TMT will not showed any sort of blockage, but positive TMT will give suspicious of some underlying blockage ,same 2D Echo test will tell you about heart anatomy and function and finding of heart atteck but not the amount of blockage , to know the blockage coronary angiogram is required .
in your case as patient is your father so i am assuming his age will be > 40 yrs in that case indian male with age > 40 with positive TMT angiography
test is indicated .
now a days angiogram test is very simple, esp. when it done through radial artery
route ( wrist),
its a 10 to 15 min procedure ,done after giving local anaesthesia and can be discharge same day usually after observation of 6 to 8 hrs.
cardiac medicine should be taken under supervision only
i think i have answer all your doubt