Post bypass diet (6 years on)

My father had quadruple bypass surgery in 2006 that seemed to work quite well.  Unfortunately, he has not followed his dietary and exercise advice at all.  He eats a huge amount of sugary sweet foods throughout the day, sometimes coffee with sugar 3 times a day, cake donuts or cookies with that, ice cream after lunch and dinner, sundaes, cokes, carmel macchiatos, and a fair amount of high carb white breads.  To top it all off, he refuses to walk or do any sort of exercise and just lays around all day and takes naps.  He's in his mid 70's.  How long can these 6 year old grafts last??  He takes quite a few pills per day but refuses to let his Dr. do bloodwork to adjust meds.  Additionally, he has very bad lungs (asthma or copd) and about 10% of his kidney use.

Thanks

[CCFCardio MD2]

Bypass grafts can often last for several years, depending on the patient and the surgeon.  In general, vein grafts last a few years but at 10 years a good amount of them (maybe 50%) go down.  If an artery from the arm was used (LITA or LIMA), it often stays open much longer.  It sounds as if your father could use some behavioral modification to improve his diet and exercise.  Talk with his cardiologist about developing a plan to keep him healthy.

[newbegining_12]

what is meant by "vein graft going down" ?