Approval of high-risk medical devices in the US: implications for clinical cardiology.

Since 1976, the US Food and Drug Administration (FDA) has used the premarket approval (PMA) process to approve high-risk medical devices, including implantable cardioverter defibrillators (ICDs), coronary stents, and artificial heart valves. The PMA process is widely viewed as a rigorous evaluation of device safety and effectiveness, though recent recalls-most notably related to underperforming ICD leads-have raised concerns about whether physicians and patients should sometimes be more wary about devices approved via this pathway. The FDA must utilize a "least burdensome" approach to approve new medical devices, and many widely used device models have been approved as supplements to existing PMA-approved devices with limited clinical testing. A recent Supreme Court ruling has made it difficult for patients harmed by unsafe PMA-approved devices to seek damages in court. Cardiologists who utilize high-risk medical devices should be aware that FDA approval of new devices relies on variable levels of evidence and does not necessarily indicate improved effectiveness over existing models. Clinician and patient engagement in postmarket surveillance and comparative effectiveness research remains imperative.