You keep asking the same question. And the only answer is the same answer.
I'm going to try to rephrase your question for you. Maybe you mean, "How are they able to confirm that the vaccine and/or the virus was the driving cause of the AMI and not a result of pre-existing conditions, environment, or genetic predispositions?"
If that's your question, that's a good question. And I have some great news for you. That information is in the study.
The great thing about science-based studies is they're required to provide you with the methods and the evidence so you can check their work (if you're so inclined). When you read the studies, they'll start with the Abstract (which is the question they're looking to answer), then the results, and then the means by which they arrived at that results. Which will include all of their data, all of the other studies, and everything they used. Along with the how & why they used that data.
The peer review process is the other scientists go through the data. They do the math. If they come up with the same answer, it's a thumbs up and it gets published. If enough people can't reproduce the results, too bad.It's a fluke and it won't get published.
They don't just make the numbers up. They contact the patients. They go through their medical history. They follow up with them on specific intervals to confirm what's happening with them. And all of that is available for you in the study.
Go read the study. The questions you want answered are answered within.