Interventional therapies for pulmonary embolism

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.

Electrocardiographic Changes after Endovascular Mechanical Thrombectomy in a Patient with Pulmonary Embolism-A Case Report and Literature Review

Background: Pulmonary embolism (PE) is a common disease with an annual incidence of about 1/1000 persons. About every sixth patient dies within the first 30 days after diagnosis. The electrocardiogram (ECG) is one of the first diagnostic tests performed, and is able to confirm the suspicion of PE with typical electrocardiographic signs. Some ECG signs and their regression are also prognostically relevant. Endovascular mechanical thrombectomy is one option for PE treatment, and aims to relieve right heart strain immediately. The first studies on endovascular mechanical thrombectomy using a dedicated device (FlowTriever System, Inari Medical, Irvine, CA, USA) yielded promising results. Methods: In the following, we report the case of a 66-year-old male patient who presented with New York Heart Association III dyspnea in our emergency department. Among typical clinical and laboratory results, he displayed very impressive electrocardiographic and radiological findings at the time of PE diagnosis. Results: After endovascular mechanical thrombectomy, the patient's complaints and pulmonary hemodynamics improved remarkably. In contrast, the ECG worsened paradoxically 18 h after intervention. Nevertheless, control echocardiography 4 days after the intervention no longer showed any signs of right heart strain, and dyspnea had disappeared completely. At a 4-month follow-up visit, the patient presented as completely symptom-free with a high quality of life. His ECG and echocardiography were normal and excluded recurrent right heart strain. Conclusions: Overall, the patient benefitted remarkably from endovascular mechanical thrombectomy, resulting in an almost complete resolution of electrocardiographic PE signs at the 4-month follow-up after exhibiting multiple typical electrocardiographic PE signs at time of diagnosis and initial electrocardiographic worsening 18 h post successful intervention.

Integrating Pharmacomechanical Treatments for Pulmonary Embolism Management within a Hub-and-Spoke System in the Swiss Ticino Region

The Swiss Ticino regional pulmonary embolism response team (PERT) features direct access to various pharmacomechanical PE management options within a hub/spoke system, by integrating evidence, guidelines' recommendations and personal experiences. This system involves a collaborative management of patients among the hospitals distributed throughout the region, which refer selected intermediate-high or high PE patients to a second-level hub center, located in Lugano at Cardiocentro Ticino, belonging to the Ente Ospedaliero Cantonale (EOC). The hub provides 24/7 catheterization laboratory activation for catheter-based intervention (CBI), surgical embolectomy and/or a mechanical support system such as extracorporeal membrane oxygenation (ECMO). The hub hosts PE patients after percutaneous or surgical intervention in two intensive care units, one specialized in cardiovascular anesthesiology, to be preferred for patients without relevant comorbidities or with hemodynamic instability and one specialized in post-surgical care, to be preferred for PE patients after trauma or surgery or with relevant comorbidities, such as cancer. From April 2022 to December 2023, a total of 65 patients were referred to the hub for CBI, including ultrasound-assisted catheter-directed thrombolysis (USAT) or large-bore aspiration intervention. No patient received ECMO or underwent surgical embolectomy.

Pulmonary Embolism: An Update Based on the Revised AWMF-S2k Guideline

Pulmonary embolism (PE) is the third most common acute cardiovascular disease. The risk of PE increases with age and mortality is high. Patients are stratified into hemodynamically stable versus unstable patients, as this has important implications for diagnosis and therapy. Since clinical signs and symptoms of acute PE are nonspecific, the clinical likelihood of PE is estimated to guide diagnostic pathways. D-dimer testing is performed in hemodynamically stable patients with low or intermediate probability of PE and the visualization of thromboembolism and its sequelae is commonly achieved with computed tomography pulmonary angiography (CTPA), supplemented by ultrasound techniques. With confirmed PE, another risk stratification estimates disease severity and defines intensity and setting of the ensuing treatment. The therapeutic spectrum ranges from outpatient treatment with initial oral anticoagulation to thrombolytic or interventional treatment in the intensive care unit or catheterization laboratory. In single cases, even acute surgical thrombectomy is attempted.

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.

Management of high and intermediate-high risk pulmonary embolism: A position paper of the Interventional Cardiology Working Group of the Italian Society of Cardiology

Pulmonary embolism (PE) is a potentially life-threatening condition that remains a major global health concern. Noteworthy, patients with high- and intermediate-high-risk PE pose unique challenges because they often display clinical and hemodynamic instability, thus requiring rapid intervention to mitigate the risk of clinical deterioration and death. Importantly, recovery from PE is associated with long-term complications such as recurrences, bleeding with oral anticoagulant treatment, pulmonary hypertension, and psychological distress. Several novel strategies to improve risk factor characterization and management of patients with PE have recently been introduced. Accordingly, this position paper of the Working Group of Interventional Cardiology of the Italian Society of Cardiology deals with the landscape of high- and intermediate-high risk PE, with a focus on bridging the gap between the evolving standards of care and the current clinical practice. Specifically, the growing importance of catheter-directed therapies as part of the therapeutic armamentarium is highlighted. These interventions have been shown to be effective strategies in unstable patients since they offer, as compared with thrombolysis, faster and more effective restoration of hemodynamic stability with a consistent reduction in the risk of bleeding. Evolving standards of care underscore the need for continuous re-assessment of patient risk stratification. To this end, a multidisciplinary approach is paramount in refining selection criteria to deliver the most effective treatment to patients with unstable hemodynamics. In conclusion, the current management of unstable patients with PE should prioritize tailored treatment in a patient-oriented approach in which transcatheter therapies play a central role.

In-Hospital versus Out-of-Hospital Pulmonary Embolism: Clinical Characteristics, Biochemical Markers and Echocardiographic Indices

BACKGROUND

A significant proportion of pulmonary embolisms (PEs) occurs in patients during hospitalisation for another reason. However, limited data regarding differences between out-of-hospital PE (OHPE) and in-hospital PE (IHPE) is available. We aimed to compare these groups regarding their clinical characteristics, biochemical markers, and echocardiographic indices.

METHODS

This was a prospective, single-arm, single-centre study. Adult consecutive patients with non-COVID-related PE from September 2019 to March 2022 were included and followed up for 12 months.

RESULTS

The study included 180 (84 women) patients, with 89 (49.4%) suffering from IHPE. IHPE patients were older, they more often had cancer, were diagnosed earlier after the onset of symptoms, they had less frequent pain and higher values of high sensitivity troponin I and brain natriuretic peptide levels compared to OHPE patients. Echocardiographic right ventricular (RV) dysfunction was detected in similar proportions in the 2 groups. IHPE had increased in-hospital mortality (14.6% vs. 3.3%, p = 0.008) and similar post-discharge to 12-month mortality with OHPE patients.

CONCLUSIONS

In this prospective cohort study, IHPE differed from OHPE patients regarding age, comorbidities, symptoms, and levels of biomarkers associated with RV dysfunction. IHPE patients had higher in-hospital mortality compared to OHPE patients and a similar risk of death after discharge.

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.

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.

Superhydrophilic and Antifriction Thin Hydrogel Formed under Mild Conditions for Medical Bare Metal Guide Wires

Medical guide wires play a crucial role in the process of intravascular interventional therapy. However, it is essential for bare metal guide wires to possess both hydrophilic lubricity and coating durability, avoiding tissue damage caused by friction inside the blood vessel during the interventional procedure. Additionally, it is still a huge challenge for diverse metal materials to bind with polymer coatings easily. Herein, we present a hydrogel coating scheme and its preparation method for various wires under mild conditions for environmental protection purposes. The preparation process involves surface pretreatment, including low-temperature heating and silanization, followed by a two-step dip coating and ultraviolet polymerization. The whole process leads to the formation of an interpenetrating cross-linked hydrogel network from the substrate to the surface section. This study confirms the superhydrophilicity and lubricity of three metal wires with the designed coating, especially reducing the friction significantly by ≥ 95%. The thin coating (average thickness <6.2 μm) demonstrates strong adhesion with various substrates and exhibits resistance to 25 or even 125 cycles of friction, indicating excellent stability and preventing easy detachment. The finally prepared composite nickel-titanium (NiTi) guide wire with stainless steel (SS) and platinum-tungsten (Pt-W) coils (overall diameter of ∼0.36 mm) shows satisfactory performance with a friction of 0.183 N for 25 cycles, meeting the clinical requirements (average friction ≤0.2 N) for interventional operation. These findings highlight the potential of this study in advancing the development of medical devices, particularly in the field of intravascular interventional therapy.

Mechanical thrombectomy in intermediate- and high-risk acute pulmonary embolism: hemodynamic outcomes at three months

BACKGROUND

Mechanical thrombectomy has been shown to reduce thrombus burden and pulmonary artery pressure (PAP) and to improve right ventricular (RV) function in patients with high-risk or intermediate-high-risk pulmonary embolism (PE). As hemodynamic data after mechanical thrombectomy for PE are scarce, we aimed to assess the hemodynamic effects of mechanical thrombectomy in acute PE with right heart overload.

METHODS

In this prospective, open-label study, patients with acute symptomatic, computed tomography-documented PE with signs of right heart overload underwent mechanical thrombectomy using the FlowTriever System. Right heart catheterization was performed immediately before and after thrombectomy and after three months. Transthoracic echocardiography was performed before thrombectomy, discharge, and at three months. This analysis was done after 20 patients completed three months of follow-up.

RESULTS

Twenty-nine patients (34% female) underwent mechanical thrombectomy, of which 20 completed three months follow-up with right heart catheterization. Most patients were at high (17%) or intermediate-high (76%) risk and had bilateral PE (79%). Before thrombectomy, systolic PAP (sPAP) was severely elevated (mean 51.3 ± 11.6 mmHg). Mean sPAP dropped by -15.0 mmHg (95% confidence interval [CI]: -18.9 to -11.0; p < 0.001) immediately after the procedure and continued to decrease from post-thrombectomy to three months (-6.4 mmHg, 95% CI: -10-0 to -2.9; p = 0.002). RV/left ventricular (LV) ratio immediately reduced within two days by -0.37 (95% CI: -0.47 to -0.27; p < 0.001). The proportion of patients with a tricuspid annular plane systolic excursion (TAPSE)/sPAP ratio < 0.31 mm/mmHg decreased from 28% at baseline to 0% before discharge and at three months (p = 0.007). There were no procedure-related major adverse events.

CONCLUSIONS

Mechanical thrombectomy for acute PE was safe and immediately reduced PAP and improved right heart function. The reduction in PAP was maintained at three months follow-up.