Interventional Therapies in Acute Pulmonary Embolism

Investigating the effects of systemic thrombolysis on electrocardiography and pulmonary artery blood pressure in patients with pulmonary embolism

Background and Aims

We aimed to evaluate the association between electrocardiography (ECG) and echocardiographic findings in patients with pulmonary embolism (PE) before and after systemic thrombolysis.

Methods

We included 38 PE patients admitted to the hospital with approved right ventricular (RV) dysfunction who were indicated for systemic thrombolysis. Indications for systemic thrombolysis were considered as patients who were either hemodynamically unstable on admission or became unstable in the course of hospital admission. Systemic thrombolysis was performed by either Reteplase or Alteplase. ECG and echocardiographic findings were documented at baseline and 12-24 h following systemic thrombolysis.

Results

Our results showed that TAPSE significantly increased while RV size and pulmonary artery systolic pressure (PAP) notably decreased after systemic thrombolysis (p < 0.001). The ECG abnormalities markedly diminished after systemic thrombolysis in PE patients (p < 0.001). Additionally, 100% of our patients had more than one ECG abnormality at baseline, while 55.3% had no ECG abnormalities after systemic thrombolysis. Further, the median number of ECG abnormalities remarkably attenuated after systemic thrombolysis (from 2.0 (1.0) to 0.0 (1.0), p < 0.001). Our results also revealed that delta RV size (r = 0.51, p = 0.001) and delta TAPSE (r = 0.4, p = 0.012) were positively correlated while mortality (r = -0.55, p = 0.001) was negatively associated with changes in the number of ECG abnormalities before and after systemic thrombolysis.

Conclusion

We showed that systemic thrombolysis improved echocardiographic and electrocardiographic findings in PE patients. Additionally, a greater decreased number of ECG abnormalities after systemic thrombolysis was accompanied by more improvement in RV size and TAPSE and a lower mortality rate.

Endovascular treatments of acute pulmonary embolism in the post-fibrinolytic era: an up-to-date review

Pulmonary embolism (PE) is a significant contributor to global cardiovascular-related mortality that mainly depends on the severity of the event. The treatment approach for intermediate and high-risk PE remains a topic of debate due to the fine balance between hemodynamic deterioration and bleeding risk. The initial treatment choice for intermediate-risk PE with hemodynamic deterioration and high-risk PE is historically systemic thrombolysis, but this approach is not always effective and carries a notable risk of severe bleeding. For such patients, various interventional treatments have been introduced to clinical practice, including catheter-directed lysis (CDL), ultrasound-assisted CDL, pharmacomechanical CDL, and aspiration thrombectomy. However, the optimal treatment approach remains uncertain. Encouraging outcomes have been presented assessing the novel endovascular treatments, in terms of reducing right ventricular dysfunction and improving hemodynamic stability, opening the possibility of using these devices to prevent hemodynamic instability in less severe cases. However, ongoing randomized trials that assess the efficacy and the association with mortality, especially for aspiration devices, have not yet published their final results. This article aims to offer a comprehensive update of the available catheter-directed therapies for PE, with a focus on novel mechanical thrombectomy techniques, assessing their safety and efficacy, after comparison to the conventional treatment. CRITICAL RELEVANCE STATEMENT: This is a comprehensive review of the indications of use, techniques, and clinical outcomes of the most novel endovascular devices for the treatment of pulmonary embolism. KEY POINTS: Mechanical thrombectomy is an effective tool for patients with PE. Aspiration devices prevent hemodynamic deterioration. Catheter directed therapy reduces bleeding complications.

Percutaneous mechanical thrombectomy in acute pulmonary embolism: Outcomes from a safety-net hospital

BACKGROUND

Our study aims to present clinical outcomes of mechanical thrombectomy (MT) in a safety-net hospital.

METHODS

This is a retrospective study of intermediate or high-risk pulmonary embolism (PE) patients who underwent MT between October 2020 and May 2023. The primary outcome was 30-day mortality.

RESULTS

Among 61 patients (mean age 57.6 years, 47% women, 57% Black) analyzed, 12 (19.7%) were classified as high-risk PE, and 49 (80.3%) were intermediate-risk PE. Of these patients, 62.3% had Medicaid or were uninsured, 50.8% lived in a high poverty zip code. The prevalence of normotensive shock in intermediate-risk PE patients was 62%. Immediate hemodynamic improvements included 7.4 mmHg mean drop in mean pulmonary artery pressure (-21.7%, p < 0.001) and 93% had normalization of their cardiac index postprocedure. Thirty-day mortality for the entire cohort was 5% (3 patients) and 0% when restricted to the intermediate-risk group. All 3 patients who died at 30 days presented with cardiac arrest. There were no differences in short-term mortality based on race, insurance type, citizenship status, or socioeconomic status. All-cause mortality at most recent follow up was 13.1% (mean follow up time of 13.4 ± 8.5 months).

CONCLUSION

We extend the findings from prior studies that MT demonstrates a favorable safety profile with immediate improvement in hemodynamics and a low 30-day mortality in patients with acute PE, holding true even with relatively higher risk and more vulnerable population within a safety-net hospital.

Association of annual volume and in-hospital outcomes of catheter-directed thrombolysis for pulmonary embolism

OBJECTIVE

We sought to evaluate the association between the institutional volume of catheter-directed thrombolysis (CDT) for pulmonary embolism and in-hospital mortality.

BACKGROUND

CDT is an increasingly utilized therapy in patients with intermediate/high-risk PE. However, data on the relationship between hospital volume and clinical outcomes remain limited.

METHODS

Patients who underwent CDT between October 1, 2015, and March 31, 2021, were identified in the Vizient Clinical Database. The primary outcome was in-hospital mortality. Secondary outcome were major complications, length of stay, and cost. Hospitals were dichotomized into <8 and ≥ 8 cases/year following restricted cubic spline analysis.

RESULTS

A total of 6741 CDT procedures at 171 hospitals were included with a median annual hospital volume of 4.1 cases (IQR = 1.9-8.3). A total of 44 hospitals (25.7%) were classified as high-volume ( ≥ 8 cases/year) and performed 60.9% of all CDT cases. CDT at high-volume centers was associated with lower in-hospital mortality (6.0% vs. 11.3%; p < 0.0001). Stroke and bleeding rates were similar, but pulmonary complications were more frequent at low-volume centers. CDT at high volume centers was associated with a significantly shorter length of stay and lower cost. The association between high CDT volume and in-hospital mortality persisted after adjustment for demographics (odds ratio [OR] = 0.49, [0.41-0.58]), demographics and risk factors (OR = 0.52 [0.44-0.62]), and demographics, risk factors, and troponin elevation (OR = 0.51 [0.40-0.66]).

CONCLUSION

In a large contemporary cohort of patients undergoing CDT in the United States, low annual institutional volume of CDT was associated with higher in-hospital mortality.

[Spontaneous fibrinolysis and possibilities of its acceleration in pulmonary embolism]

This review contains the data concerning the mechanisms of spontaneous fibrinolysis in pulmonary vessels and possibilities of its acceleration in pulmonary embolism. The spontaneous fibrinolysis system is known to be sequential and multifactorial, with the interaction of accelerators (t-PA and u-PA) and inhibitors (alpha-2-antiplasmin, PAI-1, TAFI). The fibrinolytic processes take place in case of prevailing reactions of accelerating factors over inhibiting ones. The endothelium of pulmonary vessels possesses pronounced antithrombogenic and profibrinolytic properties, therefore, the processes of fibrinolysis in the pulmonary vascular bed normally occur more intensively than in the vessels of the systemic circulation. The membrane proteins of the endothelium annexins A2 activate plasminogen, whereas thrombomodulin inhibits the activity of PAI-1. The main approaches to increase the fibrinolysis intensity in conditions of pulmonary embolism may be aimed at elevating the activity of fibrinolytic enzymes (enhancing the synthesis of annexins A2, the use of NMDA-receptor antagonists) and suppressing its inhibitors (the use of monoclonal antibodies to alpha-2-antiplasmin, as well as plasminogen activator inhibitor-1 (PAI-1) and thrombin-activatable fibrinolysis inhibitor (TAFI). Promising directions for future research can be the synthesis of a new generation of tissue-type plasminogen activators, and investigations of the possibility of clinical application of antithrombin and thrombomodulin, angiotensin converting enzyme inhibitors and cortisol antagonists. To meet these challenges, it is necessary to develop new models of venous thrombosis and acute pulmonary embolism in different animal species, with the assessment of the changes in the venous haemodynamics and pulmonary microcirculation on the background of administration of a new class of fibrinolytic agents.

Real world data on clinical profile, management and outcomes of venous thromboembolism from a tertiary care centre in India

OBJECTIVES

Venous thromboembolism (VTE) is a major cause of mortality and morbidity worldwide. This study describes a real-world scenario of VTE presenting to a tertiary care hospital in India.

METHODS

All patients presenting with acute VTE or associated complications from January 2017 to January 2020 were included in the study.

RESULTS

A total of 330 patient admissions related to VTE were included over 3 years, of which 303 had an acute episode of VTE. The median age was 50 years (IQR 38-64); 30% of patients were younger than 40 years of age. Only 24% of patients had provoked VTE with recent surgery (56%) and malignancy (16%) being the commonest risk factors. VTE manifested as isolated DVT (56%), isolated pulmonary embolism (PE; 19.1%), combined DVT/PE (22.4%), and upper limb DVT (2.3%). Patients with PE (n = 126) were classified as low-risk (15%), intermediate-risk (55%) and high-risk (29%). Reperfusion therapy was performed for 15.7% of patients with intermediate-risk and 75.6% with high-risk PE. In-hospital mortality for the entire cohort was 8.9%; 35% for high-risk PE and 11% for intermediate-risk PE. On multivariate analysis, the presence of active malignancy (OR = 5.8; 95% CI: 1.1-30.8, p = 0.038) and high-risk PE (OR = 4.8; 95% CI: 1.6-14.9, p = 0.006) were found to be independent predictors of mortality.

CONCLUSION

Our data provides real-world perspectives on the demographic sand management of patients presenting with acute VTE in a referral hospital setting. We observed relatively high mortality for intermediate-risk PE, necessitating better subclassification of this group to identify candidates for more aggressive approaches.