First, I am an 80 YO male who had a right TKR on October 1st. Unrelated to my knee, my internist had detected a slight hear murmur and he sent me to a cardiologist. The cardiologist gave me a stress test using the medicine instead of a treadmill (with my non functioning knee a treadmill was never a possibility). I can't remember if I had a radioactive dye as well but it went fine.

But there are risk factors and apparently your cardiologist thinks that the test is necessary.

There are steps short of a TKR that are not only possible but may be necessary for your insurance company to cover the costs of a TKR. Medicare requires that at least two alternative treatments have been tried and are unsuccessful before it will consider the surgery "medically necessary". There are custom braces (I had one but it wouldn't stay up on my leg), steroid shots (didn't work for me) and PT as alternative treatments. If you haven't tried these, you can.