Adverse Event Profiles of Leadless Pacemaker Systems Reported to the FDA MAUDE Database (2021–2026)

Background Leadless pacemakers represent a major advance in cardiac rhythm management. The Micra Transcatheter Pacing System (Medtronic) and Aveir Leadless Pacemaker (Abbott) are distinct leadless pacing platforms with different device architectures and implantation mechanics. The FDA Manufacturer and User Facility Device Experience (MAUDE) database provides a real‐world source of post‐market adverse event reports. Objective To characterize adverse event profiles of contemporary leadless pacing systems using structured MAUDE data from January 2021 to January 2026, and to assess temporal trends, device problem–patient problem relationships, the timing and reported mechanisms of adverse events and deaths, and generational differences within the Micra platform. Methods Adverse event reports for Micra and Aveir were extracted from the FDA MAUDE database. Records with event dates before January 1, 2021, were excluded. Reports were deduplicated using a structured multi‐step process. Analyses were restricted to structured MAUDE fields, including event type, device‐problem codes, patient‐problem codes, brand name, and dates. Report narratives were additionally analyzed by rule‐based text classification with manual validation to clarify ambiguous FDA codes, event timing, and reported mechanisms of death. Each device platform was analyzed independently using descriptive statistics with 95% Wilson confidence intervals. Results A total of 14 064 unique reports were included (9973 Micra; 4091 Aveir). Among Micra reports, 7.9% were deaths, 41.1% injuries, and 51.0% malfunctions; high capture threshold (23.7%) was the most frequent device problem, and pericardial effusion (9.0%), cardiac perforation (7.9%), and cardiac tamponade (7.3%) were the leading clinical patient problems. Among Aveir reports, 4.3% were deaths, 32.4% injuries, and 63.3% malfunctions. The leading Aveir device problems were stretching/deformation of the fixation helix (FDA code “Stretched”; 18.3%)—97.7% intra‐procedural and 87.2% without clinical consequence—and device dislodgement (18.0%). The code “Embolism/Embolus” (14.0%) denoted device embolization in 97.5% of Aveir reports and was more frequent for the atrial than the ventricular device (20.6% vs. 13.2%, p < 0.001), without decline over time. No clinical signs or symptoms were reported in 64.2% of Micra and 58.5% of Aveir reports. Events were intra‐procedural in 45.3% of Micra and 66.4% of Aveir reports, and perforation/effusion/tamponade was the leading reported mechanism of death (51.4% and 67.2%, respectively). Newer‐generation Micra devices showed lower reported death proportions than earlier models. Conclusions Leadless pacemaker systems show distinct reported adverse event patterns in real‐world post‐market surveillance. Micra was characterized mainly by perforation‐related complications, whereas Aveir was characterized by fixation‐helix damage, dislodgement with device embolization—particularly of the atrial device—and separation‐related events. For operators, these findings underscore the importance of device‐specific implantation technique, procedural experience, and ongoing learning curve effects in leadless pacing.