St. Jude Medical has announced its acquisition of Nanostim and CE Mark approval of the Nanostim leadless pacemaker. The Nanostim is the world’s first leadless pacemaker to enter the market and is less than 10 percent the size of a conventional pacemaker. The device is inserted through the femoral vein with the help of a steerable catheter and implanted directly into the right ventricle of the heart, as shown in the video below. The pacemaker itself is a VVIR pacemaker which attaches with a dual fixation system and paces the heart using a steroid-eluting electrode.
Traditional pacemakers need a surgically created subcutaneous pocket for the pacemaker and leads running from the device to the heart. Because of this, they are associated with many possible complications that are avoided by the Nanostim, including pocket infections, erosion of the pacemaker through the skin, lead dislodgement and lead fracture or perforation. Leadless pacing has been proposed for a long time, but the Nanostim is the first to overcome the technical challenges. For patients, besides a likely lower chance of complications this has the added advantage of the lack of a visible lump and scar and removal of activity restrictions that may prevent the dislodgement or damage to a conventional lead.
Results of a feasibility study in 33 patients (the LEADLESS study) were released earlier this year. The implantation success rate was 97% (in one patient cardiac perforation occurred during the implantation procedure). In two cases, the device had to be removed after implantation; in both cases the device was re-implanted successfully. Pacing threshold, R-wave amplitude and impedance were similar to traditional pacemakers with leads. Implant procedure time averaged 28 minutes and most patients were discharged from the hospital within a day after the procedure.
Despite its small size, the device battery is expected to have an average lifespan of more than 9 years at 100 percent pacing, or more than 13 years at 50 percent pacing. The Nanostim is fully retrievable so that it can be repositioned during the implant procedure and later retrieved if necessary, such as when battery replacement is needed. The device can be interrogated and programmed with St. Jude’s Merlin Programmer that is also used for the company’s other pacemakers and ICDs. The Nanostim will be available soon in select European markets, and St. Jude is working on FDA approval. Meanwhile, both Medtronic and Boston Scientific are also known to be working on leadless pacemaker designs, hopefully resulting in tangible results in the near future.
Product page: Nanostim Leadless Pacemaker…