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Safety and efficacy of shorter, lower dose EKOS therapy for PE

The EKOS system uses ultrasonic waves in combination with clot-dissolving thrombolytic drugs to effectively dissolve clots and restore healthy heart function and blood flow

One-year results from the OPTALYSE PE trial confirm that bilateral pulmonary embolism (PE) patients treated in as little as two hours with a total tissue plasminogen activator (tPA) dose as low as 8mg continue to show improvements in RV/LV ratio over the long term with a very low all-cause mortality rate of 2%. The outcomes also revealed an equally low recurrent PE rate of 2%, and continued quality of life improvements - further demonstrating the efficacy and safety of the OPTALYSE PE treatment regimens - the outcomes were presented at the International Society on Endovascular Therapy, Miami, FL.

“The long-term follow-up results reinforce that a new interventional standard is being set for PE treatment,” said principal investigator, Dr Victor Tapson, Director, VTE and Pulmonary Vascular Disease Research Program at Cedars-Sinai Medical Center, Los Angeles, CA. “The 2% one-year all-cause mortality rate observed in OPTALYSE PE is much lower than the ~8% rate seen in comparable anticoagulation studies1. This is important for institutions that are adopting the new low-dose, shorter duration treatments explored in OPTALYSE PE.”

The EKOS system uses ultrasonic waves in combination with clot-dissolving thrombolytic drugs to effectively dissolve clots and restore healthy heart function and blood flow. In clinical studies, EKOS therapy has been shown to speed time-to-clot dissolution, increase clot removal and enhance clinical improvement compared to either standard catheter-directed drug therapy or thrombectomy. EKOS therapy requires significantly shorter treatment times and less thrombolytic compared to standard catheter-directed drug therapy, lowering the risk of bleeding and other complications.

The authors followed the 12-month outcomes of 101 patients at 17 centres who participated in the OPTALYSE PE study in which the patients were randomized one of four cohorts. These patients were diagnosed with acute proximal PE in at least one main or proximal lobar pulmonary artery and a right ventricular-to-left ventricular diameter ratio (RV/LV) greater or equal to 0.9 on chest computed tomographic angiography (CTA). Patients received treatment within 48 hours of diagnosis. The four cohorts ranged from 2-6 hours in treatment duration and 8mg to 24mg total tPA for bilateral PE.

All cohorts saw a significant reduction in RV/LV by approximately 23 to 26 percent taken via CTA at 48 hours. For follow-up, patients received echocardiograms at four hours, 48 hours, 30 days, 90 days, and at one-year post-EKOS therapy. The initial significant reductions in RV/LV continued to improve in all cohorts through one year - with mean RV/LV ratios in the 0.70 range at one year for all cohorts. Multiple quality of life measurements showed valuable improvements between 30 days and 365 days - further demonstrating the long-term benefit of EKOS therapy.

“EKOS is the only device cleared for the treatment of pulmonary embolism. This is the first time that long-term mortality and quality of life data has been reported for an interventional PE treatment, which continues to show our commitment to evidence-based innovation, predictable and cost-effective procedures, and strong safety profiles that improve patient outcomes and help make the most challenging cases easier,” said EKOS Vice President and General Manager, Matt Stupfel. “Within a short time we have seen the science advance so that patients today can be treated in as little as two hours and with total tPA doses as low as 8mg, providing greater flexibility to clinicians, improved safety to patients, and potential cost savings to hospitals at a time when healthcare systems need these efficiencies.”

A separate registry study, KNOCOUT PE is currently underway to measure how hospitals are adopting and benefiting from the new standard of care. At full enrolment, the KNOCOUT PE study is expected to include as many as 100 centres internationally. Cases will include those from before and after the release of the original OPTALYSE PE study. Physicians seeking to participate in the KNOCOUT PE study or to learn more should contact the BTG IV Clinical Affairs department.

In additional studies - ULTIMA and SEATTLE II – these multi-centre trials examining ultrasound-facilitated, catheter-directed thrombolysis using a low dose of a standard clot dissolving medication called tissue plasminogen activator (tPA) to treat both acute massive and submassive pulmonary embolism. ULTIMA, a randomised controlled study comparing EKOS therapy to anticoagulation, looked at 59 patients across eight centres. SEATTLE II, a prospective single arm study, looked at 150 patients across 22 centres. OPTALYSE PE included 101 patients with acute proximal PE at 17 centres randomized to one of four treatment cohorts. The first cohort received 4mg of tPA per catheter over two hours. The second cohort received 4mg of tPA per catheter over four hours. The third cohort received 6mg of tPA per catheter over six hours. The fourth cohort received 12mg of tPA per catheter over six hours.

All cohorts saw a significant reduction in the main indicator of right heart strain from PE (measured as right ventricular to left ventricular diameter ratio (RV/LV)) by approximately 23 to 26 percent. The OPTALYSE PE results also showed a very low bleeding rate of three percent compared to 10 percent in the previous SEATTLE II study where patients were treated with 24mg for 12 or 24 hours.