). In-hospital mortality (20.6% vs 3.7%; P < 0.001) and major bleeding (10.5% vs. 3.5%; P < 0.001) were more common in high-risk PE. Multivariable regression analysis demonstrated vasopressor use (OR: 4.56; 95% CI: 3.27-6.38; P < 0.01), extracorporeal membrane oxygenation use (OR: 2.86; 95% CI: 1.12-7.30; P = 0.03), identified clot-in-transit (OR: 2.26; 95% CI: 1.13-4.52; P = 0.02), and malignancy (OR: = 1.70; 95% CI: 1.13-2.56; P = 0.01) as factors associated with in-hospital mortality. Catastrophic PE patients (n = 197 [13.7% of high-risk PE patients]) had higher in-hospital mortality (42.1% vs 17.2%; P < 0.001) than those presenting with noncatastrophic high-risk PE. Extracorporeal membrane oxygenation (13.3% vs. 4.8% P < 0.001) and systemic thrombolysis (25% vs 11.3%; P < 0.001) were used more commonly in catastrophic PE.

CONCLUSIONS

In the largest analysis of high-risk PE patients to date, mortality rates were high with the worst outcomes among patients with hemodynamic collapse.

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.

Patient-Reported Outcomes in Venous Thromboembolism: A Systematic Review of the Literature, Current Challenges, and Ways Forward

BACKGROUND

Venous thromboembolism (VTE) affects >1.2 million Americans annually. Although the clinical outcomes and economic burdens of VTE have been well described, the impact of VTE on patients' health status has yet to be summarized. This systematic review summarizes how patient-reported outcome measures (PROMs) have been used in VTE to date.

METHODS AND RESULTS

PubMed/MEDLINE was queried for literature published through March 2023 using PROMs in a population of patients with VTE. Studies were excluded if the reference was an editorial, review, or case report, or if the study included patients with conditions other than VTE. Qualitative analyses were performed. After screening and exclusion, 136 references were identified; 5 described PROM development, 20 focused on PROM validation, and 111 used PROMs in outcomes research. The most used generic PROMs were the 36-item Short-Form Health Survey and EuroQol 5-dimensional questionnaire, and the most common disease-specific PROMs were the Venous Insufficiency Epidemiological and Economic Study-Quality of Life/Symptoms and the Pulmonary Embolism Quality of Life Questionnaire. PROMs were used to quantify the changes in health status after diagnosis, characterize the trajectory of subsequent improvement, and identify drivers of continued impairments in health status like postthrombotic syndrome and postpulmonary embolism syndrome. PROMs were also used to investigate the impact of novel treatment modalities on quality of life.

CONCLUSIONS

This review demonstrates the many benefits of PROM use, including quantifying changes in health status with treatment, capturing patients' experiences with the treatment itself, and identifying complications of VTE. Incorporating PROMs into VTE care will be an essential component of evaluating the effectiveness of novel therapies and should lead to improved shared decision-making for patients with VTE.

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.

Dispelling the Saddle Pulmonary Embolism Myth (from a Comparison of Saddle Versus Non-Saddle Pulmonary Embolism)

In the setting of an acute pulmonary embolism (PE), there is often an assumed association between a saddle PE (SPE) and increased clinical severity. We aimed to determine the magnitude of SPE proximal pulmonary artery (PA) flow obstruction and its impact on right ventricular (RV) function in the setting of acute PE in a single-center series. From 2005 to 2022, patients with acute PE presenting with acute RV dysfunction requiring intervention were classified as SPE and non-SPE based on presenting computed tomography (CT) scans. SPE flow obstruction was determined by the ratio of the orthogonal cross-sectional surface area measurements of clot and native PA at the location of maximum clot burden in the right PA and left PA. Presenting RV function based on clinical and imaging parameters (CT and transthoracic echocardiography) were compared between SPE and non-SPE cohorts. A total of 174 patients were identified (SPE 92 [52.9%] and non-SPE 82 [47.1%]). Demographics and co-morbidities were similar. In patients with SPE, there was a mean 25.9% total flow obstruction (right PA 26.9% and left PA 25.5%). Non-SPE had greater clinical RV dysfunction on presentation as reflected by more high-risk PE (43.9% vs 26.1%, p = 0.01), need for venoarterial extracorporeal membrane oxygenation (21.9% vs 10.9%, p = 0.05), and more preoperative cardiopulmonary resuscitation (16.7% vs 7.8%, p = 0.08). RV:left ventricular ratio (CT and transthoracic echocardiography) and RV fractional area change were statistically similar between groups. In-hospital mortality was statistically similar between cohorts (4.9% non-SPE vs 2.1% SPE, p = 0.32). In conclusion, in a single-center series of patients with acute PE with RV dysfunction, SPE did not cause proximal flow-limiting obstruction. Non-SPE was associated with more clinical RV dysfunction than SPE. Thus, it should not be assumed that a non-SPE is a marker of patient stability.

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.