I'm assuming he would now be on the standard stack of; statin, beta-blocker, ACE inhibitor or AR2 receptor blocker and an anti-platelet (or anticoagulant depending on risk factors).
Depending on the extent- there is not much that can be done to reverse myocardial hypoxic damage from myocardial infarction- the best that can be done is to preserve the function- which is what each of the medications he would(/should) be on will do.
For CVD etiologies, aside from these medications, the primary non-pharmacological treatments should focussed on attaining and maintaining CV health through diet, physio-prescribed exercise as well as such things as quitting smoking, reducing alcohol consumption, reducing salt intake below 2grams/day.
The only staple supplement post MI recommended would be co-enzyme Q10 @ 150mg daily. There is potentially more that help- but these would be focussed on potential comorbidities/precipitating conditions of CVD.