Your treatment was as per protocol and the survival rates if the cancer was detected as an early stage are very good and yes, you can survive for 15 years and even beyond if the cancer was managed completely.
The heart problem which you are suffering from could also be due to adriamycin, as it is known to have cardiac side effects. It is advisable that you consult your cardiologist and tell him about your past history.
Also go for your regular follow up visits to your oncologist
I hope I have answered your questions.