So, there's nothing strictly preventing this in a real sense. I don't know how simple it would be in execution, as folks who are in poor health don't tend to have the best credit and credit cards can stop payment if they see irregular activity.
Also, some open question of who your fence on this would be. Who is selling you this asset on credit? Who is buying it back?
And is this really any more practical than just getting a ten year term life insurance policy? Unless you have an enormous line of credit, I can't imagine how a few grand in precious metals would be preferable to 10-100x that in an insurance policy.