Efficacy and safety of low dose recombinant tissue-type plasminogen activator for the treatment of acute pulmonary thromboembolism: a randomized, multicenter, controlled trial

Fibrinolytic uses in the emergency department: a narrative review

INTRODUCTION

Several life-threatening conditions associated with thrombosis include acute ischemic stroke (AIS), acute myocardial infarction (AMI), and acute pulmonary embolism (PE). Fibrinolytics are among the treatment algorithms for these conditions.

OBJECTIVE

This narrative review provides emergency clinicians with an overview of fibrinolytics for AIS, AMI, and PE in the emergency department (ED) setting.

DISCUSSION

Pathologic thrombosis can result in vascular occlusion and embolism, ultimately leading to end-organ injury. Fibrinolytics are medications utilized to lyse a blood clot, improving vascular flow. One of the first agents utilized was streptokinase, though this is not as often used with the availability of fibrin-specific agents including alteplase (tPA), tenecteplase (TNK), and reteplase (rPA). These agents are integral components in the management of several conditions, including AIS, AMI, and PE. Patients with AIS who present within 3-4.5 h of measurable neurologic deficit with no evidence of intracerebral hemorrhage (ICH) or other contraindications may be eligible to receive tPA or TNK. In the absence of percutaneous coronary intervention (PCI), fibrinolytics should be considered in patients with AMI presenting with chest pain for at least 30 min but less than 12 h, though it may be considered up to 24 h. Unlike in AIS and PE, anticoagulation and antiplatelet medications should be administered in those with AMI receiving fibrinolytics. Following fibrinolytics, PCI is typically necessary. Fibrinolytics are recommended in patients with high-risk PE (hemodynamic instability), as they reduce the risk of mortality. The most significant complication following fibrinolytic administration includes major bleeding such as ICH, which occurs most frequently in those with AIS compared to AMI and PE. Thus, close patient monitoring is necessary following fibrinolytic administration.

CONCLUSIONS

An understanding of fibrinolytics in the ED setting is essential, including the indications, contraindications, and dosing.

Modified infusion of recombinant tissue plasminogen activator in high-risk pulmonary thromboembolism with high bleeding risk: a case report

High-risk pulmonary thromboembolism (PTE) is a form of venous thromboembolism that refers to severe obstruction of pulmonary vessels, which causes right ventricular failure and hemodynamic instability. High-risk PTE has a high mortality rate unless immediate reperfusion treatment is done. Systemic thrombolysis is recommended for patients with high-risk PTE. The approved regimen for high-risk PTE is the accelerated intravenous administration of recombinant tissue-type plasminogen activator (rtPA) 100 mg over 2 hours. Herein, we present a case of high-risk PTE in a 74-year-old woman with a high risk of bleeding due to a recent pelvic fracture and head trauma who was successfully treated with a slower infusion of 100 mg rtPA over 4 hours. The modified infusion rate of 100 mg rtPA over 4 hours is an effective regimen for thrombolysis in acute high-risk PTE. It might have a lower risk of bleeding complications, which makes it a good option for patients with high bleeding risk.

A randomized trial of low-dose thrombolysis, ultrasound-assisted thrombolysis, or heparin for intermediate-high risk pulmonary embolism-the STRATIFY trial: design and statistical analysis plan

BACKGROUND

Intermediate-high risk pulmonary embolism (PE) carries a significant risk of hemodynamic deterioration or death. Treatment should balance efficacy in reducing clot burden with the risk of complications, particularly bleeding. Previous studies on high-dose, short-term thrombolysis with alteplase (rtPA) showed a reduced risk of hemodynamic deterioration but no change in mortality and increased bleeding complications. Catheter-based techniques, including ultrasound-assisted thrombolysis (USAT), and low-dose thrombolysis may offer reasonable efficacy with lower risk. However, studies comparing these methods have been few. This trial aims to address this gap by randomizing patients to three treatment modalities.

METHODS

Multicenter, randomized trial with 1:1:1 allocation of 210 patients with acute intermediate-high risk PE, excluding those with absolute contraindications to thrombolysis. Patients are eligible for inclusion if they are > 18 years of age, have had symptoms < 14 days, and are able to give informed consent. Patients are allocated 1:1:1 into three treatment strategies: (1) unfractionated heparin (UFH)/low molecular weight heparin (LMWH), (2) UFH/LMWH + 20 mg rtPA/6 h intravenously (IV), or (3) UFH + 20 mg rtPA/6 h via USAT. Co-primary outcomes include reduction in clot burden as assessed by refined Miller score from pre-treatment to follow-up (48-96 h) computed tomography pulmonary angiogram (CTPA) comparing low-dose rtPA (± USAT) groups to UFH/LMWH group (p < 0.01, N = 210) and reduction in refined Miller score on follow-up CT angiography comparing low-dose rtPA by USAT to intravenous rtPA, p < 0.04, N = 140). Secondary outcomes comprise bleeding complications, duration of index admission, FiO2, blood pressure, respiratory and heart rate at the time of follow-up CT angiography, mortality in the three groups, incidence of tricuspid regurgitation pressure gradient < 40 mmHg at 3 months follow-up echocardiography, 6-min walk test at 3 months comparing the three groups, and health-related quality of life at 3 months follow-up comparing the three groups.

DISCUSSION

We hypothesize that in patients with intermediate-high risk PE (1) administration of 20 mg rtPA leads to a greater reduction in clot burden compared to heparins and (2) administration of 20 mg rtPA via USAT results in a greater reduction in clot burden compared to 20 mg rtPA intravenous.

TRIAL REGISTRATION

ClinicalTrials.gov NCT04088292. Registered in September 2019 (retrospectively registered).

Warning of severe pulmonary embolism after cerebral angiography: A case report and literature review

RATIONALE

Acute pulmonary embolism (PE), which can lead to cardiac and respiratory arrest, is a rare complication of cerebral angiography. However, neurologists do not pay attention to this.

PATIENT CONCERNS

A 47-year-old male with a history of type 2 diabetes was admitted to our hospital for evaluation of surgical indications for unruptured ophthalmic aneurysms. After cerebral angiography, a fatal PE occurred. Through rapid identification and effective drug treatment, the patient recovered and was discharged.

DIAGNOSES

A diagnosis of fatal PE was made based on the bedside ultrasonography and blood d-dimer level.

INTERVENTIONS

Cardiopulmonary resuscitation and intravenous thrombolysis of "50 mg alteplase" for continuous intravenous drip for 2 hours.

OUTCOMES

The patient was recovered and no special discomfort was reported.

LESSONS

PE is a rare complication of cerebral angiography, but the fatality rate is very high. Neurologists must not only early identify and effectively treat this complication, but more importantly, pay attention to this complication, prevent it in advance, and reduce the occurrence of catastrophic events.

Polymers as Efficient Non-Viral Gene Delivery Vectors: The Role of the Chemical and Physical Architecture of Macromolecules

Gene therapy is the technique of inserting foreign genetic elements into host cells to achieve a therapeutic effect. Although gene therapy was initially formulated as a potential remedy for specific genetic problems, it currently offers solutions for many diseases with varying inheritance patterns and acquired diseases. There are two major groups of vectors for gene therapy: viral vector gene therapy and non-viral vector gene therapy. This review examines the role of a macromolecule's chemical and physical architecture in non-viral gene delivery, including their design and synthesis. Polymers can boost circulation, improve delivery, and control cargo release through various methods. The prominent examples discussed include poly-L-lysine, polyethyleneimine, comb polymers, brush polymers, and star polymers, as well as hydrogels and natural polymers and their modifications. While significant progress has been made, challenges still exist in gene stabilization, targeting specificity, and cellular uptake. Overcoming cytotoxicity, improving delivery efficiency, and utilizing natural polymers and hybrid systems are vital factors for prospects. This comprehensive review provides an illuminating overview of the field, guiding the way toward innovative non-viral-based gene delivery solutions.

Advancing the management of acute intermediate-high-risk pulmonary embolism: The enduring legacy of Professor Guy Meyer

Only few years after the first report on diagnosing acute pulmonary embolism (PE) with pulmonary angiography, studies began to investigate the effectiveness and safety of thrombolytic therapy for achieving early reperfusion. In 1992, Guy Meyer demonstrated the fast improvement of pulmonary haemodynamics after alteplase administration; this drug has remained the mainstay of thrombolysis for PE over almost 35 years. In the meantime, algorithms for PE risk stratification continued to evolve. The landmark Pulmonary Embolism International Thrombolysis (PEITHO) trial, led by Guy Meyer, demonstrated the clinical efficacy of thrombolysis for intermediate-risk PE, albeit at a relatively high risk of major, particularly intracranial bleeding. Today, systemic thrombolysis plays an only minor role in the real-world treatment of acute PE in the United States and Europe, but major trials are underway to test safer reperfusion regimens. Of those, the PEITHO-3 study, conceived by Guy Meyer and other European and North American experts, is an ongoing randomised, placebo-controlled, double-blind, multinational academic trial. The primary objective is to assess the efficacy of reduced-dose intravenous thrombolytic therapy against the background of heparin anticoagulation in patients with intermediate-high-risk PE. In parallel, trials with similar design are testing the efficacy and safety of catheter-directed local thrombolysis or mechanical thrombectomy. Increasingly, focus is being placed on long-term functional and patient-reported outcomes, including quality of life indicators, as well as on the utilization of health care resources. The pioneering work of Guy Meyer will thus continue to have a major impact on the management of PE for years to come.

Novel Challenges and Therapeutic Options for Pulmonary Embolism and Deep Vein Thrombosis

Acute pulmonary embolism (PE), often resulting from deep vein thrombosis (DVT), is the third most frequent cause of cardiovascular death and is associated with increasing incidence, causing considerable morbidity and mortality. This review aims to evaluate the efficacy, safety, and outcomes of treatment options in the management of acute PE and DVT, encompassing both established and emerging technologies, such as catheter-directed thrombolysis, aspiration thrombectomy, and other endovascular techniques. A comprehensive literature review was conducted, assessing clinical studies, trials, and case reports that detail the use of percutaneous interventions for PE and DVT and analyzing the advantages and disadvantages of each percutaneous system. Several percutaneous treatments have shown promising results, especially in cases where rapid thrombus resolution is critical, such as in high- and intermediate-high-risk patients. The incidence of major complications, such as bleeding, remains a consideration, though it is generally manageable with proper patient selection and technique. It is fundamentally important to tailor the specific treatment strategy to the clinical and anatomical characteristics of each patient. Percutaneous treatments for acute PE and DVT represent valuable options in the therapeutic arsenal, offering enhanced outcomes in appropriately selected patients. Ongoing advancements in technology and technique, along with comprehensive clinical trials, are essential to further define the role and optimize the use of these interventions.

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.

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.

Safety and Efficacy of Reduced-Dose Versus Full-Dose Alteplase for Acute Pulmonary Embolism: A Multicenter Observational Comparative Effectiveness Study

OBJECTIVES

Systemic thrombolysis improves outcomes in patients with pulmonary embolism (PE) but is associated with the risk of hemorrhage. The data on efficacy and safety of reduced-dose alteplase are limited. The study objective was to compare the characteristics, outcomes, and complications of patients with PE treated with full- or reduced-dose alteplase regimens.

DESIGN

Multicenter retrospective observational study.

SETTING

Tertiary care hospital and 15 community and academic centers of a large healthcare system.

PATIENTS

Hospitalized patients with PE treated with systemic alteplase.

INTERVENTIONS

None.

MEASUREMENTS AND MAIN RESULTS

Pre- and post-alteplase hemodynamic and respiratory variables, patient outcomes, and complications were compared. Propensity score (PS) weighting was used to adjust for imbalances of baseline characteristics between reduced- and full-dose patients. Separate analyses were performed using the unweighted and weighted cohorts. Ninety-eight patients were treated with full-dose (100 mg) and 186 with reduced-dose (50 mg) regimens. Following alteplase, significant improvements in shock index, blood pressure, heart rate, respiratory rate, and supplemental oxygen requirements were observed in both groups. Hemorrhagic complications were lower with the reduced-dose compared with the full-dose regimen (13% vs. 24.5%, p = 0.014), and most were minor. Major extracranial hemorrhage occurred in 1.1% versus 6.1%, respectively ( p = 0.022). Complications were associated with supratherapeutic levels of heparin anticoagulation in 37.5% of cases and invasive procedures in 31.3% of cases. The differences in complications persisted after PS weighting (15.4% vs. 24.7%, p = 0.12 and 1.3% vs. 7.1%, p = 0.067), but did not reach statistical significance. There were no significant differences in mortality, discharge destination, ICU or hospital length of stay, or readmission after PS weighting.

CONCLUSIONS

In a retrospective, PS-weighted observational study, when compared with the full-dose, reduced-dose alteplase results in similar outcomes but fewer hemorrhagic complications. Avoidance of excessive levels of anticoagulation or invasive procedures should be considered to further reduce complications.

Reduced-Dose Thrombolysis in Acute Pulmonary Embolism A Systematic Review

Pulmonary embolism (PE) is the third-leading cause of cardiovascular mortality and the second-leading cause of death in cancer patients. The clinical efficacy of thrombolysis for acute PE has been proven, yet the therapeutic window seems narrow, and the optimal dosing for pharmaceutical reperfusion therapy has not been established. Higher doses of systemic thrombolysis inevitably associated with an incremental increase in major bleeding risk. To date, there is no high-quality evidence regarding dosing and infusion rates of thrombolytic agents to treat acute PE. Most clinical trials have focused on thrombolysis compared with anticoagulation alone, but dose-finding studies are lacking. Evidence is now emerging that lower-dose thrombolytic administered through a peripheral vein is efficacious in accelerating thrombolysis in the central pulmonary artery and preventing acute right heart failure, with reduced risk for major bleeding. The present review will systematically summarize the current evidence of low-dose thrombolysis in acute PE.

Intraoperative circulatory arrest secondary to high-risk pulmonary embolism. Case series and updated literature review

BACKGROUND

Intraoperative pulmonary embolism (PE) with cardiac arrest (CA) represents a critical and potentially fatal condition. Available treatments include systemic thrombolysis, catheter-based thrombus fragmentation or aspiration, and surgical embolectomy. However, limited studies are focused on the optimal treatment choice for this critical condition. We present a case series and an updated review of the management of intraoperative CA secondary to PE.

METHODS

A retrospective review of patients who developed high-risk intraoperative PE was performed between June 2012 and June 2022. For the updated review, a literature search on PubMed and Scopus was conducted which resulted in the inclusion of a total of 46 articles.

RESULTS

A total of 196 174 major non-cardiac surgeries were performed between 2012 and 2022. Eight cases of intraoperative CA secondary to high-risk PE were identified. We found a mortality rate of 75%. Anticoagulation therapy was administered to one patient (12.5%), while two patients (25%) underwent thrombolysis, and one case (12.5%) underwent mechanical thrombectomy combined with thrombus aspiration. Based on the literature review and our 10-year experience, we propose an algorithm for the management of intraoperative CA caused by PE.

CONCLUSION

The essential components for adequate management of intraoperative PE with CA include hemodynamic support, cardiopulmonary resuscitation, and the implementation of a primary perfusion intervention. The prompt identification of the criteria for each specific treatment modality, guided by the individual patient's characteristics, is necessary for an optimal approach.

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.

Troponin dependent 30-day mortality in patients with acute pulmonary embolism

BACKGROUND

Troponin concentrations above upper reference are associated with increased mortality in patients with pulmonary embolism (PE). We aimed to assess whether risk of 30-day mortality increases in a dose-response relationship with concentration of troponin.

METHODS

Using Danish national registries, we identified patients ≥ 18 years of age hospitalized with first-time PE between 2013 and 2018 and available troponin measurements - 1/+1 day from admission. Patients were stratified into quintiles by increasing troponin concentration. Risk of 30-day mortality was assessed performing cumulative mortality curves and Cox regression model comparing the troponin quintiles.

RESULTS

We identified 5,639 PE patients of which 3,278 (58%) had a troponin concentration above upper reference. These patients were older (74 years), 50% male and with heavier comorbidity compared to patients with non-elevated troponin. We found increasing 30-day mortality with increasing troponin concentration (1% in 1st quintile (95% CI 0.5-1.5%), 2% in 2nd quintile (95% CI 1-2.5%), 8% in 3rd quintile (95% CI 5-9%), 11% in 4th quintile (95% CI 9-13%) and 15% in 5th quintile (95% CI 13-16%), confirmed in a Cox model comparing 1st quintile with 2nd quintile (HR 1.09; 95% CI 0.58-2.02), 3rd quintile (HR 3.68; 95% CI 2.20-6.15), 4th quintile (HR 5.51; 95% CI 3.34-9.10) and 5th quintile (HR 8.09; 95% CI 4.95-13.23).

CONCLUSION

30-day mortality was strongly associated with troponin concentration useful for improving risk stratification, treatment strategies and outcomes in PE patients.

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.

Half-Dose tPA for Massive Pulmonary Thromboembolism After Liposuction

Background

The most aggressive preventive strategies may fail to prevent pulmonary embolism (PE) after liposuction. PE can cause serious life-threatening consequences and death. If hemodynamic detoriation occurs, treatment is systemic or catheter-directed fibrinolytic therapy and, if failed, surgical embolectomy. A latent risk exists for catastrophic hemorrhage when thrombolytic is administered after surgery. Thus, the use of tissue plasminogen activator (tPA) has never been studied in postoperative patients, and the safety of this medicine is unknown. In this case study, a 31-year-old obese woman was evaluated for complaints of shortness of breath, palpitations, and hypotension in the first postoperative day after liposuction.

Conclusions

Successful management of massive PE with a half-dose regimen of tPA (alteplase 50 mg over 2 hours) is reported.

In silico assessment of histotripsy-induced changes in catheter-directed thrombolytic delivery

Introduction: For venous thrombosis patients, catheter-directed thrombolytic therapy is the standard-of-care to recanalize the occluded vessel. Limitations with thrombolytic drugs make the development of adjuvant treatments an active area of research. One potential adjuvant is histotripsy, a focused ultrasound therapy that lyses red blood cells within thrombus via the spontaneous generation of bubbles. Histotripsy has also been shown to improve the efficacy of thrombolytic drugs, though the precise mechanism of enhancement has not been elucidated. In this study, in silico calculations were performed to determine the contribution of histotripsy-induced changes in thrombus diffusivity to alter catheter-directed therapy. Methods: An established and validated Monte Carlo calculation was used to predict the extent of histotripsy bubble activity. The distribution of thrombolytic drug was computed with a finite-difference time domain (FDTD) solution of the perfusion-diffusion equation. The FDTD calculation included changes in thrombus diffusivity based on outcomes of the Monte Carlo calculation. Fibrin degradation was determined using the known reaction rate of thrombolytic drug. Results: In the absence of histotripsy, thrombolytic delivery was restricted in close proximity to the catheter. Thrombolytic perfused throughout the focal region for calculations that included the effects of histotripsy, resulting in an increased degree of fibrinolysis. Discussion: These results were consistent with the outcomes of in vitro studies, suggesting histotripsy-induced changes in the thrombus diffusivity are a primary mechanism for enhancement of thrombolytic drugs.

Low-Dose Alteplase versus Conventional Anticoagulation to treat Submassive Pulmonary Embolism in Hispanic Patients

The use of low-dose tissue plasminogen activator (tPA) in Hispanic patients with submassive pulmonary embolism (PE) is understudied. The purpose of this study is to explore the use of low-dose tPA in Hispanic patients with submissive PE compared with counterparts that received heparin alone. We retrospectively analyzed a single-center registry of patients with acute PE between 2016 and 2022. Out of 72 patients admitted for acute PE and cor pulmonale, we identified six patients that were treated with conventional anticoagulation (heparin alone) and six patients who received low-dose tPA (and heparin afterward). We analyzed if low-dose tPA was associated with differences in length of stay (LOS) and bleeding complications. Both groups were similar in regard to age, gender, and PE severity (based on Pulmonary Embolism Severity Index scores). Mean total LOS for the low-dose tPA group was 5.3 days, compared with 7.3 days in the heparin group ( p  = 0.29). Mean intensive care unit (ICU) LOS for the low-dose tPA group was 1.3 days compared with 3 days in the heparin group ( p  = 0.035). There were no clinically relevant bleeding complications documented in either the heparin or the low-dose tPA group. Low-dose tPA for submassive PE in Hispanic patients was associated with a shorter ICU LOS without a significant increase in bleeding risk. Low-dose tPA appears to be a reasonable treatment option in Hispanic patients with submassive PE who are not at high bleeding risk (<5%).

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.

Systemic reduced-dose alteplase for diffuse pulmonary thrombi in a COVID-19 patient

Pulmonary embolism has a high frequency in COVID-19 patients admitted to the intensive care unit. Low level of fibrinolysis is one of the asserted contributors to a prothrombotic state in COVID-19. Thrombotic coagulopathy is mostly encountered as diffuse pulmonary thrombi. Diffuse pulmonary microemboli was treated successfully with reduced dose thrombolysis.

Successful management of hemodynamic instability secondary to saddle pulmonary embolism-induced cardiac arrest using VA-ECMO in advanced malignancy with brain metastases

BACKGROUND

Saddle pulmonary embolism (SPE) represents a rare type of venous thromboembolism that frequently causes circulation collapse and sudden death. While venoarterial extracorporeal membrane oxygenation (VA-ECMO) has been well established as a salvage treatment for SPE-induced circulatory shock, it is infrequently administered in patients with advanced malignancy, especially those with brain metastases, given the potential bleeding complications and an uncertain prognosis. As far, there are rare case reports regarding the successful management of hemodynamic instability secondary to SPE-induced cardiac arrest using VA-ECMO in advanced malignancy patients with brain metastases.

CASE PRESENTATION

A 65-year-old woman presenting with cough and waist discomfort who had a history of lung cancer with brain metastases was admitted to the hospital to receive chemoradiotherapy. She suffered sudden cardiac arrest during hospitalization and returned to spontaneous circulation after receiving a 10-min high-quality cardiopulmonary resuscitation. Pulmonary embolism was suspected due to the collapsed hemodynamics and a distended right ventricle identified by echocardiography. Subsequent computed tomographic pulmonary angiography revealed a massive saddle thrombus straddling the bifurcation of the pulmonary trunk. VA-ECMO with adjusted-dose systemic heparinization was initiated to rescue the unstable hemodynamics despite receiving thrombolytic therapy with alteplase. Immediately afterward, the hemodynamic status of the patient stabilized rapidly. VA-ECMO was successfully discontinued within 72 h of initiation without any clotting or bleeding complications. She was weaned off invasive mechanical ventilation on the 6th day of intensive care unit (ICU) admission and discharged from the ICU 3 days later with good neurological function.

CONCLUSION

VA-ECMO may be a 'bridging' therapy to circulation recovery during reperfusion therapy for SPE-induced hemodynamic collapse in malignancy patients with brain metastases.

Pulmonary embolism in patients with severe COVID-19 treated with systemic low-dose thrombolytic therapy: A case series

Coronavirus disease 2019 (COVID-19) has been associated with respiratory failure and high mortality. Hypercoagulability and thromboembolic complications have been found in a high percentage of patients amongst which, pulmonary embolism (PE) is the most common. Currently, there are no guidelines on using thrombolysis therapy in COVID-19 patients who developed PE. We present five survivors aged 30-75 years old with confirmed COVID-19. All cases were proven by computed tomography pulmonary angiogram (CTPA) to have PE treated with low-dose recombinant tissue plasminogen activator (rtPA). PE should be suspected in all COVID-19 patients with rapid worsening of dyspnea, desaturation, unexplained shock, and increased level of D-dimer and fibrinogen. In our cases, PE developed despite preventative anticoagulation regimens with low molecular weight heparin. After thrombolytic therapy, all patients showed improvement in partial-arterial-oxygen-pressure to inspired oxygen-fraction ratio (arterial partial pressure of oxygen/inspired oxygen fraction ratio). D-dimer showed elevation after thrombolytic therapy and decreased in the following days. Fibrinogen levels decreased following thrombolytic therapy. Current anticoagulation regimens seem insufficient to halt the course of thrombosis, and thrombolytic therapy may be beneficial for patients with severe COVID-19 and PE. Systemic thrombolysis therapy is a double-edged sword, and clinicians must balance between benefit and risk of bleeding.

Dilemmas in the Choice of Adequate Therapeutic Treatment in Patients with Acute Pulmonary Embolism—From Modern Recommendations to Clinical Application

Pulmonary thromboembolism is a very common cardiovascular disease, with a high mortality rate. Despite the clear guidelines, this disease still represents a great challenge both in diagnosis and treatment. The heterogeneous clinical picture, often without pathognomonic signs and symptoms, represents a huge differential diagnostic problem even for experienced doctors. The decisions surrounding this therapeutic regimen also represent a major dilemma in the group of patients who are hemodynamically stable at initial presentation and have signs of right ventricular (RV) dysfunction proven by echocardiography and positive biomarker values (pulmonary embolism of intermediate–high risk). Studies have shown conflicting results about the benefit of using fibrinolytic therapy in this group of patients until hemodynamic decompensation, due to the risk of major bleeding. The latest recommendations give preference to new oral anticoagulants (NOACs) compared to vitamin K antagonists (VKA), except for certain categories of patients (patients with antiphospholipid syndrome, mechanical valves, pregnancy). When using oral anticoagulant therapy, special attention should be paid to drug–drug interactions, which can lead to many complications, even to the death of the patient. Special population groups such as pregnant women, obese patients, patients with antiphospholipid syndrome and the incidence of cancer represent a great therapeutic challenge in the application of anticoagulant therapy. In these patients, not only must the effectiveness of the drugs be taken into account, but great attention must be paid to their safety and possible side effects, which is why a multidisciplinary approach is emphasized in order to provide the best therapeutic option.

Trends in management and outcomes of pulmonary embolism with a multidisciplinary response team

Multidisciplinary pulmonary embolism (PE) response teams have garnered widespread adoption given the complexities of managing acute PE and provide a platform for assessment of trends in therapy and outcomes. We describe temporal trends in PE management and outcomes following the deployment of such a team. All consecutive patients managed by our multidisciplinary PE response team activated by the Emergency Department were included over a 5-year calendar period. We examined temporal trends in management and rates of a composite primary endpoint (all-cause-death, major bleeding, recurrent venous thromboembolism, and readmission) at 30 days and 6 months. We assessed 425 patients between 2015 and 2019. We observed an increase in PE acuity and use of systemic thrombolysis. The primary endpoint at 30 days decreased from 16.3% in 2015 to 7.1% in 2019 (adjusted rate ratio per period, 0.63; 95%CI, 0.47-0.84), driven by a decrease in the adjusted rate of major bleeding. Among 406 patients with complete follow-up, the adjusted rate ratio per year for the primary outcome at 6 months was 0.37 (95%CI, 0.19-0.71), driven by a decrease in all-cause mortality. We observed evidence of temporal changes in clinical presentation, therapeutic strategies, and outcomes for acute PE, in parallel to, but not necessarily because of, the implementation of a multidisciplinary response team. Over time, major bleeding, mortality and readmission rates decreased, despite an increase in PE risk category.

An Auxiliary Scoring Model for Patients with Acute Pulmonary Embolism Complicated with Atrial Fibrillation Was Established Based on Random Forests

The purpose of this study was to explore the establishment of an auxiliary scoring model for patients with acute pulmonary embolism (APE) complicated with atrial fibrillation (AF) based on random forest (RF) and its application effect. A retrospective analysis was performed on the general data, underlying diseases, laboratory indicators, and cardiac indicators of 100 patients with APE admitted to our hospital from 2018 to 2021. The occurrence of atrial fibrillation in patients with pulmonary embolism was taken as a categorical variable, and the general data, underlying diseases, laboratory indicators, and cardiac indicators were taken as input variables. Then, the risk auxiliary scoring model for patients with APE complicated with AF was established based on RF and logistic regression. Finally, the accuracy, sensitivity, specificity, recall rate, accuracy, F1 value, and the receiver operator characteristic (ROC) curve were used to evaluate the predictive value of the models. After statistical analysis, the optimal node value was 3 and the optimal number of decision trees was 500 in the RF model. The importance of predictors in descending order were Hcy, diabetes mellitus, FT3 level, UA level, left atrial diameter, hypertension, and smoking history. The prediction accuracy of the RF model was 0.934, sensitivity 0.966, specificity 0.876, recall rate 0.9660, accuracy 0.934, and F1 value 0.950. The logistic regression model prediction accuracy was 0.816, sensitivity 0.915, specificity 0.125, recall rate 0.902, accuracy 0.811, and F1 value 0.896. The RF model and logistic regression prediction model AUC values were 0.984 and 0.883, respectively. From this, we conclude that the RF model was better than the logistic regression model in predicting AF in APE patients. So, the RF model had the clinical application value.

Management of High-Risk Pulmonary Embolism: What Is the Place of Extracorporeal Membrane Oxygenation?

Pulmonary embolism (PE) is a common disease with an annual incidence rate ranging from 39-115 per 100,000 inhabitants. It is one of the leading causes of cardiovascular mortality in the USA and Europe. While the clinical presentation and severity may vary, it is a life-threatening condition in its most severe form, defined as high-risk or massive PE. Therapeutic options in high-risk PE are limited. Current guidelines recommend the use of systemic thrombolytic therapy as first-line therapy (Level Ib). However, this treatment has important drawbacks including bleeding complications, limited efficacy in patients with recurrent PE or cardiac arrest, and formal contraindications. In this context, the use of venoarterial extracorporeal membrane oxygenation (VA-ECMO) in the management of high-risk PE has increased worldwide in the last decade. Strategies, including VA-ECMO as a stand-alone therapy or as a bridge to alternative reperfusion therapies, are associated with acceptable outcomes, especially if implemented before cardiac arrest. Nonetheless, the level of evidence supporting ECMO and alternative reperfusion therapies is low. The optimal management of high-risk PE patients will remain controversial until the realization of a prospective randomized trial comparing those cited strategies to systemic thrombolysis.

How Would You Treat This Patient With Pulmonary Embolism? : Grand Rounds Discussion From Beth Israel Deaconess Medical Center

Pulmonary embolism can be acutely life-threatening and is associated with long-term consequences such as recurrent venous thromboembolism and chronic thromboembolic pulmonary hypertension. In 2020, the American Society of Hematology published updated guidelines on the management of patients with venous thromboembolism. Here, a hematologist and a cardiology and vascular medicine specialist discuss these guidelines in the context of the care of a patient with pulmonary embolism. They discuss advanced therapies such as catheter-directed thrombolysis in the short-term management of patients with intermediate-risk disease, recurrence risk stratification at presentation, and ideal antithrombotic regimens for patients whose pulmonary embolism was associated with a transient minor risk factor.

Outcomes of Catheter-Delivered Thrombolytic Therapy and Resuscitative Measures in a Cardiac Arrest Patient With Massive Pulmonary Embolism: A Case Report

Acute massive pulmonary embolism is the most critical presentation of venous thromboembolism that needs early detection and management for a better outcome. We present the case of a 42-year-old female who presented to the emergency department (ED) complaining of acute dyspnea and descended into cardiac arrest. Working through the advanced cardiac life support guidelines and appropriate resuscitative measures, having high clinical suspicion supported by bedside ultrasound findings, massive pulmonary embolism was the most likely diagnosis, and so the patient was treated with thrombolytic therapy delivered via a central venous catheter. Return of spontaneous circulation was achieved, and consequently, she made a complete recovery with no adverse neurological or hemodynamic sequelae. The aim of presenting this topic is to review the literature available on approaches to thrombolytic doses in life-threatening cases of massive pulmonary embolism and to add to an already ongoing discussion about the effects and outcomes of various dosing regimens. The above facts will lead us to conclude that any discussion seeks to remind us of the primary management principle. All physicians should bear this in mind while managing any case ("primum non-nocere," which is a Latin phrase that means "first, do no harm"); it helps to fuel ideologies to seek best practice interventions that ensure the best outcome for pulmonary embolism patients. And such experiences are worth sharing with the world.

Contemporary Treatment of Pulmonary Embolism: Medical Treatment and Management

Pulmonary embolus (PE) is defined as obstruction of the pulmonary artery or one of its branches by material (e.g., thrombus, tumor, air, or fat) but most commonly due to thrombus originating from the lower extremity deep veins.

We reviewed the current literature describing the optimal medical treatment and management of PE.

Databases (PubMed, the Cochrane Library, Embase, EBSCO, Web of Science, and CINAHL) were searched for relevant studies and guidelines for management of patients with PE.

The initial approach to patients with suspected PE should focus upon stabilizing the patient while further workup for risk stratification is in progress. In most cases, anticoagulation should ideally be started even prior to confirming PE, if risk–benefit regarding suspicion of PE and bleeding risk is favorable.

Once the diagnosis is confirmed, risk stratification will guide further therapies consisting of anticoagulation, thrombolysis, or catheter-directed interventions. Data for initial, long-term, and indefinite anticoagulation, and factors that determine whether or not a patient can be treated in the outpatient setting, are reviewed and discussed.

Association Between the Use of Pre- and Post-thrombolysis Anticoagulation With All-Cause Mortality and Major Bleeding in Patients With Pulmonary Embolism

Objective

To explore the comparative clinical efficacy and safety outcomes of anticoagulation before (pre-) or following (post-) thrombolytic therapy in systemic thrombolytic therapy for pulmonary embolism (PE).

Methods

PubMed, the Cochrane Library, EMBASE, EBSCO, Web of Science, and CINAHL databases were searched from inception through 1 May 2021. All randomized clinical trials comparing systemic thrombolytic therapy vs. anticoagulation alone in patients with PE and those that were written in English were eligible. The primary efficacy and safety outcomes were all-cause mortality and major bleeding, respectively. Odds ratios (OR) estimates and associated 95% confidence intervals (CIs) were calculated. A Bayesian network analysis was performed using R studio software, and then the efficacy and safety rankings were derived.

Results

This network meta-analysis enrolled 15 trials randomizing 2,076 patients. According to the plot rankings, the anticoagulant therapy was the best in terms of major bleeding, and the post-thrombolysis anticoagulation was the best in terms of all-cause mortality. Taking major bleeding and all-cause mortality into consideration, the most safe–effective treatment was the post-thrombolysis anticoagulation in patients who needed thrombolytic therapy. The net clinical benefit analysis comparing associated ICH benefits vs. mortality risks of post-thrombolysis anticoagulation demonstrated a net clinical benefit of 1.74%.

Conclusion

The systemic thrombolysis followed by anticoagulation had a better advantage in all-cause mortality and major bleeding than the systemic thrombolysis before anticoagulation. The adjuvant anticoagulation treatment of systemic thrombolytic therapy should be optimized.

Intermediate-risk pulmonary embolism: echocardiography predictors of clinical deterioration

Background

We determine the predictive value of transthoracic echocardiographic (TTE) metrics for clinical deterioration within 5 days in adults with intermediate-risk pulmonary embolism (PE).

Methods

This was a prospective observational study of intermediate-risk PE patients. To determine associations of TTE and clinical predictors with clinical deterioration, we used univariable analysis, Youden’s index for optimal thresholds, and multivariable analyses to report odds ratios (ORs) or area under the curve (AUC).

Results

Of 306 intermediate-risk PE patients, 115 (37.6%) experienced clinical deterioration. PE patients who had clinical deterioration within 5 days had greater baseline right ventricle (RV) dilatation and worse systolic function than the group without clinical deterioration as indicated by the following: RV basal diameter 4.46 ± 0.77 versus 4.20 ± 0.77 cm; RV/LV basal width ratio 1.14 ± 0.29 versus 1.02 ± 0.24; tricuspid annular plane systolic excursion (TAPSE) 1.56 ± 0.55 versus 1.80 ± 0.52 cm; and RV systolic excursion velocity 10.40 ± 3.58 versus 12.1 ± 12.5 cm/s, respectively. Optimal thresholds for predicting clinical deterioration were: RV basal width 3.9 cm (OR 2.85 [1.64, 4.97]), RV-to-left ventricle (RV/LV) ratio 1.08 (OR 3.32 [2.07, 5.33]), TAPSE 1.98 cm (OR 3.3 [2.06, 5.3]), systolic excursion velocity 10.10 cm/s (OR 2.85 [1.75, 4.63]), and natriuretic peptide 190 pg/mL (OR 2.89 [1.81, 4.62]). Significant independent predictors were: transient hypotension 6.1 (2.2, 18.9), highest heart rate 1.02 (1.00, 1.03), highest respiratory rate 1.02 (1.00, 1.04), and RV/LV ratio 1.29 (1.14, 1.47). By logistic regression and random forest analyses, AUCs were 0.80 (0.73, 0.87) and 0.78 (0.70, 0.85), respectively.

Conclusions

Basal RV, RV/LV ratio, and RV systolic function measurements were significantly different between intermediate-risk PE patients grouped by subsequent clinical deterioration.

Supplementary Information

The online version contains supplementary material available at 10.1186/s13054-022-04030-z.

Star Polymers as Non-Viral Carriers for Apoptosis Induction

Apoptosis is a widely controlled, programmed cell death, defects in which are the source of various diseases such as neurodegenerative diseases as well as cancer. The use of apoptosis in the therapy of various human diseases is of increasing interest, and the analysis of the factors involved in its regulation is valuable in designing specific carriers capable of targeting cell death. Highly efficient and precisely controlled delivery of genetic material by low-toxic carriers is one of the most important challenges of apoptosis-based gene therapy. In this work, we investigate the effect of the star polymer with 28 poly(N,N′-dimethylaminoethyl methacrylate) arms (STAR) on human cells, according to its concentration and structure. We show that star polymer cytotoxicity increases within its concentration and time of cells treatment. Except for cytotoxic effect, we observe morphological changes such as a shrinkage, loss of shape and begin to detach. We also prove DNA condensation after star polymer treatment, one of the most characteristic feature of apoptosis. The results indicate that the use of STAR triggers apoptosis in cancer cells compared to various normal cells, what makes these nanoparticles a promising drug in therapeutic strategy, which targets apoptosis. We demonstrate highlighting potential of star polymers as an innovative tool for anti-cancer therapy.

Massive pulmonary embolism treated with low-dose thrombolysis on the geriatric ward during the COVID-19 pandemic

A man in his 70s was admitted to hospital due to a fall, urinary tract infection and delirium. The patient had a ‘do not attempt cardiopulmonary resuscitation’ order in place and a ward-based ceiling of care was agreed. He tested positive for COVID-19 while on a geriatric ward and subsequently developed bilateral pulmonary emboli with haemodynamic instability. The patient had a significant bleeding risk; however, the expected morbidity and mortality risk from the pulmonary emboli was high. A decision was made to give the patient low-dose thrombolysis on the geriatric ward, following which he made a full recovery. Acute thrombolysis is normally performed in emergency department, high dependency unit (HDU) or intensive care unit (ICU) settings; however, this was not possible in this case due to the burden the COVID-19 pandemic had placed on HDU/ICU services and bed capacity. Adaptation of treatment guidelines allowed for emergency life-saving treatment to be delivered to this patient.

Tenecteplase in Pulmonary Embolism Patients: A Meta-Analysis and Systematic Review

Objective

To assess the efficacy and safety of tenecteplase in patients with pulmonary embolism (PE).

Methods

We completed the literature search on May 31, 2021 using PubMed, EMBASE and the Web of Science. Analyses were conducted according to PE risk stratification, study design and duration of follow-up. The pooled risk ratios (RRs) and its 95% confident intervals (CIs) for death and major bleeding were calculated using a random-effect model.

Results

A total of six studies, with four randomized controlled trials (RCTs) and two cohort studies, were included in this study out of the 160 studies retrieved. For patients with high-risk PE, tenecteplase increased 30-day survival rate (16% vs 6%; P = 0.005) and did not increase the incidence of bleeding (6% vs 5%; P = 0.73). For patients with intermediate-risk PE, four RCTs suggested that tenecteplase reduced right ventricular insufficiency at 24h early in the onset and the incidence of hemodynamic failure without affecting mortality in a short/long-term [<30 days RR = 0.83, 95% CI (0.47, 1.46);≥30 days RR = 1.04, 95% CI (0.88, 1.22)]. However, tenecteplase was associated with high bleeding risk [<30 days RR = 1.79, 95% CI (1.61, 2.00); ≥30 days RR = 1.28, 95% CI (0.62, 2.64)].

Conclusions

Tenecteplase may represent a promising candidate for patients with high risk PE. However, tenecteplase is not recommended for patients with intermediate-risk PE because of high bleeding risk. More large-scale studies focused on tenecteplase are still needed for PE patients.

Post-thrombolytic coagulopathy and complications in patients with pulmonary embolism treated with fixed-dose systemic alteplase

BACKGROUND

Alteplase treatment can cause a systemic coagulopathy although the incidence and contributory factors are unknown in pulmonary embolism (PE). Fixed-dosing of alteplase for PE may lead to interpatient variability in drug exposure and influence post-thrombolytic coagulopathy (PTC). While changes in fibrinogen and INR have been used to describe PTC, no universal PTC definition is available.

OBJECTIVES

Evaluate the incidence of PTC after alteplase treatment for PE, the effect of patient weight and blood/plasma volume and the association with bleeding complications.

METHODS

We conducted a retrospective cohort study of patients treated with alteplase for massive or high-risk submassive PE. Demographics, alteplase dosing, laboratory assessment of coagulopathy, and bleeding events were collected. The primary endpoint was incidence of PTC defined as an international normalized ratio (INR) > 1.5 or fibrinogen < 170 mg/dL. Secondary outcomes included correlation between coagulopathies and alteplase dose normalized to actual body weight (ABW), ideal body weight (IBW), plasma volume (PV), and estimated blood volume (EBV). Bleeding events in patients with and without PTC were compared.

RESULTS

125 patients met criteria for inclusion in the study. PTC occurred in 35.3% of patients, with INR >1.5 in 21.8% and fibrinogen <170 mg/dL in 26%. Alteplase dose >50 mg was associated with increased odds of PTC (OR 6.5, CI 2.1-19.9). Dose normalized to ABW and EBV correlated weakly with absolute increase in post-alteplase INR (r =0.20, p =0.06 and r =0.21, p =0.057 respectively) and to percent change in INR (r =0.20, p = 0.058 and r =0.21, p =0.048 respectively). Dose/ABW, dose/PV, and dose/EBV each correlated moderately with absolute decrease in fibrinogen (r =-0.53, -0.49, and -0.47 respectively, p <0.001 for each) and percent change in fibrinogen (r = -0.55, -0.49, and -0.49 respectively, p < 0.001 for each). Dose/IBW correlated weakly with absolute and percent decrease in fibrinogen (r = -0.32, p =0.013 and r =-0.33, p =0.011). Patients with bleeding were more likely to have PTC (58.3% vs. 28.6%, p= 0.05) and a bleeding event was predictive of PTC (OR 5.33, 1.32-23.99).

CONCLUSIONS

PTC is prevalent in patients with PE. PTC is influenced by alteplase dose and exposure parameters (ABW, IBW, PV, EBV) and may contribute to the bleeding risk.

EKOS™ Jena Experience: Safety, Feasibility, and Midterm Outcomes of Percutaneous Ultrasound-Assisted Catheter-Directed Thrombolysis in Patients with Intermediate-High-Risk or High-Risk Pulmonary Embolism

Background

Percutaneous catheter-based ultrasound-assisted thrombolysis (UACDT) is recommended for patients with intermediate-high-risk or high-risk pulmonary embolism (PE) in whom systemic thrombolysis has failed or is contraindicated.

Aim

To evaluate the safety and efficiency of UACDT in patients with intermediate-high-risk or high-risk PE.

Methods

Between October 2017 and January 2020, we performed UACDT using the EkoSonic™ Endovascular System (EKOS™) in 51 patients (21 males, age 63 ± 18 years) with a sPESI of 1.3 ± 0.7. The EKOS™-catheter was implanted within 24 h after admission. Over 15 hours, 11.5 mg of alteplase was administered per catheter. We evaluated right ventricular stress and cardiac biomarkers before and after UACDT.

Results

24 h post-UACDT, median RV/LV ratio decreased from 1.13 to 0.96 (p < 0.001) and the mean sPAP decreased from 47 ± 3 to 32 ± 2 mmHg + CVP (p < 0.0002). There were 6 major bleeding events resulting in transfusion. No stroke, myocardial infarction, right heart decompensation, or recurrent PE occurred. 31 patients (63%) were discharged without any signs of right ventricular stress. After at least 3 months, 73% of our patients did not show any signs of right ventricular dysfunction. The mean RV/LV ratio decreased to 0.75 ± 0.03 (p < 0.0001) in comparison with pre-UACDT, sPAP to 23  mmHg + CVP (p < 0.0001), and BNP to 40 pg/ml (p < 0.0001).

Conclusions

The treatment with UACDT reduced right heart stress during the first 24 hours and midterm in patients with intermediate-high-risk or high-risk PE at an acceptable rate of severe complications.

Submassive Pulmonary Embolism Treated With Catheter-Directed Thrombolysis in Resource-Limited Setting: A Case Report and Review of Literature

We describe a case of a young male who presented with acute onset progressively worsening shortness of breath for four days duration. He used to smoke cigarettes, and his profession required prolonged periods of standing. He underwent a two-dimensional echocardiogram showing right ventricular (RV) strain and computed tomography (CT) showing thrombus in the left major pulmonary artery. His pulmonary embolism severity index (PESI) score was high, predicting higher short-term mortality. Treatment options including risks and benefits were discussed with the patient, and he underwent catheter-directed thrombolysis (CDT) with rapid resolution of symptoms, oxygen saturation, and pulmonary artery pressures (PAP). He was discharged home safely after successful treatment of his condition.

Low-dose thrombolysis for submassive pulmonary embolism

The role of thrombolysis in submassive pulmonary embolism (PE) is controversial due to the high risk of hemorrhage. This study aimed to evaluate the role of half-dose tissue-type plasminogen activator (rt-PA) in preventing death/hemodynamic decompensation in submassive (intermediate-risk) PE without increasing the risk of bleeding. In a prospective, non-randomized, open-label, single-center trial, we compared 50 mg rt-PA plus low molecular weight heparin (LMWH) with LMWH in submassive (intermediate-risk) PE. Eligible cases had confirmed pulmonary hypertension on echocardiography, and/or right ventricular cavity expansion and/or interventricular septal deviation on echocardiography, and/or right to left ventricular ratio equal to or greater than 0.9 mm on CT angiography. The primary outcome was death or hemodynamic decompensation within 7 and 30 days after treatment was given. The primary safety outcome was major extracranial bleeding or hemorrhagic stroke within 7 days. Seventy-six patients were included in the study. Total death/hemodynamic decompensation in the first 7 and 30 days was significantly less in the half-dose rt-PA group than in the LMWH group (p=0.028 and p=0.009, respectively). No significant differences were found between the two groups in terms of recurrent embolism and pulmonary hypertension at 6-month follow-up (p=1.000 and p=0.778). There was no intracranial hemorrhage in any of the patients. There were no statistically significant differences between the two groups in terms of major or minor bleeding complications. This trial showed half-dose rt-PA treatment in submassive (intermediate-risk) PE prevented death/hemodynamic decompensation in the first 7-day and 30-day period compared with LMWH treatment without increasing the risk of bleeding.

Venous Thromboembolism for the Practicing Cardiologist

Venous thromboembolism (VTE), encompassing pulmonary embolism (PE) and deep vein thrombosis (DVT), is encountered commonly. Acute PE may present as a high-risk cardiovascular emergency, and acute DVT can cause acute and chronic vascular complications. The goal of this review is to ensure that cardiologists are comfortable managing VTE-including risk stratification, anticoagulation therapy, and familiarity with primary reperfusion therapy. Clinical assessment and determination of degree of right ventricular dysfunction are critical in initial risk stratification of PE and determination of parenteral versus oral anticoagulation therapy. Direct oral anticoagulants have emerged as preferred first-line oral anticoagulation strategy in VTE scenarios.

Neurological Complications of Pulmonary Embolism: a Literature Review

PURPOSE OF REVIEW

The present review discusses in-depth about neurological complications following acute venous thromboembolism (VTE).

RECENT FINDINGS

Intracranial hemorrhage, acute ischemic cerebrovascular events, and VTE in brain tumors are described as central nervous system (CNS) complications of PE, while peripheral neuropathy and neuropathic pain are reported as peripheral nervous system (PNS) sequelae of PE. Syncope and seizure are illustrated as atypical neurological presentations of PE. Mounting evidence suggests higher risk of venous thromboembolism (VTE) in patients with neurological diseases, but data on reverse, i.e., neurological sequelae following VTE, is underexplored. The present review is an attempt to explore some of the latter issues categorized into CNS, PNS, and atypical complications following VTE.

Efficacy and Safety of Different Dosage of Recombinant Tissue-type Plasminogen Activator (rt-PA) in the Treatment of Acute Pulmonary Embolism: A Systematic Review and Meta-analysis

Reperfusion therapies are recommended for patients with hemodynamic instability or high-risk acute pulmonary embolism (PE). Lower doses of tissue plasminogen activator (rt-PA) could be considered to improve bleeding complications. The aim of this study was to evaluate the efficacy and safety of a reduced dose of rt-PA for the treatment of acute PE, compared with anticoagulation and standard dose. PubMed Central, Scopus, Web of Science and Embase were searched for all relevant randomized studies and prospective observational studies that compared reduced dose of rt-PA with anticoagulation alone or standard dose of rt-PA in patients with acute PE. The risk ratios (RR, with 95% CI) were calculated according to the value of I2. Outcomes were described as bleeding events, all-cause death, and recurrence of PE. Thirteen articles, including four observational studies (4223 patients) and nine RCTs (780 patients), were included. In comparing reduced dose of rt-PA with anticoagulant, a greater incidence of total bleeding events in low dose was showed (RR, 5.08 (95% CI, (1.39–18.6), I2 = 0.0%). In the standard dose rt-PA vs. reduced dose, there was a greater incidence of total bleeding events in the standard dose of rt-PA, RR 1.48 (95% CI, (1.00–2.19), I2 = 0.0%) was shown. There were no statistical differences in recurrent PE or all-cause mortality. It concluded that in the absence of the benefit of a standard dose of rt-PA in comparison with dose reduction, a reduced dose of rt-PA showed a lower rate of total bleeding events and similar efficacy regarding mortality and PE recurrence rate.

Reduced-Dose Intravenous Thrombolysis for Acute Intermediate-High-risk Pulmonary Embolism: Rationale and Design of the Pulmonary Embolism International THrOmbolysis (PEITHO)-3 trial

Intermediate–high-risk pulmonary embolism (PE) is characterized by right ventricular (RV) dysfunction and elevated circulating cardiac troponin levels despite apparent hemodynamic stability at presentation. In these patients, full-dose systemic thrombolysis reduced the risk of hemodynamic decompensation or death but increased the risk of life-threatening bleeding. Reduced-dose thrombolysis may be capable of improving safety while maintaining reperfusion efficacy. The Pulmonary Embolism International THrOmbolysis (PEITHO)-3 study (ClinicalTrials.gov Identifier: NCT04430569) is a randomized, placebo-controlled, double-blind, multicenter, multinational trial with long-term follow-up. We will compare the efficacy and safety of a reduced-dose alteplase regimen with standard heparin anticoagulation. Patients with intermediate–high-risk PE will also fulfill at least one clinical criterion of severity: systolic blood pressure ≤110 mm Hg, respiratory rate >20 breaths/min, or history of heart failure. The primary efficacy outcome is the composite of all-cause death, hemodynamic decompensation, or PE recurrence within 30 days of randomization. Key secondary outcomes, to be included in hierarchical analysis, are fatal or GUSTO severe or life-threatening bleeding; net clinical benefit (primary efficacy outcome plus severe or life-threatening bleeding); and all-cause death, all within 30 days. All outcomes will be adjudicated by an independent committee. Further outcomes include PE-related death, hemodynamic decompensation, or stroke within 30 days; dyspnea, functional limitation, or RV dysfunction at 6 months and 2 years; and utilization of health care resources within 30 days and 2 years. The study is planned to enroll 650 patients. The results are expected to have a major impact on risk-adjusted treatment of acute PE and inform guideline recommendations.

Interventional Reperfusion Strategies for Acute Pulmonary Embolism

Acute pulmonary embolism (APE) is a common, potentially life-threatening cardiovascular emergency, and represents the third leading cause of cardiovascular mortality after myocardial infarction and stroke. Risk stratification is important to guide the management of APE, as an early reperfusion strategy is associated with improved clinical outcomes in specific high-risk conditions. Pulmonary artery reperfusion is commonly achieved by systemic intravenous administration of thrombolytic drugs, but catheter-directed thrombolysis (CDThr) and interventional techniques of catheter-based embolectomy provide novel therapeutic approaches with an improved risk-benefit ratio. Future trials will help to determine when to use these different devices in massive or sub-massive APE, and which patient population is likely to benefit from interventional treatment.