Immediate and late impact of reperfusion therapies in acute pulmonary embolism

Successful Treatment of Massive Pulmonary Embolism in Pregnancy with Catheter-Directed Embolectomy

Introduction  Pulmonary embolism (PE) is associated with approximately 10.5% of maternal deaths in the United States. Despite heightened awareness of its mortality potential, there islittle data available to guide its management in pregnancy. We present the case of a massive PE during gestation successfully treated with catheter-directed embolectomy. Case Presentation  A 37-year-old G2P1001 presented with a syncopal episode preceded by dyspnea and chest pain. Upon presentation, she was hypotensive, tachycardiac, and hypoxic. Imaging showed an occlusive bilateral PE, right heart strain, and a possible intrauterine pregnancy. Beta-human chorionic gonadotropin was positive. She was taken emergently for catheter-directed embolectomy. Her condition immediately improved afterward. Postprocedure pelvic ultrasound confirmed a viable intrauterine pregnancy at 10 weeks gestation. She was discharged with therapeutic enoxaparin and gave birth to a healthy infant at 38 weeks gestation. Conclusion  Despite being the gold standard for PE treatment in nonpregnant adults, systemic thrombolysis is relatively contraindicated in pregnancy due to concern for maternal or fetal hemorrhage. Surgical or catheter-based thrombectomies are rarely recommended. Limited alternative options force their consideration, particularly in a hemodynamically unstable patient. Catheter-directed embolectomy can possibly bypass such complications. Our case exemplifies the consideration of catheter-directed embolectomy as the initial treatment modality of a hemodynamically unstable gestational PE.

Prevalence and predictors of chronic thromboembolic pulmonary hypertension following severe forms of acute pulmonary embolism

INTRODUCTION AND OBJECTIVES

The true prevalence of chronic thromboembolic pulmonary hypertension (CTEPH) after pulmonary embolism (PE) in the Portuguese population remains unknown. We aimed to assess the prevalence and predictors of CTEPH two years after a symptomatic high- (HR) or intermediate-high risk (IHR) PE.

METHODS

We conducted a retrospective cohort study of patients admitted with PE between 2014 and 2019 to a Portuguese referral center for pulmonary hypertension.

RESULTS

In this single-center registry of 969 patients admitted with PE (annual incidence of 46/100000 population), 194 had HR (5.4%) and IHR (14.7%) PE. After excluding patients who died or had no follow-up in the first three months, 129 patients were included in the analysis. The overall prevalence of suspected CTEPH by clinical assessment, Doppler echocardiography and V/Q lung scan was 6.2% (eight patients). CTEPH was confirmed by right heart catheterization in four of these (3.1%). Increased pulmonary artery systolic pressure (PASP) at admission (OR 1.12; 95% CI 1.04-1.22; p=0.005) and the presence of varicose veins in the lower limbs (OR 7.47; 95% CI 1.53-36.41; p=0.013) were predictors of CTEPH. PASP >60 mmHg at admission identified patients with CTEPH at follow-up with sensitivity and specificity of 83.3% and 76.3%, respectively. All patients diagnosed with CTEPH had at least two radiological findings suggestive of CTEPH at the index event.

CONCLUSIONS

In our cohort, the prevalence of CTEPH in survivors of severe forms of acute PE was 6.2%. PASP above 60 mmHg and supporting radiological findings on the index computed tomography scan are highly suggestive of acute-on-chronic CTEPH.

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.

Comparative Efficacy and Safety of Thrombolytic Agents for Pulmonary Embolism: A Bayesian Network Meta-Analysis

BACKGROUND

Thrombolytic agents and anticoagulants are the two classes of medication used in the treatment of acute pulmonary embolism (PE). There is continuous renewal and iteration of thrombolytic agents, and the efficacy and adverse effects of different agents have different effects on PE due to their different mechanisms of action.

OBJECTIVES

The aim of the study was to evaluate the efficacy and safety of different thrombolytic agents in the treatment of all types of acute PE: hemodynamically unstable PE (massive PE) and hemodynamically stable PE (submassive PE and low-risk PE), using a network meta-analysis.

METHODS

A search was conducted of the following databases: PubMed, The Cochrane Library, Embase, and Web of Science to collect randomized controlled trials (RCTs) comparing thrombolytic agents with heparin or other thrombolytic agents in patients with acute PE; the clinical outcomes included patient mortality, recurrent PE, pulmonary artery systolic pressure (PASP) after treatment, and major and minor bleeding. The measurement duration of outcome indicators was the longest follow-up period. Thereafter, a network meta-analysis was performed using a Bayesian network framework.

RESULTS

A total of 29 RCTs (3,067 patients) were included, of which 6 studies (304 patients) were massive PE, 14 studies (2,173 patients) were submassive PE, 1 study (83 patients) included massive and submassive PE, and 8 studies (507 patients) were PE of unknown type. The treatment regimens included thrombolytic therapy (alteplase, reteplase, tenecteplase, streptokinase, and urokinase) and anticoagulant therapy alone. The results showed that the mortality using thrombolytic agents (except tenecteplase) was significantly lower compared with heparin. The recurrence of PE with alteplase was significantly lower compared with heparin (RR = 0.23, 95% CI, 0.04, 0.65). The PASP after using alteplase was significantly lower compared with heparin (mean difference = -11.36, 95% CI, -21.45, -1.56). Compared with heparin, the incidence of minor bleeding associated with tenecteplase was higher (RR = 3.27, 95% CI, 1.36, 7.39); compared with streptokinase, the incidence of minor bleeding associated with tenecteplase was higher (RR = 3.22, 95% CI, 1.01, 11.10).

CONCLUSION

For patients with acute PE, four thrombolytic agents (alteplase, reteplase, streptokinase, and urokinase) appeared to be superior in efficacy compared with anticoagulants alone due to a reduction in mortality and no increase in bleeding risk. Alteplase may be a better choice because it not only reduced mortality but also reduced PE recurrence rate and treated PASP. Tenecteplase did not reduce mortality compared with anticoagulants alone and may not be a good choice of thrombolytic agent due to an increase in minor bleeding compared with streptokinase and anticoagulants alone. Thrombolytic drugs should be rationally selected to optimize the thrombolytic regimen and achieve as good a balance as possible between thrombolysis and bleeding.

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

BACKGROUND

Due to the bleeding risk of full-dose systemic thrombolysis and the lack of major trials focusing on the clinical benefits of catheter-directed treatment, heparin antiocoagulation remains the standard of care for patients with intermediate-high-risk pulmonary embolism (PE).

METHODS AND RESULTS

The Higher-Risk Pulmonary Embolism Thrombolysis (HI-PEITHO) study (ClinicalTrials.gov Identifier: NCT04790370) is a multinational multicenter randomized controlled parallel-group comparison trial. Patients with: (1) confirmed acute PE; (2) evidence of right ventricular (RV) dysfunction on imaging; (3) a positive cardiac troponin test; and (4) clinical criteria indicating an elevated risk of early death or imminent hemodynamic collapse, will be randomized 1:1 to treatment with a standardized protocol of ultrasound-facilitated catheter-directed thrombolysis plus anticoagulation, vs anticoagulation alone. The primary outcome is a composite of PE-related mortality, cardiorespiratory decompensation or collapse, or non-fatal symptomatic and objectively confirmed PE recurrence, within 7 days of randomization. Further assessments cover, apart from bleeding complications, a broad spectrum of functional and patient-reported outcomes including quality of life indicators, functional status and the utilization of health care resources over a 12-month follow-up period. The trial plans to include 406 patients, but the adaptive design permits a sample size increase depending on the results of the predefined interim analysis. As of May 11, 2022, 27 subjects have been enrolled. The trial is funded by Boston Scientific Corporation and through collaborative research agreements with University of Mainz and The PERT Consortium.

CONCLUSIONS

Regardless of the outcome, HI-PEITHO will establish the first-line treatment in intermediate-high risk PE patients with imminent hemodynamic collapse. The trial is expected to inform international guidelines and set the standard for evaluation of catheter-directed reperfusion options in the future.

Current trends in image-guided chest interventions

Interventional radiology (IR) is a rapidly expanding medical subspecialty and refers to a range of image‐guided procedural techniques. The image guidance allows real‐time visualization and precision placement of a needle, catheter, wire and device to deep body structures through small incisions. Advantages include reduced risks, faster recovery and shorter hospital stays, lower costs and less patient discomfort. The range of chest interventional procedures keeps on expanding due to improved imaging facilities, better percutaneous assess devices and advancing ablation and embolization techniques. These advances permit procedures to be undertaken safely, simultaneously and effectively, hence escalating the role of IR in the treatment of chest disorders. This review article aims to cover the latest developments in some image‐guided techniques of the chest, including thermal ablation therapy of lung malignancy, targeted therapy of pulmonary embolism, angioplasty and stenting of mediastinal venous/superior vena cava occlusion, pulmonary arteriovenous malformation treatment and bronchial artery embolization for haemoptysis.

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.

Antithrombotics and new interventions for venous thromboembolism: Exploring possibilities beyond factor IIa and factor Xa inhibition

Direct oral anti-activated factor X and antithrombin agents have largely replaced vitamin K antagonists as the standard of care in treatment of venous thromboembolism. However, gaps in efficacy and safety persist, notably in end-stage renal disease, implantable heart valves or assist devices, extracorporeal support of the circulation, and antiphospholipid syndrome. Inhibition of coagulation factor XI (FXI) emerges as a promising new therapeutic target. Antisense oligonucleotides offer potential advantages as a prophylactic or therapeutic modality, with one dose-finding trial in orthopedic surgery already published. In addition, monoclonal antibodies blocking activation and/or activity of activated factor XI are investigated, as are small-molecule inhibitors with rapid offset of action. Further potential targets include upstream components of the contact pathway such as factor XII, polyphosphates, or kallikrein. Finally, catheter-directed, pharmacomechanical antithrombotic strategies have been developed for high- and intermediate-risk pulmonary embolism, and large randomized trials aiming to validate their efficacy, safety, and prognostic impact are about to start.

Clinical outcomes of very elderly patients treated with ultrasound-assisted catheter-directed thrombolysis for pulmonary embolism: a systematic review

Pulmonary embolism (PE) is a significant cause of death in the very elderly (≥ 75 years) population. Ultrasound-assisted catheter-directed thrombolysis (USCDT) emerges to improve thrombolysis safety and efficacy. However, outcomes in very elderly patients are unknown, as randomized controlled trials exclude this population. Recently, we demonstrated acute kidney injury (AKI) and ischemic hepatitis in an octogenarian intermediate-risk PE patient treated with USCDT. Considering the lack of evidence, we undertook a systematic review to evaluate the clinical outcomes in very elderly PE patients treated with USCDT. We searched for very elderly PE patients treated with USCDT from 2008 to 2019. Additionally, we conducted another systematic review without age restriction to update previous evidence and compare both populations. We also did an exploratory analysis to determine if thrombolysis was followed based on current guidelines or impending clinical deterioration factors. We identified 18 very elderly patients (age 79.2, 75-86), mostly female and with intermediate-risk PE. We found an intracranial hemorrhage (ICH), and a right pulmonary artery rupture. Additionally, two significant bleedings complicated with transient AKI, and one case of AKI and ischemic hepatic injury. The patients who survived all had clinical and echocardiographic in-hospital improvement. Despite low rt-PA doses, ICH and major bleeding remain as feared complications. Thrombolysis decision was driven by impending clinical deterioration factors instead of international guideline recommendations. Our data do not suggest prohibitive risk associated with USCDT in very elderly intermediate and high-risk PE patients. Despite long-term infusions and right ventricular dysfunction, AKI and ischemic hepatic injury were infrequent.

How I assess and manage the risk of bleeding in patients treated for venous thromboembolism

For patients with venous thromboembolism (VTE), prediction of bleeding is relevant throughout the course of treatment, although the means and goal of this prediction differ between the subsequent stages of treatment: treatment initiation, hospital discharge, 3-month follow-up, and long-term follow-up. Even in the absence of fully established risk prediction schemes and outcome studies using a prediction scheme for treatment decisions, the present evidence supports screening for and targeting of modifiable risk factors for major bleeding, as well as the application of decision rules to identify patients at low risk of bleeding complications, in whom long-term anticoagulant treatment is likely safe. Moving forward, prediction tools need to be incorporated in well-designed randomized controlled trials aiming to establish optimal treatment duration in patients at high risk of recurrent VTE. Moreover, the benefit of their longitudinal assessment rather than application as stand-alone baseline assessments should be studied, because changes in bleeding risk over time likely constitute the best predictor of major bleeding. We provide the state-of-the-art of assessing and managing bleeding risk in patients with acute VTE and highlight a practical approach for daily practice illustrated by 2 case scenarios.