Imperative Care has announced efficacy and safety results from the pivotal SYMPHONY-PE trial evaluating the company’s Symphony thrombectomy system in the treatment of acute pulmonary embolism (PE).
Results of the SYMPHONY-PE trial were presented in a late-breaking session at the Pulmonary Embolism Response Teams—PERT—Consortium 2025 Pulmonary Embolism (PE) Scientific Symposium (17–20 September, San Diego, USA), and published in Circulation: Cardiovascular Interventions.
In the trial, Symphony demonstrated a strong safety profile, high efficacy, and procedural efficiency, the company says in a press release. There were no device-related serious adverse events (SAE), with marked clot-burden reduction, short device-use time, and minimal blood loss.
The prospective investigational device exemption (IDE) trial evaluated 109 patients with acute intermediate-risk PE across 17 US institutions. The trial was led by national co-principal investigators Vivian L Bishay (Mount Sinai Health System, New York, USA), presenter of the late-breaking results at PERT, and Sripal Bangalore (NYU Grossman School of Medicine, New York, USA), lead author of the peer-reviewed paper.
“The trial results demonstrated significant improvements in right ventricle–to–left ventricle (RV/LV) ratio, systolic and mean pulmonary artery pressures (PAP), and clot burden, with no device-related SAE and no mortality reported at 30 days,” said Bishay. “These findings represent clinically meaningful progress in PE treatment, underscoring the device’s excellent safety profile. The ability to bring a large-bore catheter directly to the clot and safely deliver continuous aspiration marks an emerging paradigm shift in PE intervention. I look forward to the device’s continued impact in my practice.”
“Rapid thrombus removal using large-bore mechanical thrombectomy has the potential to improve patient haemodynamics, relieve right-heart strain, and reduce short-term morbidity and mortality in PE,” said Bangalore. “The excellent safety and efficacy demonstrated in this trial, together with short device-use times and minimal blood loss, underscore Symphony’s ability to address a critical unmet need by combining the advantages of large-bore continuous aspiration with the exceptional safety of real-time vacuum control.”
The trial met its pre-specified primary efficacy and safety endpoints, with results demonstrating a mean RV/LV reduction of 0.44±0.42 from baseline to 48 hours. The lower bound of the 97.5 % confidence interval (0.36) exceeded the prespecified performance goal of >0.20 (p<0.001).
On safety, the independent safety board adjudicated the major adverse event (MAE) rate, a composite of all-cause major bleeding, device-related deaths, and device-related SAE rate within 48 hours of the procedure, at 0.9 % (1/109). The 97.5% upper confidence interval bound (5.7 %) was significantly lower than the 15% performance goal (p<0.001).
“Symphony demonstrated an exceptional ability to deliver immediate and sustained objective and subjective improvements, achieving a 12mmHg reduction in systolic pulmonary artery pressure and a 7mmHg reduction in mean pulmonary artery pressure after aspiration, along with a 38.4% decrease in clot burden at 48 hours—all with a notably short device-use time and no safety concerns,” said Dana Tomalty (Huntsville Hospital, Huntsville, USA), the highest enroller in the trial. “These results appear to set a new benchmark for efficiency and safety in PE intervention. I am eager to bring this technology into routine clinical practice to improve outcomes for patients with acute PE.”
“Symphony introduces a new category in venous thromboembolism (VTE) treatment with Pulse Thrombectomy—the unique combination of a large-bore catheter with powerful, continuous vacuum delivered closer to the clot. This technology, paired with a streamlined procedural technique, enables physicians to remove more clot in less time,” said Doug Boyd, senior vice president and general manager of Imperative Care’s Vascular business. “We remain committed to building robust clinical evidence that validates our technologies and extends Symphony’s impact so more patients can receive life-saving care. We are deeply grateful to the patients, investigators, and clinical sites who helped make Symphony available across the USA.”
