heart attack not plaque related

49 yo female with zero calcium /plaque.  Had a heart attack due to either vasospasm, blood clot or infection. Have documented Lymphocytic Colitis and Hashimoto's Thyroiditis. After researching, all 3 above reasons for the heart attack could be autoimmune related. What do I do to prevent another attack? I have a LBBB. I have been fatiiqued lately and am unsure where to go from here.
Thank you,
pamela

[Encephalomalcia]

Are you on blood thinners to prevent blood clots?  Your doctor can monitor the thickness of your blood through blood work.  Do you have an irregular heart beat?  If so, this puts you at a higher risk for blood clots.  When people have an overactive immune system and have inflammation in the arteries, the arteries can become plugged.  It sounds like you are not having that problem, which is good.