Hi Linda
I really feel for you, you have had a terrible time of it. I can understand your concern re the chemo and the heart especially with regard to AC. But, as a triple negative(I am too) we are told that the best practice treatment is the AC taxane combination( taxol or docitaxel etc). I would raise all of your worries with the onc re the taxol. In my experience, the taxol is far less harsh than the AC but not sure of the impact on the heart. It is a difficult situation but the Drs must have an approach as floppy mitral valves are not unusual.
In terms of added percentage of longevity, I am unsure and I think it is another question for the docs. I do know that it is recommended especially with micromets. It sounds like you are really sensitive to the chemo with the blurred vision and the inflammation. I really hope the Drs can come up with a treatment plan that hits the bc without compromising your heart.
take care
Lisaxx