Coronary clot in 30 yr old triathlete, no history

I am looking for help as my Dr.'s at one of the more established cardiology hospitals in NYC can't figure out why I had a clot form in my coronary artery causing ST elevation and leading to a heart attack.  This all started 1 hour post an olympic triathlon distance race (.9 mile swim [30 min], 24 mile bike [66 min] and a 6.2 mile run [48 min].  The race was done at roughly 80% of max intensity.  I was pretty dehydrated as the weather was 80 and humid and I have been training at 40's and 50's NYC weather.  I was drinking fluids and taking in sports nutrition during the race which I have trained with for the past 2 years.  

The initial symptoms was severe fatigue and within 8 min I went to the medical tent at the race which led to chest pain.  Then was taken to the ER via ambulance and received an angiogram which found a clot in my coronary artery.  The Dr. said my troponin levels were at a 25 before the clot and then 19 after the 2 angioplasties were performed.  I was held in the hospital taking med's to break up the clot for 3 days at which point I was discharged.  

I had a cardiac MRI which ruled out a cardiac shunt.  It also showed 9.8 % muscle mass damage, slightly enlarged heart, EF at 64%.  I am awaiting the results from my hematologist to see if I have a clotting disorder.  If that comes back negative the Dr's said they have no idea what caused the clot.  

I have no history of anything.  Never been hospitalized and have no cholesterol or plaque issues.  I eat a very healthy mostly organic diet with red meat 2x/mn.  I am a 30 year old male who has played sports my whole life, just entered the triathlon world 2 years ago where I completed a full Ironman race last year.  As of now I passed a stress test last week, ran 20 min very lightly that night and rode my bike for 40 min lightly yesterday, without any symptoms.  

Can anyone please help me.  I feel great but am taking plavix, 2 coreg and a baby aspirin daily.  Any advice would be great.  Thanks in advance.