LEADLESS II study confirms positive benefits of St. Jude Medical’s Nanostim leadless pacemaker

Data from the LEADLESS II study also highlighted the St. Jude Medical Nanostim leadless pacemaker’s retrievability, projected longevity and the promising future of leadless pacing

St. Jude Medical, Inc. (NYSE:STJ), a global medical device company, today announced primary results from the LEADLESS II study that confirm the positive benefits of the Nanostim™ leadless pacemaker for patients in need of a single-chamber ventricular pacemaker. The study also demonstrated the Nanostim leadless pacemaker’s longer-term retrievability and the device’s significant projected battery longevity.

The Nanostim™ Leadless Pacemaker’s size is very different from standard pacemakers and does not leave a scar when implanted. Photo courtesy of St. Jude Medical, Inc.

The LEADLESS II investigational device exemption (IDE) study is the largest published study to date to evaluate leadless pacing technology, having enrolled 526 patients at 56 centers across the United States, Canada and Australia. Earlier today, results from the study were published online in

The New England Journal of Medicine and presented during a Hotline session at the ESC Congress 2015.

"We are excited to share the results of LEADLESS II, which continues to grow the body of evidence supporting the safety and efficacy of the Nanostim leadless pacemaker," said Dr. Vivek Reddy, the study’s principal investigator and director of electrophysiology serves at The Mount Sinai Hospital in New York. "The LEADLESS II study results are advancing our understanding of leadless pacing technology and highlighting a number of benefits for physicians seeking a minimally invasive, leadless option for patients in need of permanent, single chamber pacing therapy."

After six months, data from LEADLESS II shows the trial met both endpoints for primary effectiveness (appropriate pacing and sensing) and safety (freedom from serious adverse device effects). In addition, data from LEADLESS II also demonstrated:

• Nanostim Leadless Pacemaker’s Retrievability. Retreivability is a core benefit of the Nanostim leadless pacemaker. Over the duration of the study, LEADLESS II demonstrated that retrieval of the implanted Nanostim leadless pacemaker was successful in 100 percent of patients requiring retrieval without any associated complications.
• Projected Longevity of the Nanostim Leadless Pacemaker. Based on data from LEADLESS II, Nanostim leadless pacemaker’s battery could be projected to last an average of 15 years, and possibly projected as high as 21 years depending on pacing needs. The longevity of the Nanostim device has been estimated to be 9.8 years at 100 percent pacing.

"Leadless pacing is a new frontier for modern medicine, and a potential solution for physicians who want to retain the reliability of conventional pacing options but offer their patients a less invasive procedure," said Mark Carlson, M.D., chief medical officer for St. Jude Medical. "The Nanostim leadless pacemaker allows for a procedure without the need for a surgical pocket or the leads required by traditional pacemakers. Combined with prior data from the LEADLESS trial, the results of LEADLESS II demonstrate the Nanostim leadless pacemaker should be considered as a clinical alternative by physicians who want to provide patients a leadless pacing option that offers long-term longevity and device retrievability."

The Nanostim leadless pacemaker originally received CE Mark in October 2013. Unlike conventional pacemakers that require more invasive surgery, the Nanostim leadless pacemaker is designed to be implanted minimally invasively via the femoral vein. The system is implanted with the smallest available leadless technology delivery system, which includes the delivery system catheter and an 18 F introducer. The Nanostim leadless pacemaker eliminates the surgical pocket and leads, which represent the most vulnerable component of traditional pacing systems. The Nanostim device is entirely self-contained and at approximately 1.5 inches long and under 6mm in diameter is less than 10 percent the size of a conventional pacemaker.

Within the LEADLESS II study, a total of 22 serious adverse device effects were observed over six months, including cardiac perforation, device dislodgement, and elevated pacing capture thresholds at rates of 1.3 percent, 1.7 percent, and 1.3 percent, respectively, which is consistent with traditional pacemakers.

Dr. Reddy is the Chair of the Steering Committee for the LEADLESS II trial, and has received consulting fees from St Jude Medical.