Your B12 is in the low end range. So it would be a good idea to bring that up to 1000 at least. 5mg of active methylcobalamin daily on an empty stomach and get retested in 3 months or so.
(stop the supplement about 7 days before any testing).

I'd get information on that stent, and what metal it is made from and research that.

What medications do you take OTC and RX. Have you looked into them all in detail?

Low folate and fairly low B12 suggests a MTHFR mutation. There is a DNA test for that -- many people with heart disease have it.
I'd get that done, if I were you. It is less expensive than most of the other tests you get. 23andme does it online for 99 dollars.
If you cannot methylate properly you cannot repair nerve damage or make neurotransmitters well. Many of our posters showing up here who cannot get results from doctors, end up with having this test and show significant problems because of it.

You can learn more about this here:
http://mthfr.net/
10% to 30% have this.