It's a combination of things that are killing wrestlers, the travel, they never sleep, the pain pills, all the blow, the drinking, and the shitty diets. Living this type of life will kill anyone, the human heart can only take so much abuse before it breaks down.
So doing all of this shit and cycling on gear alll the time will kill anyone.
IFBB guys don't drink, travel, eat shitty and party as bad as wrestlers do.
The guys that are dying of heart related issues party harder more than likely.