August 24, 2015
Acute Pulmonary Embolism Trial (SEATTLE II) Published in the JACC: Cardiovascular Interventions

Bothell, WA, USA, 24 August 2015

Results show no intracranial hemorrhage, no death among massive PE patients

EKOS Corporation, a BTG International group company (BTG plc; LSE: BTG), announced the publication of results of the SEATTLE II trial in the JACC: Cardiovascular Interventions. The study concluded that treatment with ultrasound-facilitated catheter-directed low-dose thrombolysis for acute pulmonary embolism (PE) improves right heart function, reduces blood clot size, and decreases pulmonary hypertension, in patients with intermediate to high risk PE. Importantly, no patient experienced intracranial hemorrhage, a serious adverse experience related to full-dose thrombolysis treatment.

The SEATTLE II study was a prospective, single-arm, multi-center trial designed to evaluate the safety and effectiveness of ultrasound-facilitated catheter-directed low-dose thrombolysis, using the EKOS EkoSonic® Endovascular System. Onehundred fifty (150) patients diagnosed as acute massive (N=31) or submassive (N=119) PE were enrolled. Patients received low dose (24 mg) of tPA (thrombolytic) for 24 hours with a unilateral catheter or for 12 hours with bilateral catheters. The size of the right heart measured as RV/LV ratio significantly decreased from 1.55 to 1.13 (p<0.0001) by 48 hours after start of treatment.

For patients with severe PE, the mortality rate is nearly one third1. In the SEATTLE II study 31 patients presented to the emergency room with massive PE, syncope and hypotension. All 31 survived the 30-day follow up period. Of 150 patients in the study, one death was directly attributed to PE.

There were no intracranial hemorrhages and no fatal bleeding events. Major bleeds occurred in 15 patients and were comprised of one severe bleed and 16 moderate bleeds. Six of the major bleeds occurred in patients with co-morbidities known to be associated with an increased risk of bleeding during thrombolytic therapy.

“The SEATTLE II findings establish a new rationale for considering ultrasound-facilitated catheter-directed low-dose thrombolysis in both massive and submassive PE,” said Gregory Piazza, MD, MS Assistant Professor of Medicine, Harvard Medical School, Staff Physician, Cardiovascular Division, Brigham and Woman’s Hospital (Boston, MA), and Principal Investigator for SEATTLE II. “Without any intracranial hemorrhage and using a much reduced lytic dose, a substantial and clinically meaningful reduction of the RV/LV ratio was achieved.”

“The SEATTLE II and ULTIMA trials add to the body of evidence showing treatment with the EkoSonic® Endovascular System improves the standard of care for patients with acute pulmonary embolism,” said Matt Stupfel, General Manager of EKOS Corporation. “The only endovascular device cleared by the FDA for the treatment of PE, EkoSonic® represents a potential game-changer in the treatment of high-risk PE patients. EKOS® ultrasonic waves greatly accelerate lytic dispersion by driving the drug deeper into the clot and unwinding fibrin to expose plasminogen receptor sites.”

EKOS has shown a continued commitment to clinical research in PE. The ULTIMA trial, published January 2014 in Circulation, demonstrated that EKOS treatment was clinically superior to anticoagulation with heparin alone in reversing right ventricular enlargement at 24 hours, without an increase in bleeding complications. Building on the success of SEATTLE II and ULTIMA for treatment of PE, EKOS continues to improve and enhance clinical science knowledge by launching the next study, OPTALYSE PE, to better understand the optimal dose of thrombolytic and duration of its treatment.

For further information contact:

Andy Burrows, VP Corporate & Investor Relations
+44 (0)20 7575 1741; Mobile: +44 (0)7990 530 605
(For UK corporate and investor inquiries)

Chris Gale, Vice President
+1.646.695.2883; Mobile: +1.203.570.4681
(For US trade and media inquiries)

About BTG

BTG is a growing international specialist healthcare company bringing to market innovative products in specialist areas of medicine to better serve doctors and their patients. We have a portfolio of Interventional Medicine products to advance the treatment of liver tumors, severe blood clots, varicose veins and advanced emphysema, and Specialty Pharmaceuticals that help patients overexposed to certain medications or toxins. Inspired by patient and physician needs, BTG is investing to expand its portfolio to address some of today’s most complex healthcare challenges. To learn more about BTG, please visit:

About EKOS Corporation and the EkoSonic® Endovascular System

EKOS Corporation, a BTG International group company, pioneered the development and clinical application of ultrasound infusion technologies in medicine, introducing its first system for the treatment of vascular thrombosis in 2005. Today, interventional radiologists, cardiologists, cardiothoracic and vascular surgeons at leading institutions around the world use the EKOS EkoSonic® Endovascular System to provide faster, safer and more complete dissolution of thrombus. To find out more about the EKOS EkoSonic® Endovascular System, visit

EKOS and the EKOS logo are the trademarks of EKOS Corporation, a BTG International group company. BTG and the BTG roundel logo are registered trademarks of BTG International Ltd in US, EU and certain other territories and trademarks of BTG International Ltd elsewhere.

Statements of indications:

USA FDA Cleared Indications:

The EkoSonic® Endovascular System is indicated for the ultrasound facilitated, controlled and selective infusion of physician-specified fluids, including thrombolytics, into the vasculature for the treatment of pulmonary embolism; the controlled and selective infusion of physician-specified fluids, including thrombolytics, into the peripheral vasculature; and infusion of solutions into the pulmonary arteries.


Not designed for peripheral vasculature dilation purposes. The system is contraindicated when, in the medical judgement of the physician, such procedure may compromise the patient’s condition. See device instructions for use for complete prescribing information.

The CE Mark (CE0086) has been affixed to the EkoSonic® product with the following indications for use:
Peripheral Vasculature

The EkoSonic® Endovascular Device, consisting of the Intelligent Drug Delivery Catheter (IDDC) and the MicroSonic™ Device (MSD), is intended for controlled and selective infusion of physician-specified fluids, including thrombolytics, into the peripheral vasculature. All therapeutic agents utilized with the EkoSonic® Endovascular System should be fully prepared and used according to the instruction for use of the specific therapeutic agent.

Pulmonary Embolism

The EKOS EkoSonic® Endovascular System is intended for the treatment of pulmonary embolism patients with ≥ 50% clot burden in one or both main pulmonary arteries or lobar pulmonary arteries, and evidence of right heart dysfunction based on right heart pressures (mean pulmonary artery pressure ≥ 25mmHg) or echocardiographic evaluation.

Notes to Editors

Submassive Pulmonary Embolism (PE) definition – patients with pulmonary embolism that have normal systemic blood pressure and confirmed heart dysfunction.

Massive Pulmonary Embolism (PE) definition – patients with pulmonary embolism that have systemic hypotension (systemic blood pressure that is <90 mmHg) and confirmed heart dysfunction.

RV/LV ratio is the extent to which right ventricle is dilated in relation to the left ventricle. The RV/LV ratio is also known as an indicator for the right heart dysfunction.

PE occurs in approximately 1 million patients in Europe annually and 600,000 in the US, causing or contributing to 200,000 deaths each year. (According to and company internal data.)

Pulmonary hypertension (PH) is increased pressure in the pulmonary arteries. These arteries carry blood from heart to lungs to pick up oxygen. It causes symptoms such as shortness of breath during routine activity, tiredness, chest pain, and a racing heartbeat.

Syncope – transient loss of consciousness.


  1. Casazza et al. Thrombosis Research 2012: 130:847-852