There are millions of athletes in USA, when you include all the high school, college, pro teams in football, baseball, basketball, soccer, golf, track & field, skaters, swimmers, etc.
What we need to know is what percentage of those suffered heart issues.
The big data is inadequate to make sense of the impact on the smaller demos.
The best we can hope for is an unadulterated collection of data that can be objectively analyzed. Unfortunately, that’s a complicated ask these days.