Impact of Thrombolytic Therapy on the Long-Term Outcome of Intermediate-Risk Pulmonary Embolism

Thrombolysis of incidental pulmonary embolism in a stroke patient

Both acute ischemic stroke (AIS) and pulmonary embolism (PE) are major causes of morbidity and mortality, with overlapping risk factors. Incidental or silent PE therefore may be discovered during an AIS work-up. Thrombolytic therapy is considered first-line therapy for eligible patients with AIS. We present the case of an 88-year-old man with an AIS, who was incidentally found to have a PE, and then received thrombolytic therapy leading to favorable outcomes in both conditions.

Contemporary Management of Pulmonary Embolism: Review of the Inferior Vena Cava filter and Other Endovascular Devices

Inferior vena cava (IVC) filters and endovascular devices are used to mitigate the risk of pulmonary embolism in patients presenting with lower extremity venous thromboembolism in whom long-term anticoagulation is not a good option. However, the efficacy and benefit of these devices remain uncertain, and controversies exist. This review focuses on the current use of IVC filters and other endovascular therapies in clinical practice. The indications, risks, and benefits are discussed based on current data. Further research and randomized controlled trials are needed to characterize the patient population that would benefit most from these interventional therapies.

Impact of reperfusion therapies on clot resolution and long-term outcomes in patients with pulmonary embolism

OBJECTIVE

Major progress in reperfusion strategies has substantially improved the short-term outcomes of patients with pulmonary embolism (PE), however, up to 50% of patients report persistent dyspnea after acute PE.

METHODS

A retrospective study of the PE response team registry and included patients with repeat imaging at 3 to 12 months. The primary outcome was to determine the incidence of residual pulmonary vascular obstruction following acute PE. Secondary outcomes included the development of PE recurrence, right ventricular (RV) dysfunction, chronic thromboembolic pulmonary hypertension, readmission, and mortality at 12 months.

RESULTS

A total of 382 patients were included, and 107 patients received reperfusion therapies followed by anticoagulation. Patients who received reperfusion therapies including systemic thrombolysis, catheter-directed thrombolysis, and mechanical thrombectomy presented with a higher vascular obstructive index (47% vs 28%; P < .001) and signs of right heart strain on echocardiogram (81% vs 43%; P < .001) at the time of diagnosis. A higher absolute reduction in vascular obstructive index (45% vs 26%; 95% confidence interval, 14.0-25.6; P < .001), greater improvement in RV function (82% vs 65%; P = .021), and lower 12-month mortality rate (2% vs 7%; P = .038) and readmission rate (33% vs 46%; P = .031) were observed in the reperfusion group. No statistically significant differences were found between groups in the development of chronic thromboembolic pulmonary hypertension (8% vs 5%; P = .488) and PE recurrence (8% vs 6%; P = .646).

CONCLUSIONS

We observed a favorable survival and greater improvement in clot resolution and RV function in patients treated with reperfusion therapies.

Evidence-Based Update on Transcatheter Therapies for Pulmonary Embolism

PURPOSE OF REVIEW

Pulmonary embolism (PE) remains a leading cause of cardiovascular morbidity and mortality. Multiple new therapies are in development and under study to improve our contemporary care of patients with PE. We review and compare here these novel therapeutics and technologies.

RECENT FINDINGS

Multiple novel therapeutic devices have been developed and are under active study. This work has advanced the care of patients with intermediate and high-risk PE. Novel therapies are improving care of complex PE patients. These have inspired large multicenter international randomized controlled trials that are actively recruiting patients to advance the care of PE. These studies will work towards advancing guidelines for clinical care of patients with PE.

Percutaneous interventions for pulmonary embolism

Pulmonary embolism (PE) ranks as a leading cause of in-hospital mortality and the third most common cause of cardiovascular death. The spectrum of PE manifestations varies widely, making it difficult to determine the best treatment approach for specific patients. Conventional treatment options include anticoagulation, thrombolysis, or surgery, but emerging percutaneous interventional procedures are being investigated for their potential benefits in heterogeneous PE populations. These novel interventional techniques encompass catheter-directed thrombolysis, mechanical thrombectomy, and hybrid approaches combining different mechanisms. Furthermore, inferior vena cava filters are also available as an option for PE prevention. Such interventions may offer faster improvements in right ventricular function, as well as in pulmonary and systemic haemodynamics, in individual patients. Moreover, percutaneous treatment may be a valid alternative to traditional therapies in high bleeding risk patients and could potentially reduce the burden of mortality related to major bleeds, such as that of haemorrhagic strokes. Nevertheless, the safety and efficacy of these techniques compared to conservative therapies have not been conclusively established. This review offers a comprehensive evaluation of the current evidence for percutaneous interventions in PE and provides guidance for selecting appropriate patients and treatments. It serves as a valuable resource for future researchers and clinicians seeking to advance this field. Additionally, we explore future perspectives, proposing "percutaneous primary pulmonary intervention" as a potential paradigm shift in the field.

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.

Venous Thromboembolism: Review of Clinical Challenges, Biology, Assessment, Treatment, and Modeling

Venous thromboembolism (VTE) is a massive clinical challenge, annually affecting millions of patients globally. VTE is a particularly consequential pathology, as incidence is correlated with extremely common risk factors, and a large cohort of patients experience recurrent VTE after initial intervention. Altered hemodynamics, hypercoagulability, and damaged vascular tissue cause deep-vein thrombosis and pulmonary embolism, the two permutations of VTE. Venous valves have been identified as likely locations for initial blood clot formation, but the exact pathway by which thrombosis occurs in this environment is not entirely clear. Several risk factors are known to increase the likelihood of VTE, particularly those that increase inflammation and coagulability, increase venous resistance, and damage the endothelial lining. While these risk factors are useful as predictive tools, VTE diagnosis prior to presentation of outward symptoms is difficult, chiefly due to challenges in successfully imaging deep-vein thrombi. Clinically, VTE can be managed by anticoagulants or mechanical intervention. Recently, direct oral anticoagulants and catheter-directed thrombolysis have emerged as leading tools in resolution of venous thrombosis. While a satisfactory VTE model has yet to be developed, recent strides have been made in advancing in silico models of venous hemodynamics, hemorheology, fluid-structure interaction, and clot growth. These models are often guided by imaging-informed boundary conditions or inspired by benchtop animal models. These gaps in knowledge are critical targets to address necessary improvements in prediction and diagnosis, clinical management, and VTE experimental and computational models.

Long-term outcomes of pulmonary embolism in children and adolescents

ABSTRACT

Knowledge regarding the long-term consequences of pulmonary embolism (PE) in children is limited. This cohort study describes the long-term outcomes of PE in children who were followed-up at a single-center institution using a local protocol that included clinical evaluation, chest imaging, echocardiography, pulmonary function tests, and cardiopulmonary exercise tests at follow-up, starting 3 to 6 months after acute PE. Children objectively diagnosed with PE at age 0 to 18 years, who had ≥6 months of follow-up were included. Study outcomes consisted of PE resolution, PE recurrence, death, and functional outcomes (dyspnea, impaired pulmonary or cardiac function, impaired aerobic capacity, and post-PE syndrome). The frequency of outcomes was compared between patients with/without underlying conditions. In total, 150 patients were included; median age at PE was 16 years (25th-75th percentile, 14-17 years); 61% had underlying conditions. PE did not resolve in 29%, recurrence happened in 9%, and death in 5%. One-third of patients had at least 1 documented abnormal functional finding at follow-up (ventilatory impairments, 31%; impaired aerobic capacity, 31%; dyspnea, 26%; and abnormal diffusing capacity of the lungs to carbon monoxide, 22%). Most abnormalities were transient. When alternative explanations for the impairments were considered, the frequency of post-PE syndrome was lower, ranging between 0.7% and 8.5%. Patients with underlying conditions had significantly higher recurrence, more pulmonary function and ventilatory impairments, and poorer exercise capacity. Exercise intolerance was, in turn, most frequently because of deconditioning than to respiratory or cardiac limitation, highlighting the importance of physical activity promotion in children with PE.

[Update in the management of chronic thrombo-embolic pulmonary hypertension]

Chronic thrombo-embolic pulmonary hypertension (CTEPH) is a potentially curable form of pulmonary hypertension (PH) that develops in up to 3% of patients after pulmonary embolism (PE). In these patients, PE does not resolve, leading to organized fibrotic clots, with the development of precapillary PH as a result of the proximal obstruction of the pulmonary arteries. In addition, a distal microvasculopathy may also develop, contributing to the increase of pulmonary vascular resistance. Transthoracic echocardiography is the diagnostic tool that allows to establish the suspicion of PH. Ventilation-perfusion lung scintigraphy is the fundamental tool in the study of patients with suspected CTEPH; if it is normal, virtually rules out the diagnosis. Right heart catheterization is mandatory for the diagnosis of these patients. CTEPH is defined as the existence of symptoms, residual perfusion defects and precapillary PH after a minimum period of three months of anticoagulation. Pulmonary angiography helps determine the extent and surgical accessibility of thromboembolic lesions. CTEPH patients are candidates for long-term anticoagulation. Pulmonary endarterectomy is the treatment of choice, resulting in significant clinical and hemodynamic improvement. About 25% of patients have residual PH post-endarterectomy. Balloon pulmonary angioplasty is an endovascular technique that targets more distal lesions, being potentially useful for patients with inoperable CTEPH or persistent/recurrent PH post-endarterectomy. Both types of patients may also benefit from pharmacological treatment for PH. These three therapies are the cornerstone of CTEPH treatment, which has evolved towards a multimodal approach.

High and intermediate risk pulmonary embolism in the ICU

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

Risk Stratification and Management of Intermediate-Risk Acute Pulmonary Embolism

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

Thrombolysis vs Anticoagulation: Unveiling the Trade-Offs in Massive Pulmonary Embolism

Massive pulmonary embolism (MPE) is a severe form of venous thromboembolism (VTE) wherein enormous blood clots block the pulmonary arteries, resulting in substantial illness and death. Even with the progress made in diagnostic methods and treatments, the most effective approach for managing MPE is still a topic of considerable discussion. This study examines the delicate equilibrium between thrombolysis and anticoagulation in managing the problematic clinical situation posed by MPE, elucidating the compromises linked to each strategy. The genesis of MPE lies in the pathophysiology of VTE, when blood clots that originate from deep veins in the lower legs or pelvis move to the pulmonary vasculature, leading to an abrupt blockage. This obstruction leads to a series of hemodynamic alterations, such as elevated pulmonary vascular resistance, strain on the right ventricle, and compromised cardiac output, finally resulting in cardiovascular collapse. The seriousness of MPE is commonly categorized according to hemodynamic stability, with significant cases presenting immediate risks to patient survival. Traditionally, heparin has been the primary approach to managing MPE to prevent the spread of blood clots and their movement to other parts of the body. Nevertheless, there have been ongoing discussions regarding the effectiveness of thrombolysis, which entails the immediate delivery of fibrinolytic drugs to remove the blood clot. The use of thrombolysis in managing MPE is being reconsidered because of concerns over bleeding complications and long-term results despite its capacity to resolve the blocking clot quickly. This review rigorously analyzes the current body of evidence, exploring the intricacies of thrombolysis and anticoagulation in MPE. The focus is on evaluating the risk-benefit balance of each treatment option, considering aspects such as the patient's other medical conditions, hemodynamic stability, and potential long-term consequences. This review aims to clarify the complexities of the thrombolysis versus anticoagulation dilemma. It seeks to provide clinicians, researchers, and policymakers with a thorough understanding of the trade-offs in managing MPE. The goal is to facilitate informed decision-making and enhance patient outcomes.

ERS International Congress 2023: highlights from the Pulmonary Vascular Diseases Assembly

Pulmonary vascular diseases such as pulmonary embolism and pulmonary hypertension are important and frequently under-recognised conditions. This article provides an overview of key highlights in pulmonary vascular diseases from the European Respiratory Society International Congress 2023. This includes insights into disease modification in pulmonary arterial hypertension and novel therapies such as sotatercept and seralutinib. Exciting developments in our understanding of the mechanisms underpinning pulmonary hypertension associated with interstitial lung disease are also explored. A comprehensive overview of the complex relationship between acute pulmonary embolism and chronic thromboembolic pulmonary hypertension (CTEPH) is provided along with our current understanding of the molecular determinants of CTEPH. The importance of multidisciplinary and holistic care cannot be understated, and this article also addresses advances beyond medication, with a special focus on exercise training and rehabilitation.

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.

Right Ventricular Recovery: Early and Late Changes after Acute PE Diagnosis

Right ventricular (RV) failure is a critical cause of morbidity and mortality in patients presenting with pulmonary embolism (PE). The presentation of RV failure is based on the combination of clinical findings, laboratory abnormalities, and imaging evidence. An improved understanding of the pathophysiology of RV dysfunction following PE has given rise to more accurate risk stratification and broader therapeutic approaches. A subset of patients with PE develop chronic RV dysfunction with or without pulmonary hypertension. In this review, we focus on the impact of PE on the RV and its implications for risk stratification, prognosis, acute management, and long-term therapy.

Treatment of intracardiac thrombi using ultra-slow low-dose thrombolytic therapy: A case report

A 57-year-old male with previously known severe primary mitral regurgitation was admitted to the intensive care unit (ICU) due to massive venous thromboembolism, associated with right ventricular dysfunction and two large mobile right atrial thrombi. Due to deterioration in his clinical condition despite standard treatment with unfractionated heparin, it was decided to use an ultra-slow low-dose thrombolysis protocol, which consisted of a 24-hour infusion of 24 mg of alteplase at a rate of 1 mg per hour, without initial bolus. The treatment was continued for 48 consecutive hours, with clinical improvement and resolution of the intracardiac thrombi and no complications. One month after ICU admission, successful mitral valve repair surgery was conducted. This case demonstrates that ultra-slow low-dose thrombolysis is a valid bailout treatment option in patients with large intracardiac thrombi refractory to the standard approach.

Long-term sequelae following acute pulmonary embolism: A nationwide follow-up study regarding the incidence of CTEPH, dyspnea, echocardiographic and V/Q scan abnormalities

We aimed to follow a nationwide cohort of patients with pulmonary embolism (PE) without any exclusions to generate information regarding long-term symptoms, investigational findings and to determine the prevalence of chronic thromboembolic pulmonary hypertension (CTEPH). We hypothesized that this approach would yield generalizable estimates of CTEPH prevalence and incidence. All individuals diagnosed with acute PE in Sweden in 2005 were identified using the National Patient Register. In 2007, survivors were asked to complete a questionnaire regarding current symptoms. Those with dyspnea were referred for further examinations with laboratory tests, electrocardiogram (ECG), and a ventilation/perfusion scan (V/Q scan). If CTEPH was suspected, a referral to the nearest pulmonary arterial hypertension-center was recommended. Of 5793 unique individuals with PE diagnosis in 2005, 3510 were alive at the beginning of 2007. Altogether 53% reported dyspnea at some degree whereof a large proportion had V/Q scans indicating mismatched defects. Further investigation revealed 6 cases of CTEPH and in parallel 18 cases were diagnosed outside this study. The overall prevalence of CTEPH was 0.4% (95% confidence interval [CI]: 0.2%-0.6%) and 0.7% (95% CI: 0.4%-1.0%) among the survivors. The cumulative incidence of CTEPH in the group of patients who underwent a V/Q scan was 1.1% (95% CI: 0.2%-2.0%). There was a high mortality following an acute PE, a high proportion of persistent dyspnea among survivors, whereof several had pathological findings on V/Q scans and echocardiography. Only a minority developed CTEPH, indicating that CTEPH is the tip of the iceberg of post-PE disturbances.

Recovery of right ventricular function after intermediate-risk pulmonary embolism: results from the multicentre Pulmonary Embolism International Trial (PEITHO)-2

BACKGROUND

Right ventricular (RV) function plays a critical role in the pathophysiology and acute prognosis of pulmonary embolism (PE). We analyzed the temporal changes of RV function in the cohort of a prospective multicentre study investigating if an early switch to oral anticoagulation in patients with intermediate-risk PE is effective and safe.

METHODS

Echocardiographic and laboratory examinations were performed at baseline (PE diagnosis), 6 days and 6 months. Echocardiographic parameters were classified into categories representing RV size, RV free wall/tricuspid annulus motion, RV pressure overload and right atrial (RA)/central venous pressure.

RESULTS

RV dysfunction based on any abnormal echocardiographic parameter was present in 84% of patients at baseline. RV dilatation was the most frequently abnormal finding (40.6%), followed by increased RA/central venous pressure (34.6%), RV pressure overload (32.1%), and reduced RV free wall/tricuspid annulus motion (20.9%). As early as day 6, RV size remained normal or improved in 260 patients (64.7%), RV free wall/tricuspid annulus motion in 301 (74.9%), RV pressure overload in 297 (73.9%), and RA/central venous pressure in 254 (63.2%). At day 180, the frequencies slightly increased. The median NT-proBNP level decreased from 1448 pg/ml at baseline to 256.5 on day 6 and 127 on day 180.

CONCLUSION

In the majority of patients with acute intermediate-risk PE switched early to a direct oral anticoagulant, echocardiographic parameters of RV function normalised within 6 days and remained normal throughout the first 6 months. Almost one in four patients, however, continued to have evidence of RV dysfunction over the long term.

Post-Pulmonary Embolism Impairment Six Months after Acute Pulmonary Embolism: A Prospective Registry

BACKGROUND

Little evidence is available on post-pulmonary embolism impairment (PPEI), a recently defined complication of pulmonary embolism (PE) encompassing dysfunctional clinical and imaging parameters. In the present study, we sought to evaluate its frequency with a focus on the main components.

METHODS

In this prospective registry, we included patients with a confirmed diagnosis of acute PE and focused on those with initial right ventricular (RV) dysfunction. Their baseline, pre-discharge, and 6 month follow-up clinical and imaging characteristics were recorded. The main study outcomes were incomplete RV functional recovery, exercise capacity limitations (based on the 6 minute walk test), and their combination, which defines PPEI, within six months of acute PE.

RESULTS

Of 170 consecutive patients with a confirmed diagnosis of acute PE, 123 accepted to participate in the follow-up study, of whom 87 had initial RV dysfunction. The 6 month rates of incomplete RV functional recovery, signs of an intermediate-to-high echocardiographic probability of PH, and exercise limitations were observed in 58.6, 32.1, and 45.9%, respectively. A total of 22 (25.2%; 95% CI 15.5-34.4%) patients had PPEI. The RV/LV ratio and the fractional area change on discharge after acute PE were more often impaired among patients with incomplete RV recovery, exercise limitations, and a high probability of PH at 6 months. In contrast, an initial impaired RV diastolic function indices appeared to characterize patients with a limited exercise capacity at 6 months.

DISCUSSION

PPEI affects one fourth of patients surviving acute PE with half of them presenting with RV dysfunction or exercise limitations.

Observational cohort study to validate SEARCH, a novel hierarchical algorithm to define long-term outcomes after pulmonary embolism

BACKGROUND

Chronic dyspnoea and exercise impairment are common after acute pulmonary embolism (PE) but are not defined and quantified sufficiently to serve as outcomes in clinical trials. The planned project will clinically validate a novel method to determine discrete, clinically meaningful diagnoses after acute PE. The method uses an algorithm entitled SEARCH, for symptom screen, exercise testing, arterial perfusion, resting echocardiography, confirmatory imaging and haemodynamic measurements. SEARCH is a stepwise algorithm that sorts patients by a hierarchical series of dichotomous tests into discreet categories of long-term outcomes after PE: asymptomatic, post-PE deconditioning, symptoms from other causes, chronic thromboembolism with ventilatory inefficiency, chronic thromboembolism with small stroke volume augmentation, chronic thromboembolic disease and chronic thromboembolic pulmonary hypertension.

METHODS

The project will test the inter-rater reliability of the SEARCH algorithm by determining whether it will yield concordant post-PE diagnoses when six independent reviewers review the same diagnostic data on 150 patients evaluated at two time points after PE. The project will also determine whether the post-PE diagnoses are stable, according to the SEARCH algorithm, between the first evaluation and the subsequent one 6 months later.

IMPLICATIONS

Validation of the SEARCH algorithm would offer clinicians a straightforward method to diagnose post-PE conditions that are rarely distinguished clinically. Their categorisation and definition will allow post-PE conditions to be used as endpoints in clinical trials of acute PE treatment.

TRIAL REGISTRATION NUMBER

NCT05568927.

Updates in the diagnosis and management of chronic thromboembolic disease

PURPOSE OF REVIEW

Chronic thromboembolic disease (CTED) is distinct from chronic thromboembolic pulmonary hypertension (CTEPH) and is defined by dyspnea on exertion after acute pulmonary embolism with the presence of residual perfusion defects and absence of resting pulmonary hypertension. Here, we review clinical features and diagnostic criteria for CTED and summarize treatment options.

RECENT FINDINGS

The optimal management for CTED is unclear as the long-term outcomes of conservative vs. invasive treatment for this disease have not been reported. There are a few studies evaluating outcomes of pulmonary thromboendarterectomy and balloon pulmonary angioplasty (BPA) in CTED, concluding that these procedures are safe and effective in select patients. However, these trials are small nonrandomized observational studies, reporting outcomes only up to 1 year after the intervention. Conservative management of CTED with observation, pulmonary hypertension-targeted therapy, or cardiopulmonary rehabilitation has not been studied. It is unknown whether these treatments are as effective or superior to pulmonary thromboendarterectomy or BPA in CTED.

SUMMARY

The management of CTED is individualized and based on symptoms and exercise limitations. Early referral of patients with CTED to a specialized CTEPH center is recommended to determine if watchful waiting, BPA, or pulmonary thromboendarterectomy is most beneficial.

Post-thrombotic syndrome and chronic thromboembolic pulmonary hypertension: diagnosis and management

Post-thrombotic syndrome and chronic thromboembolic pulmonary hypertension are two distinct clinical syndromes associated with adverse patient outcomes following a venous thromboembolism. Clinical manifestations of post-thrombotic syndrome include persistent pain, swelling and ultimately venous ulceration following a deep venous thrombosis. Patients experiencing chronic thromboembolic pulmonary hypertension may have symptoms ranging from exertional dyspnoea to overt right heart failure. From a physician's perspective, the most effective preventative strategy is good quality anticoagulation for prophylaxis of primary and secondary venous thromboembolism. The treatment of post-thrombotic syndrome mainly involves lifestyle modifications alongside the use of elastic compression stockings while patients with chronic thromboembolic pulmonary hypertension should be offered targeted surgical and medical treatment options available at expert centres. Further research is warranted for both conditions to determine the role of direct oral anticoagulants when used with a preventive or therapeutic intent.

Indigo® Aspiration System for thrombectomy in pulmonary embolism

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

Prevalence of long-term right ventricular dysfunction after acute pulmonary embolism: a systematic review and meta-analysis

Background

Right ventricular dysfunction (RVD) is associated with adverse outcomes of acute pulmonary embolism (PE). However, there are no studies describing the long-term, full-spectrum right ventricular parameters on morphology, pressure and function at certain follow-up time points after PE onset. More exploration of right ventricular function would provide useful clues for long-term management of patients with PE.

Methods

For this systematic review and meta-analysis, we completed a literature search in Pubmed, EMBASE and WebofScience (from Jan 1st, 1998 to April 20th, 2023). Studies of patients with acute PE followed-up longer than 3 months with right ventricle assessment and written in English-language were included. Right ventricular function was assessed by either echocardiography or computed tomographic pulmonary angiography (CTPA). The primary outcome was structural and functional parameters of the right ventricle, and the secondary outcomes were functional assessments [New York Heart Association (NYHA) functional classification and 6-min walk test distance (6 MWD)], at each follow-up time points. Random effect meta-analyses were performed using R software (PROSPERO: CRD42023433332).

Findings

A total of 33 studies (3920 patients) were included in the final analysis. The 3-month, 6-month and 1-year prevalence of right ventricular dysfunction (RVD) was 0.34 [95% confidence interval (CI) 0.21-0.48, I2 = 96%], 0.26 (95% CI 0.17-0.36, I2 = 93%) and 0.34 (95% CI 0.19-0.48, I2 = 94%), respectively. Pooled tricuspid annulus plane systolic excursion (TAPSE), right ventricular to left ventricular diameter (RV/LV) ratio and pulmonary artery systolic pressure (PASP) at 1-year was 21.80 mm (95% CI 20.08-23.52, I2 = 93%), 0.64 (95% CI 0.48-0.81, I2 = 92%) and 27.33 mmHg (95% CI 18.88-35.78) (I2 = 96%), respectively. The proportion of NYHA III-IV was 0.06 (95% CI 0.0-0.12) and the pooled 6 MWD was 462.98 m (95% CI 447.55-478.41) over 1 year. Patients treated with thrombolysis had lower prevalence of RVD (1-year 0.17 and 0.07 in systemic thrombolysis and catheter-directed thrombolysis, respectively) than those treated with anticoagulation therapy alone (1-year 0.24) but the pooled risk ratio (RR) was not statistically significant.

Interpretation

Although the conclusion of this study may be limited by its high heterogeneity from varied study designs, inclusion criteria and definition of RVD of each study, our findings suggested that persistent RVD and functional impairment were of considerable high prevalence during long-term follow-up after acute PE. Treatment strategy may influence the prevalence of long-term RVD.

Funding

This study is supported by CAMS Innovation Fund for Medical Sciences (CIFMS) (2021-I2M-1-061). The National Key Research and Development Program of China (2016YFC0905600). National High Level Hospital Clinical Research Funding (2022-NHLHCRF-LX-01-02-03). CAMS Institute of Respiratory Medicine Grant for Young Scholars (2023-ZF-8).

Cardiopulmonary Exercise Testing, Rehabilitation, and Exercise Training in Postpulmonary Embolism

Long-term exercise intolerance and functional limitations are common after an episode of acute pulmonary embolism (PE), despite 3 to 6 months of anticoagulation. These persistent symptoms are reported in more than half of the patients with acute PE and are referred as "post-PE syndrome." Although these functional limitations can occur from persistent pulmonary vascular occlusion or pulmonary vascular remodeling, significant deconditioning can be a major contributing factor. Herein, the authors review the role of exercise testing to elucidate the mechanisms of exercise limitations to guide next steps in management and exercise training for musculoskeletal deconditioning.

Long-term mortality in patients with pulmonary embolism: results in a single-center registry

Background

While numerous studies have investigated short-term outcomes after pulmonary embolism (PE), long-term mortality remains insufficiently studied.

Objectives

To investigate long-term outcomes in an unselected cohort of patients with PE.

Methods

A total of 896 consecutive patients with PE enrolled in a single-center registry between May 2005 and December 2017 were followed up for up to 14 years. The observed mortality rate was compared with the expected rate in the general population.

Results

The total follow-up time was 3908 patient-years (median, 3.1 years). The 1- and 5-year mortality rates were 19.7% (95% CI, 17.2%-22.4%) and 37.1% (95% CI, 33.6%-40.5%), respectively. The most frequent causes of death were cancer (28.5%), PE (19.4%), infections (13.9%), and cardiovascular events (11.6%). Late mortality (after >30 days) was more frequent than expected in the general population, a finding that was consistent in patients without cancer (the 5-year standardized mortality ratios were 2.77 [95% CI, 2.41-3.16] and 1.80 [95% CI, 1.50-2.14], respectively). Active cancer was the strongest risk factor for death between 30 days and 3 years (hazard ratio [HR], 6.51; 95% CI, 4.67-9.08) but was not associated with later mortality. Death after >3 years was predicted by age (HR, 1.86; 95% CI, 1.51-2.29 per decade), chronic heart failure (HR, 1.66; 95% CI, 1.02-2.70), and anemia (HR, 1.62; 95% CI, 1.09-2.41).

Conclusion

The risk of mortality in patients with PE remained elevated compared with that in the general population throughout the follow-up period. The main driver of long-term mortality during the first 3 years was cancer. After that, mortality was predicted by age, chronic heart failure, and anemia.

Outcome of massive pulmonary embolism treated only with extracorporeal membrane oxygenation and anticoagulation without thrombolytic therapy or surgical embolectomy

INTRODUCTION

Although thrombolytic therapy is the standard treatment for massive pulmonary thromboembolism (PTE), it is often ineffective in patients with circulatory collapse. Surgical embolectomy is another treatment option, but whether it is absolutely necessary is controversial. We sought to evaluate the outcomes of patients with massive PTE treated with intensive critical care including extracorporeal membrane oxygenation (ECMO) without thrombolytic therapy or surgical embolectomy.

METHODS

We analyzed 39 patients who were treated for massive PTE from January 2011 to June 2019. Massive PTE was treated with anticoagulation and hemodynamic support at an intensive care unit. ECMO was applied in patients with circulatory collapse. The computed tomography (CT) obstruction index and the ratio of the right ventricle to left ventricle short-axis diameters (RV/LV) were measured using serial CT angiography to confirm changes in pulmonary emboli and RV strain.

RESULTS

Twenty-one patients were in cardiogenic shock, and 15 of them needed cardiopulmonary resuscitation (CPR). Fifteen patients were treated with ECMO and nine of them were weaned successfully. The overall in-hospital mortality was 23% (9/39). On the follow-up CT scan after 6 months, residual PTE was observed in 10 patients and their median CT obstruction index was 6.25 % (range 2.5-35). The initial mean RV/LV ratio was 1.8 ± 0.47 and the value measured at follow-up CT decreased to less than 1 (0.9 ± 0.1).

CONCLUSIONS

Intensive critical care with heparin alone and timely ECMO support without thrombolytic therapy could be an effective treatment option in patients with acute massive PTE.

Long term recovery of right ventricular function after treatment of intermediate and high risk pulmonary emboli

INTRODUCTION

Pulmonary embolism (PE) is a common and significant source of mortality and morbidity worldwide. A subset of patients with PE, particularly those who have intermediate and high risk events, are at increased risk for long-term right ventricular (RV) dysfunction; however, the impact of novel advanced therapies used for acute PE, including catheter-directed intervention, on long-term RV function remains uncertain. We sought to determine whether use of advanced therapies (catheter-directed intervention or systemic thrombolysis) is associated with improved long-term RV function.

MATERIALS AND METHODS

Retrospective, single-center cohort study of adult (≥18 year old) patients admitted and discharged alive with a diagnosis of acute PE, who fell under the category of intermediate or high risk, with available follow-up echocardiograms at least 6 months after the index, seen at a single quaternary referral center in Los Angeles, CA between 2012 and 2021.

RESULTS

There were 113 patients in this study (58 (51.3 %) treated with anticoagulation alone, 12 (10.6 %) treated with systemic thrombolysis, and 43 (38.1 %) treated with catheter-directed intervention), with approximately equal gender and racial distribution. Patients treated with advanced therapies were significantly more likely to have moderate-severe RV dysfunction (100 % for those treated with thrombolysis, 88.3 % for those treated with catheter-directed intervention, vs 55.2 % for those treated with anticoagulation alone; p < 0.001). At a follow-up of about 1.5 years, patients treated with advanced therapy (systemic thrombolysis or catheter-directed intervention) were more likely to have normalization of RV function (93-100 % vs 81 % for anticoagulation alone, p = 0.04). The subgroup of patients with intermediate-risk PE was significantly more likely to have normalization of RV function (95.6 % vs 80.4 % for anticoagulation alone, p = 0.03). Use of advanced therapy was not associated with substantial short-term adverse events among patients who survived to hospital discharge.

CONCLUSION

Patients with intermediate and high risk PE were more likely to have recovery in RV function long-term if treated with catheter-directed intervention or systemic thrombolysis, as compared to anticoagulation alone, without substantial safety issues, despite having worse RV function at baseline. Further data is needed to verify this observation.

Outcomes of venous thromboembolism care: future directions

The complete picture of the outcomes of venous thromboembolism (VTE) care consists of conventional binary clinical outcomes (death, recurrent VTE, and bleeding), patient-centered outcomes, and society-level outcomes. Combined, these allow for the introduction of outcome-driven patient-centered health care. The emerging concept of valuing health care from such a holistic point of view, ie, value-based health care, holds a huge potential to revolutionize-and improve-the organization and evaluation of care. The ultimate goal of this approach was to achieve a high value for patients, ie, the best possible clinical outcomes at the right cost, providing a framework for evaluation and comparisons of different management strategies, patient pathways, or even complete health care delivery systems. To facilitate this, outcomes of care from a patient perspective, such as symptom burden, functional limitations, and quality of life, need to be routinely captured in clinical practice and trials, complementary to the conventional clinical outcomes, to fully capture the patients' values and needs. The aim of this review was to discuss the relevant outcomes of VTE care, explore value in VTE care from different perspectives, and propose future directions to inspire change. This is a call to action to shift the focus to outcomes that matter and make a larger difference in the lives of patients.

Preexisting Chronic Thromboembolic Pulmonary Hypertension in Acute Pulmonary Embolism

BACKGROUND

Chronic thromboembolic pulmonary hypertension (CTEPH) is considered a complication of pulmonary embolism (PE). However, signs of CTEPH may exist in patients with a first symptomatic PE.

RESEARCH QUESTION

Which radiologic findings on CT pulmonary angiography (CTPA) at the time of acute PE could indicate the presence of preexisting CTEPH?

STUDY DESIGN AND METHODS

This study included unselected patients with acute PE who were prospectively followed up for 2 years with a structured visit schedule. Two expert radiologists independently assessed patients' baseline CTPAs for preexisting CTEPH; in case of disagreement, a decision was reached by a 2:1 majority with a third expert radiologist. In addition, the radiologists checked for predefined individual parameters suggesting chronic PE and pulmonary hypertension.

RESULTS

Signs of chronic PE or CTEPH at baseline were identified in 46 of 303 included patients (15%). Intravascular webs, arterial narrowing or retraction, dilated bronchial arteries, and right ventricular hypertrophy were the main drivers of the assessment. Five (1.7%) patients were diagnosed with CTEPH during follow-up. All four patients diagnosed with CTEPH early (83-108 days following acute PE) were found in enriched subgroups based on the experts' overall assessment or fulfilling a minimum number of the predefined radiologic criteria at baseline. The specificity of preexisting CTEPH diagnosis and the level of radiologists' agreement improved as the number of required criteria increased.

INTERPRETATION

Searching for predefined radiologic parameters suggesting preexisting CTEPH at the time of acute PE diagnosis may allow for targeted follow-up strategies and risk-adapted CTEPH screening, thus facilitating earlier CTEPH diagnosis.

Risk stratification and risk-adapted management of acute pulmonary embolism

Pulmonary embolism is one of the leading causes of cardiovascular death in Europe. Rapid diagnosis and treatment initiation are essential, especially in hemodynamically unstable patients. For normotensive patients, the diagnostic workflow is based on the clinical probability of pulmonary embolism. Due to numerous differential diagnoses and a highly variable clinical presentation, diagnosis of acute pulmonary embolism still remains a clinical challenge. Computed tomography angiography is the common gold standard to confirm pulmonary embolism and bedside echocardiography adds a major impact in clinical decision making. The European Society of Cardiology guidelines serve as a framework for a standardized diagnostic approach and risk prediction. Based on vital signs, clinical scores, biomarkers and imaging results, four risk categories can be defined and treatment is accordingly. To optimize the individual management of critical patients, multidisciplinary pulmonary embolism response teams are increasingly designated in specialized centers. This article provides an overview of the current risk-adapted management of patients with acute pulmonary embolism.

From acute pulmonary embolism to post-pulmonary embolism sequelae

Aim of this narrative review is to summarize the functional and hemodynamic implications of acute PE and PE sequelae, namely the post-PE syndrome. Briefly, we will first describe the epidemiology, diagnostic procedures, and therapeutic approaches of acute PE. Then, we will provide a definition of the post-PE syndrome and present the so far accumulated evidence regarding its epidemiology and the implications that arise for further diagnosis and treatment. Lastly, we will explore the most devastating long-term complication of PE, namely chronic thromboembolic pulmonary hypertension (CTEPH), and recent advances in its management.

Pulmonary embolism management in the emergency department: part 2

Pulmonary embolism (PE) can present with a range of severity. Prognostic risk stratification is important for efficacious and safe management. This second of two review articles discusses the management of high-, intermediate- and low-risk PE. We discuss strategies to identify patients suitable for urgent outpatient care in addition to identification of patients who would benefit from thrombolysis. We discuss specific subgroups of patients where optimal treatment differs from the usual approach and identify emerging management paradigms exploring new therapies and subgroups.

Percutaneous Large-Bore Pulmonary Thrombectomy with the FlowTriever Device: Initial Experience in Intermediate-High and High-Risk Patients

OBJECTIVES

This retrospective cohort study investigates outcomes of patients with intermediate-high and high-risk pulmonary embolism (PE) who were treated with transfemoral mechanical thrombectomy (MT) using the large-bore Inari FlowTriever aspiration catheter system.

MATERIAL AND METHODS

Twenty-seven patients (mean age 56.1 ± 15.3 years) treated with MT for PE between 04/2021 and 11/2021 were reviewed. Risk stratification was performed according to European Society of Cardiology (ESC) guidelines. Clinical and hemodynamic characteristics before and after the procedure were compared with the paired Student's t test, and duration of hospital stay was analyzed with the Kaplan-Meier estimator. Procedure-related adverse advents were assessed.

RESULTS

Of 27 patients treated, 18 were classified as high risk. Mean right-to-left ventricular ratio on baseline CT was 1.7 ± 0.6. After MT, a statistically significant reduction in mean pulmonary artery pressures from 35.9 ± 9.6 to 26.1 ± 9.0 mmHg (p = 0.002) and heart rates from 109.4 ± 22.5 to 82.8 ± 13.8 beats per minute (p < 0.001) was achieved. Two patients died of prolonged cardiogenic shock. Three patients died of post-interventional complications of which a paradoxical embolism can be considered related to MT. One patient needed short cardiopulmonary resuscitation during the procedure due to clot displacement. Patients with PE as primary driver of clinical instability had a median intensive care unit (ICU) stay of 2 days (0.5-3.5 days). Patients who developed PE as a complication of an underlying medical condition spent 11 days (9.5-12.5 days) in the ICU.

CONCLUSION

In this small study population of predominantly high-risk PE patients, large-bore MT without adjunctive thrombolysis was feasible with an acceptable procedure-related complication rate.

Improved long-term outcomes with catheter-directed therapies over medical management in patients with submassive pulmonary embolism-a retrospective matched cohort study

BACKGROUND

The benefit of catheter-directed therapy (CDT) for submassive pulmonary embolism (sPE) has been the subject of debate. We sought to determine the short- and long-term mortality and outcomes of CDT compared with anticoagulation for patients with sPE.

METHODS

We performed a single healthcare network, multihospital, retrospective cohort study of hospitalizations for sPE from 2012 to 2019. sPE was defined as the presence of right heart strain or elevated biomarkers (troponin I or B-type natriuretic peptide). Patients with massive PE and those who had undergone systemic thrombolysis were excluded. The sPE groups included therapeutic anticoagulation alone or anticoagulation plus CDT (ie, thrombolysis or suction thrombectomy). The primary outcome was mortality at 1, 3, and 5 years. The other measured outcomes included PE-related death, short term mortality (30 days and 3 and 6 months), 30-day treatment-related complications (eg, bleeding, transfusion, stroke), chronic thromboembolic pulmonary hypertension, and 6-minute walk test at 1 year. After 1:1 nearest-neighbor propensity score matching, Kaplan-Meier survival plots were generated, and the treatment groups were compared using log-rank testing. We used Cox multivariate analysis to evaluate the outcomes after clustering at the hospital level, generating matched hazard ratios (mHRs) with associated 95% confidence intervals (CIs).

RESULTS

Of 6746 sPE hospitalizations, the patients who had received CDT were younger (age, 58.9 ± 15.5 years vs 61.5 ± 17.4 years; P = .004), were more frequently White (92.5% vs 85.7%; P < .001), and had presented with a higher mean heart rate (104.6 bpm vs 94.9 bpm; P < .001), lower median systolic blood pressure (129 mm Hg vs 135 mm Hg; P < .001), and a greater incidence of right heart strain (79.2% vs 20.3%; P < .001). A total of 470 patients were matched, with 235 in the CDT group and 235 in the anticoagulation-only group. CDT was associated with a lower risk of mortality compared with anticoagulation at 1 year (7.6% vs 9.8%; mHR, 0.77; 95% CI, 0.65-0.92; P = .004), 3 years (11.1% vs 16.6%; mHR, 0.64; 95% CI, 0.55-0.73; P < .001), and 5 years (14.5% vs 19.1%; mHR, 0.71; 95% CI, 0.66-0.77; P < .001). Anticoagulation alone resulted in a greater incidence of PE-related deaths at 1, 3, and 5 years. The mortality at 30 days and 3 months was similar; however, CDT had resulted in better survival at 6 months (mHR, 0.81; 95% CI, 0.68-0.97; P = .02). No differences were found between the two groups in the incidence of bleeding complications at 30 days, development of chronic thromboembolic pulmonary hypertension, or the mean walking distance at 1 year.

CONCLUSIONS

CDT plus anticoagulation for sPE was associated with improved long-term survival compared with anticoagulation alone, with a lower incidence of PE-related death and a low complication rate. CDT should be considered for select patients with sPE given its survival benefit.

Comparison of Efficacy and Safety between Thrombolysis Plus Anticoagulation vs. Anticoagulation Alone for the Treatment of Acute Submassive Pulmonary Embolism: A Systematic Review and Meta-analysis

OBJECTIVE

The objective of this study is to compare the efficacy and safety of thrombolysis plus anticoagulant therapy vs. anticoagulant therapy alone in acute submassive pulmonary embolism (PE).

MATERIALS AND METHODS

The PubMed, Embase, and Cochrane Library databases were searched for randomized clinical trials comparing thrombolytic therapy and anticoagulation vs. anticoagulation alone in acute submassive PE patients from 1 Jan 1980 to 20 Jan 2021, with no drug or dose restrictions. Data on upgraded treatment of clinical deterioration, all-cause mortality, PE recurrence and bleeding events were extracted and analyzed using Revman 5.3 software.

RESULTS

A total of 10 randomized controlled trials involving 1871 patients were included in the study after screening. In terms of efficacy, thrombolysis combined with anticoagulant therapy reduced the need for upgrading treatment (3.6 vs. 10.9%, risk ratio (RR) 0.36, 95% confidence interval (CI) 0.24- 0.54, p<0.00001) and PE recurrence (0.8 vs. 2.9%, RR 0.33, 95% CI 0.16-0.69, p=0.003) in patients with acute submassive PE. Compared with anticoagulant therapy alone, the concomitant use of thrombolysis was associated with lower all-cause mortality (1.3 vs. 3.0%, RR 0.47, 95% CI 0.26-0.87, p=0.02), but it increased minor bleeding rate (31.4 vs. 8.4%, RR 3.71, 95% CI 2.82-4.88, p<0.0001) and major bleeding rate (8.8 vs. 2.6%, RR 3.35, 95%CI 2.03-5.54, p<0.0001).

CONCLUSION

The use of thrombolysis plus anticoagulant therapy in acute submassive PE was negatively associated with patients requiring escalation of treatment, PE recurrence, and all-cause mortality, but it was positively associated with bleeding.

["Guiding lights" for the diagnosis of chronic thromboembolic pulmonary hypertension in the flow of patients with pulmonary embolism]

On December 13, 2021, an expert council was held to determine the position of experts of different specialties regarding the reasons for the low level of diagnosis of chronic thromboembolic pulmonary hypertension (CTEPH) in real clinical practice in a pandemic of a new coronavirus infection and possible ways to improve detection in patients with pulmonary embolism (PE) ) in history. The reasons for the low level of diagnosis of CTEPH are the insufficient level of knowledge of specialists, especially primary care physicians; lack of clear regulatory documents and expert centers for the management of this category of patients. Primary diagnosis of CTEPH in a pandemic can be strengthened through the widespread use of telemedicine for consultations of primary care physicians with specialists from expert centers; to maximize the role of echocardiography and computed tomography (CT) as differential diagnostic tools for dyspnea, in particular in patients with COVID-19. To increase the detection rate of CTEPH, diagnostic vigilance is required in patients with risk factors and episodes of venous thromboembolism. To improve the screening of CTEPH, it is necessary to create an algorithm for monitoring patients who have had PE; provide educational activities, including through the media; create materials for patients with accessible information. The regulatory documents should designate the circle of responsible specialists who will be engaged in long-term monitoring of patients with PE. Educational programs are needed for primary care physicians, cardiologists, and other physicians who come into the field of view of patients with CTEPH; introduction of a program to create expert centers for monitoring and managing patients with the possibility of performing ventilation-perfusion lung scintigraphy, cardiopulmonary stress test, CT, right heart catheterization. It seems important to build cooperation with the Ministry of Health of Russia in order to create special protocols, procedures for managing patients with PE and CTEPH.

Acute Pulmonary Embolism: A Review

IMPORTANCE

Pulmonary embolism (PE) is characterized by occlusion of blood flow in a pulmonary artery, typically due to a thrombus that travels from a vein in a lower limb. The incidence of PE is approximately 60 to 120 per 100 000 people per year. Approximately 60 000 to 100 000 patients die from PE each year in the US.

OBSERVATIONS

PE should be considered in patients presenting with acute chest pain, shortness of breath, or syncope. The diagnosis is determined by chest imaging. In patients with a systolic blood pressure of at least 90 mm Hg, the following 3 steps can be used to evaluate a patient with possible PE: assessment of the clinical probability of PE, D-dimer testing if indicated, and chest imaging if indicated. The clinical probability of PE can be assessed using a structured score or using clinical gestalt. In patients with a probability of PE that is less than 15%, the presence of 8 clinical characteristics (age <50 years, heart rate <100/min, an oxygen saturation level of > 94%, no recent surgery or trauma, no prior venous thromboembolism event, no hemoptysis, no unilateral leg swelling, and no estrogen use) identifies patients at very low risk of PE in whom no further testing is needed. In patients with low or intermediate clinical probability, a D-dimer level of less than 500 ng/mL is associated with a posttest probability of PE less than 1.85%. In these patients, PE can be excluded without chest imaging. A further refinement of D-dimer threshold is possible in patients aged 50 years and older, and in patients with a low likelihood of PE. Patients with a high probability of PE (ie, >40% probability) should undergo chest imaging, and D-dimer testing is not necessary. In patients with PE and a systolic blood pressure of 90 mm Hg or higher, compared with heparin combined with a vitamin K antagonist such as warfarin followed by warfarin alone, direct oral anticoagulants such as apixaban, edoxaban, rivaroxaban, or dabigatran, are noninferior for treating PE and have a 0.6% lower rate of bleeding. In patients with PE and systolic blood pressure lower than 90 mm Hg, systemic thrombolysis is recommended and is associated with an 1.6% absolute reduction of mortality (from 3.9% to 2.3%).

CONCLUSIONS AND RELEVANCE

In the US, PE affects approximately 370 000 patients per year and may cause approximately 60 000 to 100 000 deaths per year. First-line therapy consists of direct oral anticoagulants such as apixaban, edoxaban, rivaroxaban, or dabigatran, with thrombolysis reserved for patients with systolic blood pressure lower than 90 mm Hg.

Contemporary Management of Acute Pulmonary Embolism: Evolution of Catheter-based Therapy

Acute pulmonary embolism (PE) affects more than 100 000 people in the United States annually and is the third leading cardiovascular cause of death. The standard management for PE is systemic anticoagulation therapy. However, a subset of patients experience hemodynamic decompensation, despite conservative measures. Traditionally, these patients have been treated with systemic administration of thrombolytic agents or open cardiac surgery, although attempts at endovascular treatment have a long history that dates back to the 1960s. The technology for catheter-based therapy for acute PE is rapidly evolving, with multiple devices approved over the past decade. Currently available devices fall into two broad categories of treatment methods: catheter-directed thrombolysis and percutaneous suction thrombectomy. Catheter-directed thrombolysis is the infusion of thrombolytic agents directly into the occluded pulmonary arteries to increase local delivery and decrease the total dose. Suction thrombectomy involves the use of small- or large-bore catheters to mechanically aspirate a clot from the pulmonary arteries without the need for a thrombolytic agent. A thorough understanding of the various risk stratification schemes and the available evidence for each device is critical for optimal treatment of this complex entity. Multiple ongoing studies will improve our understanding of the role of catheter-based therapy for acute PE in the next 5-10 years. A multidisciplinary approach through PE response teams has become the management standard at most institutions. An invited commentary by Bulman and Weinstein is available online. Online supplemental material is available for this article. ^©RSNA, 2022.

Intermediate-Risk Pulmonary Embolism: A Review of Contemporary Diagnosis, Risk Stratification and Management

Pulmonary embolism (PE) can have a wide range of hemodynamic effects, from asymptomatic to a life-threatening medical emergency. Pulmonary embolism (PE) is associated with high mortality and requires careful risk stratification for individualized management. PE is divided into three risk categories: low risk, intermediate-risk, and high risk. In terms of initial therapeutic choice and long-term management, intermediate-risk (or submassive) PE remains the most challenging subtype. The definitions, classifications, risk stratification, and management options of intermediate-risk PE are discussed in this review.

Evaluating cardiopulmonary function following acute pulmonary embolism

INTRODUCTION

Pulmonary embolism is a common cause of cardiopulmonary mortality and morbidity worldwide. Survivors of acute pulmonary embolism may experience dyspnea, report reduced exercise capacity, or develop overt pulmonary hypertension. Clinicians must be alert for these phenomena and appreciate the modalities and investigations available for evaluation.

AREAS COVERED

In this review, the current understanding of available contemporary imaging and physiologic modalities is discussed, based on available literature and professional society guidelines. The purpose of the review is to provide clinicians with an overview of these modalities, their strengths and disadvantages, and how and when these investigations can support the clinical work-up of patients post-pulmonary embolism.

EXPERT OPINION

Echocardiography is a first test in symptomatic patients post-pulmonary embolism, with ventilation/perfusion scanning vital to determination of whether there is chronic residual emboli. The role of computed tomography and magnetic resonance in assessing the pulmonary arterial tree in post-pulmonary embolism patients is evolving. Functional testing, in particular cardiopulmonary exercise testing, is emerging as an important modality to quantify and determine cause of functional limitation. It is possible that future investigations of the post-pulmonary embolism recovery period will better inform treatment decisions for acute pulmonary embolism patients.

A brief review on failed hybrid treatment for massive pulmonary embolism: catheter-directed thrombolysis (CDT) and pharmaco-mechanical thrombolysis (PMT)

Acute massive or high-risk pulmonary embolism (PE), described as a lung arteries occlusion by an embolus, causes a significant compromise of hemodynamic stability and could lead to a lethal event. Systemic fibrinolytic therapy has been accepted as the standard reperfusion therapy in massive PE, except when there is an increased risk of bleeding. Catheter-based mechanical strategies (thrombofragmentation, thromboaspiration with catheter-guided thrombolysis) are described as options when there are absolute contraindications to systemic thrombolysis. We briefly reviewed clinical situations when patients with severe pneumonia due to COVID-19 are complicated by a high-risk saddle pulmonary embolism and underwent repeated pharmacomechanical thrombolysis and high-flow oxygen therapy. There are scarce reports of failed catheter-guided pharmacomechanical thrombolysis in patients with PE secondary to COVID-19. Re-administration of systemic thrombolysis and alteplase (15 mg dose) can show favorable results.

Ultra-Low-Dose Systemic Tissue Plasminogen Activator in High-Risk Submassive Pulmonary Embolism

Risk stratification of pulmonary embolism (PE) is vital for clinical management. While low-risk and high-risk PE management are clearly defined in many societal guidelines, the management of moderate-risk, also called submassive, PE remains unsettled. There is a subgroup of patients with submassive PE that progress to the severe category despite receiving systemic anticoagulation. The role of thrombolysis in the management of submassive PE remains to be established. We share our experience with ultra-low-dose (25-mg) systemic tissue plasminogen activator in a series of 4 patients with high-risk submassive PE.