STORM-PE: Mechanical Thrombectomy Boosts Walking and Daily Living Gains

Mechanical thrombectomy for acute intermediate-high-risk pulmonary embolism (PE) results in better walking scores and a higher likelihood of a return to pre-PE levels of functional status when compared with anticoagulation alone, according to an interim analysis from the STORM-PE trial.

At 90 days, patients randomized to computer-assisted vacuum thrombectomy (CAVT) had an average 6-minute walk distance of 479 meters compared with 368 meters for those randomized to anticoagulation (P = 0.003). Fully 97% were in NYHA functional class I versus 76% in the anticoagulation arm (P = 0.022).

These data come just months after the main results from STORM-PE showed that mechanical thrombectomy resulted in a greater reduction in the surrogate endpoint of RV/LV ratio at 48 hours compared with anticoagulation alone. An RV/LV ratio ≥ 1.0 has been shown to be associated with risk of early death and PE death. Since then, contemporary data from the Pulmonary Embolism Response Team (PERT) Consortium Registry have confirmed that even before STORM-PE or the PEERLESS trial, mechanical thrombectomy had firmly taken hold and is increasing steadily in clinical practice.

Robert Lookstein, MD (Icahn School of Medicine at Mount Sinai, New York, NY), who presented the STORM-PE functional results last week at the Society of Interventional Radiology 2026 meeting, said the data thus far fill important evidence gaps.

“Earlier and more uniform physiologic recovery and stabilization of right-heart function at 48 hours, and also at 7 days, appears to be translating to greater functional status and greater functional capacity in the endovascular group, and this certainly creates a greater level of confidence amongst the vascular community that this is a therapy that should likely be offered to patients in a more uniform matter,” he told TCTMD.

At a media briefing, Vivian L. Bishay MD (Icahn School of Medicine at Mount Sinai), an interventional radiologist, said the STORM-PE data are helpful when speaking with providers in other specialties about the options for acute intermediate-high-risk PE patients.

“Data continues to move the needle towards intervention,” Bishay said. She noted that the evidence in support of the safety of mechanical thrombectomy as seen in both STORM-PE and STRIKE-PE, which also is studying CAVT, continue to add reassurance for clinicians considering their patients for this therapy.

“Once you have that, you could start to talk about those functional outcomes, which really matter to patients. When they’re going home, if they’re able to achieve what they were doing at baseline [it] is very, very important,” she added.

Also in the media briefing, Brian Schiro, MD (Baptist Health Miami Cardiac & Vascular Institute, FL), agreed that the return of functional status adds much needed clarity to the discussion of sending patients for advanced therapies like CAVT.

“The RV/LV ratio is an interesting marker, but to the referring physician that doesn’t mean a whole lot,” he said. “I think what we have right now is extremely compelling and we should bring this to the forefront of every discussion that we have with referring physicians.”

Near-Normal Walking Distance

For STORM-PE, Lookstein and colleagues enrolled 100 patients (mean age about 60 years; 46% female) from 22 clinical sites. All had a 14-day or less history of clinical signs and symptoms of acute PE, evidence on CT pulmonary angiography (CTPA) of a filling defect in at least one main or proximal lobar pulmonary artery, an RV/LV ratio ≥ 1.0, and elevated cardiac biomarkers. Patients were randomized to continue anticoagulation with or without CAVT (Lightning Flash; Penumbra).

On the 6-minute walk test, the change from 30 to 90 days showed almost a doubling of the distance walked in the mechanical thrombectomy arm compared with the anticoagulation-alone arm (84.7 m vs 48 m; P = 0.412), and the difference remained significant even after accounting for patients unable to complete the test.

Those in the mechanical thrombectomy group also were more likely than the anticoagulation group to reach their predicted 6-minute walk distance at 90 days based on their pre-PE function (94% vs 75.2%; P = 0.022).

“The CAVT patients achieved a near-normal walking distance for their age, gender, and body surface area, where the anticoagulation patients did not,” Lookstein noted.

The mechanical thrombectomy arm also showed better outcomes on the Post-VTE Functional Status scale than the anticoagulation arm, and less shortness of breath on the modified Medical Research Council (mMRC) dyspnea scale.

Expert Consensus May Be Coming Soon

To TCTMD, Lookstein said STORM-PE taken together with the recent HI-PEITHO trial, which showed better short-term outcomes with ultrasound-facilitated, catheter-directed fibrinolysis plus heparin-based anticoagulation compared with anticoagulation alone, may be poised to shake up expert recommendations sooner rather than later.

Both trials were unable to be considered in the recent 2026 joint clinical practice guideline from the American Heart Association (AHA) and the American College of Cardiology (ACC) because the outcomes were not available before the committee’s data-lock date.  

When HI-PEITHO was presented last month in a late-breaking session at the ACC 2026 Scientific Session, Jay Giri, MD, MPH (University of Pennsylvania Perelman School of Medicine, Philadelphia), a member of the guideline’s writing committee, told TCTMD that the trial was probably the most important clinical study that’s been performed in more than 10 years in the intermediate-risk PE population.

“When you look at those two trials in aggregate, you have over 650 patients randomized,” Lookstein noted. “I think it presents a clear signal that endovascular therapy, in addition to anticoagulation, is benefiting patients previously referred to as an intermediate-high risk population.”

The guidelines recently shifted PE classification from four categories (low, intermediate-low, intermediate-high, and high risk) to an A through E structure within which patients can fall into various subcategories. Under this classification system, intermediate-high risk PE would likely be considered C3 or D1. As they stand now, the guidelines give those categories a class 2a or 2b recommendation for endovascular therapy.

“We do not believe that the AHA will revise their guideline document for some time now,” Lookstein said. “I can assure you that several of the medical specialty organizations that care for these patients are discussing a vascular specialist update to hopefully address the concerns of our members and practitioners about the discordance between the guidelines and the recent introduction of level I evidence.

“We believe we have consensus and hopefully there’ll be more information about that coming in the near future,” he added.

The influx of new data has some in the PE community referring to this moment in time as the “golden age of pulmonary embolism care,” he noted. “We are all collectively committed to not only decreasing the mortality of this devastating [disease], but also addressing the quality of life issues that many patients are facing so that we can really turn the page on the historic suboptimal care that patients were receiving before these trials were initiated.”