Thrombolysis in hemodynamically unstable patients: still underused: a review based on multicenter prospective registries on acute pulmonary embolism

Fibrinolytic uses in the emergency department: a narrative review

INTRODUCTION

Several life-threatening conditions associated with thrombosis include acute ischemic stroke (AIS), acute myocardial infarction (AMI), and acute pulmonary embolism (PE). Fibrinolytics are among the treatment algorithms for these conditions.

OBJECTIVE

This narrative review provides emergency clinicians with an overview of fibrinolytics for AIS, AMI, and PE in the emergency department (ED) setting.

DISCUSSION

Pathologic thrombosis can result in vascular occlusion and embolism, ultimately leading to end-organ injury. Fibrinolytics are medications utilized to lyse a blood clot, improving vascular flow. One of the first agents utilized was streptokinase, though this is not as often used with the availability of fibrin-specific agents including alteplase (tPA), tenecteplase (TNK), and reteplase (rPA). These agents are integral components in the management of several conditions, including AIS, AMI, and PE. Patients with AIS who present within 3-4.5 h of measurable neurologic deficit with no evidence of intracerebral hemorrhage (ICH) or other contraindications may be eligible to receive tPA or TNK. In the absence of percutaneous coronary intervention (PCI), fibrinolytics should be considered in patients with AMI presenting with chest pain for at least 30 min but less than 12 h, though it may be considered up to 24 h. Unlike in AIS and PE, anticoagulation and antiplatelet medications should be administered in those with AMI receiving fibrinolytics. Following fibrinolytics, PCI is typically necessary. Fibrinolytics are recommended in patients with high-risk PE (hemodynamic instability), as they reduce the risk of mortality. The most significant complication following fibrinolytic administration includes major bleeding such as ICH, which occurs most frequently in those with AIS compared to AMI and PE. Thus, close patient monitoring is necessary following fibrinolytic administration.

CONCLUSIONS

An understanding of fibrinolytics in the ED setting is essential, including the indications, contraindications, and dosing.

Sex Differences in Advanced Therapeutic Interventions for Intermediate- and High-Risk Pulmonary Embolism

PURPOSE

Advanced interventions are increasingly used to treat intermediate- and high-risk acute pulmonary embolism (PE). While sex-based differences exist in treatment of other diseases, it is unknown whether these disparities extend to PE.

METHODS

This is a secondary analysis of a prospective cohort study of adult patients diagnosed with radiographically confirmed intermediate- and high-risk acute PE at a tertiary hospital between 1/1/2012 and 12/31/2021 for whom the PE Response Team was activated. Primary outcome was receipt of any advanced intervention. Descriptive and inferential analyses using Chi-square tests, t tests, and logistic regression were performed to evaluate for factors associated with the primary outcome.

FINDINGS

We analyzed 902 patients, of whom 439 (49%) were female. Although women were more likely to present with right heart strain on echo (78.6% vs 71.1% P = 0.012) and elevated NT-proBNP (69.2% vs 55.7% P < 0.001), there was no significant sex-based difference in clinical PE severity, defined as intermediate- versus high-risk, at presentation. Primary outcome did not differ significantly by sex (18.7% vs 23.5% P = 0.129). In multivariate models, high-risk PE decreased odds of receiving an advanced therapy (0.50 [0.31, 0.79] P = 0.003), while receiving assisted ventilation (4.70 [2.90, 7.62], P < 0.001) and full code status (4.18 [1.60, 10.91], P = 0.003) increased odds.

IMPLICATIONS

This study adds to the scant literature on sex differences in interventions for acute PE. Significant baseline variation exists between female and male patients presenting with acute PE. Clinical factors were predictive of receiving advanced PE therapies, while sex was not.

International Clinical Practice Guideline Recommendations for Acute Pulmonary Embolism: Harmony, Dissonance, and Silence

Despite abundant clinical innovation and burgeoning scientific investigation, pulmonary embolism (PE) has continued to pose a diagnostic and management challenge worldwide. Aging populations, patients living with a mounting number of chronic medical conditions, particularly cancer, and increasingly prevalent health care disparities herald a growing burden of PE. In the meantime, navigating expanding strategies for immediate and long-term anticoagulation, as well as advanced therapies, including catheter-based interventions for patients with more severe PE, has become progressively daunting. Accordingly, clinicians frequently turn to evidence-based clinical practice guidelines for diagnostic and management recommendations. However, numerous international guidelines, heterogeneity in recommendations, as well as areas of uncertainty or omission may leave the readers and clinicians without a clear management pathway. In this review of international PE guidelines, we highlight key areas of consistency, difference, and lack of recommendations (silence) with an emphasis on critical clinical and research needs.

Catheter Interventions for Pulmonary Embolism: Mechanical Thrombectomy Versus Thrombolytics

Pulmonary embolism is a debilitating and potentially life-threatening disease characterized by high mortality and long-term adverse outcomes. Traditional treatment options are fraught with serious bleeding risks and incomplete thrombus removal, necessitating the development of innovative treatment strategies. While new interventional approaches offer promising potential for improved outcomes with fewer serious complications, their rapid development and need for more comparative clinical evidence makes it challenging for physicians to select the optimal treatment for each patient among the many options. This review summarizes the current published clinical data for both traditional treatments and more recent interventional approaches indicated for pulmonary embolism. While published studies thus far suggest that these newer interventional devices offer safe and effective options, more data is needed to understand their impact relative to the standard of care. The studies in progress that are anticipated to provide needed evidence are reviewed here since they will be critical for helping physicians make informed treatment choices and potentially driving necessary guideline changes.

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.

Prognostic impact of the e-TAPSE ratio in intermediate-high risk pulmonary embolism patients

We assess the prognostic role of a new index (Age-T index), based on age and the tricuspid annular plane systolic excursion (TAPSE) for the estimation of 30-day mortality and risk of 48-h clinical deterioration since admission, in intermediate-high risk Pulmonary Embolism (PE) patients. A post-hoc analysis of intermediate-high risk PE patients enrolled in the Italian Pulmonary Embolism Registry (IPER) (Trial registry: ClinicalTrials.gov; No.: NCT01604538) was performed. The Age-T index was calculated as the ratio between age and TAPSE. The primary outcome was the 30-day mortality risk while the risk of clinical deterioration within 48 h in the same patients was chosen as the secondary outcome. Among 450 intermediate-high risk PE patients (mean age 71.4 ± 13.8 years, 298 males), 40 (8.8%) experienced clinical deterioration within 48 h since admission and 32 (7.1%) died within 30-day. Receiver operating characteristic analysis established ≥ 4.9 as the optimal cut-off value for the Age-T index in predicting 30-day mortality (AUC of 0.76 ± 0.1). Sensitivity, specificity, PPV and NPV were 81.2, 85.6, 30.2 and 98.3%, respectively. Multivariate Cox regression analysis showed that an Age-T index ≥ 4.9 predicts 30-day mortality (HR: 3.24, 95% CI: 1.58-4.96, p < 0.001) and was also associated with a significantly higher risk of 48-h clinical deterioration (HR: 2.02, 95% CI 1.96-2.08, p < 0.0001) in intermediate-high risk PE patients. Age-T Index appears as a useful, bed-side and non-invasive prognostic tool to identify intermediate-high risk PE patients at higher risk of death and/or 48-h clinical deterioration.

Addressing the rising trend of high-risk pulmonary embolism mortality: Clinical and research priorities

BACKGROUND

Deaths from high-risk pulmonary embolism (PE) appear to have increased in the US over the last decade. Modifiable risks contributing to this worrisome trend present opportunities for physicians, researchers, and healthcare policymakers to improve care.

METHODS

We sought to contextualize contemporary, high-risk PE epidemiology and examine clinical trials, quality improvement opportunities, and healthcare policy initiatives directed at reducing mortality.

RESULTS

We observed significant and modifiable excess mortality due to high-risk PE. We identified several opportunities to improve care including: (1) rapid translation of forthcoming data on reperfusion strategies into clinical practice; (2) improved risk stratification tools; (3) quality improvement initiatives to address presumptive anticoagulation practice gaps; and (3) adoption of health policy initiatives to establish pulmonary embolism response teams and address the social determinants of health.

CONCLUSION

Addressing knowledge and practice gaps in intermediate and high-risk PE management must be prioritized and informed by forthcoming high-quality data. Implementation efforts are needed to improve acute PE management and resolve treatment disparities.

Comparison of In-Hospital Outcomes between Early and Late Catheter-Directed Thrombolysis in Acute Pulmonary Embolism: A Retrospective Observational Study

The purpose of this study is to evaluate whether early initiation of catheter-directed thrombolysis (CDT) in patients presenting with acute pulmonary embolism is associated with improved in-hospital outcomes. A retrospective cohort was extracted from the 2016-2019 National Inpatient Sample database, consisting of 21,730 weighted admissions undergoing CDT acute PE. From the time of admission, the sample was divided into early (<48 h) and late interventions (>48 h). Outcomes were measured using regression analysis and propensity score matching. No significant differences in mortality, cardiac arrest, cardiogenic shock, or intracranial hemorrhage (p > 0.05) were found between the early and late CDT groups. Late CDT patients had a higher likelihood of receiving systemic thrombolysis (3.21 [2.18-4.74], p < 0.01), blood transfusion (1.84 [1.41-2.40], p < 0.01), intubation (1.33 [1.05-1.70], p = 0.02), discharge disposition to care facilities (1.32 [1.14-1.53], p < 0.01). and having acute kidney injury (1.42 [1.25-1.61], p < 0.01). Predictors of late intervention were older age, female sex, non-white ethnicity, non-teaching hospital admission, hospitals with higher bed sizes, and weekend admission (p < 0.01). This study represents a comprehensive evaluation of outcomes associated with the time interval for initiating CDT, revealing reduced morbidity with early intervention. Additionally, it identifies predictors associated with delayed CDT initiation. The broader ramifications of these findings, particularly in relation to hospital resource utilization and health disparities, warrant further exploration.

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.

A Review of the Usefulness of Catheter-Directed Thrombolysis for Pulmonary Embolism

Venous thromboembolic disease (VTE) is a health problem; around 10 million cases occur yearly with substantial morbidity and mortality. Those who survive may be left with long-term sequelae. Those sequelae might include chronic thromboembolic pulmonary hypertension, persistent right ventricular dysfunction, exercise intolerance, and reduced quality of life. Current PE management consists of anticoagulation alone, systemic thrombolysis, catheter-directed thrombolysis, and surgical embolectomy. The severity of patients with pulmonary embolism (PE) depends on the clinic and not exclusively on the extent of radiological or anatomical involvement. In this review, we present the main clinical and functional characteristics of patients in whom thrombotic fragmentation plus catheter-guided thrombolysis is used to manage acute PE of intermediate-high risk and torpid evolution within the first hours of admission.

Contemporary trends in mortality related to high-risk pulmonary embolism in US from 1999 to 2019

BACKGROUND

Population-based data on high-risk pulmonary embolism (PE) mortality trends in the United States (US) are scant.

OBJECTIVES

To assess current trends in US mortality related to high-risk PE over the past 21 years and determine differences by sex, race, ethnicity, age and census region.

METHODS

Data were extracted from the Centers for Disease Control and Prevention (CDC) Wide-ranging ONline Data for Epidemiologic Research (WONDER) to determine trends in age-adjusted mortality rates (AAMR) per 100,000 people, due to high-risk PE. To calculate nationwide annual trends, we assessed the average (AAPC) and annual percent change (APC) with relative 95 % confidence intervals (CIs) using Joinpoint regression.

RESULTS

Between 1999 and 2019, high-risk PE was listed as the underlying cause of death in 209,642 patients, corresponding to an AAMR of 3.01 per 100,000 people (95 % CI: 2.99 to 3.02). AAMR from high-risk PE remained stable from 1999 to 2007 [APC: -0.2 %, (95 % CI: -2.0 to 0.5, p = 0.22)] and then significantly increased [APC: 3.1 % (95 % CI: 2.6 to 3.6), p < 0.0001], especially in males [AAPC: 1.9 % (95 % CI: 1.4 to 2.4), p < 0.001 vs AAPC: 1.5 % (95 % CI: 1.1 to 2.2), p < 0.001]. AAMR increase was more pronounced in those <65 years, Black Americans, and residents of rural areas.

CONCLUSIONS

In an US population analysis, high-risk PE mortality rate increased, with racial, sex-based, and regional variations. Further studies are needed to understand root causes for these trends and to implement appropriate corrective strategies.

[Ultrasound-accelerated thrombolysis. Initial experience in patients with contraindications to systemic thrombolysis]

Background

acute pulmonary embolism (APE) is a complex and potentially deadly entity, with a variable clinical course, considered the third cardiovascular cause of death. Its management varies according to the stratified risk from anticoagulation to reperfusion therapy, suggesting systemic thrombolysis as a first-choice strategy; however, in a large group of patients their use will be contraindicated, discouraged or will have failed, thus recommending as options in such cases endovascular therapies or surgical embolectomy. With the presentation of 3 clinical cases and a review of the literature, we seek to communicate our initial experience in the use of ultrasound-accelerated thrombolysis with the EKOS system and to investigate key elements for its understanding and application.

Clinical cases

the cases of 3 patients with APE of high and intermediate risk with contraindications for systemic thrombolysis taken to accelerated thrombolysis therapy by ultrasound are discussed. They presented adequate clinical and hemodynamic evolution in the short term, achieving a rapid decrease in thrombolysis, systolic and mean pulmonary arterial pressure, improvement of right ventricular function and reduction of thrombotic burden.

Conclusion

Ultrasound-accelerated thrombolysis is a novel pharmaco-mechanical therapy that combines the emission of ultrasonic waves with the infusion of a local thrombolytic agent, a strategy that, according to different trials and clinical registries, has a high success rate and a good safety profile.

Comparative clinical prognosis of massive and non-massive pulmonary embolism: A registry-based cohort study

AIMS

Little is known about the prognosis of patients with massive pulmonary embolism (PE) and its risk of recurrent venous thromboembolism (VTE) compared with non-massive PE, which may inform clinical decisions. Our aim was to compare the risk of recurrent VTE, bleeding, and mortality after massive and non-massive PE during anticoagulation and after its discontinuation.

METHODS AND RESULTS

We included all participants in the RIETE registry who suffered a symptomatic, objectively confirmed segmental or more central PE. Massive PE was defined by a systolic hypotension at clinical presentation (<90 mm Hg). We compared the risks of recurrent VTE, major bleeding, and mortality using time-to-event multivariable competing risk modeling. There were 3.5% of massive PE among 38 996 patients with PE. During the anticoagulation period, massive PE was associated with a greater risk of major bleeding (subhazard ratio [sHR] 1.72, 95% confidence interval [CI] 1.28-2.32), but not of recurrent VTE (sHR 1.15, 95% CI 0.75-1.74) than non-massive PE. An increased risk of mortality was only observed in the first month after PE. After discontinuation of anticoagulation, among 11 579 patients, massive PE and non-massive PE had similar risks of mortality, bleeding, and recurrent VTE (sHR 0.85, 95% CI 0.51-1.40), but with different case fatality of recurrent PE (11.1% versus 2.4%, P = .03) and possibly different risk of recurrent fatal PE (sHR 3.65, 95% CI 0.82-16.24).

CONCLUSION

In this large prospective registry, the baseline hemodynamic status of the incident PE did not influence the risk of recurrent VTE, during and after the anticoagulation periods, but was possibly associated with recurrent PE of greater severity.

Popliteal Venous Aneurysm With Pulmonary Embolism: A Case Report

Popliteal venous aneurysm (PVA) is defined as an increase in the diameter of the popliteal vein, twice its normal dimension. Herein, we report a case of right PVA with severe pulmonary embolism in a 75-year-old woman who presented with sudden chest tightness and dyspnea. Clinical examination revealed hypotension and hypoxemia. Radiographic investigations revealed extensive pulmonary embolism and right fusiform PVA. Following thrombolysis, her blood pressure and oxygen saturation normalized. However, she developed right calf swelling, and angiography revealed a thrombus in the right PVA, which was managed by catheter-directed thrombolysis. Thereafter, a vascular bypass was performed using the left great saphenous vein as a conduit to treat recurrent thrombosis. Subsequent venography indicated a patent vein graft, acceptable blood flow velocity, no thrombosis residue, and no significant thrombosis. Follow-ups at 3, 6, and 12 months revealed satisfactory outcomes. In conclusion, if the systemic condition is conducive, a surgical resection and reconstruction of the popliteal vein is recommended for the treatment of PVAs.

Massive pulmonary embolism: embolectomy or extracorporeal membrane oxygenation?

PURPOSE OF REVIEW

To highlight updates on the use of extracorporeal membrane oxygenation (ECMO) and surgical embolectomy in the treatment of massive pulmonary embolism.

RECENT FINDINGS

Outcomes for surgical embolectomy for massive pulmonary embolism have improved in the recent past. More contemporary therapeutic options include catheter embolectomy, which although offer less invasive means of treating this condition, need further study. The use of ECMO as either a bridge or mainstay of treatment in patients with contraindications to fibrinolysis and surgical embolectomy, or have failed initial fibrinolysis, has increased, with data suggesting improved outcomes with earlier implementation in selected patients.

SUMMARY

Although surgical embolectomy continues to be the initial treatment of choice in massive pulmonary embolism with contraindications or failed fibrinolysis, the use of ECMO in these high-risk patients provides an important tool in managing this often fatal condition.

Immediate and late impact of reperfusion therapies in acute pulmonary embolism

Haemodynamic instability and right ventricular dysfunction are the key determinants of short-term prognosis in patients with acute pulmonary embolism (PE). Residual thrombi and persistent right ventricular dysfunction may contribute to post-PE functional impairment, and influence the risk of developing chronic thromboembolic pulmonary hypertension. Patients with haemodynamic instability at presentation (high-risk PE) require immediate primary reperfusion to relieve the obstruction in the pulmonary circulation and increase the chances of survival. Surgical removal of the thrombi or catheter-directed reperfusion strategies is alternatives in patients with contraindications to systemic thrombolysis. For haemodynamically stable patients with signs of right ventricular overload or dysfunction (intermediate-risk PE), systemic standard-dose thrombolysis is currently not recommended, because the risk of major bleeding associated with the treatment outweighs its benefits. In such cases, thrombolysis should be considered only as a rescue intervention if haemodynamic decompensation develops. Catheter-directed pharmaco-logical and pharmaco-mechanical techniques ensure swift recovery of echocardiographic and haemodynamic parameters and may be characterized by better safety profile than systemic thrombolysis. For survivors of acute PE, little is known on the effects of reperfusion therapies on the risk of chronic functional and haemodynamic impairment. In intermediate-risk PE patients, available data suggest that systemic thrombolysis may have little impact on long-term symptoms and functional limitation, echocardiographic parameters, and occurrence of chronic thromboembolic pulmonary hypertension. Ongoing and future interventional studies will clarify whether ‘safer’ reperfusion strategies may improve early clinical outcomes without increasing the risk of bleeding and contribute to reducing the burden of long-term complications after intermediate-risk PE.

Systolic blood pressure and mortality in acute symptomatic pulmonary embolism

BACKGROUND

The optimal cutoff for systolic blood pressure (SBP) level to define high-risk pulmonary embolism (PE) remains to be defined.

METHODS

To evaluate the relationship between SBP levels on admission and mortality in patients with acute symptomatic PE, the current study included 39,257 consecutive patients with acute symptomatic PE from the RIETE registry between 2001 and 2018. Primary outcomes included all-cause and PE-specific 30-day mortality. Secondary outcomes included major bleeding and recurrent venous thromboembolism (VTE).

RESULTS

There was a linear inverse relationship between admission SBP and 30-day all-cause and PE-related mortality that persisted after multivariable adjustment. Patients in the lower SBP strata had higher rates of all-cause death (reference: SBP 110-129 mmHg) (adjusted odds ratio [OR] 2.9; 95% confidence interval [CI], 2.0-4.2 for SBP <70 mmHg; and OR 1.7; 95% CI, 1.4-2.1 for SBP 70-89 mmHg). The findings for 30-day PE-related mortality were similar (adjusted OR 4.4; 95% CI, 2.7-7.2 for SBP <70 mmHg; and OR 2.6; 95% CI, 1.9-3.4 for SBP 70-89 mmHg). Patients in the higher strata of SBP had significantly lower rates of 30-day all-cause mortality compared with the same reference group (adjusted OR 0.7; 95% CI, 0.5-0.9 for SBP 170-190 mmHg; and OR 0.6; 95% CI, 0.4-0.9 for SBP >190 mmHg). Consistent findings were also observed for 30-day PE-related death.

CONCLUSIONS

In patients with acute symptomatic PE, a low SBP portends an increased risk of all-cause and PE-related mortality. The highest mortality was observed in patients with SBP <70 mmHg.

Is there an optimal "door to cath time" in the treatment of acute pulmonary embolism with catheter-directed thrombolysis?

Ultrasound assisted catheter-directed thrombolysis (UACT) is a relatively novel approach to treating acute pulmonary embolism (PE). It is an alternative to systemic thrombolysis with good success rates and low reported in-hospital mortality, and low rates of procedure-related major and minor bleeding. Since UACT received FDA approval for the treatment of PE in 2014, there is paucity of data regarding the optimal timing of initiation of the procedure after the initial diagnosis is made. We reviewed the available literature regarding UACT for acute PE and found six studies that included time to procedure. Based on our review, patients may benefit from early (<24-48 h after presentation) rather than delayed (>48 h) initiation. Early initiation of therapy has shown to improve pulmonary arterial pressures, right ventricular (RV) to left ventricular (LV) ratios, with low rates of bleeding and low post procedural and in hospital mortality. However, further studies are required to confirm these findings and establish the appropriate timeline for initiation of UACT.