When the medical device trade association AdvaMed petitioned the FDA to reclassify annuloplasty rings in 1997, it argued that data on adverse events involving the rings showed few problems, pointing out that just 465 events had been reported to the FDA between 1991 and 1995. Based in part on that analysis, the FDA moved the rings from Class III to Class II in 2001, which allowed manufacturers to market new models without having to conduct clinical trials. Today, there have been about 3,400 adverse events involving annuloplasty rings during the most recent five-year period, and the rings have had more deaths associated with them than any other device in their class. They have been linked to just 56 fewer deaths than replacement heart valves, a Class III device that requires clinical data to gain approval.
