In 1 case reported to the FDA’s adverse events database, the device became dislodged and traveled into the pulmonary artery, where it was later removed.
The company 1st paused enrollment in its European post-market trial in April 2014, reporting 6 instances of perforation, including 2 patient deaths, out of more than 200 implants. According to a letter St. Jude sent to physicians in February, after that trial resumed in June 2014, there were another 2 cases of perforation or excess fluid around the heart, 1 of which required an invasive intervention.
That trial halted again Jan. 5 of this year, according to the letter.* Between Feb. 4, 2014, and the 2nd pause of the European trial, the IDE trial showed 5 incidents of perforation or pericardial effusion, 4 of which required invasive intervention, and 6 dislodgments.
All told since the end of the 1st pause last June, among a total of 415 patients in both trials, there were 7 incidents of perforation or pericardial effusion, 5 requiring intervention, and 6 dislodgments, according to the letter.
“St. Jude Medical is analyzing interim data from our worldwide Nanostim studies with a focus on adverse events. These data will be shared for review with regulatory agencies, including the Notified Body, Competent Authorities (European national regulatory bodies) and, where appropriate, research ethics committees,” according to the “Dear Doctor” letter sent to physicians Feb. 20, “[W]e are temporarily suspending new implants in the [Post Market Clinical Follow-up] study at participating centers during this review. This temporary suspension in enrollment is not due to a new safety concern. It is a precautionary measure to allow for a thorough comparison of the risks and benefits of the Nanostim treatment option, following further incidents of pericardial effusion since the PMCF study resumed in June 2014 including in the IDE study.
“Upon completion of the review we will determine the most appropriate conditions and time frame for resumption of implants at the PMCF study centers. No further enrollment will take place until we receive approval from the above agencies,” the company wrote.
In another incident reported in March in the FDA’s “Manufacturer and User Facility Device Experience” database, a Nanostim device dislodged and advanced to the pulmonary artery.
“The doctor attempted to retrieve it and was unable to retrieve the device. It remained in the patient,” according to the MAUDE report. “Patient was admitted to the ICU and they were later able to successfully remove the device.”
Medtronic (NYSE:MDT) this month said it passed an initial safety & efficacy milestone with a 96-patient trial of its Micra leadless pacemaker. Reporting at the annual Heart Rhythm Management conference in Boston, Dr. Philippe Ritter of the University Hospital of Bordeaux said there were 8 serious adverse events in 7 patients in the Micra trial. One patient, in whom physicians tried to reposition the device multiple times, suffered pericardial effusion without tamponade and had a myocardial infarction 3 days later. Ritter said that patient is still alive.
The Micra device is shorter and wider than the rival Nanostim leadless pacer St. Jude Medical (NYSE:STJ) acquired in 2013, Ritter said, but the major difference lies in how the device is attached to the myocardium.
“The Nanostim has a very big screw and you have to be careful not to overturn the screw,” Ritter explained. “But whichever system you use, you have to be well trained, because this is a new technique.”
Nanostim won CE Mark approval in the European Union in October 2013. Medtronic’s Micra won a CE Mark just last month.
A St. Jude Medical spokeswoman told MassDevice.com via email that the company is “confident in the safety profile of Nanostim.”
“Nanostim is an exciting technology that has provided hundreds of patients with a minimally invasive, non-surgical option for pacing therapy,” Kate Stoltenberg told us via email. “We continue to share data with FDA and are on track to submit our PMA in the second half of 2015. Perforations and dislodgments are anticipated adverse events with traditional pacemakers as well as the Nanostim leadless pacemaker.”
*Correction, May 26, 2015: This article originally stated that the U.S. IDE trial was halted. This is not the case and we regret the error. Return to the corrected sentence.