Treatment of submassive pulmonary embolism with tenecteplase or placebo: cardiopulmonary outcomes at 3 months: multicenter double-blind, placebo-controlled randomized trial

Fibrinolytic Agents in Thromboembolic Diseases: Historical Perspectives and Approved Indications

Fibrinolytic agents catalyze the conversion of the inactive proenzyme plasminogen into the active protease plasmin, degrading fibrin within the thrombus and recanalizing occluded vessels. The history of these medications dates to the discovery of the first fibrinolytic compound, streptokinase, from bacterial cultures in 1933. Over time, researchers identified two other plasminogen activators in human samples, namely urokinase and tissue plasminogen activator (tPA). Subsequently, tPA was cloned using recombinant DNA methods to produce alteplase. Several additional derivatives of tPA, such as tenecteplase and reteplase, were developed to extend the plasma half-life of tPA. Over the past decades, fibrinolytic medications have been widely used to manage patients with venous and arterial thromboembolic events. Currently, alteplase is approved by the U.S. Food and Drug Administration (FDA) for use in patients with pulmonary embolism with hemodynamic compromise, ST-segment elevation myocardial infarction (STEMI), acute ischemic stroke, and central venous access device occlusion. Reteplase and tenecteplase have also received FDA approval for treating patients with STEMI. This review provides an overview of the historical background related to fibrinolytic agents and briefly summarizes their approved indications across various thromboembolic diseases.

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.

Safety and efficacy of clot-dissolving therapies for submassive pulmonary embolism: A network meta-analysis of randomized controlled trials

BACKGROUND

Acute pulmonary embolism (PE) is a serious condition that needs quick and effective treatment. Anticoagulation therapy is the usual care for most PE patients but may not work well for higher-risk ones. Thrombolysis breaks the clot and improves blood flow. It can be given systemically or locally. Ultrasound-assisted catheter-directed thrombolysis (USAT) is a new technique that boosts clot-busting drugs. This network meta-analysis compares death, bleeding, and benefits of four treatments in acute submassive PE.

METHODS

We comprehensively searched relevant databases up to July 2023 for RCTs. The outcomes encompassed all-cause mortality, major and minor bleeding, PE recurrence, and hospital stay duration. Bayesian network meta-analysis computed odds ratios (OR) and 95 % CI estimates.

RESULTS

In this network meta-analysis of 23 RCTs involving 2521 PE patients, we found that SCDT had the most favorable performance for mortality, as it had the lowest odds ratio (OR) among the four interventions (OR 5.41e-42; 95 % CI, 5.68e-97, 1.37e-07). USAT had the worst performance for major bleeding, as it had the highest OR among the four interventions (OR 4.73e+04; 95 % CI, 1.65, 9.16e+13). SCDT also had the best performance for minor bleeding, as it had the lowest OR among the four interventions (OR 5.68e-11; 95 % CI, 4.97e-25, 0.386).

CONCLUSION

Our meta-analysis suggests that SCDT is the most effective treatment intervention in improving the risks of All-cause mortality and bleeding. Thrombolytic therapy helps in improving endpoints including the risk of PE recurrence and the duration of hospital stay.

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.

Safety and Efficacy of Reduced-Dose Versus Full-Dose Alteplase for Acute Pulmonary Embolism: A Multicenter Observational Comparative Effectiveness Study

OBJECTIVES

Systemic thrombolysis improves outcomes in patients with pulmonary embolism (PE) but is associated with the risk of hemorrhage. The data on efficacy and safety of reduced-dose alteplase are limited. The study objective was to compare the characteristics, outcomes, and complications of patients with PE treated with full- or reduced-dose alteplase regimens.

DESIGN

Multicenter retrospective observational study.

SETTING

Tertiary care hospital and 15 community and academic centers of a large healthcare system.

PATIENTS

Hospitalized patients with PE treated with systemic alteplase.

INTERVENTIONS

None.

MEASUREMENTS AND MAIN RESULTS

Pre- and post-alteplase hemodynamic and respiratory variables, patient outcomes, and complications were compared. Propensity score (PS) weighting was used to adjust for imbalances of baseline characteristics between reduced- and full-dose patients. Separate analyses were performed using the unweighted and weighted cohorts. Ninety-eight patients were treated with full-dose (100 mg) and 186 with reduced-dose (50 mg) regimens. Following alteplase, significant improvements in shock index, blood pressure, heart rate, respiratory rate, and supplemental oxygen requirements were observed in both groups. Hemorrhagic complications were lower with the reduced-dose compared with the full-dose regimen (13% vs. 24.5%, p = 0.014), and most were minor. Major extracranial hemorrhage occurred in 1.1% versus 6.1%, respectively ( p = 0.022). Complications were associated with supratherapeutic levels of heparin anticoagulation in 37.5% of cases and invasive procedures in 31.3% of cases. The differences in complications persisted after PS weighting (15.4% vs. 24.7%, p = 0.12 and 1.3% vs. 7.1%, p = 0.067), but did not reach statistical significance. There were no significant differences in mortality, discharge destination, ICU or hospital length of stay, or readmission after PS weighting.

CONCLUSIONS

In a retrospective, PS-weighted observational study, when compared with the full-dose, reduced-dose alteplase results in similar outcomes but fewer hemorrhagic complications. Avoidance of excessive levels of anticoagulation or invasive procedures should be considered to further reduce complications.

Management of high-risk pulmonary embolism in the emergency department: A narrative review

BACKGROUND

High-risk pulmonary embolism (PE) is a complex, life-threatening condition, and emergency clinicians must be ready to resuscitate and rapidly pursue primary reperfusion therapy. The first-line reperfusion therapy for patients with high-risk PE is systemic thrombolytics (ST). Despite consensus guidelines, only a fraction of eligible patients receive ST for high-risk PE.

OBJECTIVE

This review provides emergency clinicians with a comprehensive overview of the current evidence regarding the management of high-risk PE with an emphasis on ST and other reperfusion therapies to address the gap between practice and guideline recommendations.

DISCUSSION

High-risk PE is defined as PE that causes hemodynamic instability. The high mortality rate and dynamic pathophysiology of high-risk PE make it challenging to manage. Initial stabilization of the decompensating patient includes vasopressor administration and supplemental oxygen or high-flow nasal cannula. Primary reperfusion therapy should be pursued for those with high-risk PE, and consensus guidelines recommend the use of ST for high-risk PE based on studies demonstrating benefit. Other options for reperfusion include surgical embolectomy and catheter directed interventions.

CONCLUSIONS

Emergency clinicians must possess an understanding of high-risk PE including the clinical assessment, pathophysiology, management of hemodynamic instability and respiratory failure, and primary reperfusion therapies.

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.

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

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

Performance-based outcome measures for assessing physical capacity in patients with pulmonary embolism: A scoping review

INTRODUCTION

Up to 50 % of patients surviving a pulmonary embolism (PE) report persisting shortness of breath, reduced physical capacity and psychological distress. As the PE population is heterogeneous compared to other cardiovascular patient groups, outcome measures for assessing physical capacity traditionally used in cardiac populations may not be reliable for the PE population as a whole. This scoping review aims to 1) map performance-based outcome measures (PBOMs) used for assessing physical capacity in PE research, and 2) to report the psychometric properties of the identified PBOMs in a PE population.

METHODS

The review was conducted according to the Joanna Briggs Institute framework for scoping reviews and reported according to the PRISMA-Extension for Scoping Reviews guideline.

RESULTS

The systematic search of five databases identified 4585 studies, of which 243 studies met the inclusion criteria. Of these, 185 studies focused on a subgroup of patients with chronic thromboembolic pulmonary hypertension. Ten different PBOMs were identified in the included studies. The 6-minute walk test (6MWT) and cardiopulmonary exercise test (CPET) were the most commonly used, followed by the (Modified) Bruce protocol and Incremental Shuttle Walk test. No studies reported psychometric properties of any of the identified PBOMs in a PE population.

CONCLUSIONS

Publication of studies measuring physical capacity within PE populations has increased significantly over the past 5-10 years. Still, not one study was identified, reporting the validity, reliability, or responsiveness for any of the identified PBOMs in a PE population. This should be a priority for future research in the field.

Treatment of acute pulmonary embolism after catheter-directed thrombolysis with dabigatran vs warfarin: results of a multicenter randomized RE-SPIRE trial

BACKGROUND

Thrombolytic therapy is effective method in the high-risk acute pulmonary embolism (PE) treatment. Reduced-dose thrombolysis (RDT) plus oral anticoagulation therapy is effective and safe method in the moderate and severe PE treatment. It is leading to good early and intermediate-term outcomes. In the RE-COVER and RE-COVER II studies, dabigatran showed similar effectiveness as warfarin in the treatment of acute PE. Dabigatran leads to fewer hemorrhagic complications and is not inferior in efficacy to warfarin in the prevention of PE after mechanical fragmentation and RDT (catheter-directed treatment [CDT]+RDT) in patients with high and intermediate to high PE risk. We sought to evaluate the efficacy and safety (incidence of clinically significant recurrence of venous thromboembolic complications and deaths) during a 6-month course of treatment with dabigatran or warfarin in patients with high and intermediate to high acute PE risk after endovascular mechanical thrombus fragmentation procedure with RDT (CDT+RDT).

METHODS

The RE-SPIRE is a prospective, multicenter randomized double-arm study. Over a 5-year period, 66 consecutive patients with symptomatic high and intermediate to high PE risk after endovascular mechanical thrombus fragmentation procedure with RDT (CDT+RDT) were randomized into two groups within the next 48 hours. The first group continued treatment with dabigatran 150 mg twice a day for 6 months; the second group continued treatment with warfarin under the control of international normalized ratio (2.0-3.0) for 6 months. Both groups received low molecular weight heparins for 2 days after surgery. Then, group 1 continued to receive low molecular-weight-heparin for 5 to 7 days, followed by a switch to dabigatran at a dosage of 150 mg two times a day. Group 2 received both low-molecular-weight heparin and warfarin up to an international normalized ratio of >2.0, followed by heparin withdrawal. The follow-up period was 6 months.

RESULTS

There were 63 patients who completed the study (32 in the dabigatran group and 31 in the warfarin group). In both groups, there was a statistically significant decrease in the mean pulmonary artery pressure. The mean pulmonary artery pressure at the 6-month follow-up after surgery was 24 mm Hg (interquartile range, 20.3-29.25 mm Hg) in the dabigatran group and 23 mm Hg (interquartile range, 20.0-26.3 mm Hg) in the warfarin group. The groups did not differ statistically in the deep vein thrombosis dynamics. Partial recanalization occurred in 52.0% vs 73.1% in the dabigatran and warfarin groups, respectively (P = .15). Complete recanalization occurred in 28.0% vs 19.2% in the dabigatran and warfarin groups, respectively (P = .56). The groups did not differ in the frequency of major bleeding events according to the International Society for Thrombosis and Hemostasis (0% vs 3.2% in the dabigatran and warfarin groups, respectively; P = 1.00). However, there were more nonmajor bleeding events in the warfarin group than in the dabigatran group (16.1% vs 0%, respectively; P = .02).

CONCLUSIONS

The results of the study show that dabigatran is comparable in effectiveness to warfarin. Dabigatran has greater safety in comparison with warfarin in the occurrence of all cases of bleeding in the postoperative and long-term periods. Thus, dabigatran may be recommended for the treatment and prevention of PE after CDT with RDT in patients with high and intermediate to high PE risk.

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.

Comparison of important factors to patients recovering from pulmonary embolism and items covered in patient-reported outcome measures: A mixed-methods systematic review

OBJECTIVE

Up to 50 % of patients recovering from pulmonary embolism (PE) experience negative long-term outcomes. Patient-reported outcome measures (PROMs) are important in identifying what matters to patients. We aimed to identify PROMs used in clinical studies and recommended by the International Consortium of Health Outcomes (ICHOM) and compare individual items with factors considered important by patients recovering from PE.

METHODS

This was a convergent mixed-methods systematic review, including quantitative studies, using PROMs and qualitative studies with non-cancer-related PE patients. Items from each PROM and qualitative findings were categorised using an International Classification of Function linking process to allow for integrated synthesis.

RESULTS

A total of 68 studies using 34 different PROMs with 657 items and 13 qualitative studies with 408 findings were included. A total of 104 individual ICF codes were used, and subsequently sorted into 20 distinct categories representing patient concerns. Identified PROMs were found to adequately cover 17/20 categories, including anxiety, fear of bleeding, stress, depression, dizziness/nausea, sleep disturbance, pain, dyspnea, fatigue, activity levels, family and friends, socializing, outlook on life, and medical treatment. PROMs from the ICHOM core set covered the same categories, except for dizziness/nausea.

CONCLUSIONS

No single PROM covered all aspects assessed as important by the PE population. PROMs recommended in the ICHOM core set cover 16/20 aspects. However, worrisome thoughts, hypervigilance around symptoms, and uncertainty of illness were experienced by patients with PE but were not covered by PROMS.

Systemic thrombolysis with newer thrombolytics vs anticoagulation in acute intermediate risk pulmonary embolism: a systematic review and meta-analysis

BACKGROUND

Randomized controlled trials (RCTs) comparing systemic thrombolysis to anticoagulation in intermediate risk pulmonary embolism (PE) have yielded mixed results. A prior meta-analysis on this topic had included studies that used lower than standard dose of thrombolytics and included thrombolytic agents that are no longer available. Hence, interpreting the findings of that paper is not valid in contemporary practice.

OBJECTIVES

We undertook a systematic review and meta-analysis of randomized controlled trials of systemic thrombolysis with newer thrombolytic agents vs anticoagulation in intermediate risk PE.

METHODS

This systematic review and meta-analysis is reported according to the Preferred Reporting Items for Systematic Reviews and Meta-Analysis (PRISMA) statement.

RESULTS

Nine randomized controlled trials were included in the study. We did not find any difference in in-hospital mortality (RR: 0.79; 95% CI: 0.42-1.50; I2: 0) or risk of major bleeding (RR:2.08;95% CI: 0.98-4.42; I2: 23.9%) between systemic thrombolysis and anticoagulation. Systemic thrombolysis was associated with lower risks for vasopressor use (RR: 0.27; 95% CI: 0.11-0.64, I2: 0) and secondary/rescue thrombolysis (RR: 0.25; 95% CI: 0.14-0.45; I2: 0). But systemic thrombolysis was found to have an increased risk of intracranial hemorrhage (RR: 4.55; 95% CI: 1.30-15.91; I2:0). There was no difference in mechanical ventilation between the two groups (RR: 0.61; 95% CI: 0.31-1.19, I2:0).

CONCLUSION

In our meta-analysis of randomized controlled trials of systemic thrombolysis vs anticoagulation in intermediate risk PE, we did not find any difference in in-hospital mortality or overall risk of major bleeding. With systemic thrombolysis, we found lower risks for vasopressor use and need for secondary/ rescue thrombolysis and an increased risk of intracranial hemorrhage.

Quality of life 1 month after acute pulmonary embolism in emergency department patients

OBJECTIVE

The Pulmonary Embolism Quality-of-Life (PEmb-QoL) questionnaire assesses quality of life (QoL) after pulmonary embolism (PE). We aimed to determine whether any clinical or pathophysiologic features of PE were associated with worse PEmb-QoL scores 1 month after PE.

METHODS

In this prospective multicenter registry, we conducted PEmb-QoL questionnaires. We determined differences in QoL domain scores for four primary variables: clinical deterioration (death, cardiac arrest, respiratory failure, hypotension requiring fluid bolus, catecholamine support, or new dysrhythmia), right ventricular dysfunction (RVD), PE risk stratification, and subsequent rehospitalization. For overall QoL score, we fit a multivariable regression model that included these four primary variables as independent variables.

RESULTS

Of 788 PE patients participating in QoL assessments, 156 (19.8%) had a clinical deterioration event, 236 (30.7%) had RVD of which 38 (16.1%) had escalated interventions. For those without and with clinical deterioration, social limitations had mean (±SD) scores of 2.07 (±1.27) and 2.36 (±1.47), respectively (p = 0.027). For intensity of complaints, mean (±SD) scores for patients without RVD (4.32 ± 2.69) were significantly higher than for those with RVD with or without reperfusion interventions (3.82 ± 1.81 and 3.83 ± 2.11, respectively; p = 0.043). There were no domain score differences between PE risk stratification groups. All domain scores were worse for patients with rehospitalization versus without. By multivariable analysis, worse total PEmb-QoL scores with effect sizes were subsequent rehospitalization 11.29 (6.68-15.89), chronic obstructive pulmonary disease (COPD) 8.17 (3.91-12.43), and longer index hospital length of stay 0.06 (0.03-0.08).

CONCLUSIONS

Acute clinical deterioration, RVD, and PE severity were not predictors of QoL at 1 month post-PE. Independent predictors of worsened QoL were rehospitalization, COPD, and index hospital length of stay.

Low-Dose Alteplase versus Conventional Anticoagulation to treat Submassive Pulmonary Embolism in Hispanic Patients

The use of low-dose tissue plasminogen activator (tPA) in Hispanic patients with submassive pulmonary embolism (PE) is understudied. The purpose of this study is to explore the use of low-dose tPA in Hispanic patients with submissive PE compared with counterparts that received heparin alone. We retrospectively analyzed a single-center registry of patients with acute PE between 2016 and 2022. Out of 72 patients admitted for acute PE and cor pulmonale, we identified six patients that were treated with conventional anticoagulation (heparin alone) and six patients who received low-dose tPA (and heparin afterward). We analyzed if low-dose tPA was associated with differences in length of stay (LOS) and bleeding complications. Both groups were similar in regard to age, gender, and PE severity (based on Pulmonary Embolism Severity Index scores). Mean total LOS for the low-dose tPA group was 5.3 days, compared with 7.3 days in the heparin group ( p  = 0.29). Mean intensive care unit (ICU) LOS for the low-dose tPA group was 1.3 days compared with 3 days in the heparin group ( p  = 0.035). There were no clinically relevant bleeding complications documented in either the heparin or the low-dose tPA group. Low-dose tPA for submassive PE in Hispanic patients was associated with a shorter ICU LOS without a significant increase in bleeding risk. Low-dose tPA appears to be a reasonable treatment option in Hispanic patients with submassive PE who are not at high bleeding risk (<5%).

Mortality and bleeding associated with the management of sub-massive pulmonary embolism: a systematic review and Bayesian network meta-analysis

Current guidelines recommend anticoagulation (AC) for low and intermediate-risk pulmonary embolism (PE) and systemic thrombolysis (tPA) for high risk (massive) PE. How these treatment options compare with other modalities of treatment such as catheter directed thrombolysis (CDT), ultrasound assisted catheter thrombolysis (USAT), and administering lower dose of thrombolytics (LDT) is unclear. There is no study that has compared all these treatment options. We conducted a systematic review and Bayesian network meta-analysis of randomized controlled trials in patients with submassive (intermediate risk) PE. Fourteen randomized controlled trials were included, comprising 2132 patients. On Bayesian network meta-analysis, a significant decrease in mortality was noted in tPA versus AC. There was no significant difference between USAT versus CDT. For risk of major bleeding, there was no significant difference in relative risk of major bleeding between tPA versus AC and USAT versus CDT. tPA was found to have a significantly higher risk of minor bleeding and a lower risk of recurrent PE compared to AC. Systemic thrombolysis is associated with a significant reduction in mortality and recurrent PE compared to anticoagulation but an increased risk of minor bleeding. There was no difference in risk of major bleeding. Our study also shows that while the newer modalities of treatment for pulmonary embolism are promising, there is lack of data to comment on the purported advantages.

Mental Health and Quality of Life in Pulmonary Embolism: A Literature Review

Pulmonary embolismis an acute disease with chronic complications and, although it is not considered a chronic disease, it requires close follow-up. The scope of the present literature review is to decode the existing data concerning quality of life and the mental health impact of PE during the acute and long-term phases of the disease. The majority of studies reported impaired quality of life in patients with PE when compared to population norms, both in the acute phase and >3 months after PE. Quality of life improves over time, irrespectively of the measurement used. Fear of recurrences, elderly, stroke, obesity, cancer and cardiovascular comorbidities are independently associated with worse QoL at follow-up. Although disease specific instruments exist (e.g., the Pulmonary Embolism Quality of Life questionnaire), further research is required in order to develop questionnaires that may fulfil international guideline requirements. The fear of recurrences and the development of chronic symptoms, such as dyspnea or functional limitations, may further impair the mental health burden of PE patients. Mental health may be implicated by post-traumatic stress disorder, anxiety and depressive symptoms present following the acute event. Anxiety may persist for 2 years following diagnosis and may be exaggerated by persistent dyspnea and functional limitations. Younger patients are at higher risk of anxiety and trauma symptoms while elderly patients and patients with previous cardiopulmonary disease, cancer, obesity or persistent symptoms exhibit more frequently impaired QoL. The optimal strategy for the assessment of mental health in this patient pool is not well defined in the literature. Despite mental burden being common following a PE event, current guidelines have not incorporated the assessment or management of mental health issues. Further studies are warranted to longitudinally assess the psychological burden and elucidate the optimal follow-up approach.

The Challenge of Intermediate-Risk Pulmonary Embolism

BACKGROUND

Intermediate-risk pulmonary embolism is a common disease that is associated with significant morbidity and mortality; however, a standardized treatment protocol is not well-established.

AREAS OF UNCERTAINTY

Treatments available for intermediate-risk pulmonary embolisms include anticoagulation, systemic thrombolytics, catheter-directed therapies, surgical embolectomy, and extracorporeal membrane oxygenation. Despite these options, there is no clear consensus on the optimal indication and timing of these interventions.

THERAPEUTIC ADVANCES

Anticoagulation remains the cornerstone of treatment for pulmonary embolism; however, over the past 2 decades, there have been advances in the safety and efficacy of catheter-directed therapies. For massive pulmonary embolism, systemic thrombolytics and, sometimes, surgical thrombectomy are considered first-line treatments. Patients with intermediate-risk pulmonary embolism are at high risk of clinical deterioration; however, it is unclear whether anticoagulation alone is sufficient. The optimal treatment of intermediate-risk pulmonary embolism in the setting of hemodynamic stability with right heart strain present is not well-defined. Therapies such as catheter-directed thrombolysis and suction thrombectomy are being investigated given their potential to offload right ventricular strain. Several studies have recently evaluated catheter-directed thrombolysis and embolectomies and demonstrated the efficacy and safety of these interventions. Here, we review the literature on the management of intermediate-risk pulmonary embolisms and the evidence behind those interventions.

CONCLUSIONS

There are many treatments available in the management of intermediate-risk pulmonary embolism. Although the current literature does not favor 1 treatment as superior, multiple studies have shown growing data to support catheter-directed therapies as potential options for these patients. Multidisciplinary pulmonary embolism response teams remain a key feature in improving the selection of advanced therapies and optimization of care.

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.

An adaptive clinical trial design to identify the target dose of tenecteplase for treatment of acute pulmonary embolism

BACKGROUND/AIMS

Fibrinolytic therapy with tenecteplase has been proposed for patients with pulmonary embolism but the optimal dose is unknown. Higher-than-necessary dosing is likely to cause excess bleeding. We designed an adaptive clinical trial to identify the minimum and assumed safest dose of tenecteplase that maintains efficacy.

METHODS

We propose a Bayesian adaptive, placebo-controlled, group-sequential dose-finding trial using response-adaptive randomization to preferentially allocate subjects to the most promising doses, dual analyses strategies (continuous and dichotomized) using a gatekeeping approach to maximize clinical impact, and interim stopping rules to efficiently address competing trial objectives. The operating characteristics of the proposed design were evaluated using Monte Carlo simulation across multiple hypothetical efficacy scenarios.

RESULTS

Simulation demonstrated response-adaptive randomization can preferentially allocate subjects to doses which appear to be performing well based on interim data. Interim decision-making, including the interim evaluation of both analysis strategies with gatekeeping, allows the trial to continue enrollment when success with the dichotomized analysis strategy appears sufficiently likely and to stop enrollment and declare superiority based on the continuous analysis strategy when there is little chance of ultimately declaring superiority with the dichotomized analysis.

CONCLUSION

The proposed design allows evaluation of a greater number of dose levels than would be possible with a non-adaptive design and avoids the need to choose either the continuous or the dichotomized analysis strategy for the primary endpoint.

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.

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.

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.

An Update on the Management of Acute High-Risk Pulmonary Embolism

Hemodynamic instability and right ventricular (RV) dysfunction are the key determinants of short-term prognosis in patients with acute pulmonary embolism (PE). High-risk PE encompasses a wide spectrum of clinical situations from sustained hypotension to cardiac arrest. Early recognition and treatment tailored to each individual are crucial. Systemic fibrinolysis is the first-line pulmonary reperfusion therapy to rapidly reverse RV overload and hemodynamic collapse, at the cost of a significant rate of bleeding. Catheter-directed pharmacological and mechanical techniques ensure swift recovery of echocardiographic parameters and may possess a better safety profile than systemic thrombolysis. Further clinical studies are mandatory to clarify which pulmonary reperfusion strategy may improve early clinical outcomes and fill existing gaps in the evidence.

Echocardiographic predictors of mortality in intermediate-risk pulmonary embolism

Data regarding further risk stratification of intermediate-risk pulmonary embolism (IR-PE) are scanty. Whether transthoracic echocardiography may be helpful in further risk assessment of death in such population has still to be proven. Two-hundred fifty-four consecutive patients (51.6% females, age 63.7 ± 17.3 years) with IR-PE admitted to a tertiary regional referral center were enrolled. Patients underwent a complete transthoracic echocardiography within 36 h from hospital admission, on top of clinical assessment, physical examination, computer tomography pulmonary angiography (CTPA), and serum measurement of Troponin I (TnI) levels. The occurrence of 90 day mortality was chosen as primary outcome measure. When compared to survivors, non-surviving IR-PE patients had smaller left-ventricular end-diastolic volumes (39.8 ± 20.9 vs 49.4 ± 19.9 ml/m², p = 0.006) with reduced stroke volume index (SVi) (24.7 ± 10.9 vs 30.9 ± 12.6 ml/m², p: 0.004) and time-velocity integral at left-ventricular outflow tract (VTI_LVOT) (0.17 ± 0.03 vs 0.20 ± 0.04 m, p = 0.0001), whereas no differences were recorded regarding right heart parameters. Cox regression analysis revealed that right atrial enlargement (RAE) (HR 3.432, 5-95% CI 1.193-9.876, p: 0.022), the ratio between tricuspid annulus plane excursion and pulmonary arterial systolic pressure (TAPSE/PASp) (HR 4.833, 5-95% 1.230-18.986, p = 0.024), as well as SVi (HR 11.199, 5-95% CI 2.697-48.096, p = 0.001) and VTI_LVOT (HR 4.212, 5-95% CI 1.384-12.820, p = 0.011) were powerful independent predictors of mortality. Neither CTPA RV/LV nor TnI resulted associated with impaired survival. In intermediate-risk pulmonary embolism, RAE, TAPSE/PASp ratio, SVi, and VTI_LVOT predict independently prognosis to a greater extent than CTPA and TnI.

Contemporary Treatment of Pulmonary Embolism: Medical Treatment and Management

Pulmonary embolus (PE) is defined as obstruction of the pulmonary artery or one of its branches by material (e.g., thrombus, tumor, air, or fat) but most commonly due to thrombus originating from the lower extremity deep veins.

We reviewed the current literature describing the optimal medical treatment and management of PE.

Databases (PubMed, the Cochrane Library, Embase, EBSCO, Web of Science, and CINAHL) were searched for relevant studies and guidelines for management of patients with PE.

The initial approach to patients with suspected PE should focus upon stabilizing the patient while further workup for risk stratification is in progress. In most cases, anticoagulation should ideally be started even prior to confirming PE, if risk–benefit regarding suspicion of PE and bleeding risk is favorable.

Once the diagnosis is confirmed, risk stratification will guide further therapies consisting of anticoagulation, thrombolysis, or catheter-directed interventions. Data for initial, long-term, and indefinite anticoagulation, and factors that determine whether or not a patient can be treated in the outpatient setting, are reviewed and discussed.

Association Between the Use of Pre- and Post-thrombolysis Anticoagulation With All-Cause Mortality and Major Bleeding in Patients With Pulmonary Embolism

Objective

To explore the comparative clinical efficacy and safety outcomes of anticoagulation before (pre-) or following (post-) thrombolytic therapy in systemic thrombolytic therapy for pulmonary embolism (PE).

Methods

PubMed, the Cochrane Library, EMBASE, EBSCO, Web of Science, and CINAHL databases were searched from inception through 1 May 2021. All randomized clinical trials comparing systemic thrombolytic therapy vs. anticoagulation alone in patients with PE and those that were written in English were eligible. The primary efficacy and safety outcomes were all-cause mortality and major bleeding, respectively. Odds ratios (OR) estimates and associated 95% confidence intervals (CIs) were calculated. A Bayesian network analysis was performed using R studio software, and then the efficacy and safety rankings were derived.

Results

This network meta-analysis enrolled 15 trials randomizing 2,076 patients. According to the plot rankings, the anticoagulant therapy was the best in terms of major bleeding, and the post-thrombolysis anticoagulation was the best in terms of all-cause mortality. Taking major bleeding and all-cause mortality into consideration, the most safe–effective treatment was the post-thrombolysis anticoagulation in patients who needed thrombolytic therapy. The net clinical benefit analysis comparing associated ICH benefits vs. mortality risks of post-thrombolysis anticoagulation demonstrated a net clinical benefit of 1.74%.

Conclusion

The systemic thrombolysis followed by anticoagulation had a better advantage in all-cause mortality and major bleeding than the systemic thrombolysis before anticoagulation. The adjuvant anticoagulation treatment of systemic thrombolytic therapy should be optimized.

Contemporary Practice Patterns and Outcomes of Systemic Thrombolysis in Acute Pulmonary Embolism

OBJECTIVE

While systemic thrombolysis (ST) is standard of care in treatment of high-risk pulmonary embolism, large variation in real world usage exists, including use in intermediate-risk pulmonary embolism. There is a paucity of data defining the outcomes, practice patterns of ST dose, duration, and treatment in presumed or imaging confirmed pulmonary embolism.

METHODS

We performed a multicenter retrospective study evaluating real world practice patterns of systemic thrombolysis use in the setting of acute pulmonary embolism (presumed versus imaging confirmed intermediate- and high-risk). Patients who received tissue plasminogen activator for pulmonary embolism between 2017 and 2019 were included. We compared baseline clinical characteristics, tissue plasminogen activator practice patterns, and outcomes in those with confirmed versus presumed pulmonary embolism.

RESULTS

104 patients received systemic thrombolysis for pulmonary embolism; 52 patients had confirmed pulmonary embolism and 52 patients had presumed pulmonary embolism. Significantly more patients treated for presumed pulmonary embolism experienced cardiac arrest (n=47, 90%) than those with confirmed pulmonary embolism (n=23, 44%, p<0.01). Survival to hospital discharge was 65% in patients with confirmed pulmonary embolism versus 6% for those with presumed pulmonary embolism (p<0.01). Systemic thrombolysis was contraindicated in 56% of patients with confirmed pulmonary embolism, with major bleeding in 26% but no intracranial hemorrhage.

CONCLUSIONS

The in-hospital mortality of confirmed acute pulmonary embolism remains high (35%) in contemporary practice in those treated with systemic thrombolysis. A large proportion of these patients had contraindications to systemic thrombolysis and major bleeding rates were significant. Confirmed pulmonary embolism had higher survival rate compared to presumed, including those with cardiac arrest. This observation suggests a limited role of empiric thrombolysis in cardiac arrest situations.

Tenecteplase in Pulmonary Embolism Patients: A Meta-Analysis and Systematic Review

Objective

To assess the efficacy and safety of tenecteplase in patients with pulmonary embolism (PE).

Methods

We completed the literature search on May 31, 2021 using PubMed, EMBASE and the Web of Science. Analyses were conducted according to PE risk stratification, study design and duration of follow-up. The pooled risk ratios (RRs) and its 95% confident intervals (CIs) for death and major bleeding were calculated using a random-effect model.

Results

A total of six studies, with four randomized controlled trials (RCTs) and two cohort studies, were included in this study out of the 160 studies retrieved. For patients with high-risk PE, tenecteplase increased 30-day survival rate (16% vs 6%; P = 0.005) and did not increase the incidence of bleeding (6% vs 5%; P = 0.73). For patients with intermediate-risk PE, four RCTs suggested that tenecteplase reduced right ventricular insufficiency at 24h early in the onset and the incidence of hemodynamic failure without affecting mortality in a short/long-term [<30 days RR = 0.83, 95% CI (0.47, 1.46);≥30 days RR = 1.04, 95% CI (0.88, 1.22)]. However, tenecteplase was associated with high bleeding risk [<30 days RR = 1.79, 95% CI (1.61, 2.00); ≥30 days RR = 1.28, 95% CI (0.62, 2.64)].

Conclusions

Tenecteplase may represent a promising candidate for patients with high risk PE. However, tenecteplase is not recommended for patients with intermediate-risk PE because of high bleeding risk. More large-scale studies focused on tenecteplase are still needed for PE patients.

Submassive Pulmonary Embolism Treated With Catheter-Directed Thrombolysis in Resource-Limited Setting: A Case Report and Review of Literature

We describe a case of a young male who presented with acute onset progressively worsening shortness of breath for four days duration. He used to smoke cigarettes, and his profession required prolonged periods of standing. He underwent a two-dimensional echocardiogram showing right ventricular (RV) strain and computed tomography (CT) showing thrombus in the left major pulmonary artery. His pulmonary embolism severity index (PESI) score was high, predicting higher short-term mortality. Treatment options including risks and benefits were discussed with the patient, and he underwent catheter-directed thrombolysis (CDT) with rapid resolution of symptoms, oxygen saturation, and pulmonary artery pressures (PAP). He was discharged home safely after successful treatment of his condition.

Low-dose thrombolysis for submassive pulmonary embolism

The role of thrombolysis in submassive pulmonary embolism (PE) is controversial due to the high risk of hemorrhage. This study aimed to evaluate the role of half-dose tissue-type plasminogen activator (rt-PA) in preventing death/hemodynamic decompensation in submassive (intermediate-risk) PE without increasing the risk of bleeding. In a prospective, non-randomized, open-label, single-center trial, we compared 50 mg rt-PA plus low molecular weight heparin (LMWH) with LMWH in submassive (intermediate-risk) PE. Eligible cases had confirmed pulmonary hypertension on echocardiography, and/or right ventricular cavity expansion and/or interventricular septal deviation on echocardiography, and/or right to left ventricular ratio equal to or greater than 0.9 mm on CT angiography. The primary outcome was death or hemodynamic decompensation within 7 and 30 days after treatment was given. The primary safety outcome was major extracranial bleeding or hemorrhagic stroke within 7 days. Seventy-six patients were included in the study. Total death/hemodynamic decompensation in the first 7 and 30 days was significantly less in the half-dose rt-PA group than in the LMWH group (p=0.028 and p=0.009, respectively). No significant differences were found between the two groups in terms of recurrent embolism and pulmonary hypertension at 6-month follow-up (p=1.000 and p=0.778). There was no intracranial hemorrhage in any of the patients. There were no statistically significant differences between the two groups in terms of major or minor bleeding complications. This trial showed half-dose rt-PA treatment in submassive (intermediate-risk) PE prevented death/hemodynamic decompensation in the first 7-day and 30-day period compared with LMWH treatment without increasing the risk of bleeding.

Neurological Complications of Pulmonary Embolism: a Literature Review

PURPOSE OF REVIEW

The present review discusses in-depth about neurological complications following acute venous thromboembolism (VTE).

RECENT FINDINGS

Intracranial hemorrhage, acute ischemic cerebrovascular events, and VTE in brain tumors are described as central nervous system (CNS) complications of PE, while peripheral neuropathy and neuropathic pain are reported as peripheral nervous system (PNS) sequelae of PE. Syncope and seizure are illustrated as atypical neurological presentations of PE. Mounting evidence suggests higher risk of venous thromboembolism (VTE) in patients with neurological diseases, but data on reverse, i.e., neurological sequelae following VTE, is underexplored. The present review is an attempt to explore some of the latter issues categorized into CNS, PNS, and atypical complications following VTE.

Detection of right ventricular dysfunction in acute pulmonary embolism by computed tomography or echocardiography: A systematic review and meta-analysis

BACKGROUND

Right ventricular (RV) dysfunction predicts worse outcomes in acute pulmonary embolism (PE). Because computed tomography (CT) pulmonary angiography visualizes cardiac structures, it is a potential method for assessing RV function without the delays associated with inpatient echocardiography.

OBJECTIVES

We conducted a systematic review and meta-analysis to assess the diagnostic accuracy of CT scan findings for detecting RV dysfunction compared with echocardiography.

METHODS

We searched MEDLINE and EMBASE from inception to April 2020 for studies comparing RV dysfunction on CT scan with echocardiography standard. Study quality was assessed with the QUADAS-2 risk of bias tool. Meta-analysis was performed using a bivariate mixed effects regression framework.

RESULTS

After screening, 26 studies (3508 patients) were included. In a pooled analysis, septal deviation (5 studies; 459 patients) had a sensitivity of 0.31 (95% CI 0.25-0.38; I2  = 0%), specificity of 0.98 (95% CI 0.90-1.00; I2  = 59.4%), and positive likelihood ratio of 13.6 (95% CI 3.1-60.4) for RV dysfunction compared with echocardiography. The pooled sensitivity of increased RV/left ventricular ratio (21 studies; 3111 patients) was 0.83 (95% CI 0.78-0.87; I2  = 81.8%), whereas the pooled specificity was 0.75 (95% CI 0.66-0.82; I2  = 94.2%) and negative likelihood ratio was 0.23 (0.18-0.29).

CONCLUSIONS

Overall, RV dysfunction can be detected by CT imaging but the diagnostic accuracy when compared with echocardiography varies depending on specific findings. The presence of septal bowing appears to be highly specific for RV dysfunction. Our findings suggest that multiple CT findings of RV dysfunction may improve diagnostic accuracy and further studies are warranted.

Advanced management of intermediate-high risk pulmonary embolism

This article is one of ten reviews selected from the Annual Update in Intensive Care and Emergency Medicine 2021. Other selected articles can be found online at https://www.biomedcentral.com/collections/annualupdate2021 . Further information about the Annual Update in Intensive Care and Emergency Medicine is available from https://link.springer.com/bookseries/8901 .

Submassive Pulmonary Embolism: Current Perspectives and Future Directions

Submassive pulmonary embolism (PE) lies on a spectrum of disease severity between standard and high-risk disease. By definition, patients with submassive PE have a worse outcome than the majority of those with standard-risk PE, who are hemodynamically stable and lack imaging or laboratory features of cardiac dysfunction. Systemic thrombolytic therapy has been proven to reduce mortality in patients with high-risk disease; however, its use in submassive PE has not demonstrated a clear benefit, with haemodynamic improvements being offset by excess bleeding. Furthermore, meta-analyses have been confusing, with conflicting results on overall survival and net gain. As such, significant interest remains in optimising thrombolysis, with recent efforts in catheter-based delivery as well as upcoming studies on reduced systemic dosing. Recently, long-term cardiorespiratory limitations following submassive PE have been described, termed post-PE syndrome. Studies on the ability of thrombolytic therapy to prevent this condition also present conflicting evidence. In this review, we aim to clarify the current evidence with respect to submassive PE management, and also to highlight shortcomings in current definitions and prognostic factors. Additionally, we discuss novel therapies currently in preclinical and early clinical trials that may improve outcomes in patients with submassive PE.

Thrombolytics for venous thromboembolic events: a systematic review with meta-analysis

Thrombolytic therapy might reduce venous thromboembolism-related mortality and morbidity, but it could also increase the risk of major bleeding. We systematically reviewed the literature to evaluate the effectiveness and safety of thrombolytics in patients with pulmonary embolism (PE) and/or deep venous thrombosis (DVT). We searched Medline, Embase, and Cochrane databases for relevant randomized controlled trials up to February 2019. Multiple investigators independently screened and collected data. We included 45 studies (4740 participants). Pooled estimates of PE studies indicate probable reduction in mortality with thrombolysis (risk ratio [RR], 0.61; 95% confidence interval [CI], 0.40-0.94) (moderate certainty) and possible reduction in nonfatal PE recurrence (RR, 0.56; 95% CI, 0.35-0.89) (low certainty). Pooled estimates of DVT studies indicate the possible absence of effects on mortality (RR, 0.77; 95% CI, 0.26-2.28) (low certainty) and recurrent DVT (RR, 0.99; 95% CI, 0.56-1.76) (low certainty), but possible reduction in postthrombotic syndrome (PTS) with thrombolytics (RR, 0.70; 95% CI, 0.59-0.83) (low certainty). Pooled estimates of the complete body of evidence indicate increases in major bleeding (RR, 1.89; 95% CI, 1.46-2.46) (high certainty) and a probable increase in intracranial bleeding (RR, 3.17; 95% CI 1.19-8.41) (moderate certainty) with thrombolytics. Our findings indicate that thrombolytics probably reduce mortality in patients with submassive- or intermediate-risk PE and may reduce PTS in patients with proximal DVT at the expense of a significant increase in major bleeding. Because the balance between benefits and harms is profoundly influenced by the baseline risks of critical outcomes, stakeholders involved in decision making would need to weigh these effects to define which clinical scenarios merit the use of thrombolytics.

Accelerated treatment with rtPA for pulmonary embolism induced circulatory arrest

Patients with circulatory arrest due to pulmonary embolism (PE) should be treated with fibrinolytics. Current guidelines do not specify which regimen to apply, and it has been suggested that the regimen of 100 mg rtPA/2 h should be used, because this is recommended for hemodynamic instable PE in the ESC/ERS Guideline. This two hour regimen, however, is incompatible with key principles of cardiopulmonary resuscitation (CPR), such as employment of interventions that allow fast evaluation of effectiveness, and limitation of the total duration of CPR to avoid poor neurological outcomes. Additionally, the low flow-state during CPR has important consequences for the pharmacokinetic properties of rtPA. Arguably, the volume of distribution is lower, the metabolism reduced and the half life time longer. Therefore, these changes largely discard the rationale to use high dosages of rtPA over a prolonged period of time. More importantly, these changes highlight that the guideline recommendations, based on studies in patients without circulatory arrest, cannot be easily translated to the situation of circulatory arrest. An accelerated regimen of rtPA (0.6 mg/kg/15 min., max 50 mg) is mentioned by the 2019 ESC/ERS Guideline. However, empirical support or a rationale is not provided. Due to the rarity of the situation and ethical difficulties associated with randomizing unconscious patients, a randomized head-to-head comparison between the two regimens is unlikely to ever be performed. With this comprehensive overview of the pharmacokinetics of rtPA and current literature, a strong rationale is provided that the accelerated protocol is the regimen of choice for patients with PE-induced circulatory arrest.

Successful Surgical Embolectomy for a Rapidly Deteriorating Patient with Pulmonary Embolism and Hemorrhagic Stroke

Pulmonary embolism (PE) is a life-threatening condition. High-risk PE is defined as pulmonary embolism with either hemodynamic collapse, persistent hypotension, and/or organ hypoperfusion. The overall mortality rate associated with high-risk PE remains at approximately 30%.

Intermediate–high risk PE is a new term introduced to identify hemodynamically stable PE patients with evidence of right ventricular dysfunction.

Thrombolytics therapy is the first choice for treatment of high-risk PE with hemodynamic instability; however, in a patient who failed thrombolytics or have contraindication to thrombolytics, thrombus removal either with open surgical or catheter embolectomy is a good alternative.

We report a case of a patient who presented with hemorrhagic stroke complicated by intermediate–high-risk PE that rapidly deteriorated before undergoing successful surgical embolectomy.

Thrombolytic therapy for pulmonary embolism

BACKGROUND

Thrombolytic therapy is usually reserved for people with clinically serious or massive pulmonary embolism (PE). Evidence suggests that thrombolytic agents may dissolve blood clots more rapidly than heparin and may reduce the death rate associated with PE. However, there are still concerns about the possible risk of adverse effects of thrombolytic therapy, such as major or minor haemorrhage. This is the fourth update of the Cochrane review first published in 2006.

OBJECTIVES

To assess the effects of thrombolytic therapy for acute pulmonary embolism.

SEARCH METHODS

The Cochrane Vascular Information Specialist searched the Cochrane Vascular Specialised Register, CENTRAL, MEDLINE, Embase, and CINAHL databases and the World Health Organization International Clinical Trials Registry Platform and ClinicalTrials.gov trials registers to 17 August 2020. We undertook reference checking to identify additional studies.

SELECTION CRITERIA

We included randomised controlled trials (RCTs) that compared thrombolytic therapy followed by heparin versus heparin alone, heparin plus placebo, or surgical intervention for people with acute PE (massive/submassive). We did not include trials comparing two different thrombolytic agents or different doses of the same thrombolytic drug.

DATA COLLECTION AND ANALYSIS

Two review authors (ZZ, QH) assessed the eligibility and risk of bias of trials and extracted data. We calculated effect estimates using the odds ratio (OR) with a 95% confidence interval (CI) or the mean difference (MD) with a 95% CI. The primary outcomes of interest were death, recurrence of PE and haemorrhagic events. We assessed the certainty of the evidence using GRADE criteria.

MAIN RESULTS

We identified three new studies for inclusion in this update. We included 21 trials in the review, with a total of 2401 participants. No studies compared thrombolytics versus surgical intervention. We were not able to include one study in the meta-analysis because it provided no extractable data. Most studies carried a high or unclear risk of bias related to randomisation and blinding. Meta-analysis showed that, compared to control (heparin alone or heparin plus placebo), thrombolytics plus heparin probably reduce both the odds of death (OR 0.58, 95% CI 0.38 to 0.88; 19 studies, 2319 participants; low-certainty evidence), and recurrence of PE (OR 0.54, 95% CI 0.32 to 0.91; 12 studies, 2050 participants; low-certainty evidence). Effects on mortality weakened when six studies at high risk of bias were excluded from analysis (OR 0.71, 95% CI 0.45 to 1.13; 13 studies, 2046 participants) and in the analysis of submassive PE participants (OR 0.61, 95% CI 0.37 to 1.02; 1993 participants). Effects on recurrence of PE also weakened after removing one study at high risk of bias for sensitivity analysis (OR 0.60, 95% CI 0.35 to 1.04; 11 studies, 1949 participants). We downgraded the certainty of evidence to low because of 'Risk of bias' concerns. Major haemorrhagic events were probably more common in the thrombolytics group than in the control group (OR 2.84, 95% CI 1.92 to 4.20; 15 studies, 2101 participants; moderate-certainty evidence), as were minor haemorrhagic events (OR 2.97, 95% CI 1.66 to 5.30; 13 studies,1757 participants; low-certainty evidence). We downgraded the certainty of the evidence to moderate or low because of 'Risk of bias' concerns and inconsistency. Haemorrhagic stroke may occur more often in the thrombolytics group than in the control group (OR 7.59, 95% CI 1.38 to 41.72; 2 studies, 1091 participants). Limited data indicated that thrombolytics may benefit haemodynamic outcomes, perfusion lung scanning, pulmonary angiogram assessment, echocardiograms, pulmonary hypertension, coagulation parameters, composite clinical outcomes, need for escalation and survival time to a greater extent than heparin alone. However, the heterogeneity of the studies and the small number of participants involved warrant caution when interpreting results. The length of hospital stay was shorter in the thrombolytics group than in the control group (mean difference (MD) -1.40 days, 95% CI -2.69 to -0.11; 5 studies, 368 participants). Haemodynamic decompensation may occur less in the thrombolytics group than in the control group (OR 0.36, 95% CI 0.20 to 0.66; 3 studies, 1157 participants). Quality of life was similar between the two treatment groups. None of the included studies provided data on post-thrombotic syndrome or on cost comparison.

AUTHORS' CONCLUSIONS

Low-certainty evidence suggests that thrombolytics may reduce death following acute pulmonary embolism compared with heparin (the effectiveness was mainly driven by one trial with massive PE). Thrombolytic therapy may be helpful in reducing the recurrence of pulmonary emboli but may cause more major and minor haemorrhagic events, including haemorrhagic stroke. More studies of high methodological quality are needed to assess safety and cost effectiveness of thrombolytic therapy for people with pulmonary embolism.

Low-dose urokinase thrombolytic therapy for patients with acute intermediate-high-risk pulmonary embolism: A retrospective cohort study

Introduction

Patients at intermediate-high risk of developing a pulmonary embolism (PE) are very likely to experience adverse outcomes, such as cardiovascular instability and death. The role of thrombolytic therapy in intermediate-high-risk PE remains controversial.

Objectives

This study aimed to determine the efficacy and safety of low-dose urokinase (UK) thrombolytic therapy for intermediate-high-risk PE.

Patients and methods

This retrospective study included 81 consecutive patients with intermediate-high-risk PE from two centers. Patients received low-dose UK or low-molecular-weight heparin (anticoagulant therapy group). The efficacy outcomes were mortality, computed tomography pulmonary angiography (CTPA)-confirmed absorption, and dyspnea. Safety was assessed as the incidence of bleedings.

Results

The in-hospital mortality, 9-month mortality, and long-term mortality at the last follow-up were comparable for the low-dose UK group and the anticoagulant therapy group (6.45% vs. 0%, p = 0.144, 9.68% vs. 8.16%, p = 0.815, and 12.90% vs. 12.24%, p = 0.931, respectively). CTPA-confirmed absorption at one month after admission was higher in the low-dose UK group than in the anticoagulant therapy group (p = 0.016). The incidences of short-term dyspnea at discharge and long-term dyspnea at the last follow-up were lower in the low-dose UK group than in the anticoagulant therapy group (27.59% vs. 52%, p = 0.035, 33.33% vs. 58.14%, p = 0.043, respectively). No major bleeding occurred. The incidence of minor bleeding was not significantly different between the two groups (3.23% vs. 6%, p = 0.974).

Conclusion

In intermediate-high-risk PE, a low-dose UK might increase CTPA-confirmed absorption and improve short-term and long-term dyspnea without affecting mortality or increasing the bleeding risk.

Successful thrombolysis of normotensive pulmonary embolism with life-threatening hypoxia in a young man with Klinefelter syndrome

Klinefelter syndrome (KS) affects males born with an additional X chromosome giving the genotype 47XXY classically. This syndrome has primary features of infertility and hypogonadism along with other features including a genetically hypercoagulable state. When associated with other risk factors, KS further increases the risk of venous thromboembolism and could result in life-threatening pulmonary embolism (PE). There should be a lower threshold in suspecting PE as a cause of acute respiratory failure in this patient group and thrombolysis should be considered early in normotensive PE with severe hypoxia for best patient outcomes. Furthermore, clinicians should be cautious in managing testosterone therapy in patients with KS and additional thromboembolic risk factors.

Aggressive Therapy for Acute Pulmonary Embolism: Systemic Thrombolysis and Catheter-Directed Approaches

Venous thromboembolism (VTE) is the third most common cause of cardiovascular disease after myocardial infarction and stroke. Population-based studies estimate that up to 94,000 new cases of pulmonary embolism (PE) occur in the United States annually with an increasing incidence with age. Mortality from PE is the greatest in the first 24 hours, with a decreased survival extending out 3 months. Thus, acute PE is a potentially fatal illness if not recognized and treated in a timely manner. Contemporary management includes systemic anticoagulation, thrombolysis, catheter-based procedures, and surgical embolectomy. This article reviews current clinical evidence and societal guidelines for the use of systemic and catheter-directed thrombolysis for treatment of acute PE.

Clinical outcomes of submassive pulmonary embolism thrombolysis-an Indian experience

BACKGROUND

Acute pulmonary thromboembolism is the most dangerous presentation of venous thromboembolic disease. The role of thrombolysis in massive pulmonary embolism has been studied extensively, but the same is not there for submassive pulmonary embolism. This study is aimed at evaluating the effects of thrombolysis in acute submassive pulmonary embolism. This was a prospective, case-control, observational study. Patients presenting with acute submassive pulmonary embolism were divided into thrombolysis group and control group depending on whether they received thrombolysis plus anticoagulation or anticoagulation only, respectively.

RESULTS

A total of 86 patients were included in the study. Forty-two patients were in the thrombolysis group, and 44 patients were in the control group. The mean ± SD age in the control and thrombolysis groups was 63.3 ± 14.7 and 56.4 ± 13.8 years, respectively. The two groups were well matched in sex distribution and associated comorbidities like COPD, active surgery, major trauma, and immobilization. On echocardiography, dilated RA/RV in pre-treatment vs. post-treatment was seen in 20 (45.5%) vs. 20 (45.5%) in the control group and 26 (61.9%) vs. 11 (26.2%) in the thrombolysis group. Similarly, RV systolic dysfunction in pre-treatment vs. post-treatment was seen in 24 (54.5%) vs. 21 (47.7%) in the control group and 22 (52.4%) vs. 8 (19.0%) in the thrombolysis group. Pulmonary artery pressure in pre-treatment vs. post-treatment was 64.4 ± 15.0 vs. 45.9 ± 9.9 mmHg in the control group and 68.3 ± 17.4 vs. 31.4 ± 6.9 mmHg in the thrombolysis group. In control vs. thrombolysis group, there were 5 vs. 1 death, 6 vs. 1 hemodynamic decompensation, and 6 vs. 1 patient needing mechanical ventilation.

CONCLUSION

Thrombolysis in submassive pulmonary embolism is associated with better right ventricular functions, lower pulmonary artery pressures, and comparable mortality rates.

Use of hospital resources in the care of patients with intermediate risk pulmonary embolism

BACKGROUND

Risk stratification and management of hemodynamically stable pulmonary embolism remains challenging. Professional societies have published stratification schemes, but little is known about the management of patients with intermediate risk pulmonary embolism. We describe the care of these patients at an academic health system.

METHODS

Patient encounters from 1 January 2016 to 30 June 2017 were retrospectively identified utilizing a multihospital, electronic health record-based data warehouse. Using the 2019 European Society of Cardiology criteria, differences in hospital resource utilization, defined as intensive care unit admission, use of invasive therapies, and length of stay, were examined in patients with intermediate risk characteristics.

RESULTS

A cohort of 322 intermediate risk patients, including 165 intermediate-low and 157 intermediate-high risk patients, was identified. Intermediate-high risk patients more often underwent catheter-directed therapy (14.0% vs. 1.8%; P<0.001) compared to intermediate-low risk patients and had a 50% higher rate of intensive care unit admission (relative risk 1.50; 95% confidence interval 1.06, 2.12; P=0.023). There was no difference in median intensive care unit length of stay (2.7 vs. 2.0 days; P=0.761) or hospital length of stay (5.0 vs. 5.0 days; P=0.775) between intermediate-high risk and intermediate-low risk patients. Patients that underwent invasive therapies had a 3.8-day shorter hospital length of stay (beta -3.75; 95% confidence interval -6.17, -1.32; P=0.002).

CONCLUSION

This study presents insights into the hospital resource utilization of patients with intermediate risk pulmonary embolism. The 2019 European Society of Cardiology risk stratification criteria are a clinically relevant scheme that identifies patients more often treated with intensive care unit admission and advanced therapies.