Implantable Infusion Pump Treats Pulmonary Hypertension

A fully implantable drug delivery system continuously administers Remodulin through a cardiac catheter to treat pulmonary arterial hypertension (PAH).

The Implantable System for Remodulin (ISR), the result of a collaboration between Medtronic (Dublin, Ireland) and United Therapeutics (Silver Spring, MD, USA), is designed to deliver Remodulin (treprostinil) to the pulmonary artery via a proprietary intravascular infusion catheter which is connected to a Medtronic SynchroMed II implantable infusion pump and other system components. Remodulin is designed to lower blood pressure by mimicking some of the effects of natural prostacyclins, making it easier for the heart to pump blood to the lungs.

The entire delivery system is implanted into the body and can be refilled at intervals of up to 16 weeks (depending on the patient's dose), using a syringe needle through the patient's skin into a reservoir. The system can operate continuously for four to seven years, depending on battery life. The DelIVery for PAH clinical trial, a safety study of the ISR drug delivery system, demonstrated a rate of catheter-related complications below 2.5 per 1,000 patient-days, with 10% of the patients experiencing pump failures after four years of use.

“External infusion pumps have been used to deliver prostacyclins for PAH, but managing the therapy places a significant burden on patients, interferes with their daily activities, and runs a high risk of infections,” said David Steinhaus, MD, general manager of the Heart Failure business at Medtronic. “This fully implantable drug delivery system was designed to address these serious patient care concerns.”

“We are extremely excited to offer this new option to patients suffering from PAH,” said Martine Rothblatt, PhD, chairman and CEO of United Therapeutics. “During the course of the DelIVery study, we received considerable physician and patient interest in the implantable system. We are grateful to our collaborators at Medtronic for reaching this milestone and look forward to continuing our collaboration.”

PAH is a rare, progressive disorder characterized by high blood pressure in the pulmonary artery for no apparent reason. Symptoms of PAH include shortness of breath (dyspnea) especially during exercise, chest pain, and fainting episodes. Advanced stages of PAH may manifest in cyanosis due to low levels of circulating oxygen. In severe cases of PAH, the right ventricle is abnormally enlarged, potentially leading to right heart failure. The exact cause of PAH is unknown, and although treatable, there is no known cure.