Ultrasound-facilitated, catheter-directed thrombolysis vs anticoagulation alone for acute intermediate-high-risk pulmonary embolism: Rationale and design of the HI-PEITHO study

Fibrinolytic Agents in Thromboembolic Diseases: Historical Perspectives and Approved Indications

Fibrinolytic agents catalyze the conversion of the inactive proenzyme plasminogen into the active protease plasmin, degrading fibrin within the thrombus and recanalizing occluded vessels. The history of these medications dates to the discovery of the first fibrinolytic compound, streptokinase, from bacterial cultures in 1933. Over time, researchers identified two other plasminogen activators in human samples, namely urokinase and tissue plasminogen activator (tPA). Subsequently, tPA was cloned using recombinant DNA methods to produce alteplase. Several additional derivatives of tPA, such as tenecteplase and reteplase, were developed to extend the plasma half-life of tPA. Over the past decades, fibrinolytic medications have been widely used to manage patients with venous and arterial thromboembolic events. Currently, alteplase is approved by the U.S. Food and Drug Administration (FDA) for use in patients with pulmonary embolism with hemodynamic compromise, ST-segment elevation myocardial infarction (STEMI), acute ischemic stroke, and central venous access device occlusion. Reteplase and tenecteplase have also received FDA approval for treating patients with STEMI. This review provides an overview of the historical background related to fibrinolytic agents and briefly summarizes their approved indications across various thromboembolic diseases.

Risks and Benefits of Device-Assisted Treatment of Pulmonary Embolism

Pulmonary embolism (PE) is a common disease associated with significant morbidity and mortality. Despite the familiarity with this disease, the best treatment remains undefined. Traditionally, treatment of PE has involved a choice of anticoagulation, thrombolysis, or surgery. However, the debate over pharmacologic versus mechanical treatment of acute PE reared up again with the advent of user-friendly mechanical and aspiration thrombectomy technologies. This is especially true for submassive PE, which is an area for potential growth both for understanding the pathophysiology of the disease process and management. Multiple devices are available for treatment of PE. Understanding the risks and benefits of each device is paramount in the complex management of PE.

Mechanical Circulatory Support Devices in Patients with High-Risk Pulmonary Embolism

Pulmonary embolism (PE) is a common acute cardiovascular condition. Within this review, we discuss the incidence, pathophysiology, and treatment options for patients with high-risk and massive pulmonary embolisms. In particular, we focus on the role of mechanical circulatory support devices and their possible therapeutic benefits in patients who are unresponsive to standard therapeutic options. Moreover, attention is given to device selection criteria, weaning protocols, and complication mitigation strategies. Finally, we underscore the necessity for more comprehensive studies to corroborate the benefits and safety of MCS devices in PE management.

Optimal hemodynamic parameters for risk stratification in acute pulmonary embolism patients

Hemodynamic assessment of patients with pulmonary embolism (PE) remains a fundamental component of early risk stratification that in turn, influences subsequent monitoring and therapeutic strategies. The current body of literature and international evidence-based clinical practice guidelines focus mainly on the use of systolic blood pressure (SBP). The accuracy of this single hemodynamic parameter, however, and its optimal values for the identification of hemodynamic instability have been recently questioned by clinicians. For example, abnormal SBP or shock index may be a late indicator of adverse outcomes, signaling a patient in whom the cascade of hemodynamic compromise is already well underway. The aim of the present article is to review the current evidence supporting the use of SBP and analyze the potential integration of other parameters to assess the hemodynamic stability, impending clinical deterioration, and guide the reperfusion treatment in patients with PE, as well as to suggest potential strategies to further investigate this issue.

Catheter Interventions for Pulmonary Embolism: Mechanical Thrombectomy Versus Thrombolytics

Pulmonary embolism is a debilitating and potentially life-threatening disease characterized by high mortality and long-term adverse outcomes. Traditional treatment options are fraught with serious bleeding risks and incomplete thrombus removal, necessitating the development of innovative treatment strategies. While new interventional approaches offer promising potential for improved outcomes with fewer serious complications, their rapid development and need for more comparative clinical evidence makes it challenging for physicians to select the optimal treatment for each patient among the many options. This review summarizes the current published clinical data for both traditional treatments and more recent interventional approaches indicated for pulmonary embolism. While published studies thus far suggest that these newer interventional devices offer safe and effective options, more data is needed to understand their impact relative to the standard of care. The studies in progress that are anticipated to provide needed evidence are reviewed here since they will be critical for helping physicians make informed treatment choices and potentially driving necessary guideline changes.

Safety and efficacy of clot-dissolving therapies for submassive pulmonary embolism: A network meta-analysis of randomized controlled trials

BACKGROUND

Acute pulmonary embolism (PE) is a serious condition that needs quick and effective treatment. Anticoagulation therapy is the usual care for most PE patients but may not work well for higher-risk ones. Thrombolysis breaks the clot and improves blood flow. It can be given systemically or locally. Ultrasound-assisted catheter-directed thrombolysis (USAT) is a new technique that boosts clot-busting drugs. This network meta-analysis compares death, bleeding, and benefits of four treatments in acute submassive PE.

METHODS

We comprehensively searched relevant databases up to July 2023 for RCTs. The outcomes encompassed all-cause mortality, major and minor bleeding, PE recurrence, and hospital stay duration. Bayesian network meta-analysis computed odds ratios (OR) and 95 % CI estimates.

RESULTS

In this network meta-analysis of 23 RCTs involving 2521 PE patients, we found that SCDT had the most favorable performance for mortality, as it had the lowest odds ratio (OR) among the four interventions (OR 5.41e-42; 95 % CI, 5.68e-97, 1.37e-07). USAT had the worst performance for major bleeding, as it had the highest OR among the four interventions (OR 4.73e+04; 95 % CI, 1.65, 9.16e+13). SCDT also had the best performance for minor bleeding, as it had the lowest OR among the four interventions (OR 5.68e-11; 95 % CI, 4.97e-25, 0.386).

CONCLUSION

Our meta-analysis suggests that SCDT is the most effective treatment intervention in improving the risks of All-cause mortality and bleeding. Thrombolytic therapy helps in improving endpoints including the risk of PE recurrence and the duration of hospital stay.

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

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

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.

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.

Drivers and recent trends of hospitalisation costs related to acute pulmonary embolism

BACKGROUND AND AIMS

The socio-economic burden imposed by acute pulmonary embolism (PE) on European healthcare systems is largely unknown. We sought to determine temporal trends and identify cost drivers of hospitalisation for PE in Germany.

METHODS AND RESULTS

We analysed the totality of reimbursed hospitalisation costs in Germany (G-DRG system) in the years 2016-2020. Overall, 484 884 PE hospitalisations were coded in this period. Direct hospital costs amounted to a median of 3572 (IQR, 2804 to 5869) euros, resulting in average total reimbursements of 710 million euros annually. Age, PE severity, comorbidities and in-hospital (particularly bleeding) complications were identified by multivariable logistic regression as significant cost drivers. Use of catheter-directed therapy (CDT) constantly increased (annual change in the absolute proportion of hospitalisations with CDT + 0.40% [95% CI + 0.32% to + 0.47%]; P < 0.001), and it more than doubled in the group of patients with severe PE (28% of the entire population) over time. Although CDT use was overall associated with increased hospitalisation costs, this association was no longer present (adjusted OR 1.02 [0.80-1.31]) in patients with severe PE and shock; this was related, at least in part, to a reduction in the median length of hospital stay (for 14.0 to 8.0 days).

CONCLUSIONS

We identified current and emerging cost drivers of hospitalisation for PE, focusing on severe disease and intermediate/high risk of an adverse early outcome. The present study may inform reimbursement decisions by policymakers and help to guide future health economic analysis of advanced treatment options for patients with PE.

Ultrasound-assisted endovascular thrombolysis versus large-bore thrombectomy in acute intermediate-high risk pulmonary embolism: The propensity-matched EKNARI cohort study

BACKGROUND

Ultrasound-assisted thrombolysis (USAT) and large-bore-thrombectomy (LBT) are under investigation for the treatment of intermediate-high and high-risk pulmonary embolisms (PE). Comparative studies investigating both devices are scarce.

AIMS

This study aimed to compare the safety and efficacy of the two most frequently used devices for treatment of acute PE.

METHODS

This multicenter, retrospective study included 125 patients undergoing LBT or USAT for intermediate- or high-risk PE between 2019 and 2023. Nearest neighbor propensity matching with logistic regression was used to achieve balance on potential confounders. The primary outcome was the change in the right to left ventricular (RV/LV) ratio between baseline and 24 h.

RESULTS

A total of 125 patients were included. After propensity score matching, 95 patients remained in the sample, of which 69 (73%) underwent USAT and 26 (27%) LBT. The RV/LV ratio decrease between baseline and 24 h was greater in the LBT than in the USAT group (adjusted between-group difference: -0.10, 95% CI: -0.16 to -0.04; p = 0.001). Both procedures were safe and adverse events occurred rarely (10% following USAT vs. 4% following LBT; p = 0.439).

CONCLUSION

In acute intermediate-high and high-risk PE, both LBT and USAT were feasible and safe. The reduction in RV/LV ratio was greater following LBT than USAT. Further randomized controlled trials are needed to confirm these findings.

Pulmonary embolism with paradoxical embolization to right coronary artery in the presence of a large patent foramen ovale: a case report

Background

Pulmonary embolism (PE) is the leading cause of in-hospital death and the third most frequent cause of cardiovascular death. The clinical presentation of PE is variable, and choosing the appropriate treatment for individual patients can be challenging.

Case summary

A 64-year-old man presented to hospital with acute chest pain, shortness of breath, and pulmonary oedema. Electrocardiogram revealed ST-elevation myocardial infarction. D-dimer was 18.8 mg/L fibrinogen equivalent units (FEU) (normal <0.64), and troponin was 25 (normal 5-14 ng/L). After systemic thrombolysis, respiratory failure persisted, and the arterial blood gas showed PaO2 of 6.0 kPa (normal 10.5-13.5 kPa), with 100% oxygen delivery via high-flow nasal cannula. A computed tomography diagnosed bilateral lobar PE, and coronary angiogram showed multiple thrombus in the right coronary artery. A bubble study with thoracic echocardiogram revealed a large right-left inter-atrial shunt. The patient denied treatment with extracorporeal membrane oxygenation and surgical thrombectomy. With no access to percutaneous catheter-directed thrombectomy, the patient received three separate thrombolysis treatments followed by a continued infusion for 22 h. After 6 weeks in hospital, the patient was discharged to rehab.

Discussion

For a long time, PE has been largely seen as a medical disease. Intra-cardiac shunts such as patent foramen ovale can complicate thrombo-venous disease and introduce paradoxical shunts leading to arterial emboli and persistent hypoxaemia. Over recent years, modern percutaneous catheter-directed thrombectomy has been developed for both high-risk and intermediate to high-risk PEs. Thrombectomy might improve right ventricular function and haemodynamics, but there is lacking evidence from randomized trials on efficacy, safety, and long-term outcome.

Effectiveness and Safety of Large-Bore Aspiration Thrombectomy for Intermediate- or High-Risk Pulmonary Embolism

PURPOSE

To evaluate effectiveness and safety of large-bore mechanical thrombectomy of intermediate- or high-risk pulmonary embolism (PE) and factors associated with effectiveness.

MATERIALS AND METHODS

A retrospective review of 257 patients with intermediate- or high-risk PE who underwent mechanical thrombectomy using the Flowtriever system (Inari Medical, Irvine, California) between July 2019 and November 2021 was conducted. Data were analyzed using the linear regression and Kaplan-Meier methods with a Type 1 error set at 0.05.

RESULTS

Patients' mean age was 62 years, and 51% were male. PE risk was classified as high, intermediate-high, and intermediate-low in 37 (14%), 201 (78%), and 18 (7%) of the patients, respectively. Procedural technical success was 100%. The mean pulmonary artery pressure (MPAP) decreased from a mean of 32 mmHg (SD ± 9) before to 24 mmHg (SD ± 9) after thrombectomy (mean decrease, 8 mmHg [SD ± 6]; P < .0001). Immediate complications occurred in 2% of the patients. Postprocedural 30-day and all-time PE-attributable mortality in a mean of 1.3-year follow-up was 2% and 6%, respectively. In multivariate analysis, the presence of lower extremity DVT at presentation (β ± SE, -7.60 ± 3.22; P = .019) and a higher prethrombectomy MPAP (β ± SE, -0.19 ± 0.04; P < .001) were associated with lower degrees of decrease in MPAP in the intermediate-high-risk PE group. Among 14 patients with postthrombectomy PE-attributable mortality, 13 had postthrombectomy MPAPs of >20 mmHg.

CONCLUSIONS

Large-bore aspiration thrombectomy is a safe and effective treatment for reducing PAP in patients with intermediate- or high-risk PE. Postthrombectomy MPAPs of >20 mmHg might indicate postthrombectomy PE-attributable mortality in high-risk patients.

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.

Comparison of Treatment Approaches and Subsequent Outcomes within a Pulmonary Embolism Response Team Registry

Objectives

To characterize the association between pulmonary embolism (PE) severity and bleeding risk with treatment approaches, outcomes, and complications.

Methods

Secondary analysis of an 11-hospital registry of adult ED patients treated by a PE response team (August 2016-November 2022). Predictors were PE severity and bleeding risk. The primary outcome was treatment approach: anticoagulation monotherapy vs. advanced intervention (categorized as "immediate" or "delayed" based on whether the intervention was received within 12 hours of PE diagnosis or not). Secondary outcomes were death, clinical deterioration, and major bleeding.

Results

Of the 1832 patients, 139 (7.6%), 977 (53.3%), and 9 (0.5%) were classified as high-risk, intermediate-high, intermediate-low, and low-risk severity, respectively. There were 94 deaths (5.1%) and 218 patients (11.9%) had one or more clinical deterioration events. Advanced interventions were administered to 86 (61.9%), 195 (27.6%), and 109 (11.2%) patients with high-risk, intermediate-high, and intermediate-low severity, respectively.Major bleeding occurred in 61/1440 (4.2%) on ACm versus 169/392 (7.6%) with advanced interventions (p <0.001): bleeding withcatheter-directed thrombolysiswas 19/145 (13.1%) versus 33/154(21.4%) with systemic thrombolysis,p= 0.07. High risk was twice as strong as intermediate-high risk for association with advanced intervention (OR: 5.3 (4.2 and 6.9) vs. 1.9 (1.6 and 2.2)). High risk (OR: 56.3 (32.0 and 99.2) and intermediate-high risk (OR: 2.6 (1.7 and 4.0)) were strong predictors of clinical deterioration. Major bleeding was significantly associated with advanced interventions (OR: 5.2 (3.5 and 7.8) for immediate, 3.3 (1.8 and 6.2)) for delayed, and high-risk PE severity (OR: 3.4 (1.9 and 5.8)).

Conclusions

Advanced intervention use was associated with high-acuity patients experiencing death, clinical deterioration, and major bleeding with a trend towards less bleeding with catheter-directed interventions versus systemic thrombolysis.

Need for a Cardiogenic Shock Team Collaborative-Promoting a Team-Based Model of Care to Improve Outcomes and Identify Best Practices

Cardiogenic shock continues to carry a high mortality rate despite contemporary care, with no breakthrough therapies shown to improve survival over the past few decades. It is a time-sensitive condition that commonly results in cardiovascular complications and multisystem organ failure, necessitating multidisciplinary expertise. Managing patients with cardiogenic shock remains challenging even in well-resourced settings, and an important subgroup of patients may require cardiac replacement therapy. As a result, the idea of leveraging the collective cognitive and procedural proficiencies of multiple providers in a collaborative, team-based approach to care (the "shock team") has been advocated by professional societies and implemented at select high-volume clinical centers. A slowly maturing evidence base has suggested that cardiogenic shock teams may improve patient outcomes. Although several registries exist that are beginning to inform care, particularly around therapeutic strategies of pharmacologic and mechanical circulatory support, none of these are currently focused on the shock team approach, multispecialty partnership, education, or process improvement. We propose the creation of a Cardiogenic Shock Team Collaborative-akin to the successful Pulmonary Embolism Response Team Consortium-with a goal to promote sharing of care protocols, education of stakeholders, and discovery of how process and performance may influence patient outcomes, quality, resource consumption, and costs of care.

Early predictors of clinical deterioration in intermediate-high risk pulmonary embolism: clinical needs, research imperatives, and pathways forward

A subset of intermediate-high risk pulmonary embolism (PE) patients will suffer clinical deterioration in the early hours following the acute event. Current evidence-based guidelines for the management of acute PE have provided limited direction for identification of which intermediate-high risk PE patients will go on to develop haemodynamic decompensation. Furthermore, a paucity of data further hampers guideline recommendations regarding the optimal approach and duration of intensive monitoring, best methods to assess the early response to anticoagulation, and the ideal window for reperfusion therapy, if decompensation threatens. The aim of the present article is to identify the current unmet needs related to the early identification of intermediate-high risk PE patients at higher risk of clinical deterioration and mortality during the early hours after the acute cardiovascular event and suggest some potential strategies to further explore gaps in the literature.

Performance-based outcome measures for assessing physical capacity in patients with pulmonary embolism: A scoping review

INTRODUCTION

Up to 50 % of patients surviving a pulmonary embolism (PE) report persisting shortness of breath, reduced physical capacity and psychological distress. As the PE population is heterogeneous compared to other cardiovascular patient groups, outcome measures for assessing physical capacity traditionally used in cardiac populations may not be reliable for the PE population as a whole. This scoping review aims to 1) map performance-based outcome measures (PBOMs) used for assessing physical capacity in PE research, and 2) to report the psychometric properties of the identified PBOMs in a PE population.

METHODS

The review was conducted according to the Joanna Briggs Institute framework for scoping reviews and reported according to the PRISMA-Extension for Scoping Reviews guideline.

RESULTS

The systematic search of five databases identified 4585 studies, of which 243 studies met the inclusion criteria. Of these, 185 studies focused on a subgroup of patients with chronic thromboembolic pulmonary hypertension. Ten different PBOMs were identified in the included studies. The 6-minute walk test (6MWT) and cardiopulmonary exercise test (CPET) were the most commonly used, followed by the (Modified) Bruce protocol and Incremental Shuttle Walk test. No studies reported psychometric properties of any of the identified PBOMs in a PE population.

CONCLUSIONS

Publication of studies measuring physical capacity within PE populations has increased significantly over the past 5-10 years. Still, not one study was identified, reporting the validity, reliability, or responsiveness for any of the identified PBOMs in a PE population. This should be a priority for future research in the field.

Addressing the rising trend of high-risk pulmonary embolism mortality: Clinical and research priorities

BACKGROUND

Deaths from high-risk pulmonary embolism (PE) appear to have increased in the US over the last decade. Modifiable risks contributing to this worrisome trend present opportunities for physicians, researchers, and healthcare policymakers to improve care.

METHODS

We sought to contextualize contemporary, high-risk PE epidemiology and examine clinical trials, quality improvement opportunities, and healthcare policy initiatives directed at reducing mortality.

RESULTS

We observed significant and modifiable excess mortality due to high-risk PE. We identified several opportunities to improve care including: (1) rapid translation of forthcoming data on reperfusion strategies into clinical practice; (2) improved risk stratification tools; (3) quality improvement initiatives to address presumptive anticoagulation practice gaps; and (3) adoption of health policy initiatives to establish pulmonary embolism response teams and address the social determinants of health.

CONCLUSION

Addressing knowledge and practice gaps in intermediate and high-risk PE management must be prioritized and informed by forthcoming high-quality data. Implementation efforts are needed to improve acute PE management and resolve treatment disparities.

Comparison of In-Hospital Outcomes between Early and Late Catheter-Directed Thrombolysis in Acute Pulmonary Embolism: A Retrospective Observational Study

The purpose of this study is to evaluate whether early initiation of catheter-directed thrombolysis (CDT) in patients presenting with acute pulmonary embolism is associated with improved in-hospital outcomes. A retrospective cohort was extracted from the 2016-2019 National Inpatient Sample database, consisting of 21,730 weighted admissions undergoing CDT acute PE. From the time of admission, the sample was divided into early (<48 h) and late interventions (>48 h). Outcomes were measured using regression analysis and propensity score matching. No significant differences in mortality, cardiac arrest, cardiogenic shock, or intracranial hemorrhage (p > 0.05) were found between the early and late CDT groups. Late CDT patients had a higher likelihood of receiving systemic thrombolysis (3.21 [2.18-4.74], p < 0.01), blood transfusion (1.84 [1.41-2.40], p < 0.01), intubation (1.33 [1.05-1.70], p = 0.02), discharge disposition to care facilities (1.32 [1.14-1.53], p < 0.01). and having acute kidney injury (1.42 [1.25-1.61], p < 0.01). Predictors of late intervention were older age, female sex, non-white ethnicity, non-teaching hospital admission, hospitals with higher bed sizes, and weekend admission (p < 0.01). This study represents a comprehensive evaluation of outcomes associated with the time interval for initiating CDT, revealing reduced morbidity with early intervention. Additionally, it identifies predictors associated with delayed CDT initiation. The broader ramifications of these findings, particularly in relation to hospital resource utilization and health disparities, warrant further exploration.

High and intermediate risk pulmonary embolism in the ICU

Pulmonary embolism (PE) is a common and important medical emergency, encountered by clinicians across all acute care specialties. PE is a relatively uncommon cause of direct admission to the intensive care unit (ICU), but these patients are at high risk of death. More commonly, patients admitted to ICU develop PE as a complication of an unrelated acute illness. This paper reviews the epidemiology, diagnosis, risk stratification, and particularly the management of PE from a critical care perspective. Issues around prevention, anticoagulation, fibrinolysis, catheter-based techniques, surgical embolectomy, and extracorporeal support are discussed.

Risk Stratification and Management of Intermediate-Risk Acute Pulmonary Embolism

Pulmonary embolism (PE) is the third most common cause of cardiovascular death and necessitates prompt, accurate risk assessment at initial diagnosis to guide treatment and reduce associated mortality. Intermediate-risk PE, defined as the presence of right ventricular (RV) dysfunction in the absence of hemodynamic compromise, carries a significant risk for adverse clinical outcomes and represents a unique diagnostic challenge. While small clinical trials have evaluated advanced treatment strategies beyond standard anticoagulation, such as thrombolytic or endovascular therapy, there remains continued debate on the optimal care for this patient population. Here, we review the most recent risk stratification models, highlighting differences between prediction scores and their limitations, and discuss the utility of serologic biomarkers and imaging modalities to detect right ventricular dysfunction. Additionally, we examine current treatment recommendations including anticoagulation strategies, use of thrombolytics at full and reduced doses, and utilization of invasive treatment options. Current knowledge gaps and ongoing studies are highlighted.

Ultrasound-Assisted Catheter-Directed Thrombolysis for the Management of Pulmonary Embolism: A Single Center Experience in a Community Hospital

Current guidelines recommend anticoagulation alone for low-risk pulmonary embolism (PE) with the addition of systemic thrombolysis for high-risk PE. However, treatment recommendations for intermediate-risk PE are not well-defined. Due to bleeding risks associated with systemic thrombolysis, ultrasound-assisted catheter-directed thrombolysis (USAT) has evolved as a promising treatment modality. USAT is thought to decrease the rate of major bleeding by using localized delivery with lower thrombolytic dosages. Currently, there is little guidance on the implementation of USAT in the real-world clinical setting. This study was designed to evaluate our experience with USAT at this single community hospital with a newly initiated Pulmonary Embolism Response Team (PERT). All patients identified by the PERT with an acute PE diagnosed by a computed tomography (CT) scan from January 2021 to January 2023 were included. During the study period, there were 89 PERT activations with 40 patients (1 high-risk and 37 intermediate-risk PE) receiving USAT with alteplase administered at a fixed rate of 1 mg/h per catheter for 6 h. The primary efficacy outcome was the change in Pulmonary Embolism Severity Index (PESI) score within 48 h after USAT. The primary safety outcome was major bleeding within 72 h. The mean age was 57.4 ± 17.4 years and 50% (n = 20) were male, 17.5% (n = 7) had active malignancy, and 20% (n = 8) had a history of prior deep vein thrombosis (DVT) or PE. The mean PESI score decreased from baseline to 48 h post-USAT (84.7 vs 74.9; p = 0.025) and there were no major bleeding events. The overall hospital length of stay was 7.5 ± 9.8 days and ICU length of stay was 2.2 ± 2.8 days. This study outlined our experience at this single community hospital which resulted in an improvement in PESI scores and no major bleeding events observed.

Mechanical Support Strategies for High-Risk Procedures in the Invasive Cardiac Catheterization Laboratory: A State-of-the-Art Review

Thanks to advancements in percutaneous cardiac interventions, an expanding patient population now qualifies for treatment through percutaneous endovascular procedures. High-risk interventions far exceed coronary interventions and include transcatheter aortic valve replacement, endovascular management of acute pulmonary embolism and ventricular tachycardia ablation. Given the frequent impairment of ventricular function in these patients, frequently deteriorating during percutaneous interventions, it is hypothesized that mechanical ventricular support may improve periprocedural survival and subsequently patient outcome. In this narrative review, we aimed to provide the relevant evidence found for the clinical use of percutaneous mechanical circulatory support (pMCS). We searched the Pubmed database for articles related to pMCS and to pMCS and invasive cath lab procedures. The articles and their references were evaluated for relevance. We provide an overview of the clinically relevant evidence for intra-aortic balloon pump, Impella, TandemHeart and ECMO and their role as pMCS in high-risk percutaneous coronary intervention, transcatheter valvular procedures, ablations and high-risk pulmonary embolism. We found that the right choice of periprocedural pMCS could provide a solution for the hemodynamic challenges during these procedures. However, to enhance the understanding of the safety and effectiveness of pMCS devices in an often high-risk population, more randomized research is needed.

Randomized controlled trial of mechanical thrombectomy vs catheter-directed thrombolysis for acute hemodynamically stable pulmonary embolism: Rationale and design of the PEERLESS study

BACKGROUND

The identification of hemodynamically stable pulmonary embolism (PE) patients who may benefit from advanced treatment beyond anticoagulation is unclear. However, when intervention is deemed necessary by the PE patient's care team, data to select the most advantageous interventional treatment option are lacking. Limiting factors include major bleeding risks with systemic and locally delivered thrombolytics and the overall lack of randomized controlled trial (RCT) data for interventional treatment strategies. Considering the expansion of the pulmonary embolism response team (PERT) model, corresponding rise in interventional treatment, and number of thrombolytic and nonthrombolytic catheter-directed devices coming to market, robust evidence is needed to identify the safest and most effective interventional option for patients.

METHODS

The PEERLESS study (ClinicalTrials.gov identifier: NCT05111613) is a currently enrolling multinational RCT comparing large-bore mechanical thrombectomy (MT) with the FlowTriever System (Inari Medical, Irvine, CA) vs catheter-directed thrombolysis (CDT). A total of 550 hemodynamically stable PE patients with right ventricular (RV) dysfunction and additional clinical risk factors will undergo 1:1 randomization. Up to 150 additional patients with absolute thrombolytic contraindications may be enrolled into a nonrandomized MT cohort for separate analysis. The primary end point will be assessed at hospital discharge or 7 days post procedure, whichever is sooner, and is a composite of the following clinical outcomes constructed as a hierarchal win ratio: (1) all-cause mortality, (2) intracranial hemorrhage, (3) major bleeding, (4) clinical deterioration and/or escalation to bailout, and (5) intensive care unit admission and length of stay. The first 4 components of the win ratio will be adjudicated by a Clinical Events Committee, and all components will be assessed individually as secondary end points. Other key secondary end points include all-cause mortality and readmission within 30 days of procedure and device- and drug-related serious adverse events through the 30-day visit.

IMPLICATIONS

PEERLESS is the first RCT to compare 2 different interventional treatment strategies for hemodynamically stable PE and results will inform strategy selection after the physician or PERT determines advanced therapy is warranted.

Predictors of chronic thromboembolic pulmonary hypertension in patients with submassive pulmonary embolism treated with catheter-directed thrombolysis versus anticoagulation alone: A secondary analysis of the SUNSET sPE trial

OBJECTIVE

Chronic thromboembolic pulmonary hypertension (CTEPH) after pulmonary embolism (PE) is a morbid complication with suboptimal treatment. We aimed to evaluate the biomarker profile and functional outcomes in patients with submassive PE (sPE) treated with catheter-directed thrombolysis (CDT) compared with anticoagulation alone (ACA). We performed a secondary biomarker and survey analysis of the SUNSET sPE (standard vs ultrasound-assisted catheter thrombolysis for submassive pulmonary embolism) randomized trial comparing standard CDT to ultrasound-assisted thrombolysis in patients with sPE.

METHODS

As a part of the SUNSET sPE study, patients who did not receive an intervention were enrolled in the medical (ACA) arm. The biomarkers associated with CTEPH in the literature (ie, CCL2, CXCL10, PTX3, GDF-15, RAGE, BCA-1, TFPI) were collected and measured using a multiplex assay at diagnosis, discharge, and 3-month follow-up. Patients underwent a 6-minute walk test and answered quality-of-life questionnaires (pulmonary embolism quality of life; University of California, San Diego, shortness of breath questionnaire; 36-item short-form survey) at 3 months after diagnosis. Comparisons were made using the Student t test. Nonparametric tests were used when the distributions were not normal. Significance was set at P ≤ .05.

RESULTS

A total of 72 patients (age, 56 ± 15 years; 40.3% women) were included in the present analysis. Of these 72 patients, 53 underwent CDT and 19 were included in the ACA arm. The baseline right ventricle/left ventricle ratios were similar between the two groups (CST, 1.8; ACA, 1.7). The survival and complication rates were similar between the two groups. At discharge, CXCL10 (768.9 ± 148.6 pg/mL vs 3032.0 ± 1201.0 pg/mL; P = .018) and PTX3 (3203.5 ± 1298.0 pg/mL vs 12,716.2 ± 6961.5 pg/mL; P = .029) were lower in the CDT group and displayed a quicker return to baseline than in the ACA group. This trend, although not significant, was also seen with the other biomarkers. At 3 months, the 6-minute walking distance and quality-of-life scores were similar between both groups.

CONCLUSIONS

In patients with sPE, the biomarkers of CTEPH were lower with CDT compared with ACA. At 3 months, both groups demonstrated similar biomarker levels, 6-minute walking distances, and quality-of-life scores.

COVID-19-Associated Pulmonary Embolism: Review of the Pathophysiology, Epidemiology, Prevention, Diagnosis, and Treatment

COVID-19 is associated with endothelial activation in the setting of a potent inflammatory reaction and a hypercoagulable state. The end result of this thromboinflammatory state is an excess in thrombotic events, in particular venous thromboembolism. Pulmonary embolism (PE) has been of special interest in patients with COVID-19 given its association with respiratory deterioration, increased risk of intensive care unit admission, and prolonged hospital stay. The pathophysiology and clinical characteristics of COVID-19-associated PE may differ from the conventional non-COVID-19-associated PE. In addition to embolic events from deep vein thrombi, in situ pulmonary thrombosis, particularly in smaller vascular beds, may be relevant in patients with COVID-19. Appropriate prevention of thrombotic events in COVID-19 has therefore become of critical interest. Several changes in viral biology, vaccination, and treatment management during the pandemic may have resulted in changes in incidence trends. This review provides an overview of the pathophysiology, epidemiology, clinical characteristics, and risk factors of COVID-19-associated PE. Furthermore, we briefly summarize the results from randomized controlled trials of preventive antithrombotic therapies in COVID-19, focusing on their findings related to PE. We discuss the acute treatment of COVID-19-associated PE, which is substantially similar to the management of conventional non-COVID-19 PE. Ultimately, we comment on the current knowledge gaps in the evidence and the future directions in the treatment and follow-up of COVID-19-associated PE, including long-term management, and its possible association with long-COVID.

Comparative Outcomes of Catheter-Directed Thrombolysis Plus Systemic Anticoagulation Versus Systemic Anticoagulation Alone in the Management of Intermediate-Risk Pulmonary Embolism in a Systematic Review and Meta-Analysis

There are limited and conflicting data on the initial management of intermediate-risk (or submassive) pulmonary embolism (PE). This study sought to compare the outcomes of catheter-directed thrombolysis (CDT) in combination with systemic anticoagulation (SA) to SA alone. A systematic search was conducted in MEDLINE, EMBASE, PubMed, and the Cochrane databases from inception to March 1, 2023 for studies comparing the outcomes of CDT + SA versus SA alone in intermediate-risk PE. The outcomes were in-hospital, 30-day, 90-day, and 1-year mortality; bleeding; blood transfusion; right ventricular recovery; and length of stay. Random-effects models was used to calculate the pooled incidence and risk ratios (RRs) with 95% confidence intervals (CIs). A total of 15 (2 randomized and 13 observational) studies with 10,549 (2,310 CDT + SA and 8,239 SA alone) patients were included. Compared with SA, CDT + SA was associated with significantly lower in-hospital mortality (RR 0.41, 95% CI 0.30 to 0.56, p <0.001), 30-day mortality (RR 0.34, 95% CI 0.18 to 0.67, p = 0.002), 90-day mortality (RR 0.34, 95% CI 0.17 to 0.67, p = 0.002), and 1-year mortality (RR 0.58, 95% CI 0.34 to 0.97, p = 0.04). There were no significant differences between the 2 cohorts in the rates of major bleeding (RR 1.39, 95% CI 0.72 to 2.68, p = 0.56), minor bleeding (RR 1.83, 95% CI 0.97 to 3.46, p = 0.06), and blood transfusion (RR 0.34, 95% CI 0.10 to 1.15, p = 0.08). In conclusion, CDT + SA is associated with significantly lower short-term and long-term all-cause mortality, without any differences in major/minor bleeding, in patients with intermediate-risk PE.

The Post-Venous Thromboembolism Functional Status Scale: From Call to Action to Application in Research, Extension to COVID-19 Patients, and Its Use in Clinical Practice

A broad spectrum of long-term sequelae may be present in venous thromboembolism (VTE) survivors, affecting their quality of life and functioning. To monitor recovery and improve the prognosis of patients with persistent functional limitations, the development of a new outcome measure that could better capture the consequences of VTE was an unmet need. Starting as a call to action, the Post-VTE Functional Status (PVFS) scale was developed to meet this need. The PVFS scale is an easy-to-use clinical tool to measure and quantify functional outcomes after VTE by focusing on key aspects of daily life. As the scale was considered useful in coronavirus disease 2019 (COVID-19) patients as well, the Post-COVID-19 Functional Status (PCFS) scale was introduced early in the pandemic after slight adaptation. The scale has been well incorporated into both the VTE and COVID-19 research communities, contributing to the shift of focus toward patient-relevant functional outcomes. Psychometric properties have been evaluated, mainly for the PCFS scale but recently also for the PVFS scale, including validation studies of translations, showing adequate validity and reliability. In addition to serving as outcome measure in studies, guidelines and position papers recommend using the PVFS and PCFS scale in clinical practice. As broad use of the PVFS and PCFS scale in clinical practice is valuable to capture what matters most to patients, widespread implementation is a crucial next step. In this review, we discuss the development of the PVFS scale and introduction in VTE and COVID-19 care, the incorporation of the scale in research, and its application in clinical practice.

Interventional therapies for pulmonary embolism

Pulmonary embolism (PE) is the leading cause of in-hospital death and the third most frequent cause of cardiovascular death. The clinical presentation of PE is variable, and choosing the appropriate treatment for individual patients can be challenging. Traditionally, treatment of PE has involved a choice of anticoagulation, thrombolysis or surgery; however, a range of percutaneous interventional technologies have been developed that are under investigation in patients with intermediate-high-risk or high-risk PE. These interventional technologies include catheter-directed thrombolysis (with or without ultrasound assistance), aspiration thrombectomy and combinations of the aforementioned principles. These interventional treatment options might lead to a more rapid improvement in right ventricular function and pulmonary and/or systemic haemodynamics in particular patients. However, evidence from randomized controlled trials on the safety and efficacy of these interventions compared with conservative therapies is lacking. In this Review, we discuss the underlying pathophysiology of PE, provide assistance with decision-making on patient selection and critically appraise the available clinical evidence on interventional, catheter-based approaches for PE treatment. Finally, we discuss future perspectives and unmet needs.

Systemic thrombolysis with newer thrombolytics vs anticoagulation in acute intermediate risk pulmonary embolism: a systematic review and meta-analysis

BACKGROUND

Randomized controlled trials (RCTs) comparing systemic thrombolysis to anticoagulation in intermediate risk pulmonary embolism (PE) have yielded mixed results. A prior meta-analysis on this topic had included studies that used lower than standard dose of thrombolytics and included thrombolytic agents that are no longer available. Hence, interpreting the findings of that paper is not valid in contemporary practice.

OBJECTIVES

We undertook a systematic review and meta-analysis of randomized controlled trials of systemic thrombolysis with newer thrombolytic agents vs anticoagulation in intermediate risk PE.

METHODS

This systematic review and meta-analysis is reported according to the Preferred Reporting Items for Systematic Reviews and Meta-Analysis (PRISMA) statement.

RESULTS

Nine randomized controlled trials were included in the study. We did not find any difference in in-hospital mortality (RR: 0.79; 95% CI: 0.42-1.50; I2: 0) or risk of major bleeding (RR:2.08;95% CI: 0.98-4.42; I2: 23.9%) between systemic thrombolysis and anticoagulation. Systemic thrombolysis was associated with lower risks for vasopressor use (RR: 0.27; 95% CI: 0.11-0.64, I2: 0) and secondary/rescue thrombolysis (RR: 0.25; 95% CI: 0.14-0.45; I2: 0). But systemic thrombolysis was found to have an increased risk of intracranial hemorrhage (RR: 4.55; 95% CI: 1.30-15.91; I2:0). There was no difference in mechanical ventilation between the two groups (RR: 0.61; 95% CI: 0.31-1.19, I2:0).

CONCLUSION

In our meta-analysis of randomized controlled trials of systemic thrombolysis vs anticoagulation in intermediate risk PE, we did not find any difference in in-hospital mortality or overall risk of major bleeding. With systemic thrombolysis, we found lower risks for vasopressor use and need for secondary/ rescue thrombolysis and an increased risk of intracranial hemorrhage.

Interventional therapies in acute pulmonary embolus-current trends and future directions

Venous thromboembolic disease presenting with acute pulmonary embolus (PE) can be treated in a variety of ways from anticoagulation as an outpatient to surgical embolectomy with many new interventional therapies being developed. Mortality in these patients can be as high as 50% and many of these treatments are also considered to be high risk. Early involvement of a multidisciplinary team and patient risk stratification can aid management decisions in these complex patients who can suddenly deteriorate.In this review, we summarise the evidence behind new and developing interventional therapies in the treatment of high and intermediate-high risk PE including catheter-directed thrombolysis, pharmacomechanical thrombolysis, thromboaspiration and the growing role of extracorporeal membrane oxygenation in the stabilisation and management of this cohort of patients.

When should we involve interventional radiology in the management of acute pulmonary embolism?

Pulmonary embolism (PE) is a common disease associated with high morbidity and mortality. Currently, guidelines recommend systemic thrombolysis in patients with haemodynamic instability (high-risk PE) or patients with intermediate-high-risk PE with haemodynamic deterioration. Nevertheless, more than half of high-risk PE patients do not receive systemic thrombolysis due to a perceived increased risk of bleeding. In these cases, percutaneous catheter-directed therapy (CDT) or surgical embolectomy should be considered. CDT has emerged and appears to be an effective alternative in treating PE, with a hypothetical lower risk of bleeding than systemic thrombolysis, acting directly in the thrombus with a much lower dose of thrombolytic drug or even without thrombolytic therapy. CDT techniques include catheter-directed clot aspiration or fragmentation, mechanical embolectomy, local thrombolysis, and combined pharmaco-mechanical approaches. A few observational prospective studies have demonstrated that CDT improves right ventricular function with a low rate of haemorrhage. Nevertheless, the evidence from randomised controlled trials is scarce. Here we review different scenarios where CDT may be useful and trials ongoing in this field. These results may change the upcoming guidelines for management and treatment of PE, establishing CDT as a recommended treatment in patients with acute intermediate-high-risk PE.

Indigo® Aspiration System for thrombectomy in pulmonary embolism

Anticoagulation is mainstay therapy for patients with acute pulmonary embolism while systemic thrombolysis is reserved for those with hemodynamic instability. Over the last decade, percutaneous interventional options have entered the landscape aimed to achieve rapid pharmacomechanical pulmonary artery recanalization. The Penumbra Indigo® Aspiration System (Penumbra Inc., CA, USA) is a US FDA-approved large-bore aspiration thrombectomy device for the treatment of pulmonary embolism. Recent data has demonstrated improved radiographic end points with low rates of major adverse events in cases of intermediate-risk pulmonary embolism. In this review article, we outline device technology, applications, evidence and future directions.

Prediction of in-hospital deterioration in normotensive pulmonary embolism remains elusive: external validation of the calgary acute pulmonary embolism score

Acute pulmonary embolism (PE) is a frequently diagnosed condition. Prediction of in-hospital deterioration is challenging with current risk models. The Calgary Acute Pulmonary Embolism (CAPE) score was recently derived to predict in-hospital adverse PE outcomes but has not yet been externally validated. Retrospective cohort study of normotensive acute pulmonary embolism cases diagnosed in our emergency department between 2017 and 2019. An external validation of the CAPE score was performed in this population for prediction of in-hospital adverse outcomes and a secondary outcome of 30-day all-cause mortality. Performance of the simplified Pulmonary Embolism Severity Index (sPESI) and Bova score was also evaluated. 712 patients met inclusion and exclusion criteria, with 536 patients having a sPESI score of 1 or more. Among this population, the CAPE score had a weak discriminative power to predict in-hospital adverse outcomes, with a calculated c-statistic of 0.57. In this study population, an external validation study found weak discriminative power of the CAPE score to predict in-hospital adverse outcomes among normotensive PE patients. Further efforts are needed to define risk assessment models that can identify normotensive PE patients at risk for in hospital deterioration. Identification of such patients will better guide intensive care utilization and invasive procedural management of PE.

[Thromboembolic diseases from a cardiological point of view]

Thromboembolic disease is associated with a high mortality. It can be divided into two groups: embolism from a venous and embolism from an arterial side. This article gives an overview on thromboembolic disease (with a focus on pulmonary embolism and ischemic stroke) from a cardiologist's perspective.The therapeutic options for acute pulmonary embolism range from anticoagulation to fibrinolysis to interventional recanalization and surgery. The deciding factor for choice of therapy is the risk of early death. Besides clinical parameters, laboratory markers like cardiac troponin and right ventricular function on echocardiography or CTPA (computed tomography pulmonary angiography) are used to determine the early mortality risk. In hemodynamically instable patients, immediate thrombolysis is required, whereas patients with intermediate and low risk can be treated with anticoagulation. Interventional recanalization is currently being studied in patients at risk for development of CTEPH (chronic thromboembolic pulmonary hypertension) or an intermediate risk of early mortality.In ischemic stroke, early interdisciplinary workup involving a cardiologist is paramount. Post stroke screening should include monitoring for arrythmias (especially atrial fibrillation) and transthoracic echocardiography as well as sonography of extra- and intracranial arteries. If no embolic source can be detected (embolic stroke of undetermined source), transesophageal echo can be helpful to detect intracardiac shunts like patent foramen ovale (PFO) or intracardiac tumors. Post stroke care includes secondary prevention measures like risk factor modification and lipid lowering therapy as well as anticoagulation. In high risk for paradoxical embolization, interventional PFO closure can be performed. Interventional closure of the left atrial appendage (LAA) can be discussed in patients with both high thromboembolic and bleeding risk.

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.

Amoeba-Inspired Magnetic Venom Microrobots

Nature provides a successful evolutionary direction for single-celled organisms to solve complex problems and complete survival tasks - pseudopodium. Amoeba, a unicellular protozoan, can produce temporary pseudopods in any direction by controlling the directional flow of protoplasm to perform important life activities such as environmental sensing, motility, predation, and excretion. However, creating robotic systems with pseudopodia to emulate environmental adaptability and tasking capabilities of natural amoeba or amoeboid cells remains challenging. Here, this work presents a strategy that uses alternating magnetic fields to reconfigure magnetic droplet into Amoeba-like microrobot, and the mechanisms of pseudopodia generation and locomotion are analyzed. By simply adjusting the field direction, microrobots switch in monopodia, bipodia, and locomotion modes, performing all pseudopod operations such as active contraction, extension, bending, and amoeboid movement. The pseudopodia endow droplet robots with excellent maneuverability to adapt to environmental variations, including spanning 3D terrains and swimming in bulk liquids. Inspired by the "Venom," the phagocytosis and parasitic behaviors have also been investigated. Parasitic droplets inherit all the capabilities of amoeboid robot, expanding their applicable scenarios such as reagent analysis, microchemical reactions, calculi removal, and drug-mediated thrombolysis. This microrobot may provide fundamental understanding of single-celled livings, and potential applications in biotechnology and biomedicine.

Mortality and bleeding associated with the management of sub-massive pulmonary embolism: a systematic review and Bayesian network meta-analysis

Current guidelines recommend anticoagulation (AC) for low and intermediate-risk pulmonary embolism (PE) and systemic thrombolysis (tPA) for high risk (massive) PE. How these treatment options compare with other modalities of treatment such as catheter directed thrombolysis (CDT), ultrasound assisted catheter thrombolysis (USAT), and administering lower dose of thrombolytics (LDT) is unclear. There is no study that has compared all these treatment options. We conducted a systematic review and Bayesian network meta-analysis of randomized controlled trials in patients with submassive (intermediate risk) PE. Fourteen randomized controlled trials were included, comprising 2132 patients. On Bayesian network meta-analysis, a significant decrease in mortality was noted in tPA versus AC. There was no significant difference between USAT versus CDT. For risk of major bleeding, there was no significant difference in relative risk of major bleeding between tPA versus AC and USAT versus CDT. tPA was found to have a significantly higher risk of minor bleeding and a lower risk of recurrent PE compared to AC. Systemic thrombolysis is associated with a significant reduction in mortality and recurrent PE compared to anticoagulation but an increased risk of minor bleeding. There was no difference in risk of major bleeding. Our study also shows that while the newer modalities of treatment for pulmonary embolism are promising, there is lack of data to comment on the purported advantages.

Clinical controversies in the management of acute pulmonary embolism: evaluation of four important but controversial aspects of acute pulmonary embolism management that are still subject of debate and research

INTRODUCTION

Acute pulmonary embolism (PE) is a disease with a broad spectrum of clinical presentations. While some patients can be treated at home or may even be left untreated, other patients require an aggressive approach with reperfusion treatment.

AREAS COVERED

(1) Advanced reperfusion treatment in hemodynamically stable acute PE patients considered to be at high risk of decompensation and death, (2) the treatment of subsegmental pulmonary embolism, (3) outpatient treatment for hemodynamically stable PE patients with signs of right ventricle (RV) dysfunction, and (4) the optimal approach to identify and treatpost-PE syndrome.

EXPERT OPINION

Outside clinical trials, hemodynamically stable acute PE patients should not be treated with primary reperfusion therapy. Thrombolysis and/or catheter-directed therapy are only to be considered as rescue treatment. Subsegmental PE can be left untreated in selected low-risk patients, after proximal deep vein thrombosis has been ruled out. Patients with an sPESI or Hestia score of 0 criteria can be treated at home, independent of the presence of RV overload. Finally, health-care providers should be aware of post-PE syndrome and diagnose chronic thromboembolic pulmonary disease (CTEPD) as early as possible. Persistently symptomatic patients without CTEPD benefit from exercise training and cardiopulmonary rehabilitation.