Research Explores New Advanced Treatment for Patients with Pulmonary Embolism.

The global HI-PEITHO study explored a new treatment for acute, intermediate-risk pulmonary embolism, offering patients and providers an advanced option.

MedStar investigators participated in HI-PEITHO, a global study of a new treatment for acute, intermediate-risk pulmonary embolism, for which there is a significant need for better treatments.

Heart attack and stroke get a lot of attention because they’re common and fatal. But leading researchers are exploring another major cardiovascular condition: Pulmonary embolism (PE), which is a blood clot that blocks an artery in the lungs.

PE is the third leading cause of cardiovascular-related death in the U.S., accounting for about 100,000 deaths per year. Low-risk PE can be treated with blood thinners. For large, high-risk clots, doctors use aggressive drugs known as “clot busters” or thrombolytics. The guidelines are less clear for patients who fall in the middle. 

The HI-PEITHO study, published in the New England Journal of Medicine, aimed to test a more precise way to help patients with intermediate-risk PE. By using advanced ultrasound-based technologies together with low doses of clot-busters to break up clots, the study shows a new way to achieve great outcomes without increasing bleeding risk.

Road closure: Understanding PE.

A pulmonary embolism is like a sudden road closure. The clot blocks the flow of blood (traffic) through the arterial highway system to the lungs. When the road is blocked, the body can’t get enough oxygen, and the heart must work harder to push blood to the lungs. 

PE most often begins in a vein deep in the legs or, less often, in the arms (deep vein thrombosis). If the clot breaks loose, it can become lodged in the arteries that lead to the lungs.

PE is a medical emergency. Call 911 if you experience symptoms such as:

• Chest pain that can feel like a heart attack

• Clammy or bluish skin

• Cough that might include bloody mucus

• Feeling faint or dizzy

• Sudden shortness of breath, especially when active

When the road is closed and blood faces significant resistance, the right side of the heart can begin to enlarge in response. During this high-stress process, the heart muscle leaks proteins called troponins that we can detect in the blood. When the right heart is affected by PE, the patient’s risk increases from low to intermediate.

Limits of traditional PE treatment.

For many years, the primary tool to treat intermediate-risk PE was through anticoagulation with blood-thinning drugs such as heparin. While these important drugs can help, they don’t eliminate an existing clot; they stop it from getting bigger.

Stronger “clot-busting” medications called thrombolytics can also be administered to the patient’s entire body via IV. These medications can be lifesaving, but they also raise the risk of internal bleeding. The HI-PEITHO Trial set out to explore a new way.

Related: Read “Know the Risk Factors for Deep Vein Thrombosis and Other Serious Blood Clots.”

A more precise approach for intermediate-risk PE.

The HI-PEITHO study enrolled about 550 participants worldwide to help identify a new treatment for intermediate-risk PE: ultrasound-facilitated catheter-directed thrombolysis (USCDT). 

Patients were randomly assigned to receive anticoagulant medication or the new method. In USCDT, a tiny tube called a catheter is inserted into a vein in the groin through a small incision and guided through the cardiovascular system to the clot.

Once there, the instrument emits ultrasound waves that gently vibrate the clot. This vibration opens the clot and makes it more porous, like a sponge. With the clot loosened, doctors then use a much smaller dose of clot-busting medication delivered directly to the blockage.

Research explores a safe, effective option.

This study tracked participants to determine whether they had a major complication within the first week after treatment. These complications included death from PE, sudden heart failure or collapse (cardiorespiratory decompensation), or a new, symptomatic PE.

The results showed a significant difference between the two groups. Among patients who received ultrasound-facilitated treatment, only 4% experienced a serious complication. In contrast, 10.3% of participants who received standard blood thinners alone saw their condition worsen. While the study was not designed to show a difference in mortality, the results for preventing cardiovascular decompensation were clearly in favor of the new intervention.

Importantly, the safety data showed a similar risk for bleeding, long-term instability, and intracranial hemorrhage (brain bleeding). We now know this method can help improve outcomes for patients with intermediate-risk PE without increasing their bleeding risk. 

Related: Read “Research: AI Can Make Echocardiography More Efficient for Diagnostics.”

Improving outcomes for patients with pulmonary embolism.

MedStar Health Research Institute is proud to take part in groundbreaking studies like HI-PEITHO, helping advance treatments that improve care for our patients every day. In this study, MedStar Health played a key role, with Dr. Federico Asch serving as the lead cardiac imaging investigator and MedStar acting as the imaging core laboratory responsible for the analysis of all echocardiograms. Collaborating with colleagues around the world allows our work to reach more patients and communities.

Ultrasound-guided, catheter-based procedures are an important tool as we look to bring groundbreaking treatments directly to our patients. We know that personalizing treatment means understanding each patient as an individual and working together to create the right plan to help them achieve their best health.

By participating in studies like HI-PEITHO, we’re ensuring that a “road closure” in the lungs can be reopened with the most advanced tools and latest data.