Interventional devices for treatment of acute pulmonary embolism do not have a high level of evidence, and stakeholders must generate more evidence, according to a scientific statement published by the American Heart Association.
Although the FDA has cleared two endovascular devices to treat acute PE — an ultrasound accelerated thrombolysis system (EkoSonic, EKOS Corp.) and an embolectomy device (FlowTriever, Inari Medical) — the decisions were based on the results of small single-arm studies using surrogate endpoints such as change in right ventricular/left ventricular ratio, Cardiology Today Next Gen Innovator Jay Giri, MD, MPH, FAHA, director of peripheral intervention at the Hospital of the University of Pennsylvania and assistant professor of medicine at the Perelman School of Medicine at the University of Pennsylvania, and colleagues wrote.
“We think intermediate-risk patients with PE should be studied in a randomized manner,” Giri told Healio. “However, the mortality rates are low, which means it is not easy to power a study for mortality. But we did take issue with the fact that only one main surrogate outcome, RV/LV ratio on CT or echocardiography, is being analyzed right now. It did not feel like this is where things need to be going.”
The committee concluded, however, that prospective nonrandomized studies are appropriate in high-risk patients with acute PE if short-term mortality is the primary endpoint, he said.
The statement was published in Circulation and presented by Giri at the Pulmonary Embolism Symposium.
“It became clear to the members of the committee and the American Heart Association that the care of hospitalized patients with acute pulmonary embolism seems to be evolving rather rapidly over the last 5 to 7 years,” Giri told Healio. “While traditionally, acute pulmonary embolism in hospitalized patients was almost universally treated with anticoagulation alone, there is a rapidly growing move to more advanced therapies.”
The authors also wrote that systemic thrombolysis with tenecteplase (TNKase, Genentech) has reduced mortality and recurrent PE but increased major bleeding risk compared with anticoagulation. Among patients at intermediate risk, the risk-benefit tradeoff is close, and the optimal dose and duration remain unknown, they wrote.
Catheter-based approaches for PE treatment have not yet demonstrated a benefit for reduction of mortality or recurrent PE, according to Giri and colleagues. However, they wrote, the devices have been shown to more rapidly reverse RV dysfunction among patients with acute PE than anticoagulation alone, although it is not clear how they compare with thrombolysis.
Rheolytic thrombectomy devices are contraindicated for PE treatment, and large-bore thrombectomy devices have been observed to cause complications in the PE population, although there are little data on the safety of small-bore embolectomy devices in these patients, according to the authors.
“In an ideal world, PE studies would be looking at harder endpoints like mortality and hemodynamic decompensation,” Giri told Healio. “But we think there is also room to study patient-centric functional outcomes.” – by Erik Swain
Giri J, et al. AHA Guidelines on PE. Presented at: Pulmonary Embolism Symposium; Oct. 4-5, 2019; Boston.
Giri J, et al. Circulation. 2019;doi:10.1161/CIR.0000000000000707.
Disclosures: Giri reports no relevant financial disclosures. Please see the statement for all other authors’ relevant financial disclosures.