Actually, I was thinking cocaine. Anytime an actor drops dead, my first biased assumption is drugs.
Sorry I misunderstood your line of thinking. Cocaine can cause cardiomyopathy and Heart attacks/electrical issues probably less likely a structural issue with the valve. if not congenital the most likely culprit is endocarditis - a bacterial infection. of the valve that can cause subacute issues or acutely destroy the valve. That is usually associated with IV drug abuse so could be drug issues but I’m not familiar with using cocaine IV. It does tend to attack already abnormal valves with a higher affinity but who knows. Whatever the cause I feel for the family who lost a brother and son car too young