Friday, April 20, 2012

Was the valve used in National Heart Centre operation approved as a medical device?

While the HSA was conducting their briefing about how they were going to tweak the regulatory processes for low risk devices, we have this bit of exciting news about the groundbreaking operation done at the National Heart Centre.

Exciting because it was the first such operation done in Asia. Essentially, the operation was a minimally invasive insertion of a bioprosthetic (cow tissue in steel) valve to correct for a mitral valve failure. The valve-in-valve design was developed in 2007 when it first underwent clinical studies. In November last year the Edwards SAPIEN valve received a much heralded approval from the FDA. But here is where there is a bit of problem. The FDA approval was only for the use of the valve for aortic valve stenosis, not for correction of the mitral valve. And only in patients who are too ill for open heart surgery. In fact the US FDA had made a note in its approval that the valvular operation, even for aortic stenosis was not without problem - patients had 3 times more chance of developing a stroke.  But there had been no similar FDA approval for a modified valve for mitral valvular disease. Gigamole is not sure if any major regulatory agencies have approved the mitral version of the valve, let alone the HSA.

So here are Gigamole's questions:

a] Did the FDA approve the mitral valve-in-valve as a medical device?
b] Did any regulatory agency world wide approve the mitral valve-in-valve medical device?
c] Did the HSA approve the mitral valve-in-valve medical device?  And if so, on what grounds? If not, what was the approval process for surgeons at the National Heart Centre to go ahead and operate using an FDA and HSA unapproved medical device?

Please do not mistake my questions as being anti-innovation and anti-progress. Devices such as this valve-in-valve device needs to be properly evaluated in terms of risk benefits before use. The aortic version was studied since 2007 before it was approved by the FDA. Although the valve had been modified for mitral valve use also in 2007, this never received the same warm response, and as far as Gigamole is aware, the FDA in its wisdom never gave approval for the mitral valve version. Treating the mitral valve is not as straightforward on terms of risk-benefit assessments as for aortic stenosis. To those who advocate that we blindly follow the FDA's approval must also accept that we should also take guidance from the FDA's tardiness in approving this procedure.

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