Angiogram review. For some more time.

Hi Respected Dr, My father is a diabetic and BP patient had a stroke 3 years back which made his speech blabbering. Also last year he had to undergo kidney stone operation with surgery. Currently my concern is to avoid any further chances of stroke.After the kidney stone surgery he again had a mild stroke as observed by doctors when he was in ICU. Later once stroke passed and ecg came normal he was discharged.later we had discussed this issue with cardiologist he suggested medicines like ecosprin,sobertel for this issue. Doctor also suggested to undergo angiogram test to check any blockage which we didn't under went since kidney operation was fresh that time. Now he has underwent TMT test recently which has came -ve and doctor suggested no angiogram since there was no complaints of chest pain and continue medication. I am not sure what to do here whether to undergo angiogram test or delay for some more time. Regards, Akash