"I'm wondering whether a CT-scan of the arteries can detect blocked arteries that can be
worked on with surgery... before my dad gets a heartattack. "
Investigation as to where blockages are is normal before any intervention surgery. In an angioplasty procedure the arteries are examined to find the culprits before they are treated. You mention bypass surgery, but I don't understand why. There could just be one blockage somewhere causing problems that simply requires a stent. It doesn't always come to a bypass.
If he gives up smoking, he will notice a huge improvement.
QUESTION: He sometimes experiences being out of breath as well as chest pain,
but this could be related to stress as he is a very anxious person....
>>>It can be related to stress, but stress can damage the heart cells, and the experience of the symptoms stated can be the action of damaging heart cells from the stress. A stress test with perfusion (dye circulating the vessel system with exertion) can identify any blockage of vessels or a ct san angiogram can as well..
If there is blockage and successfully treated, that would cerrtainly reduce the risk of a heart attack. Not smoking and a healthy diet can stop or delay any progression, but if there is blockage untreated there is a higher risk of a heart attack. is high