My cardiologist said my ana came back slightly positive in my blood test so i have to have the test again to check again. what does this mean?

Probably nothing but: It is a non specific test, so it probably means nothing, but if in doubt see a rheumatologist.

Remote risk: This is generally a search for lupus or similar diseases. Low-titer positive anas up to 1:80 seldom turn up any information of use, but your cardiologist is probably being extra-careful andnd gathering information for what may lie ahead.