Hi Rose, and thanks for your post - you've posed a good question. I do hope others in the community will see your concern and respond by sharing their own personal anecdotal experience here with the community.
I have something to contribute as well. Some years ago, I was hospitalized (for a surgical procedure for which I would be in the hospital for 6 days), unrelated to asthma. Naturally, the hospital expects to match one's medication regimen but, often times they maintain different medications on formulary. Once admitted, I had found they planned to substitute Symbicort for Advair.
I was (like you), very unhappy with this substitution. I asked my surgeon to add to my medical chart that I could use my entire medication regimen and the nurses/hospital complied.
That was how I managed my care (for asthma and other issues), while hospitalized.
In your case, I understand how you're feeling but, this may be the safest way for you to proceed in view of the theoretical (cardiac) risk (using Advair) you shared here with us. What are you thinking?
Wishing you well,
Leon (site moderator asthma.net)