Right ventricular stroke distance predicts death and clinical deterioration in patients with pulmonary embolism

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.

Echocardiographic Evaluation of Pulmonary Embolism: A Review

Pulmonary embolism (PE) is the third most common cause of cardiovascular death in the United States. Appropriate risk stratification is an important component of the initial evaluation for acute management of these patients. Echocardiography plays a crucial role in the risk stratification of patients with PE. In this literature review, we describe the current strategies in risk stratification of patients with PE using echocardiography and the role of echocardiography in the diagnosis of PE.

Catheter-directed therapies for the treatment of high risk (massive) and intermediate risk (submassive) acute pulmonary embolism

BACKGROUND

Acute pulmonary embolism (APE) is a major cause of acute morbidity and mortality. APE results in long-term morbidity in up to 50% of survivors, known as post-pulmonary embolism (post-PE) syndrome.  APE can be classified according to the short-term (30-day) risk of mortality, based on a variety of clinical, imaging and laboratory findings. Most mortality and morbidity is concentrated in high-risk (massive) and intermediate-risk (submassive) APE. The first-line treatment for APE is systemic anticoagulation.  High-risk (massive) APE accounts for less than 10% of APE cases and is a life-threatening medical emergency, requiring immediate reperfusion treatment to prevent death. Systemic thrombolysis is the recommended treatment for high-risk (massive) APE. However, only a minority of the people affected receive systemic thrombolysis, due to comorbidities or the 10% risk of major haemorrhagic side effects. Of those who do receive systemic thrombolysis, 8% do not respond in a timely manner. Surgical pulmonary embolectomy is an alternative reperfusion treatment, but is not widely available.  Intermediate-risk (submassive) APE represents 45% to 65% of APE cases, with a short-term mortality rate of around 3%. Systemic thrombolysis is not recommended for this group, as major haemorrhagic complications outweigh the benefit. However, the people at higher risk within this group have a short-term mortality of around 12%, suggesting that anticoagulation alone is not an adequate treatment. Identification and more aggressive treatment of people at intermediate to high risk, who have a more favourable risk profile for reperfusion treatments, could reduce short-term mortality and potentially reduce post-PE syndrome. Catheter-directed treatments (catheter-directed thrombolysis and catheter embolectomy) are minimally invasive reperfusion treatments for high- and intermediate-risk APE. Catheter-directed treatments can be used either as the primary treatment or as salvage treatment after failure of systemic thrombolysis. Catheter-directed thrombolysis administers 10% to 20% of the systemic thrombolysis dose directly into the thrombus in the lungs, potentially reducing the risks of haemorrhagic side effects. Catheter embolectomy mechanically removes the thrombus without the need for thrombolysis, and may be useful for people with contraindications for thrombolysis.  Currently, the benefits of catheter-based APE treatments compared with existing medical and surgical treatment are unclear despite increasing adoption of catheter treatments by PE response teams. This review examines the evidence for the use of catheter-directed treatments in high- and intermediate-risk APE. This evidence could help guide the optimal treatment strategy for people affected by this common and life-threatening condition.

OBJECTIVES

To assess the effects of catheter-directed therapies versus alternative treatments for high-risk (massive) and intermediate-risk (submassive) APE.

SEARCH METHODS

We used standard, extensive Cochrane search methods. The latest search was 15 March 2022.

SELECTION CRITERIA

We included randomised controlled trials (RCTs) of catheter-directed therapies for the treatment of high-risk (massive) and intermediate-risk (submassive) APE. We excluded catheter-directed treatments for non-PE. We applied no restrictions on participant age or on the date, language or publication status of RCTs.

DATA COLLECTION AND ANALYSIS

We used standard Cochrane methods. The main outcomes were all-cause mortality, treatment-associated major and minor haemorrhage rates based on two established clinical definitions, recurrent APE requiring retreatment or change to a different APE treatment, length of hospital stay, and quality of life. We used GRADE to assess certainty of evidence for each outcome.

MAIN RESULTS

We identified one RCT (59 participants) of (ultrasound-augmented) catheter-directed thrombolysis for intermediate-risk (submassive) APE. We found no trials of any catheter-directed treatments (thrombectomy or thrombolysis) in people with high-risk (massive) APE or of catheter-based embolectomy in people with intermediate-risk (submassive) APE. The included trial compared ultrasound-augmented catheter-directed thrombolysis with alteplase and systemic heparinisation versus systemic heparinisation alone. In the treatment group, each participant received an infusion of alteplase 10 mg or 20 mg over 15 hours. We identified a high risk of selection and performance bias, low risk of detection and reporting bias, and unclear risk of attrition and other bias. Certainty of evidence was very low because of risk of bias and imprecision.  By 90 days, there was no clear difference in all-cause mortality between the treatment group and control group. A single death occurred in the control group at 20 days after randomisation, but it was unrelated to the treatment or to APE (odds ratio (OR) 0.31, 95% confidence interval (CI) 0.01 to 7.96; 59 participants). By 90 days, there were no episodes of treatment-associated major haemorrhage in either the treatment or control group. There was no clear difference in treatment-associated minor haemorrhage between the treatment and control group by 90 days (OR 3.11, 95% CI 0.30 to 31.79; 59 participants). By 90 days, there were no episodes of recurrent APE requiring retreatment or change to a different APE treatment in the treatment or control group. There was no clear difference in the length of mean total hospital stay between the treatment and control groups. Mean stay was 8.9 (standard deviation (SD) 3.4) days in the treatment group versus 8.6 (SD 3.9) days in the control group (mean difference 0.30, 95% CI -1.57 to 2.17; 59 participants). The included trial did not investigate quality of life measures.  AUTHORS' CONCLUSIONS: There is a lack of evidence to support widespread adoption of catheter-based interventional therapies for APE. We identified one small trial showing no clear differences between ultrasound-augmented catheter-directed thrombolysis with alteplase plus systemic heparinisation versus systemic heparinisation alone in all-cause mortality, major and minor haemorrhage rates, recurrent APE and length of hospital stay. Quality of life was not assessed.  Multiple small retrospective case series, prospective patient registries and single-arm studies suggest potential benefits of catheter-based treatments, but they provide insufficient evidence to recommend this approach over other evidence-based treatments. Researchers should consider clinically relevant primary outcomes (e.g. mortality and exercise tolerance), rather than surrogate markers (e.g. right ventricular to left ventricular (RV:LV) ratio or thrombus burden), which have limited clinical utility. Trials must include a control group to determine if the effects are specific to the treatment.

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.

Risk Stratification in Patients with Acute Pulmonary Embolism: Current Evidence and Perspectives

Risk stratification is one of the cornerstones of the management of acute pulmonary embolism (PE) and determines the choice of both diagnostic and therapeutic strategies. The first step is the identification of patent circulatory failure, as it is associated with a high risk of immediate mortality and requires a rapid diagnosis and prompt reperfusion. The second step is the estimation of 30-day mortality based on clinical parameters (e.g., original and simplified version of the pulmonary embolism severity index): low-risk patients without right ventricular dysfunction are safely managed with ambulatory anticoagulation. The remaining group of hemodynamically stable patients, labeled intermediate-risk PE, requires hospital admission, even if most of them will heal without complications. In recent decades, efforts have been made to identify a subgroup of patients at an increased risk of adverse outcomes (intermediate-high-risk PE), who might benefit from a more aggressive approach, including reperfusion therapies and admission to a monitored unit. The cur-rent approach, combining markers of right ventricular dysfunction and myocardial injury, has an insufficient positive predictive value to guide primary thrombolysis. Sensitive markers of circulatory failure, such as plasma lactate, have shown interesting prognostic accuracy and may play a central role in the future. Furthermore, the improved security of reduced-dose thrombolysis may enlarge the indication of this treatment to selected intermediate–high-risk PE.

Acute submassive pulmonary embolism after SARS-CoV-2 infection: a case report of reinfection or prolonged hypercoagulable state

Background

Coronavirus disease 19 (COVID-19) reinfection has been a topic of discussion with data still emerging. Viral antibodies are known to develop upon initial infection; however, it is unclear the amount of protection this confers against reinfection. Additionally, COVID-19-associated coagulopathy (CAC) is a well-documented phenomenon; however, there are no high-quality studies to support the treatment of outpatients beyond standard indications of venous thromboembolism (VTE) prophylaxis. This case describes a patient with either COVID-19 reinfection or prolonged course of CAC resulting in pulmonary embolism (PE).

Case summary

A 40-year-old healthy man presented with fever and cough. He tested positive for COVID-19 and was sent home to self-quarantine. His symptoms resolved and repeat COVID-19 testing returned negative. Two months later, he developed dyspnoea on exertion and syncope. Computed tomography with PE protocol demonstrated acute bilateral PE, and repeat COVID-19 testing returned positive. He was escalated to catheter-directed thrombolysis, but prior to the procedure went into cardiopulmonary arrest. Cardiopulmonary resuscitation was initiated and full-dose systemic alteplase was administered. Cardiothoracic surgery was consulted for consideration of veno-arterial extracorporeal membrane oxygenation; however, return of spontaneous circulation was unable to be achieved.

Discussion

This case raises the question of COVID-19 reinfection and prolonged risk of VTE due to CAC. We believe the patient was reinfected with COVID-19 provoking his PE; however, a single COVID-19 infection causing a prolonged course of CAC is possible. Until better data exists, decisions regarding outpatient prophylaxis must be individualized to weigh the risks of bleeding against the risk of thrombosis.

Evaluating the Right Ventricle in Acute and Chronic Pulmonary Embolism: Current and Future Considerations

The right ventricle (RV), due to its morphologic and physiologic differences, is susceptible to sudden increase in RV afterload, as noted in patients with acute pulmonary embolism (PE). Functional impairment of RV function is a stronger presage of adverse outcomes in acute PE than the location or burden of emboli. While current iterations of most clinical prognostic scores do not incorporate RV dysfunction, advancements in imaging have enabled more granular and accurate assessment of RV dysfunction in acute PE. RV enlargement and dysfunction on imaging is noted only in a subset of patients with acute PE and is dependent on underlying cardiopulmonary reserve and clot burden. Specific signs like McConnell's and "60/60" sign are noted in less than 20% of patients with acute PE. About 2% of patients with acute PE develop chronic thromboembolic pulmonary hypertension, characterized by continued deterioration in RV function in a subset of patients with a continuum of RV function from preserved to overt right heart failure. Advances in molecular and other imaging will help better characterize RV dysfunction in this population and evaluate the response to therapies.