Major pulmonary embolism: review of a pathophysiologic approach to the golden hour of hemodynamically significant pulmonary embolism

Extracorporal Membrane Oxygenation in Massive Pulmonary Embolism

BACKGROUND

Massive pulmonary embolism (MPE) carries significant 30-day mortality risk, and a change in societal guidelines has promoted the increasing use of extracorporeal membrane oxygenation (ECMO) in the immediate management of MPE-associated cardiovascular shock. This narrative review examines the current status of ECMO in MPE.

METHODS

A literature review was performed from 1982 to 2022 searching for the terms "Pulmonary embolism" and "ECMO," and the search was refined by examining those publications that covered MPE.

RESULTS

In the patient with MPE, veno-arterial ECMO is now recommended as a bridge to interventional therapy. It can reliably decrease right ventricular overload, improve RV function, and allow hemodynamic stability and restoration of tissue oxygenation. The use of ECMO in MPE has been associated with lower mortality in registry reviews, but there has been no significant difference in outcomes between patients treated with and without ECMO in meta-analyses. Applying ECMO is also associated with substantial multisystem morbidity due to systemic inflammatory response, bleeding with coagulopathy, hemorrhagic stroke, renal dysfunction, and acute limb ischemia, which must be factored into the outcomes.

CONCLUSIONS

The application of ECMO in MPE should be combined with an aggressive interventional pulmonary interventional program and should strictly adhere to the current selection criteria.

Mechanical Support in High-Risk Pulmonary Embolism: Review Article

Acute pulmonary embolism (PE) may manifest with mild nonspecific symptoms or progress to a more severe hemodynamic collapse and sudden cardiac arrest. A substantial thrombotic burden can precipitate sudden right ventricular strain and failure. Traditionally, systemic thrombolytics have been employed in such scenarios; however, patients often present with contraindications, or these interventions may prove ineffective. Outcomes for this medically complex patient population are unfavorable, necessitating a compelling argument for advanced therapeutic modalities or alternative approaches. Moreover, patients frequently experience complications beyond hemodynamic instability, such as profound hypoxia and multiorgan failure, necessitating assertive early interventions to avert catastrophic consequences. The existing data on the utilization of mechanical circulatory support (MCS) devices are not exhaustive. Various options for percutaneous MCS devices exist, each possessing distinct advantages and disadvantages. There is an imminent imperative to develop a tailored approach for this high-risk patient cohort to enhance their overall outcomes.

Association between right ventricular global longitudinal strain and mortality in intermediate-risk pulmonary embolism

BACKGROUND

Right ventricular (RV) systolic dysfunction has been identified as a prognostic marker for adverse clinical events in patients presenting with acute pulmonary embolism (PE). However, challenges exist in identifying RV dysfunction using conventional echocardiography techniques. Strain echocardiography is an evolving imaging modality which measures myocardial deformation and can be used as an objective index of RV systolic function. This study evaluated RV Global Longitudinal Strain (RVGLS) in patients with intermediate risk PE as a parameter of RV dysfunction, and compared to traditional echocardiographic and CT parameters evaluating short-term mortality.

METHODS

Retrospective single center cohort study of 251 patients with intermediate-risk PE between 2010 and 2018. The primary outcome was all-cause mortality at 30 days. Statistical analysis evaluated each parameter comparing survivors versus non-survivors at 30 days. Receiver operating characteristic (ROC) curves and Kaplan-Meier curves were used for comparison of the two cohorts.

RESULTS

Altogether 251 patients were evaluated. Overall mortality rate was 12.4%. Utilizing an ROC curve, an absolute cutoff value of 17.7 for RVGLS demonstrated a sensitivity of 93% and specificity of 70% for observed 30-day mortality. Individuals with an RVGLS ≤17.7 had a 25 times higher mortality rate than those with RVGLS above 17.7 (HR 25.24, 95% CI = 6.0-106.4, p < .001). Area under the curve was (.855), RVGLS outperformed traditional echocardiographic parameters, CT findings, and cardiac biomarkers on univariable and multivariable analysis.

CONCLUSIONS

Reduced RVGLS values on initial echocardiographic assessment of patients with intermediate-risk PE identified patients at higher risk for mortality at 30 days.

The Role of IVC Filters in the Management of Acute Pulmonary Embolism

Venous thromboembolism (VTE), comprising deep venous thrombosis (DVT) and pulmonary embolism (PE), is a prevalent cardiovascular condition, ranking third globally after myocardial infarction and stroke. The risk of VTE rises with age, posing a growing concern in aging populations. Acute PE, with its high morbidity and mortality, emphasizes the need for early diagnosis and intervention. This review explores prognostic factors for acute PE, categorizing it into low-risk, intermediate-risk, and high-risk based on hemodynamic stability and right ventricular strain. Timely classification is crucial for triage and treatment decisions. In the contemporary landscape, low-risk PE patients are often treated with Direct Oral Anticoagulants (DOACS) and rapidly discharged for outpatient follow-up. Intermediate- and high-risk patients may require advanced therapies, such as systemic thrombolysis, catheter-directed thrombolysis, mechanical thrombectomy, and IVC filter placement. The latter, particularly IVC filters, has witnessed increased usage, with evolving types like retrievable and convertible filters. However, concerns arise regarding complications and the need for timely retrieval. This review delves into the role of IVC filters in acute PE management, addressing their indications, types, complications, and retrieval considerations. The ongoing debate surrounding IVC filter use, especially in patients with less conventional indications, reflects the need for further research and data. Despite complications, recent studies suggest that clinically significant issues are rare, sparking discussions on the appropriate and safe utilization of IVC filters in select PE cases. The review concludes by highlighting current trends, gaps in knowledge, and potential avenues for advancing the role of IVC filters in future acute PE management.

The correlation between the CT angiographic pulmonary artery obstructive index and clinical data in patients with acute pulmonary thromboembolism

PURPOSE

The potentially fatal consequences of pulmonary embolism emphasize the need for more effective diagnostic methods. The Qanadli obstruction index has been described as a convenient tool for risk stratification to determine and quantify the degree of obstruction. This study aimed to assess the correlations between the Qanadli index with clinical and paraclinical findings (D-dimer, troponin, and echocardiographic findings) in patients with pulmonary embolism.

MATERIALS AND METHODS

A total of 102 patients with pulmonary embolism underwent echocardiography and CT pulmonary angiography at a single tertiary referral center between 2019 and 2020. The clinical and paraclinical findings, pulmonary arterial obstruction index, atrial measurements, right and left ventricle size and function, tricuspid annular plane systolic excursion, pulmonary artery pressure, and pulmonary hypertension (PH) were analyzed. Vital signs were recorded and assessed. The Qanadli index score was measured, and graded risk stratification was measured based on the quantified index score.

RESULTS

The total mean Qanadli index was 28.75 ± 23.75, and there was no significant relationship between the Qanadli index and gender. Patients' most common clinical findings were exertional dyspnea (84.3%; n = 86) and chest pain (71.7%; n = 73). There were significant correlations between the Qanadli index and pulse rate (PR), troponin, D-dimer levels, and PH. Four patients died during the study, including one from a cardiac condition and three with non-cardiac conditions.

CONCLUSIONS

It is possible to determine the severity, prognosis, and appropriate treatment by the Qanadli index based on strong correlations with PR, troponin, D-dimer levels, and PH.

Incidence and outcomes of surgical pulmonary embolectomy in the UK

BACKGROUND

Surgical pulmonary embolectomy is rarely used for the treatment of massive acute pulmonary embolism. The aim of this study was to assess the incidence and outcomes of this operation by undertaking a retrospective analysis of a large national registry in the UK.

METHODS

All acute pulmonary embolectomies performed between 1996 and 2018 were captured in the National Institute of Cardiovascular Outcomes Research central database. Trends in the number of operations performed during this interval and reported in-hospital outcomes were analysed retrospectively. Multivariable logistic regression was used to identify independent risk factors for in-hospital death.

RESULTS

All 256 patients treated surgically for acute pulmonary embolism during the study interval were included in the analysis. Median age at presentation was 54 years, 55.9% of the patients were men, 48.0% had class IV heart failure symptoms, and 37.5% had preoperative cardiogenic shock. The median duration of bypass was 73 min, and median cross-clamp time was 19 min. Cardioplegic arrest was used in 53.1% of patients. The median duration of hospital stay was 11 days. The in-hospital mortality rate was 25%, postoperative stroke occurred in 5.4%, postoperative dialysis was required in 16%, and the reoperation rate for bleeding was 7.5%. Risk-adjusted multivariable analysis revealed cardiogenic shock (OR 2.54, 95% c.i. 1.05 to 6.21; P = 0.038), preoperative ventilation (OR 5.85, 2.22 to 16.35; P < 0.001), and duration of cardiopulmonary bypass exceeding 89 min (OR 7.82, 3.25 to 20.42; P < 0.001) as significant independent risk factors for in-hospital death.

CONCLUSION

Surgical pulmonary embolectomy is rarely performed in the UK, and is associated with significant mortality and morbidity. Preoperative ventilation, cardiogenic shock, and increased duration of bypass were significant predictors of in-hospital death.

Acute Pulmonary Embolism and Immunity in Animal Models

Venous thromboembolism, encompassing acute pulmonary embolism (APE) and deep vein thrombosis (DVT), is a potentially fatal disease with complex pathophysiology. Traditionally, the Virchow triad provided a framework for understanding the pathogenic contributors to thrombus formation, which include endothelial dysfunction, alterations in blood flow and blood hypercoagulability. In the last years, it has become apparent that immunity plays a central role in thrombosis, interacting with classical prothrombotic mechanisms, oxidative stress and vascular factors. Thrombosis amplifies inflammation, and exaggerated inflammatory processes can trigger thrombosis mainly due to the activation of leukocytes, platelets, and endothelial cells. APE-related endothelium injury is a major trigger for immune system activation. Endothelium is also a key component mediating inflammatory reaction and it is relevant to maintain vascular permeability. Exaggerated right ventricular wall stress and overload, with coexisting systemic hypotension and hypoxemia, result in myocardial injury and necrosis. Hypoxia, tissue factor activation and cytokine storm are engaged in the thrombo-inflammatory processes. Thrombus development is characterized by inflammatory state vascular wall caused mainly by an early extravasation of leukocytes and intense selectins and cytokines production. Nevertheless, immunity of DVT is well described, little is known about potential chemokine and cellular differences between thrombus that develops in the vein and thrombus that detaches and lodges in the pulmonary circulation being a cause of APE. There is a paucity of data considering inflammatory state in the pulmonary artery wall during an acute episode of pulmonary embolism. The main aim of this review is to summarize the knowledge of immunity in acute phase of pulmonary embolism in experimental models.

Validation of Echocardiographic Measurements in Patients with Pulmonary Embolism in the RIETE Registry

Background  In acute pulmonary embolism (PE), echocardiographic identification of right ventricular (RV) dysfunction will inform prognostication and clinical decision-making. Registro Informatizado Enfermedad TromboEmbolica (RIETE) is the world's largest registry of patients with objectively confirmed PE. The reliability of site-reported RV echocardiographic measurements is unknown. We aimed to validate site-reported key RV echocardiographic measurements in the RIETE registry. Methods  Fifty-one randomly chosen patients in RIETE who had transthoracic echocardiogram (TTE) performed for acute PE were included. TTEs were de-identified and analyzed by a core laboratory of two independent observers blinded to site-reported data. To investigate reliability, intraclass correlation coefficients (ICCs) and Bland-Altman plots between the two observers, and between an average of the two observers and the RIETE site-reported data were obtained. Results  Core laboratory interobserver variations were very limited with correlation coefficients >0.8 for all TTE parameters. Agreement was substantial between core laboratory observers and site-reported data for key parameters including tricuspid annular plane systolic excursion (ICC 0.728; 95% confidence interval [CI], 0.594-0.862) and pulmonary arterial systolic pressure (ICC 0.726; 95% CI, 0.601-0.852). Agreement on right-to-left ventricular diameter ratio (ICC 0.739; 95% CI, 0.443-1.000) was validated, although missing data limited the precision of the estimates. Bland-Altman plots showed differences close to zero. Conclusion  We showed substantial reliability of key RV site-reported measurements in the RIETE registry. Ascertaining the validity of such data adds confidence and reliability for subsequent investigations.

Current status of ECMO for massive pulmonary embolism

Massive pulmonary embolism (MPE) carries significant 30-day mortality and is characterized by acute right ventricular failure, hypotension, and hypoxia, leading to cardiovascular collapse and cardiac arrest. Given the continued high mortality associated with MPE, there has been ongoing interest in utilizing extracorporeal membrane oxygenation (ECMO) to provide oxygenation support to improve hypoxia and offload the right ventricular (RV) pressure in the belief that rapid reduction of hypoxia and RV pressure will improve outcomes. Two modalities can be employed: Veno-arterial-ECMO is a reliable process to decrease RV overload and improve RV function, thus allowing for hemodynamic stability and restoration of tissue oxygenation. Veno-venous ECMO can support oxygenation but is not designed to help circulation. Several societal guidelines now suggest using ECMO in MPE with interventional therapy. There are three strategies for ECMO utilization in MPE: bridge to definitive interventional therapy, sole therapy, and recovery after interventional treatment. The use of ECMO in MPE has been associated with lower mortality in registry reviews, but there has been no significant difference in outcomes between patients treated with and without ECMO in meta-analyses. Considerable heterogeneity in studies is a significant weakness of the available literature. Applying ECMO is also associated with substantial multisystem morbidity due to a systemic inflammatory response, hemorrhagic stroke, renal dysfunction, and bleeding, which must be factored into the outcomes. The application of ECMO in MPE should be combined with an aggressive pulmonary interventional program and should strictly adhere to the current selection criteria.

Time-based reperfusion in haemodynamically unstable pulmonary embolism patients: does early reperfusion therapy improve survival?

High-risk pulmonary embolism (PE) is associated with significant morbidity and mortality. Systemic thrombolysis remains the most evidenced-based treatment for haemodynamically unstable PE, but in daily clinical practice, it remains largely underused. In addition, unlike acute myocardial infarction or stroke, a clear time window for reperfusion therapy, including fibrinolysis, for high-risk PE has not been defined either for fibrinolysis or for the more recently incorporated options of catheter-based thrombolysis or thrombectomy. The aim of the present article is to review the current evidence supporting the potential benefit of earlier administration of reperfusion in haemodynamically unstable PE patients and suggest some potential strategies to further explore this issue.

[Pulmonary embolism]

Pulmonary embolism is a frequent cardiovascular disease which in recent years has shown a reduction in the mortality but an increase in the incidence. Due to the optimization of clinical probability scores and the interpretation of the D‑dimer test, unnecessary examinations using computed tomography with respect to the exclusion of an acute pulmonary embolism can be avoided, also in pregnant women. The evaluation of the right ventricle contributes to a risk-adapted treatment. Treatment consists of anticoagulation, alone or in combination with reperfusion treatment, such as systemic thrombolysis and also catheter-assisted or surgical treatment. In addition to acute treatment of pulmonary embolisms, an adequate aftercare is important, particularly for the early detection of long-term sequelae. This review article summarizes the current recommendations of international guidelines for patients with pulmonary embolism, accompanied by clinical case examples and a critical discussion.

Blueprint for developing an effective pulmonary embolism response network

INTRODUCTION

Acute pulmonary embolism (PE) is a major cause of morbidity and mortality in Portugal. It is the third most common cause of cardiovascular death after stroke and myocardial infarction. However, the management of acute PE remains poorly standardized, and there is a lack of access to mechanical reperfusion when indicated.

METHODS AND RESULTS

This working group analyzed the current clinical guidelines for the use of percutaneous catheter-directed treatment in this setting and proposed a standardized approach for severe forms of acute PE. This document also proposes a methodology for the coordination of regional resources in order to create an effective PE response network, based on the hub-and-spoke organization design.

CONCLUSION

This model can be applied at the regional level, but it is desirable to extend it to the national level.

Home Treatment of Patients with Pulmonary Embolism: A Single Center 10-Year Experience from Ljubljana Registry

Current guidelines suggest careful risk stratification using a structured clinical approach when selecting patients with pulmonary embolism (PE) for home treatment. The aim of our study was to assess whether PE patients referred to home treatment are appropriately risk-stratified according to guidelines prior to referral and what the real-life course of the disease in these patients is. We included patients with confirmed PE referred to outpatient management and treated with anticoagulants between 2010 and 2019, whose data were collected in a prospective management registry. Using simplified PE severity index and/or signs of right ventricular strain, we classified patients to either appropriate or inappropriate low-risk classes for outpatient management. We compared 30-day mortality, overall mortality, and rates of recurrent thromboembolism or major bleeding between both classes. Among 278 patients, 188 (67.6%) and 90 (32.4%) were classified as appropriate or inappropriate class, respectively. In total, 30-day mortality was low in both groups: 0% in appropriate class and 1.1% in inappropriate class. The overall mortality rate was higher in the inappropriate than in the appropriate class (12.1 vs 0.9/100 patient-years, respectively, P < .001). Rates of recurrent thromboembolism and major bleeding were similar for both classes. We conclude that in real-life, a significant proportion of inappropriate low-risk class PE patients are referred to outpatient management. However, with careful follow-up, early mortality is low, even in home-treated patients inappropriately classified as low-risk.

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]

Pulmonary embolism is a frequent cardiovascular disease which in recent years has shown a reduction in the mortality but an increase in the incidence. Due to the optimization of clinical probability scores and the interpretation of the D‑dimer test, unnecessary examinations using computed tomography with respect to the exclusion of an acute pulmonary embolism can be avoided, also in pregnant women. The evaluation of the right ventricle contributes to a risk-adapted treatment. Treatment consists of anticoagulation, alone or in combination with reperfusion treatment, such as systemic thrombolysis and also catheter-assisted or surgical treatment. In addition to acute treatment of pulmonary embolisms, an adequate aftercare is important, particularly for the early detection of long-term sequelae. This review article summarizes the current recommendations of international guidelines for patients with pulmonary embolism, accompanied by clinical case examples and a critical discussion.

Current Diagnosis and Management of Acute Pulmonary Embolism: A Strategy for General Practitioners in Emergency Department

Pulmonary embolism (PE) is a disease with a relatively good prognosis when diagnosed and treated properly. This review aims to analyse available data and combine them into algorithms that physicians can use in the emergency department for quick decision-making in diagnosing and treating PE. The available data show that PE can be excluded through highly sensitive clinical decision rules, i.e. Pulmonary Embolism Rule-Out Criteria (PERC), Wells criteria, and Revised Geneva criteria, combined with D-dimer assessment. In cases where PE could not be excluded through the mentioned strategies, imaging modalities, such as compression ultrasonography (CUS), computed tomographic pulmonary angiography (CTPA), and planar ventilation/perfusion (V/Q) scan, are indicated for a definite diagnosis. Once a diagnosis has been made, treatment of PE depends on its mortality risk as patients are divided into low-, intermediate-, and high-risk cases. High-risk cases are treated for their hemodynamic instability, given parenteral or oral anticoagulant therapy, and are indicated for reperfusion therapy. Intermediate-risk PE is only given parenteral or oral anticoagulants and reperfusion is indicated when anticoagulants fail. Low-risk cases are given oral anticoagulants and based on the Hestia criteria, patients may be discharged and treated as outpatients.

Correlation of qanadli obstruction index (QOI) and atrial size on CT pulmonary angiography (CTPA) in patients with pulmonary thromboembolism

Background

Pulmonary thromboembolism (PTE) is a potentially fatal and life-threatening variation of venous thromboembolism (Faghihi Langroudi et al. in Radiol Res Pract 2:1–6, 2019). Computed Tomography Pulmonary Angiography (CTPA) has been proven to be an invaluable first-line diagnostic tool in the early identification of pulmonary thromboembolism (Aviram et al. J Thromb Haemost 9(2):293–299, 2011; Ghaye et al. in RadioGraphics. 26 1 23 39, 2006). Preliminary studies have suggested the correlation between atrial size and clot burden in the pulmonary arteries in patients with pulmonary thromboembolism (Faghihi Langroudi et al. in Radiol Res Pract 2:1–6, 2019; Aviram et al. J Thromb Haemost 9(2):293–299, 2011). Clot burden is calculated by applying the CTPA dependent score—Qanadli Obstruction Index (QOI)/Pulmonary Arterial Obstruction Index (PAOI) in the pulmonary arteries.

Results

There was a significant negative correlation between left atrial/right atrial area, left atrial/right atrial short axis and left atrial/right atrial long axis with the PAOI, especially the left atrial/right atrial area ratio and left atrial/right atrial short axis ratio, which showed the most significant negative correlation. Additionally, an LA/RA area of ≤ 0.60 correlated with a PAOI of > 20 and an obstruction percentage of > 50%, which can serve as a predictor of right ventricular dysfunction.

Conclusions

These atrial dimensions can serve as additional early parameters that reflect changes in the cardiac morphology in response to the clot load within the pulmonary arteries, and can thus contribute towards a more comprehensive risk assessment in patients with acute pulmonary thrombo-embolism.

Pulmonary embolism in pregnancy and the puerperium

Pulmonary embolism (PE) in pregnant women appears to be increasing. This could be related in part to improved health care allowing more women with risk factors to conceive, as well as increase in the high-risk groups which include pregnancies conceived on artificial reproductive technology, advancing maternal age, obesity, and caesarean deliveries. Prevention and early diagnosis with prompt effective treatment can reduce maternal mortality and improve pregnancy outcome, so that obstetricians should be on the lookout for venous thrombosis and PE, especially when in the majority of cases, risk factors only start to emerge or develop in the course of pregnancy and delivery. Management includes accurate diagnosis with ventilation/perfusion scan and CT pulmonary angiography, followed by effective anticoagulation and more aggressive measures such as thrombolysis as indicated, together with general supportive measures. Postpartum management should cover subsequent health issues, including breastfeeding, contraception, mood changes, and recurrence in subsequent pregnancies.

Examination of Impact of After-Hours Admissions on Hospital Resource Use, Patient Outcomes, and Costs

Background. Nighttime and weekends in hospital and intensive care unit (ICU) contexts are thought to present a greater risk for adverse events than daytime admissions. Although some studies exist comparing admission time with patient outcomes, the results are contradictory. No studies currently exist comparing costs with the time of admission. We investigated the differences in-hospital mortality, ICU length of stay, ICU mortality, and cost between daytime and nighttime admissions. Methods. All adult patients (≥18 years of age) admitted to a large academic medical-surgical ICU between 2011 and 2015 were included. Admission cohorts were defined as daytime (8:00–16:59) or nighttime (17:00–07:59). Student’s t-tests and chi-squared tests were used to test for associations between days spent in the ICU, days on mechanical ventilation, comorbidities, diagnoses, and cohort membership. Regression analysis was used to test for associations between patient and hospitalization characteristics and in-hospital mortality and total ICU costs. Results. The majority of admissions occurred during nighttime hours (69.5%) with no difference in the overall Elixhauser comorbidity score between groups ( $p=0.22$ ). Overall ICU length of stay was 7.96 days for daytime admissions compared to 7.07 days ( $p=0.001$ ) for patients admitted during nighttime hours. Overall mortality was significantly higher in daytime admissions (22.5% vs 20.6, $p=0.012$ ); however, ICU mortality was not different. The average MODS was 2.9 with those admitted during the daytime having a significantly higher MODS (3.0, $p=0.046$ ). Total ICU cost was significantly higher for daytime admissions ( $p=0.003$ ). Adjusted ICU mortality was similar in both groups despite an increased rate of adverse events for nighttime admissions. Daytime admissions were associated with increased cost. There was no difference in all hospital total cost or all hospital direct cost between groups. These findings are likely due to the higher severity of illness in daytime admissions. Conclusion. Daytime admissions were associated with a higher severity of illness, mortality rate, and ICU cost. To further account for the effect of staffing differences during off-hours, it may be beneficial to compare weekday and weeknight admission times with associated mortality rates.

Left iliac vein involvement is a protective factor against symptomatic pulmonary embolism in lower left extremity deep vein thrombosis

OBJECTIVE

Left iliac vein compression is associated with left iliac vein thrombosis (IVT), potentially limiting the migration of the thrombus from this stenotic segment to the pulmonary arteries. We sought to investigate the differences in clinical characteristics and risk factors of symptomatic pulmonary embolism (SPE) in patients with deep vein thrombosis (DVT) in different limbs and anatomical locations.

METHODS

A retrospective analysis was conducted of 1476 patients with acute unilateral lower extremity DVT. Differences of clinical characteristics and risk factors between left-sided and right-sided DVT, IVT, and non-IVT, cases with SPE and cases without SPE were compared. Risk factors for SPE were investigated using logistic regression analysis.

RESULTS

SPE was more common in patients with right-sided DVT than patients with left-sided DVT (13.8% vs 7.0%; P < .001). SPE incidence in left IVT (5.4%) was lower than that in left non-IVT, right IVT, and right non-IVT (12.8%, 10.1%, 16.6%, respectively; P < .001). There was no difference in SPE incidence among patients with left non-IVT, right IVT and right non-IVT (P > .05). In patients with left-sided DVT, male sex was associated with an increased odds of SPE (odds ratio [OR], 1.77; 95% confidence interval [CI], 1.10-2.85; P = .02). IVT, surgery, and immobilization were associated with a decreased odds of SPE (OR, 0.46 [95% CI, 0.28-0.76; P < .01]; OR, 0.55 [95% CI, 0.32-0.95; P = .03]; and OR, 0.53 [95% CI, 0.32-0.86; P = .01]). In patients with right-sided DVT, provoked DVT was associated with a decreased odds of SPE (OR, 0.50; 95% CI, 0.27-0.93; P = .03).

CONCLUSIONS

Left IVT is associated with a lower SPE incidence than right-sided DVT. Left IVT and may be a relative protective factor against SPE.

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.

Management of Massive Pulmonary Embolism

Pulmonary embolism is a potentially lethal manifestation of venous thromboembolic disease. It is one of the three main causes of cardiovascular morbidity and mortality in developed countries. Over the years, better diagnostic and risk stratification measures were implemented. A generous range of new treatment options is becoming available, particularly for management of massive pulmonary embolism. Nonetheless, clinicians often face uncertainty in clinical practice due to lack of scientific support for available treatment options. The aim of this article is to review management of massive pulmonary embolism.

Progress in interventional radiology treatment of pulmonary embolism: A brief review

Pulmonary embolism represents a common life-threatening condition. Prompt identification and treatment of this pathological condition are mandatory. In cases of massive pulmonary embolism and hemodynamic instability or right heart failure, interventional radiology treatment for pulmonary embolism is emerging as an alternative to medical treatment (systemic thrombolysis) and surgical treatment. Interventional radiology techniques include percutaneous endovascular catheter directed therapies as selective thrombolysis and thrombus aspiration, which can prove useful in cases of failure or infeasibility of medical and surgical approaches.

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.

Management of bleeding risk in patients who receive anticoagulant therapy for venous thromboembolism: Communication from the ISTH SSC Subcommittee on Predictive and Diagnostic Variables in Thrombotic Disease

Patients with acute venous thromboembolism (VTE) require anticoagulant therapy to prevent recurrent VTE and death, which exposes them to an inherent increased risk of bleeding. Identification of patients at high risk of bleeding, and mitigating this risk, is an essential component of the immediate and long-term therapeutic management of VTE. The bleeding risk can be estimated by either implicit judgment, weighing individual predictors (clinical variables or biomarkers), or by risk prediction tools developed for this purpose. Management of bleeding risk in clinical practice is, however, far from standardized. International guidelines are contradictory and lack clear and consistent guidance on the optimal management of bleeding risk. This report of the ISTH subcommittee on Predictive and Diagnostic Variables in Thrombotic Disease summarizes the evidence on the prediction of bleeding in VTE patients. We systematically searched the literature and identified 34 original studies evaluating either predictors or risk prediction models for prediction of bleeding risk on anticoagulation in VTE patients. Based on this evidence, we provide recommendations for the standardized management of bleeding risk in VTE patients.

Investigation of the need for computed tomography pulmonary angiography in the decision to discontinue treatment for pulmonary thromboembolism

BACKGROUND

Acute pulmonary thromboembolism (PTE) is an important cause of morbidity and mortality that can reduce quality of life due to long-term complications during and after treatment discontinuation.

OBJECTIVES

The aim of this study was to evaluate patients for these complications before discontinuing treatment and determine the necessity of computed tomography pulmonary angiography (CTPA) imaging.

METHODS

This retrospective study included 116 patients over the age of 18 who received anticoagulant treatment for at least 3 months and presented for treatment discontinuation to the Atatürk University Research Hospital Chest Diseases Outpatient Clinic between January 2015 and September 2019.

RESULTS

CTPA performed at treatment discontinuation showed complete thrombus resolution with treatment in 73 patients (62.9%). High pulmonary artery obstruction index (PAOI) at diagnosis was statistically associated with findings of residual or chronic thrombus on CTPA at treatment discontinuation (p = 0.001). In the differentiation of patients with residual/chronic thrombus and those with thrombus resolution, D-dimer at a cut-off value of 474 µg/L had 60% sensitivity and 70% specificity. At a cut-off value of 35.5 mmHg, mean pulmonary artery pressure on echocardiography had sensitivity and specificity of 72% and 77%, respectively. At a cut-off of 23.75, PAOI had sensitivity and specificity of 93% and 69%, respectively.

CONCLUSION

In addition to physical examination findings, D-dimer and echocardiography were guiding parameters in the evaluation of treatment discontinuation and thrombus resolution in patients presenting to the outpatient clinic for discontinuation of treatment for acute PTE. PAOI at diagnosis may be another important guiding parameter in addition to these examinations.

Extracorporeal Membrane Oxygenation—First Strategy for Acute Life-Threatening Pulmonary Embolism

Background

Both venoarterial extracorporeal membrane oxygenation (VA-ECMO) and percutaneous mechanical thrombectomy (PMT) are increasingly used to treat acute life-threatening pulmonary embolism (PE). However, there are little data regarding their effectiveness. This study aimed to present the short-term outcomes after managing nine patients with acute life-threatening massive or submassive PE by VA-ECMO with or without complemented PMT and propose a preliminary treatment algorithm.

Methods

This study was a single-center retrospective review of a prospectively maintained registry. It included nine consecutive patients with massive or submassive pulmonary embolism who underwent VA-ECMO for initial hemodynamic stabilization, with or without PMT, from August 2018 to November 2021.

Results

Mean patient age was 54.7 years. Four of nine patients (44.4%) required cardiopulmonary resuscitation before or during VA-ECMO cannulation. All cannulations (100%) were successfully performed percutaneously. Overall survival was 88.9% (8 of 9 patients). One patient died from a hemorrhagic stroke. Of the survivors, the median ECMO duration was 8 days in patients treated with ECMO alone and 4 days in those treated with EMCO and PMT. Five of nine patients (55.6%) required concomitant PMT to address persistent right heart dysfunction, with the remaining survivors (44.4%) receiving VA-ECMO and anticoagulation alone. For survivors receiving VA-ECMO plus PMT, median hospital lengths of stay were 7 and 13 days, respectively.

Conclusions

An ECMO-first strategy complemented with PMT can be performed effectively and safely for acute life-threatening massive or submassive PE. VA-ECMO is feasible for initial stabilization, serving as a bridge to therapy primarily in inoperable patients with massive PE. Further evaluation in a larger cohort of patients is warranted to assess whether VA-ECMO plus PMT may offer an alternative or complementary therapy to thrombolysis or surgical thrombectomy.

Type of Research

Single-center retrospective review of a prospectively maintained registry.

Clinical experiences of high-risk pulmonary thromboembolism receiving extracorporeal membrane oxygenation in single institution

Background

The main cause of death in pulmonary embolism (PE) is right-heart failure due to acute pressure overload. In this sense, extracorporeal membrane oxygenation (ECMO) might be useful in maintaining hemodynamic stability and improving organ perfusion. Some previous studies have reported ECMO as a bridge to reperfusion therapy of PE. However, little is known about the patients that benefit from ECMO.

Methods

Patients who underwent ECMO due to pulmonary thromboembolism at a single university-affiliated hospital between January 2010 and December 2018 were retrospectively reviewed.

Results

During the study period, nine patients received ECMO in high-risk PE. The median age of the patients was 60 years (range, 22–76 years), and six (66.7%) were male. All nine patients had cardiac arrests, of which three occurred outside the hospital. All the patients received mechanical support with veno-arterial ECMO, and the median ECMO duration was 1.1 days (range, 0.2–14.0 days). ECMO with anticoagulation alone was performed in six (66.7%), and ECMO with reperfusion therapy was done in three (33.3%). The 30-day mortality rate was 77.8%. The median time taken from the first cardiac arrest to initiation of ECMO was 31 minutes (range, 30–32 minutes) in survivors (n=2) and 65 minutes (range, 33–482 minutes) in non-survivors (n=7).

Conclusion

High-risk PE with cardiac arrest has a high mortality rate despite aggressive management with ECMO and reperfusion therapy. Early decision to start ECMO and its rapid initiation might help save those with cardiac arrest in high-risk PE.

Diuretics Versus Volume Expansion in the Initial Management of Acute Intermediate High-Risk Pulmonary Embolism

AIMS

The very early management of pulmonary embolism (PE), a part from antithrombotic treatment, has been little studied. Our aim was to compare the effects of diuretic therapy (DT) versus volume expansion (VE) in patients hospitalized for PE with RV dysfunction.

METHODS AND RESULTS

We conducted a randomized open-label multicentric study including patients with intermediate high-risk PE. Patients were randomized between diuretics or saline infusion. The primary endpoint was time to troponin (Tp) normalization. Secondary endpoints were time to normalization of B-type natriuretic peptide (BNP), changes in echocardiographic RV function parameters and treatment tolerance. Sixty patients presenting intermediate high-risk PE were randomized. Thirty received DT and 30 VE. We noted no changes in Tp kinetics between the two groups. In contrast, faster normalization of BNP was obtained in the DT group: 56 [28-120] vs 108 [48-144] h: p = 0.05, with a shorter time to 50%-decrease from peak value 36 [24-48] vs 54 [41-67] h, p = 0.003 and a higher rate of patients with a lower BNP concentration within the first 12 h (42% vs 12% p < 0.001). RV echocardiographic parameters were unchanged between the groups. One dose 40 mg furosemide was well-tolerated and not associated with any serious adverse events.

CONCLUSION

In the acute management of intermediate high-risk PE, initial therapy including diuretic treatment is well-tolerated and safe. Although changes in Tp kinetics and echocardiographic RV dysfunction parameters did not differ, normalization of BNP is achieved more quickly in the DT group. This finding, which need to be confirmed in trials with clinical end points, may reflects a rapid improvement in RV function using one dose 40 mg furosemide.

TRIAL REGISTRY

Clinical Trial Registration NCT02531581.

Pulmonary Embolism and Pregnancy-Challenges in Diagnostic and Therapeutic Decisions in High-Risk Patients

Diagnosis of acute PE in pregnant women with haemodynamic instability is following the general integrated risk-adapted diagnostic algorithm and starts with bedside echocardiography to assess RV function. If RV dysfunction is identified, a prompt and immediate reperfusion without further imaging should be initiated. Although pregnancy is listed as a relative contraindication of systemic thrombolysis, in pregnant women with acute PE and haemodynamic instability thrombolysis must be considered. In those cases, other treatment strategies as surgical embolectomy or catheter-directed low-dose thromboylysis or percutaneous thrombectomy should be taken into consideration as well. A multidisciplinary team with experience of PE management in pregnancy should be consulted to reach consensus on the best treatment approach.

Pulmonary artery capacitance and pulmonary vascular resistance as prognostic indicators in acute pulmonary embolism

Aims

The non-invasive calculation of right ventricular (RV) haemodynamics as pulmonary artery (PA) capacitance (PAC) and pulmonary vascular resistance (PVR) have proved to be feasible, easy to perform, and of high prognostic value. We, therefore, evaluated whether baseline PAC and PVR could predict clinical outcomes for patients with acute pulmonary embolism (PE).

Methods and results

We prospectively followed 373 patients [mean (standard deviation) age, 64.1 (14.9) years; 58.4% were men, and 27.9% had cancer] who had acute PE and transthoracic echocardiography within 1 day of diagnosis from 1 March 2013 through 30 June 2020. Pulmonary artery capacitance was calculated as left ventricular stroke volume/(PA systolic pressure − PA diastolic pressure). Pulmonary vascular resistance was calculated as (tricuspid regurgitant velocity/RV outflow tract velocity time integral) × 10 + 0.16. These two variables were calculated retrospectively from the values obtained with transthoracic echocardiography. Pulmonary artery capacitance was acquired in 99 (27%) patients and PVR in 65 (17%) patients. Univariable and bivariable logistic regression analyses, and receiver operating characteristic curves were used to evaluate the ability of these haemodynamic measurements to predict mortality up to 6 months. After using bivariable models to adjust individually for age, cancer, and pulmonary hypertension. Pulmonary vascular resistance was associated with all-cause mortality at 3 months [area under the curve (AUC) 0.75, 95% confidence interval (CI) 0.61–0.86; P = 0.01], and 6 months (AUC 0.81; 95% CI 0.69–0.91; P≤ 0.03). Pulmonary artery capacitance was associated with all-cause mortality at 30 days (AUC 0.95; 95% CI 0.82–0.99; P &lt; 0.001) and 3 months (AUC 0.84; 95% CI 0.65–0.99; P = 0.003).

Conclusion

Non-invasive measurement of RV haemodynamics could provide prognostic information of patients with acute PE. Pulmonary artery capacitance and PVR are potentially important predictors of all-cause mortality in these patients and should be explored in future studies.

Can right ventricular assessments improve triaging of low risk pulmonary embolism?

OBJECTIVES

Identifying right ventricle (RV) abnormalities is important to stratifying pulmonary embolism (PE) severity. Disposition decisions are influenced by concerns about early deterioration. Triaging strategies, like the Simplified Pulmonary Embolism Severity Index (sPESI), do not include RV assessments as predictors or early deterioration as outcome(s). We aimed to (1) determine if RV assessment variables add prognostic accuracy for 5-day clinical deterioration in patients classified low risk by sPESI, and (2) determine the prognostic importance of RV assessments compared to other variables and to each other.

METHODS

We identified low risk sPESI patients (sPESI = 0) from a prospective PE registry. From a large field of candidate variables, we developed, and compared prognostic accuracy of, full and reduced random forest models (with and without RV assessment variables, respectively) on a validation database. We reported variable importance plots from full random forest and provided odds ratios for statistical inference of importance from multivariable logistic regression. Outcomes were death, cardiac arrest, hypotension, dysrhythmia, or respiratory failure within 5 days of PE.

RESULTS

Of 1736 patients, 610 (35.1%) were low risk by sPESI and 72 (11.8%) experienced early deterioration. Of the 610, RV abnormality was present in 157 (25.7%) by CT, 121 (19.8%) by echocardiography, 132 (21.6%) by natriuretic peptide, and 107 (17.5%) by troponin. For deterioration, the receiver operating characteristics for full and reduced random forest prognostic models were 0.80 (0.77-0.82) and 0.71 (0.68-0.73), respectively. RV assessments were the top four in the variable importance plot for the random forest model. Echocardiography and CT significantly increased predicted probability of 5-day clinical deterioration by the multivariable logistic regression.

CONCLUSIONS

A PE triaging strategy with RV imaging assessments had superior prognostic performance at classifying low risk for 5-day clinical deterioration versus one without.

Acute Pulmonary Embolism and Chronic Thromboembolic Pulmonary Hypertension: Clinical and Serial CT Pulmonary Angiographic Features

In acute pulmonary embolism (PE), circulatory failure and systemic hypotension are important clinically for predicting poor prognosis. While pulmonary artery (PA) clot loads can be an indicator of the severity of current episode of PE or treatment effectiveness, they may not be used directly as an indicator of right ventricular (RV) failure or patient death. In other words, pulmonary vascular resistance or patient prognosis may not be determined only with mechanical obstruction of PAs and their branches by intravascular clot loads on computed tomography pulmonary angiography (CTPA), but determined also with vasoactive amines, reflex PA vasoconstriction, and systemic arterial hypoxemia occurring during acute PE. Large RV diameter with RV/left ventricle (LV) ratio > 1.0 and/or the presence of occlusive clot and pulmonary infarction on initial CTPA, and clinically determined high baseline PA pressure and RV dysfunction are independent predictors of oncoming chronic thromboembolic pulmonary hypertension (CTEPH). In this pictorial review, authors aimed to demonstrate clinical and serial CTPA features in patients with acute massive and submassive PE and to disclose acute CTPA and clinical features that are related to the prediction of oncoming CTEPH.

Efficacy and Safety of Veno-Arterial Extracorporeal Membrane Oxygenation in the Treatment of High-Risk Pulmonary Embolism: A Retrospective Cohort Study

Objectives

Veno-arterial extracorporeal membrane oxygenation (ECMO) is increasingly used to treat high-risk pulmonary embolism (PE). However, its efficacy and safety remain uncertain. This retrospective cohort study aimed to determine whether ECMO could improve the clinical outcomes of patients with high-risk PE.

Methods

Forty patients with high-risk PE, who were admitted to Kaohsiung Chang Gung Memorial Hospital between January 2012 and December 2019, were included in this study. Demographic data and clinical outcomes were compared between patients treated without ECMO (non-ECMO group) and those treated with ECMO (ECMO group). Appropriate statistical tools were used to compare variables between groups and the survival was analyzed using the Kaplan-Meier method.

Results

The overall in-hospital mortality rate was 55%, in which 65% (26/40) of patients presented with cardiac arrest with a mortality rate of 77%, which was higher than that of patients without cardiac arrest (14%). There was no significant difference in major complications and in-hospital mortality between the non-ECMO and ECMO groups. However, in subgroup analysis, compared with patients treated without ECMO, earlier ECMO treatment was associated with a reduced risk of cardiac arrest (P = 0.023) and lower in-hospital mortality (P = 0.036). A log-rank test showed a significantly higher cumulative overall survival in the earlier ECMO treatment group (P = 0.033).

Conclusions

In this retrospective cohort study, earlier ECMO treatment was associated with lower in-hospital mortality among unstable patients without cardiac arrest. Our findings suggest that ECMO can be considered as an initial treatment option for patients with high-risk PE in higher-volume hospitals.

Outcome After Thrombolysis in Patients With Intermediate High-Risk Pulmonary Embolism: A Propensity Score Analysis

BACKGROUND

The role of thrombolytic treatment in patients with intermediate high-risk pulmonary embolism (IHR-PE) remains controversial.

OBJECTIVES

In this study, we assessed whether systemic thrombolysis decreases hemodynamic decompensation and mortality in a cohort of unselected patients with IHR compared with patients with conventional anticoagulation.

METHODS

Between January 2014 and December 2018, 137 patients with IHR-PE were identified among 539 consecutive patients treated for symptomatic PE. In 35 patients (25.5%), systemic thrombolysis was used. Propensity score matching was performed based on 17 pretreatment variables. The primary outcome was hemodynamic decompensation, defined by systolic hypotension, need for catecholamines or signs of end-organ hypoperfusion, and all-cause mortality during hospitalization. Secondary outcomes, such as 1-year survival, and safety outcomes, such as bleeding events, were analyzed.

RESULTS

The effects of systemic thrombolysis and anticoagulation were compared in 55 matched patients with IHR-PE (systemic thrombolysis n = 21; anticoagulation n = 34). Thrombolysis was associated with a reduction (0% vs. 31%; p = 0.004) of the primary outcome during hospitalization and a 1-year survival benefit (100% vs. 83.2%; p = 0.036). Severe bleeding events occurred in 4.8% vs. 0% (p = 0.382) and moderate bleeding was observed in 14.3% vs. 7.1% (p = 0.359) in patients with thrombolysis compared with anticoagulation, respectively.

CONCLUSIONS

Thrombolysis was associated with a significant reduction of the combined endpoint of hemodynamic decompensation and death during hospitalization and lower all-cause mortality after 1 year in an unselected group of patients with IHR-PE. Further studies are required to improve the therapy of IHR-PE and to identify the subgroup of patients that might benefit from thrombolytic therapy.

Echocardiographic findings in patients with acute pulmonary embolism at Sohag University Hospitals

Background

Acute pulmonary thromboembolism (PTE) is one of the serious medical issues with higher prevalence and mortality rates. As mentioned in several medical reports, most of the chest pain patients, visiting the emergency departments, are usually diagnosed with either acute PTE, acute coronary syndromes, or acute aortic syndromes. The current study aimed to study the risk factors and explore the echocardiographic findings in patients with PTE.

Results

Forty patients with acute pulmonary embolism were enrolled in the study. Echocardiography and computed tomography pulmonary angiography (CTPA) were evaluated for all participants. The echocardiography showed that 29 patients (72.5%) had echocardiographic findings suggestive of acute PTE. Twenty-four patients (60%) had tricuspid regurge. Twenty-one patients (52.5%) had dilated right ventricle (RV). Also, 13 patients (32.5%) had an echocardiographic finding of pulmonary hypertension. Furthermore, ten patients (25%) had McConnell’s sign, and 21 patients (52.5%) had RV systolic dysfunction where only two (5%) showed RV thrombosis. Echocardiographic data of the eight high-risk patients showed that 6 patients (75%) had TR, 8 patients (100%) had dilated RV, 5 patients (62.5%) had pulmonary hypertension, 8 patients (100%) had McConnell’s sign, one patient (12.5%) had RV thrombus, and 8 patients (100%) had RV systolic dysfunction.

Conclusion

The results revealed that thrombus in the main pulmonary trunk was a high-risk factor for patients with acute pulmonary embolism. The current study suggested that echocardiography is an important bedside imaging tool for the diagnosis of PTE. Echocardiography could detect the tricuspid regurge, pulmonary hypertension, McConnell’s sign, RV dilatation, thrombosis, and dysfunction. Furthermore, echocardiography was considered a non-invasive test for rapid diagnosis of PTE and determining the degree of the risk category (high- or low-risk patients) specially with the presence of McConnell’s sign, dilated RV, and RV systolic dysfunction.

Acoustic pulse thrombolysis complemented by ECMO improved survival in patients with high-risk pulmonary embolism

BACKGROUND

The optimal treatment of high-risk pulmonary embolism (PE) with cardiac arrest is still controversial although various treatment approaches have been developed and improved. Here, we present a serie of patients with high-risk PE showing hemodynamic collapse, who were successfully treated with extracorporeal membrane oxygenation (ECMO) as an adjunct to EKOS™ acoustic pulse thrombolysis (APT).

METHODS

From April 2016 to June 2020, 29 patients with high-risk PE with cardiac arrest were retrospectively included. The mean age was 55.3 ± 9.2 years. A total of 12 (41.3%) patients were female. All patients had cardiac arrest, either as an initial presentation or in-hospital after presentation. All patients exhibited acute symptoms, computed tomography evidence of large thrombus burden, and severe right ventricular dysfunction. Primary outcome was all-cause 30-day mortality.

RESULTS

Twenty-two patients survived to hospital discharge, with a mean intensive care unit stay of 9.9 ± 1.6 days (range: 7-22 days) and mean length of hospital stay of 23.7 ± 8.5 days (range: 11-44 days). Six patients died from refractory shock. Ninety-day mortality was 24.1% (7/29). The Mean ECMO duration was 3.5 ± 1.1 days and the mean RV/LV ratio decreased from 1.31 ± 0.17 to 0.92 ± 0.11 in patients who survived to discharge. The mean tissue plasminogen activator dose for survivor patients was 20.5 ± 1.6 mg.

CONCLUSION

Patients with high-risk pulmonary embolism who suffer a cardiac arrest have high morbidity and mortality. APT complemented by ECMO could be a successful treatment option for the patients who have high-risk PE with circulatory collapse.

The role of ultrasonography in anesthesia for bariatric surgery

Bariatric surgeries are effective long-term management for morbid obesity with its adverse sequelae. Anesthesia of bariatric surgeries poses unique challenges for the anesthesiologist in every step starting with vascular access till tracheal extubation. The usage of ultrasound in anesthesia is becoming more prevalent with a variety of benefits, especially in the obese population. Ultrasound is successfully used for obtaining vascular access, with more than 15 million catheters placed in the United States alone. Ultrasound can also be used to predict difficult intubation, as it can confirm the tracheal intubation and assess the gastric content to prevent pulmonary aspiration. Ultrasound is also used in the management of mechanically ventilated patients to monitor lung aeration and to identify respiratory complications during positive pressure ventilation. Moreover, intraoperative echocardiography helps to discover the pulmonary embolism and guides the fluid therapy. Finally, ultrasound can be used to perform neuraxial and fascial plane block with a less overall time of the procedures and minimal complications. The wide use of ultrasound in bariatric anesthesia reflects the learning curve of the anesthesiologists and their mounting efforts to provide safe anesthesia utilizing the updated technology. In this review, we highlight the role of ultrasonography in anesthesia of bariatric surgery and discuss the recent guidelines.

[Pulmonary Embolism]

Pulmonary embolism (PE) is a life-threatening disease and the third most frequent cardiovascular cause of death after stroke and myocardial infarction. The annual incidence is increasing (in Germany from 85 cases per 100000 population in the year 2005 to 109 cases per 100000 population in the year 2015). The individual risk for PE-related complications and death increases with the number of comorbidities and severity of right ventricular dysfunction. Using clinical, laboratory and imaging parameters, patients with PE can be stratified to four risk classes (high, intermediate-high, intermediate-low and low risk). This risk stratification has concrete therapeutic consequences ranging from out-of-hospital treatment of low-risk patients to reperfusion treatment of (intermediate)-high-risk patients. For haemodynamically unstable patients, treatment decision should preferably be made in interdisciplinary "Pulmonary Embolism Response Teams" (PERT). Due to their comparable efficacy and preferable safety profile compared to vitamin-K antagonists (VKAs), non-vitamin K-dependent oral anticoagulants (NOACs) are increasingly considered the treatment of choice for initial and prolonged anticoagulation of patients with pulmonary embolism. Use of low molecular weight heparins (LMWHs) is recommended for PE patients with cancer; however, recent studies indicate that treatment with factor Xa-inhibitors may be effective and safe (in patients without gastrointestinal cancer). Only prolonged anticoagulation (in reduced dosage) will ensure reduction of VTE recurrence and should thus be considered for all patients with unprovoked events.

Diuretic vs. placebo in intermediate-risk acute pulmonary embolism: a randomized clinical trial

AIMS

The role of diuretics in patients with intermediate-risk pulmonary embolism (PE) is controversial. In this multicentre, double-blind trial, we randomly assigned normotensive patients with intermediate-risk PE to receive either a single 80 mg bolus of furosemide or a placebo.

METHODS AND RESULTS

Eligible patients had at least a simplified PE Severity Index (sPESI) ≥1 with right ventricular dysfunction. The primary efficacy endpoint assessed 24 h after randomization included (i) absence of oligo-anuria and (ii) normalization of all sPESI items. Safety outcomes were worsening renal function and major adverse outcomes at 48 hours defined by death, cardiac arrest, mechanical ventilation, or need of catecholamine. A total of 276 patients underwent randomization; 135 were assigned to receive the diuretic, and 141 to receive the placebo. The primary outcome occurred in 68/132 patients (51.5%) in the diuretic and in 49/132 (37.1%) in the placebo group (relative risk = 1.30, 95% confidence interval 1.04-1.61; P = 0.021). Major adverse outcome at 48 h occurred in 1 (0.8%) patients in the diuretic group and 4 patients (2.9%) in the placebo group (P = 0.19). Increase in serum creatinine level was greater in diuretic than placebo group [+4 µM/L (-2; 14) vs. -1 µM/L (-11; 6), P < 0.001].

CONCLUSION

In normotensive patients with intermediate-risk PE, a single bolus of furosemide improved the primary efficacy outcome at 24 h and maintained stable renal function. In the furosemide group, urine output increased, without a demonstrable improvement in heart rate, systolic blood pressure, or arterial oxygenation.ClinicalTrials.gov identifier NCT02268903.

Repeat angiography in patients undergoing conventional catheter-directed thrombolysis for submassive pulmonary embolism: a large single-center experience

PURPOSE

Few studies have examined conventional catheter directed thrombolysis (CDT) for the treatment of submassive pulmonary embolism (PE). Moreover, angiographic resolution of thrombus burden following CDT has infrequently been characterized. This study describes a single-center experience treating submassive PE with CDT while utilizing repeat angiography to determine treatment efficacy.

METHODS

A retrospective analysis of 140 consecutive patients who underwent CDT for submassive PE from December 2012 to June 2019 was performed. Angiographic resolution of thrombus burden after CDT was reported as high (>75%), moderate (51-75%), low (26-50%), or insignificant (≤25%). All angiograms were reviewed by two interventional radiologists. Secondary endpoints included reduction in pulmonary artery pressure (PAP) and clinical outcomes. Bleeding events were classified according to the Society of Interventional Radiology (SIR) adverse event criteria.

RESULTS

CDT was performed in 140 patients with a mean rtPA dose of 25.3 mg and a mean treatment time of 26.0 hours. Angiographic resolution of thrombus burden was high in 70.0%, moderate in 19.3%, low in 5.7%, and insignificant in 3.6%; in 2 patients (1.4%) repeat angiography was not performed. Systolic PAP was reduced (47 vs. 35 mmHg, p < 0.001), mean PAP was reduced (25 vs 21 mmHg, p < 0.001), and 129 patients (92.1%) improved clinically. Patients with high or moderate resolution of thrombus burden had a clinical improvement rate of 95.2%, while patients with low or insignificant thrombus burden resolution had a clinical improvement rate of 76.9% (p=0.011). Ten patients (7.1%) had hemodynamic or respiratory decompensation requiring mechanical ventilation, systemic thrombolysis, cardiopulmonary resuscitation, or surgical intervention. Seven patients (5.0%) experienced moderate bleeding events and one patient (0.7%) with metastatic disease developed severe gastrointestinal bleeding that resulted in death. Thirty-day mortality was 1.4%.

CONCLUSION

In patients with submassive PE undergoing CDT, angiographic resolution of thrombus burden is a safe and directly observable metric that can be used to determine procedural success. In this study, CDT with repeat angiography was associated with a 5.7% bleeding event rate and thirty-day mortality of 1.4%.