Background: The Manufacturer and User Facility Device Experience (MAUDE) database houses medical device reports of adverse events involving medical devices marketed in the United States submitted to the U.S. Food and Drug Administration (FDA) by mandatory and voluntary reporters. The MAUDE database is frequently used in clinical studies to report on device-related complications. Data about its efficacy are scarce., Objective: We aimed to compare the mandatory MAUDE database (MAUDE group) with the invitation-based POTTER-AF study (POTTER-AF 1 group) regarding data quality, procedural characteristics, diagnosis, treatment, and survival., Methods: The reports of esophageal fistula esophageal fistula following atrial fibrillation (AF) ablation in the MAUDE database were compared with those in the POTTER-AF study between August 1, 2009, and August 31, 2019., Results: Esophageal fistulas were reported in 47 patients in the MAUDE group and in 81 in the POTTER-AF 1 group. Procedures were performed with radiofrequency, cryoenergy, or laser energy in 66.0%, 31.9%, and 2.1% (MAUDE group) and in 96.3%, 2.5%, and 1.2% (POTTER-AF 1 group). The median time to symptoms was 21 (14, 32.5) days (MAUDE group) and 18.0 (6.8, 22.3) days (POTTER-AF 1 group; P = .031). The diagnostic method was reported in 38.3% of patients in the MAUDE group and in 98.8% in the POTTER-AF 1 group, the treatment in 57.4% and 100%, and the outcome in all patients. In the MAUDE group, treatment was surgical (51.9%), endoscopic (37.0%), combined (3.7%), or conservative (7.4%), compared with 43.2%, 19.8%, 7.4%, and 29.6% in the POTTER-AF 1 group. Overall mortality was 76.6% in the MAUDE group and 61.7% in the POTTER-AF 1 group (P = .118)., Conclusion: In the mandatory MAUDE database, fewer esophageal fistula cases were reported compared with an invitation-based study. The data quality in the MAUDE database was significantly poorer., Competing Interests: Disclosures Dr Tilz is a consultant for Boston Scientific, Philips, Medtronic Biosense Webster, and Abbott Medical; he has received speaker`s honoraria from Boston Scientific, Biotronik, Biosense Webster, Abbott Medical, Lifetech, and Pfizer and research grants from Abbott, Biotronik, Medtronic, Biosense Webster, and Lifetech. He has received travel grants from Abbott, Biosense Webster, Boston Scientific, Medtronic, and Philips. Dr Heeger has received travel grants and research grants from Abbott, Boston Scientific, Lifetech, Biosense Webster, and Haemonetics and speaker honoraria from Abbott, Boston Scientific, Lifetech, Biosense Webster, CTI GmbH, Doctrina Med, Wikonnekt, Haemonetics, and Pfizer. Dr Popescu has received travel grants and congress grants from Lifetech and an educational grant and speaker grant from Abbott Medical. Dr Pürerfellner servers as a consultant for Boston Scientific, Biosense Webster, Abbott Medical, and Medtronic; he has received speaker`s honoraria from Boston Scientific, Biotronik, Biosense Webster, Abbott, and Medtronic. Dr Catanzaro has received royalties from the University of Florida Research Foundation and research funding from Circa Scientific. Dr Kuck has received grants and personal fees from Abbott Vascular, Medtronic, and Biosense Webster outside the submitted work. Dr Vogler has received speaker honoraria from Abbott, Boston Scientific, Impulse Dynamics, Pfizer, and Doctrina Med. Dr Steven has received speaker honoraria from Abbott and Biosense Webster and is a consultant for Abbott and Boston Scientific. Dr Veltmann is a consultant for Biotronik and Medtronic; he has received speaker`s honoraria from Boston Scientific, Biotronik, Abbott Medical, BMS, Medtronic, and Zoll. Dr Merino has received fees and honoraria for lectures, education, and scientific advice from Biotronik, Microport, and Zoll. The other authors have no conflicts of interest to disclose., (Copyright © 2024 Heart Rhythm Society. All rights reserved.)