Leadless pacemaker tine damage and fracture: novel complications of a novel device fixation mechanism

Abstract

BackgroundLeadless pacemakers represent a paradigm-changing advancement. However, they required innovative and novel device design, including the use of nitinol tines for fixation. ObjectiveWe aimed to understand the potential for fracture in the novel tine-based fixation mechanism. MethodsA retrospective approach was used to search the Manufacturer and User Facility Device Experience (MAUDE) database for events related to Micra pacemaker tine fracture and damage. Review of each report was performed to ascertain frequency of tine fracture and damage. ResultsOf 4241 MAUDE reports (2104 Micra VR, 2167 Micra AV), 230 included the terms “fracture” or “tine”, which yielded 7 tine fractures and 19 reports of tine damage. Overall, 2/7(29%) tine fractures were noted during implant, whereas 2/7(29%) were discovered ≥1 week after implant; 5/7(71%) tine fracture reports described no associated patient signs or symptoms, and 4/7 (57%) described no change in pacing parameters. Tine damage occurred during implant in 16/19 (84%), compared with 2/19 (11%) noted ≥1 week after implant;15/19 (79%) tine damage cases reported no associated signs or symptoms, and 7/19 (37%) described no changes in pacing parameters. Among all cases, there was 1 case of device embolization. ConclusionsThe novel tine-based fixation mechanism appears susceptible to a novel failure mechanism – tine fracture and/or damage. Our analysis suggests these events may not always be associated with adverse signs or symptoms. Diligent attention at implant, and future bench or clinical studies are needed to understand the rate, clinical impact, and mechanism of such failures, and role of surveillance.