Approximately 10% of patients who receive a pacemaker experience complications related to the use of transvenous leads, the surgical pocket, or the pulse generator.  A leadless pacemaker inserted in the right ventricle by way of a transvenous catheter may result in lower complication rates. These leadless pacemakers include electronics, battery, and electrodes all in a single encapsulated device.  In this study, investigators report on a nonrandomized trial of nonsurgical implantation of a leadless cardiac pacemaker in patients who required permanent ventricular pacing.  The primary efficacy end-point was acceptable pacing and sensing thresholds with a safety end-point of device-related serious adverse events at 6 months.  Reporting on data from the initial 300 patients in the study, implantation was successful in 270 (90%) with 6.7% experiencing a device related complication by 6 months including dislodgement requiring percutaneous retrieval (1.7%), cardiac perforation and tamponade (1.2%) and pacing threshold increase requiring retrieval and repositioning (1.3%).  The study also suggested an operator learning curve with a complication rate of 6.8% for the initial 10 cases by each operator as compared with a 3.6% complication rate for subsequent implants.

Conclusions

The leadless cardiac pacemaker is a novel technology that may eliminate issues commonly encountered with conventional pacing devices. This trial speaks to the importance of adequate operator training to reap the potential benefits of leadless device implantation.  With further refinements and operator experience, leadless pacemakers are likely to represent a significant evolution in pacing technology.

Summarized by Hussain Contractor and Steven M. Bradley

Reddy VY, Exner DV, Cantillon DJ, Doshi R, Bunch TJ, Tomassoni GF, Friedman PA, Estes NA 3rd, Ip J, Niazi I, Plunkitt K, Banker R, Porterfield J, Ip JE, Dukkipati SR; LEADLESS II Study Investigators. Percutaneous Implantation of an Entirely Intracardiac Leadless Pacemaker. N Engl J Med. 2015 Sep 17;373(12):1125-35.