Your father can expect to become short of breath and feel chest pressure when the stent begins to occlude and/or a new blockages causes symptoms. He sounds depressed, and hopefully he can understand that he needs to change behaviors and his mindset. Does he have access to Hospital Rehab services? That would be a logical first step to mental/physical recovery.
Thanks for the response! Even though it wasn't quite what I wanted to hear. He is very stubborn and there's nothing I can really say. He didn't even go to his follow up appointment with the cardiologist. I didn't know the stent could close up I thought the meds were just to thin out his blood. How would he know if the stent was closing?
If your father continues to smoke and not take his medications, the risk of your father developing future complications is not trivial. I can't quote you numbers, but given his relatively young age, he carries significant risk for future major cardiovascular events. Most importantly, given that he had a stent placed recently, he is at a high risk for complications in the short-term if he is not taking his heart medications (ie the stent closing off).
Instead of preparing mentally for the next event to occur, I recommend helping him to understand the seriousness of his disease and his responsibility (to you and your family) to take care of himself. You are not alone in this fight; his physician should be your advocate and partner in this.