A Study to Evaluate the Safety of Withholding Anticoagulation in Patients With Subsegmental PE Who Have a Negative Serial Bilateral Lower Extremity Ultrasound (SSPE)
|The safety and scientific validity of this study is the responsibility of the study sponsor and investigators. Listing a study does not mean it has been evaluated by the U.S. Federal Government. Read our disclaimer for details.|
|ClinicalTrials.gov Identifier: NCT01455818|
Recruitment Status : Completed
First Posted : October 20, 2011
Last Update Posted : May 28, 2021
- Study Details
- Tabular View
- Results Submitted
- How to Read a Study Record
Blood clots in lung arteries (pulmonary embolism) are usually detected using a radiological test called computed tomography (CT scan). As technology advances, the CT scans are able to detect smaller and smaller blood clots. Over time, the frequency of blood clots in the pulmonary arteries has increased significantly (CT scan are now detecting very small blood clots that the investigators could not see before). As a result, more and more people are on blood thinners to treat these small blood clots but their true clinical significance is unknown.
The management of blood thinners is costly and also utilizes scarce healthcare resources. These blood thinners need to be monitored with frequent blood work. Furthermore, every year, approximately 3 percent of patients on blood thinners will have a major bleeding event requiring medical attention.
The investigators don't think that treating these small blood clots in the pulmonary arteries detected on CT scan is worth the risk of bleeding from the blood thinners.
The main goal of this study is to find out if it is safe to not treat very small blood clots in the pulmonary arteries.
The investigators plan to follow 300 patients with small blood clots in their lungs for 90 days. These patients will not be treated with blood thinners but will be followed closely with other non-invasive tests to avoid progression or recurrence of blood clots.
|Condition or disease|
|Subsegmental (Single or Multiple) Pulmonary Embolism|
|Study Type :||Observational|
|Actual Enrollment :||292 participants|
|Official Title:||A Multicenter Prospective Cohort Management Study to Evaluate the Safety of Withholding Anticoagulation in Patients With Subsegmental PE Who Have a Negative Serial Bilateral Lower Extremity Ultrasound|
|Study Start Date :||March 2011|
|Actual Primary Completion Date :||March 2021|
|Actual Study Completion Date :||May 2021|
- Recurrent VTE [ Time Frame: 90 day follow-up ]Recurrent VTE will be diagnosed according to previously published criteria: 1)Lower extremity US revealing non-compressibility at the trifurcation of the popliteal vein or above; OR 2) Venography demonstrating a constant intraluminal filling defect above the trifurcation of the popliteal vein; OR 3) Pulmonary angiography demonstrating a new constant intraluminal filling defect or a cut off of a vessel; OR 4) Ventilation/perfusion scanning with a high probability of PE; OR 5) CTPA demonstrating new intraluminal filling defect in a subsegmental or greater sized pulmonary artery; OR 6) PE discovered at autopsy.
- Interobserver agreement for SSPE diagnosis on CTPA (local Vs. central interpretation) [ Time Frame: 90 day follow-up ]
- Death due to PE [ Time Frame: 90 day follow-up ]Definition of death due to PE Certain: hypotension, hypoxia, cardiac arrest with no other explanation other than PE and autopsy or radiographic confirmation Highly probable: criteria for certain but another disease could have caused the death Probable: other cause suspected based on clinical evidence but 100% certainty not available Unlikely: all other cases
- Death probably due to PE [ Time Frame: 90 day follow-up ]Certain: hypotension, hypoxia, cardiac arrest with no other explanation other than PE and autopsy or radiographic confirmation Highly probable: criteria for certain but another disease could have caused the death Probable: other cause suspected based on clinical evidence but 100% certainty not available Unlikely: all other cases
- Major bleeding [ Time Frame: 90 day follow-up ]
Major bleeding will be defined according to previously published criteria (51):
- Fatal bleeding; OR
- Symptomatic bleeding in a critical area or organ, such as intracranial, intraspinal, intraocular, retroperitoneal, intraarticular or pericardial, or intramuscular with compartment syndrome; OR
- Bleeding causing a fall in hemoglobin level of 20 g/L (1.24 mmol/L) or more, or leading to transfusion of two or more units of whole blood or red cells
- Minor bleeding [ Time Frame: 90 day follow-up ]Minor bleeding will be defined as any bleeding not meeting the requirements of a major bleeding event.
Choosing to participate in a study is an important personal decision. Talk with your doctor and family members or friends about deciding to join a study. To learn more about this study, you or your doctor may contact the study research staff using the contacts provided below. For general information, Learn About Clinical Studies.
|Ages Eligible for Study:||18 Years and older (Adult, Older Adult)|
|Sexes Eligible for Study:||All|
|Accepts Healthy Volunteers:||No|
|Sampling Method:||Non-Probability Sample|
- Age greater or equal to 18 years old.
Patients with newly diagnosed isolated SSPE* (any number).
- Isolated SSPE is defined as CTPA demonstrating an intraluminal filling defect in a subsegmental artery with no filling defects visualized at more proximal pulmonary artery levels.
- Proximal lower extremity (popliteal vein or above) or upper extremity (subclavian vein or above) DVT.
- Need for long term oral anticoagulant therapy for reasons other than VTE.
- SSPE diagnosed in a hospitalized patient (> 48 hours after hospital admission).
- Requiring oxygen therapy to maintain an O2 saturation over 92%
- Previous history of DVT (proximal or distal) of upper or lower extremities, PE, or unusual site thrombosis (e.g. splanchnic or cerebral vein thrombosis).
- Geographically inaccessible for follow-up
- Active Malignancy (defined as other than basal-cell or squamous cell carcinoma of the skin; cancer within the past 6 months; any treatment for cancer in the past 6 months; or recurrent or metastatic cancer)
Have received more than 48 hours of therapeutic anticoagulation.
- Prophylactic dose allowed if required for separate indication and acceptable by the investigator.
- Unable/refuse to sign informed consent
- Asymptomatic SSPE (e.g. SSPE is an incidental finding on a CT scan conducted for reasons other than suspected PE)
To learn more about this study, you or your doctor may contact the study research staff using the contact information provided by the sponsor.
Please refer to this study by its ClinicalTrials.gov identifier (NCT number): NCT01455818
|Canada, Nova Scotia|
|Capital District Health Authority|
|Halifax, Nova Scotia, Canada, B3H 1V7|
|Hamilton General Hospital|
|Hamilton, Ontario, Canada, L8L 2X2|
|London Health Sciences Centre|
|London, Ontario, Canada|
|Ottawa, Ontario, Canada, K1H 8L6|
|Toronto General Hospital|
|Toronto, Ontario, Canada, M5G 2C4|
|Sir Mortimer B. Davis Jewish General Hospital|
|Montreal, Quebec, Canada, H3T 1E2|
|St. Mary's Hospital Centre|
|Montreal, Quebec, Canada, H3T 1MS|
|Centre Hospitalier Universitaire de Brest|
|Responsible Party:||Ottawa Hospital Research Institute|
|Other Study ID Numbers:||
|First Posted:||October 20, 2011 Key Record Dates|
|Last Update Posted:||May 28, 2021|
|Last Verified:||May 2021|
Embolism and Thrombosis
Respiratory Tract Diseases