NCT07519876 · Tufts Medical Center
Pulmonary Embolism and Right-to-Left Shunts
(PEaRLS)
What this study is about
Every fetus has a small hole in their heart, called a foramen ovale when they are developing in the womb. For most people this hole closes shortly after birth, but it doesn't close completely in 1 out of every 4 people. This is called a "patent" foramen ovale, or PFO.
View original scientific description
Every fetus has a small hole in their heart, called a foramen ovale when they are developing in the womb. For most people this hole closes shortly after birth, but it doesn't close completely in 1 out of every 4 people. This is called a "patent" foramen ovale, or PFO. In people with a PFO it is possible for a blood clot in a vein to enter the heart, pass through the opening, and then go into an artery - this is referred to as a paradoxical embolism which passes through a "Right-to-Left Shunt," or RLS. If this occurs, the blood clot can cause a stroke. The most common RLS (more than 90%) is a PFO. Much rarer causes include other types of holes in the heart (like an atrial septal defect, or ASD), or a vascular communication in the lungs (like a pulmonary arteriovenous malformation, or AVM). We are investigating whether people with a PE are at higher risk of stroke if they happen to have an RLS compared to PE patients who don't have an RLS. This study will simply observe and compare the differences in stroke-related outcomes between those 2 groups. Participation in the study last roughly 90-days and includes the following activities: * The study team will review your medical records to collect general information such as your age, sex, race/ethnicity, height, weight, medications, medical history, and other medical information * Magnetic Resonance Imaging (MRI) of your brain will be done as soon as possible following your enrollment in the study. For more information on MRI scans, please see the "MRI scan" section below. * A Transcranial Doppler (TCD) with bubble study will be performed to determine if an opening is present in your heart or lungs. TCD is performed using ultrasound. A contrast called agitated saline will be injected into your vein for this test. * You will be asked to return for a follow-up visit 90 days after your pulmonary embolism. At this visit, the following will occur: 1. A second MRI of your brain will be performed. 2. You will complete a questionnaire to evaluate whether you may have had a stroke since being discharged from the hospital 3. You will meet with a member of the study team who will collect information about your health status.
Who can participate
This study lists these criteria on ClinicalTrials.gov. A study coordinator reviews eligibility during screening — this page does not determine whether you qualify.
Inclusion criteria
- Acute pulmonary embolism (any grade/size)
- Patient or legally authorized representative is able to provide consent to participate in the study
Exclusion criteria
- Patients who, in the opinion of the study investigators, are unable to participate in required study activities
- Patients unable to undergo MRI imaging
Where
- Boston, Massachusetts
Frequently asked questions
What is a clinical trial?
A clinical trial is a research study that tests new medical treatments, drugs, devices, or procedures to determine their safety and effectiveness. Trials are carefully designed and monitored to protect participants while advancing medical knowledge.
Is it safe to participate?
Clinical trials follow strict safety guidelines and ethical standards. Trials must be reviewed and approved, and participants are closely monitored by medical professionals throughout the study. You can withdraw at any time if you choose.
Will I be compensated?
Many clinical trials offer compensation for your time, travel expenses, and inconvenience. The specific compensation varies by study and will be discussed during the screening process. All study-related medical care is typically provided at no cost to participants.
Will I receive a placebo instead of treatment?
When effective treatment exists, participants typically receive either the standard treatment plus the study intervention, or the standard treatment plus placebo. You would not be denied effective care. Placebos are primarily used when no proven treatment is available, or in addition to standard care. Your trial consent form will clearly explain what treatments you may receive.
Can I leave a trial if I change my mind?
Absolutely. Participation in clinical trials is completely voluntary. You have the right to withdraw from the study at any time, for any reason, without penalty or loss of benefits to which you are otherwise entitled.
How long does a clinical trial last?
Trial duration varies widely depending on the study design and purpose. Some trials last just a few weeks, while others may continue for months or years. The study coordinator will provide specific timeline information during your screening call.
Data: ClinicalTrials.gov · synced Apr 9, 2026 · Source of record for eligibility and locations