Pumps & PMAs: Is FDA overstepping its bounds on advising panels?

An advisory panel to the FDA voted Dec. 6 to retain nonroller type cardiopulmonary bypass blood pumps as Class III devices, meaning that pump manufacturers will need to prepare premarket approval (PMAs) packages. George W. Vetrovec, MD, of Virginia Commonwealth University's Pauley Heart Center in Richmond, Va., expressed concern about the decision and the FDA’s reasons for proposing the action in an interview with Cardiovascular Business.

Nonroller type cardiopulmonary bypass blood pumps are used in various cardiac surgeries and procedures to provide hemodynamic support. According to the FDA, they are some of the few remaining devices to have been cleared for marketing under the “pre-amendment 510(k) pathway,” meaning, among other things, that the manufacturers of the device did not have to submit safety and efficacy data to FDA prior to marketing the device because it was considered substantially equivalent in both safety and efficacy to devices already cleared for marketing. As a result of changes to the 510(k) process in 2009, the FDA has been reviewing devices cleared for marketing in this way to determine whether manufacturers should be required to submit PMAs to FDA supporting the safety and efficacy of their devices.

Currently, the FDA classifies the pumps as Class III devices. They may be used for temporary (less than six hours) extracorporeal cardiopulmonary or circulatory bypass during surgery on the heart, major vessels, aorta or vena cava, and for ventricular support during high-risk interventional procedures not requiring cardiopulmonary bypass. According to the executive summary of the proposed agency action, the FDA proposes to require PMAs for the pump’s use for ventricular support during high-risk interventional or surgical procedures not requiring cardiopulmonary bypass. At the same time, the agency proposes to change the device classification to Class II (Special Controls) for use to provide full or partial cardiopulmonary bypass during surgery.

In addition, the FDA asked the Circulatory System Devices Panel to enquire into the use of nonroller type blood pumps for high-risk PCI, noting that the technology used for ventricular support “is not well-known and insufficient historical depth of knowledge/experience is available to leverage regarding the safe and effective use of these devices for ventricular support. The technical requirements for temporary nonroller pumps used to provide ventricular support are not well-characterized.”  

Vetrovec explained in an interview that 510(k) clearances tend to be very broad, but that over time devices initially approved through the 510(k) pathway can evolve for very specific uses, and be marketed for those uses. He cited the nonroller pump and its use in PCI as one of several examples of this type of morphing of a device grandfathered under the 510(k) pathway. Vetrovec said that FDA concern about a device evolving to perform very specific functions without data supporting its safety and efficacy for that specific function may be driving the agency’s proposed action.

Vetrovec testified before the panel on behalf of the Society for Cardiovascular Angiography and Interventions (SCAI), supporting continued access to the pump for left ventricular support and PCI. In his testimony, he noted that, “These devices assist in the treatment of some of the sickest patients undergoing clinically necessary and guideline-supported PCI, who most often are not acceptable candidates for surgical revascularization.”

However, in an interview, Vetrovec, a past member of the panel, expressed concern that “the FDA seemed to be guiding the panel toward a decision.” Regarding the FDA’s directive to the panel to enquire into the devices’ use in PCI, Vetrovec remarked, “Why are they raising questions about outcomes? It isn’t the job of FDA to decide how doctors choose to use hemodynamic support. It isn’t their concern. The FDA cannot regulate the practice of medicine.”

Vetrovec noted that if the FDA requires the manufacturers to submit PMAs, the devices will continue to be available as long as the manufacturers agree to collect and submit the necessary data. But he said some of the smaller manufacturers may be daunted by the cost of preparing the PMAs and may choose to stop producing the device. In addition, Vetrovec pointed out that the resources the device manufacturers will have to expend preparing the PMA could be better used elsewhere. “The PMA process [for nonroller-type pumps] may slow down development [of other devices],” he said.

The advisory panel's vote is not binding to the FDA. The agency is free to accept or reject the recommendation of the panel, although it typically follows its votes.