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.

High and intermediate risk pulmonary embolism in the ICU

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

Underuse of reperfusion therapy with systemic thrombolysis in high-risk acute pulmonary embolism in a Portuguese center

INTRODUCTION

Reperfusion therapy is generally recommended in acute high-risk pulmonary embolism (HR-PE), but several population-based studies report that it is underused. Data on epidemiology, management and outcomes of HR-PE in Portugal are scarce.

OBJECTIVE

To determine the reperfusion rate in HR-PE patients, the reasons for non-reperfusion, and how it influences outcomes.

METHODS

In this retrospective cohort study of consecutive HR-PE patients admitted to a thromboembolic disease referral center between 2008 and 2018, independent predictors for non-reperfusion were assessed by multivariate logistic regression. PE-related mortality and long-term MACE (cardiovascular mortality, PE recurrence and chronic thromboembolic disease) were calculated according to the Kaplan-Meier method. Differences stratified by reperfusion were assessed using the log-rank test.

RESULTS

Of 1955 acute PE patients, 3.8% presented with hemodynamic instability. The overall reperfusion rate was 50%: 35 patients underwent systemic thrombolysis, one received first-line percutaneous embolectomy and one rescue endovascular treatment. Independent predictors of non-reperfusion were: age, with >75 years representing 12 times the risk of non-treatment (OR 11.9, 95% CI 2.7-52.3, p=0.001); absolute contraindication for thrombolysis (31.1%), with recent major surgery and central nervous system disease as the most common reasons (OR 16.7, 95% CI 3.2-87.0, p<0.001); and being hospitalized (OR 7.7, 95% CI 1.4-42.9, p=0.020). At a mean follow-up of 2.5±3.3 years, the survival rate was 33.8%. Although not reaching statistical significance for hospital mortality, mortality in the reperfusion group was significantly lower at 30 days, 12 months and during follow-up (relative risk reduction of death of 64% at 12 months, p=0.013). Similar results were found for MACE.

CONCLUSIONS

In this population, the recommended reperfusion therapy was performed in only 50% of patients, with advanced age and absolute contraindications to fibrinolysis being the main predictors of non-reperfusion. In this study, thrombolysis underuse was associated with a significant increase in short- and long-term mortality and events.

In-hospital mortality of high-risk pulmonary embolism: a nationwide population-based cohort study in Portugal from 2010 to 2018

BACKGROUND

The mortality associated with high-risk pulmonary embolism (PE) is remarkably high, and reperfusion to unload right ventricle should be a priority. However, several registries report reperfusion underuse. In Portugal, epidemiological data about the incidence, rate of reperfusion and mortality of high-risk PE are not known.

METHODS

Nationwide population-based temporal trend study in the incidence and outcome of high-risk PE, who were admitted to hospitals of the National Health Service in Portugal between 2010 and 2018. High-risk PE was defined as patients with PE who developed cardiogenic shock or cardiac arrest. International Classification of Diseases (ICD), 9th and 10th revision, Clinical Modification codes, were used for data from the period between 2010 and 2016 (ICD-9-CM) and 2017-2018 (ICD-10-CM), respectively. The assessment focused on trends in the use of reperfusion treatment, which was defined by application of thrombolysis or pulmonary embolectomy. A comparison was made between the use or non-use of reperfusion therapy in order to examine trends in in-hospital mortality among high-risk PE cases.

RESULTS

From 2010 and 2018, there were 40.311 hospitalization episodes for PE in adult patients at hospitals of the National Health Service in mainland Portugal. There was a significant increase in the annual incidence of PE (41/100.000 inhabitants in 2010 to 46/100.000 in 2018; R2=0.582, p = 0.010). The average annual incidence was 45/100.000 inhabitants/year, with 2,7% of the PE episodes (1104) categorized as high-risk. The mortality rate associated with high-risk PE was high, although it has decreased over the years (74.2% in 2010 to 63.6% in 2018; R2=0.484; p = 0.022). Thrombolytic therapy was underused in high-risk PE, and its usage has not increased in recent years (17.3% in 2010 to 21.1% in 2018, R2=-0.127; p = 0.763). Surgical pulmonary embolectomy was used in 0.27% of cases, and there was no registry of catheter-directed thrombolysis. Patients with high-risk PE undergoing reperfusion therapy had lower in-hospital mortality compared to non-reperfused patients (OR=0.52; IC95% 0.38-0.70).

CONCLUSION

In Portugal, between 2010 and 2018, very few patients with PE developed high-risk forms of the disease, but the mortality rate among those patients was high. The low reperfusion rate could be associated with high in-hospital mortality and highlights the need to implement advanced therapies, as an alternative to systemic thrombolysis.

Nineteen-Year Trends in Mortality of Patients Hospitalized in the United States with High-Risk Pulmonary Embolism

BACKGROUND

Several advanced treatments of high-risk patients with pulmonary embolism have been used in recent decades. We assessed the 19-year national trend in mortality of high-risk patients with pulmonary embolism to determine what impact, if any, advanced therapy might have had on mortality.

METHODS

Mortality (case fatality rate) was assessed in patients with a primary (first-listed) diagnosis of high-risk pulmonary embolism who were hospitalized during the period from 1999 to 2014 and in 2016 and 2017. High-risk was defined as patients with pulmonary embolism who were in shock or suffered cardiac arrest. International Classification of Diseases, 9th revision, Clinical Modification codes were used for data on the period from 1999 to 2014, and version 10 codes were used for data on the years 2016 and 2017. Trends in mortality were assessed according to treatment.

RESULTS

From 1999 to 2017 (excluding 2015), 58,784 patients were hospitalized in United States with a primary diagnosis of pulmonary embolism that was high risk. Mortality in all high-risk patients decreased from 72.7% in 1999 to 49.8% in 2017 (P < .0001). Most high-risk patients (60.3%) were treated with anticoagulants alone and did not receive an inferior vena cava filter. Mortality in these patients decreased from 79.0% in 1999 to 55.7% in 2017 (P < .0001). Thrombolytic therapy was administered to 16.1% of high-risk patients, open pulmonary embolectomy alone was used in 4.3%, and extracorporeal membrane oxygenation was used in 0.4%.

CONCLUSIONS

Mortality of high-risk patients with pulmonary embolism has decreased. This decrease can be attributed to improved treatment of patients with shock and with cardiac arrest, and does not reflect advances in therapy for pulmonary embolism.

Clinical conundrum: concomitant high-risk pulmonary embolism and acute ischemic stroke

High-risk PE can be complicated by the presence of a patent foramen ovale (PFO), which can lead to paradoxical systemic embolization, including cerebral embolism ultimately leading to acute ischemic stroke (AIS). Acute management is challenging given the competing benefits and risks of systemic thrombolysis. Herein, we aim to provide a review of clinical presentations, diagnostic findings, and treatment and outcome from the available literature, with the hopes of providing insight into treatment options. We followed the guidelines outlined by the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA). A systematic literature search using PubMed/MEDLINE database, Cochrane Library, and Google Scholar for all reported cases/case series of concomitant high-risk PE and paradoxical ischemic stroke was conducted from inception to July 2019. Twenty-nine cases from 27 articles (26 single case reports, 1 case series of 3 patients) were included. There were 10 men and 19 women, ranging in age from 29 to 81 years (mean 56.1 ± 13.5 years). PFO was diagnosed in 89.7% of patients, mostly by transesophageal echocardiography. Treatment modalities included systemic thrombolysis (40%), anticoagulation alone (36%), surgical thrombectomy (16%), and percutaneous thrombectomy (8%). Overall mortality rate was 31%. Patients receiving thrombolysis and surgical thrombectomy had the most favorable outcome. Survival to discharge was 90% (9 out of 10), 100% (5 out of 5), and 50% (4 out of 8) in the systemic thrombolysis, surgical thrombectomy, and anticoagulation alone groups respectively. In the setting of combined high-risk PE and ischemic stroke, PFO can be detected in 90% of published cases. Thrombolysis and surgical thrombectomy seem to be effective management, but further studies are needed for validation.