Can my mother travel through air after angioplasty?

My mother is 65 years old. She had an angioplasty in 2004 and is OK now with regular medication. She goes for a regular check up every 3 to 4 months. She does her daily chores and even climbs stairs sometimes. We are planning to go to Chennai via plane. Is it advisable for her to take the plane journey? What precautions should be taken?