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To boost safety and effectiveness, some changes could be made to the premarket approval supplement pathway through which some high-risk medical devices are cleared for use, according to a commentary in Annals of Internal Medicine.

Although first-generation versions of high-risk devices, such as pacemakers, implantable cardioverter-defibrillators (ICDs), and cardiac resynchronization therapy (CRT) devices, require proof of safety and effectiveness through the premarket approval (PMA) process before going on the market, subsequent changes to those approved devices can be made through the PMA supplement pathway, which doesn't always require additional clinical data.

A study published in the Journal of the American Medical Association in January highlighted how often this supplement process is used. It showed that 77 high-risk cardiac devices approved from 1979 to 2012 were subject to a total of more than 5,800 approved supplements, some of which involved major design changes.

In the new Annals commentary, Sarah Zheng, and Rita Redberg, MD, of the University of California San Francisco, said that "recent events have raised safety concerns for this alternate pathway, and understanding these implications is important for clinicians and policymakers."

Sparking those concerns were two recalls of ICD leads, first involving the Sprint Fidelis leads in 2007 and then the Riata leads in 2011. In both cases, the leads in use at the time of the recall were substantially different from the versions subject to the original PMA approvals because of the approval of numerous supplements.

And that phenomenon is not unusual, as some devices can be subject to hundreds of supplements. Thus, some clinicians may not be aware that the device they're currently using is not the same one that was studied in the clinical trials before the original PMA approval, according to Zheng and Redberg.

They suggested three changes that could be made to preserve the flexibility needed to approve incremental changes to devices while at the same time improving safety and effectiveness:

A requirement for at least some clinical data for each supplement that goes beyond simple changes: "Requiring clinical data for anything except clearly cosmetic or packaging changes before supplement approval or in a transparent postapproval registry would help ensure safety and effectiveness of modified devices and would document clinical testing of sequential changes."

Beefed-up post-market surveillance for outcomes and adverse events: "Although collecting additional clinical data for device modifications may be cumbersome and costly for industry sponsors, a robust post-market surveillance mechanism could allow faster market entry while collecting and analyzing critical data on approved devices. Publicly accessible data registries that record ongoing clinical outcomes and adverse events for all device recipients would allow us to best identify patients who could benefit from specific devices."

Improved information about supplements on device labeling: "More direct and accessible labeling of devices to make clear any relevant supplements would alleviate some of the uncertainty physicians face with high-risk devices. These improvements would allow physicians to help patients make better-informed medical decisions by more accurately reflecting risks and benefits."

Zheng and Redberg acknowledged that need for flexibility so improvements to devices are not delayed, but said that it "must be balanced with the need to protect patients from preventable harm, particularly because many implanted PMA devices cannot be easily removed after a recall."

CardioBuzz is a blog by Todd Neale for readers with an interest in cardiology.