CRT: FDA guidance addresses heart valves, but not perc repair
Washington, D.C.--In late January, the FDA released a draft guidance on heart valve devices—the first in 16 years—assessing the premarket approval (PMA) and investigational device exemption of the devices. Carolyn D. Vaughan, an FDA lead reviewer, explicated the context and content of the guidance at the Cardiovascular Research Technologies (CRT) conference on Feb. 22.

Vaughan, a mechanical engineer at the FDA's division of cardiovascular devices, explained that the new draft heart valve guidance document (HVGD) addresses valves constructed of prosthetic materials, biologic materials (e.g., porcine valves) or a combination of prosthetic and biologic materials. She stressed that the document is not currently in effect, and is open for a public comment period until April 20.

However, the HVGD does not address valve-repair devices (e.g., annuloplasty rings or mitral valve repair devices) or allograft heart valves or more-than-minimally-manipulated allograft valves—the latter of which is regulated by the FDA’s Center for Biologics, Evaluation and Research.

She noted that percutaneous valves “will likely need different or additional testing.”

Despite the fact that the guidance hasn’t taken effect, Vaughan drew some contrasts with the previous heart valve guidance, issued in 1994. For instance, the older draft was “very prescriptive from preclinical custom, and the new one is risk based to be more in line with ISO 5840,” she said. Also, the older draft discussed mechanical and tissue valves and the new one reviews rigid and flexible valves—again to be in line with ISO 5840.

In fact, the new guidance was written to essentially “supplement” information in ISO 5840 cardiac valve standard. The ISO 5840, (or International Organization for Standardization 5840:2005, Cardiovascular Implants-Cardiac Valve Prostheses) is an FDA-Recognized Standard. Vaughan explained that some ISO 5840 testing requirements are different than the new HVGD, and a new ISO 5840 percutaneous heart valve addendum is currently being drafted.

For in vitro bench testing for percutaneous valves, she said the FDA would require same testing as surgical valves, plus:
  • Durability & hydrodynamics of non-cylindrical shape (misaligned, misshapen, under and oversized);
  • Delivery system performance;
  • Valve migration/embolization;
  • Valve-in-valve placement; and
  • Additional device-specific testing.

“Establishing preclinical testing boundary conditions for percutaneous valves is very important because these are needed to perform device-specific testing,” according to Vaughan.

Also, there will be new stipulations for in vivo animal studies for both surgical and percutaneous valves (see slide show).

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