Lost a close friend through a heart attack (?). Would like to ask some questions

28M, no known medical issues except for a little fat, unsure if overweight Hi everyone, its my first time posting on this subreddit and I would like to ask some questions. So just some background, I lost a close friend recently. His death was very sudden and caught many off guard. I...got what I could out of his family but I figured it would not be a good time to pry into more details given that they are going through a tough time now. So the story is as follows. My friend, 28 Male, is a little overweight but not very severe. He does not exercise often but recently has slowly begun to try to get into running. The other day, he was running on his own when he collapsed. He was wearing a smart watch that captured his heartbeat at 160 - 170 BPM, which did not seem normal. When he collapsed, it was in an urban area with people, so he was attended to immediately. CPR was performed and they managed to get an AED in. Whether it was used, I am not sure. At this point, there was a off duty doctor on site who treated him and noticed he had a faint and very weak pulse. The ambulance was called which arrived in 10 minutes. They spent about 10 minutes on site trying to stabilize him before evacuating him in the ambulance. The ride to the hospital took 15 mins, so a total of roughly 35 minutes had passed. They continued to try to save him at the hospital but sadly was pronounced dead. The official cause of death was given as "Coronary Thrombosis with Coronary Artery Disease". I'm not well versed in medical terminologies, hence would like to try to ask some questions from the professionals. I would have asked the doctor, but as I'm not an immediate family member, I want to give the family some space for now. Hence, would appreciate if anyone could give any opinions on the following questions. I have done some searching on google but as you all know, it probably isn't the best source of information... 1. From what I understand, the cause of death, simplified, was due to a blood clot that formed when plaque from the coronary artery dislodged. Meaning coronary artery, which carries blood to the heart, was jammed. An AED is used to shock two types of abnormal heart rhythms, Ventricular fibrillation and Ventricular tachycardia. Unfortunately, I do not know if he had these rhythms or not, or even whether the AED was used... CPR is used to prevent cessation of blood flow to the brain to prevent brain damage. So my question is, if the coronary artery was blocked, would the AED or CPR have helped him? I mean, the pipe is physically blocked. AED delivers an electric shock to the heart while CPR pumps blood manually. I can see how maybe CPR can help to unblock the clot, but I don't quite understand how the AED could have helped. Perhaps the protocol is to shock if the 2 rhythms are detected regardless of the cause of the cardiac problem ? 2. Is it normal to spend 10 minutes at the site to try to stabilize him ? Wouldn't it be better to stabilize him in the ambulance on the way to the hospital ? 3. A few days before the accident, he had complained of minor chest pains. Perhaps this was a precursor to the accident? In that case, I sometimes also have minor chest pains. When should these chest pains be investigated to prevent such accidents from occuring ? 4. One striking info that I didn't mention above is what was told me from the family. The off duty doctor actually got in touch with the family after the incident to offer condolences and mentioned that his condition was not survivable... How true would this be? 5. Lastly, what could, if anything, have been done to save him? I suppose you'll have to unblock the coronary artery, but that means getting to the hospital ASAP, which sort of contradicts what happened in point 2 Thank you to anyone who has read this far and even more thank you to those who replied. I do apologise if I do not reply on time as I don't really use reddit too much... Thank you