Diagonal 1 D1 LAD totally occluded was attempted to open with angioplsaty in your fathers case , which was unsuccessful .
In this case before attempting next angioplasty
or bypass surgery
, he need to undergo stress
thalium scan test to asses severity of disease and viable myocardium .
If it is not causing severe angina
on stress thalium , we can avoid further procedure and maintain him on optimum doses of anti anginal drugs .
Doing surgery only for D1 LAD disease is not recomended .