A cardiologist's guide to treating pulmonary embolism
Pulmonary embolism (PE), a potentially life-threatening condition where blood clots travel to the lungs, is gaining more and more attention within interventional cardiology.
Interventional cardiologist Peter Monteleone, MD, director of the interventional cardiology fellowship program at Ascension Texas Cardiovascular, national director of cardiovascular research at Ascension Health and an assistant professor at the UT Austin Dell School of Medicine, spoke to Cardiovascular Business about the latest advancements in interventional PE treatment.
"The whole field is really being revolutionized as we go, both the acute phase as well as the chronic phase of PE," Monteleone explained.
Catheter-based thrombolytic administration for PE
One of the foremost techniques in managing PE is catheter-based thrombolytic administration. The introduction of the Ekos system from Boston Scientific has revolutionized the delivery of tissue plasminogen activator (tPA). Traditionally, TPA was administered as a large systemic IV bolus, often leading to significant bleeding risks. However, with the Ekos device, tPA is delivered directly into the pulmonary arteries and ultrasonic transducers spaced along the catheter help create fissures in the clots to help speed up deeper tPA deliver. The technique significantly reduces the required dose, speeds up clot resolution and minimizes bleeding complications.
"The Ekos device employs ultrasound-assisted catheter-directed thrombolysis," explains Monteleone. "This approach uses ultrasound energy to loosen the fibrin within the clot, allowing lower doses of tPA to penetrate effectively."
Clinical trials have shown that this method, administering about 7-14 milligrams of tPA over several hours, is far safer than the historical 100-milligram systemic dose.
Mechanical thrombectomy in PE
In cases where PE is life threatening or poses danger of permanent lung damage and rapid clot removal is critical, mechanical thrombectomy offers an effective solution. This technique involves physically extracting the clot using specialized devices. Two notable systems are the Inari device, which uses a syringe to create suction, and the Penumbra device, which employs powered aspiration driven by a continuous suction engine.
Inari also makes the FlowTriever catheter, which can be used in combination with aspiration. It deploys a series of three nitinol mesh disks designed to engage and macerate the clot mechanically.
"Mechanical thrombectomy allows for swift clot extraction, essential for patients in critical condition," Monteleone said. "However, it requires significant expertise, as these devices can be large and challenging to maneuver in the delicate pulmonary arteries."
The choice between catheter-based thrombolysis and mechanical thrombectomy often depends on the patient's condition. For instance, patients on the verge of collapse might benefit more from the rapid intervention provided by thrombectomy, he said. Conversely, those with less immediate threats may be better suited for catheter-based thrombolysis.
Balancing risks and benefits of interventional PE therapy
Both treatment modalities have their unique challenges and benefits. Catheter-directed thrombolysis is relatively straightforward and familiar to many interventional cardiologists. It tends to be less invasive, reducing the risk of perforation and other complications associated with mechanical devices. On the other hand, mechanical thrombectomy can provide immediate relief but poses a higher risk of tissue damage, particularly when dealing with wall-adherent or organized clots.
Monteleone highlights the ongoing need for further research to determine the optimal use of these therapies.
"We need to continue parsing out what the best device is for each scenario. There’s no single answer, and learning when to stop intervention is crucial to prevent complications," he said.
Long-term considerations in treating chronic PE patients
In addition to acute interventions, managing the long-term effects of PE is vital. Some patients may develop chronic thromboembolic pulmonary hypertension (CTEPH), a condition characterized by recurrent clots leading to persistent pulmonary hypertension. Treatments for CTEPH can include chronic medications and, in severe cases, open surgery known as pulmonary endarterectomy.
Find more information on the recent REAL-PE trial Monteleone was involved in.
Dave Fornell has covered healthcare for more than 17 years, with a focus in cardiology and radiology. Fornell is a 5-time winner of a Jesse H. Neal Award, the most prestigious editorial honors in the field of specialized journalism. The wins included best technical content, best use of social media and best COVID-19 coverage. Fornell was also a three-time Neal finalist for best range of work by a single author. He produces more than 100 editorial videos each year, most of them interviews with key opinion leaders in medicine. He also writes technical articles, covers key trends, conducts video hospital site visits, and is very involved with social media. E-mail: dfornell@innovatehealthcare.com