My Mama (90) has angina attacks. Any advice?

She has started to have angina attacks with the one on Sunday night being severe (I thought it was her time). I now have a RX for nitro. Health care directive in place. I have an appointment scheduled with the cardiologist, however I am thinking it may be best to cancel it. Her wish and mine is for palliative / comfort care only. I think going to the cardiologist would only be upsetting - as I understand it this is all a precursor to a heart attack and I don't think she needs to hear that. Is there any reason I should take her to such an appointment? I know she does not want to go and I only want to take her if there is something helpful that can be done such as oxygen (?). I will do and won't do for her what I would want for myself.