Ventilation and Perfusion Scan in Pulmonary Embolism Following Catheter Directed Thrombectomy Versus Anticoagulation Alone

Study Overview
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Brief Summary
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Clinical presentation of acute pulmonary embolism (PE) is complex and varied and not uncommonly involves respiratory failure with dyspnea or hypoxia. Patients with persisting signs of respiratory failure despite anticoagulation, may benefit from catheter directed thrombectomy. Additionally, patient who receive thrombectomy are likely to have a lower residual thrombus burden measurable by ventilation-perfusion (V/Q) scan, and thereby less likely to develop chronic sequela, including chronic thromboembolic pulmonary hypertension (CTEPH) and post PE syndrome.

Detailed Description
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Acute pulmonary embolism (PE) is a common disease with variable presentation and clinical outcomes. Chronic sequelae including chronic thromboembolic pulmonary hypertension (CTEPH) and post-PE syndrome are common pathologies for patient who survive the already significant inpatient mortality, and have a significant impact on both quality of life and life expectancy. To date, the ELOPE trial is the only study to prospectively compare quality of life (QoL) and dyspnea measures and six-minute walk distance (6MWD) to cardiopulmonary exercise test, revealing worse post-PE syndrome in select populations, however this study is limited to a single arm that received anticoagulation alone. New catheter directed therapies, developed in response to such poor outcomes, provide treatment options for acute PE patients when first line therapies including anticoagulation are contraindicated or have failed. Long term studies utilizing imaging have shown a majority of patients diagnosed with PE have residual pulmonary thrombi after 6 months, which is likely to be a large contributor to the development of CTEPH. Ventilation-perfusion (V/Q) scans remain the gold standard for detection of both acute and chronic pulmonary embolism and will serve as a primary outcome measure at 6 months post initial treatment. Clinical measures including 6MWD, QoL and dyspnea questionaries will be assessed prior to discharge, and at 1 and 6 months, in order to characterize the development of chronic symptomatology.

Official Title
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Ventilation and Perfusion Imaging in Acute Pulmonary Embolism Following Catheter Directed Aspiration Thrombectomy Versus Conservative Therapy Alone: A Pilot Study

Conditions
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Pulmonary Embolism, Pulmonary Hypertension, Chronic Thromboembolic Pulmonary Hypertension

Intervention / Treatment
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* Device: Catheter directed therapy
* Drug: Systemic anticoagulation


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: Age >18 years Clinical signs and symptoms consistent with acute PE Echocardiogram, CT pulmonary angiogram (CTPA) or pulmonary angiographic evidence of proximal filling defect in at least one main or lobar pulmonary artery Scheduled for PE treatment with catheter directed therapy and systemic anticoagulation or anticoagulation alone per the investigator's discretion Signs of respiratory failure including a. arterial blood saturation <90%, or b. partial arterial oxygen pressure <60 mmHg, or c. persistent tachypnea with respiratory rates > 20/min Exclusion Criteria: Unable to be anticoagulated with heparin or alternative therapy Diagnosis with a minor PE without signs of right ventricular (RV) dysfunction Known sensitivity to radiographic contrast agents that, in the Investigator's opinion, cannot be adequately pre-treated Imaging evidence or other evidence that suggests, in opinion of the Investigator, the patient is not appropriate for mechanical thrombectomy intervention (e.g., inability to navigate to target location or predominately chronic clot) Life expectancy <6 months, as determined by the Investigator

Ages Eligible for Study
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Minimum Age: 18 Years

Sexes Eligible for Study
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All

Study Plan
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How is the study designed?
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Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Catheter directed thrombectomy<br> | Device: Catheter directed therapy<br>* Thrombectomy<br>Drug: Systemic anticoagulation<br>* Conservative therapy<br>|
| Systemic anticoagulation<br> | Drug: Systemic anticoagulation<br>* Conservative therapy<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Ventilation-perfusion mismatch | Mismatch on ventilation-perfusion scintigraphy per Prospective Investigation of Pulmonary Embolism Diagnosis (PIOPED) criteria | 6 months | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| 6-minute walk distance |  | 30 days | 
| 6-minute walk distance |  | 6 months | 
| Hospital length of stay |  | Up to 30 days | 
| Dyspnea questionnaire |  | up to 72 hours | 
| Dyspnea questionnaire |  | 30 days | 
| Dyspnea questionnaire |  | 6 months | 
| Quality of life questionnaire |  | 30 days | 
| Quality of life questionnaire |  | 6 months |