Dear smith,
Heart catheterization is the "gold standard" for determining heart blockages. There are other methods but they are not as accurate as a cath. A heart cath has some risks but is in general a safe procedure. The doctor doing the procedure should go through all the risks and alternatives prior to the procedure. Good luck.
Everybody is different, but I just wanted to tell you my mom went through 2 catheters with both diabetes and congestive heart failure at 65 and then ?. She made out just fine. I hope all goes well for you.