What are my dad's risks if his mother died of a heart attack at 39 (his age now) and he has extremely low cholesterol (74:42) and high BP?

Hard to say. When there is heart disease at an early age that does tend to increase the risk of heart disease in offspring. That is a risk factor that you cannot modify but to work on the ones you can. This is something you can discuss with your doctor,

Related Questions

Dad heart attack 54, mom stroke 54, mom's mom died late 40 heart attack, dad's dad died late 50. All thin, low cholesterol, low bp. Microvascular?

Cardiologist. You have described enough risk factors in your family history, heart rate and history of inflammation that you should consult a cardiologist for a proper investigation. The issue is not suitable for this forum as it requires in-person evaluation. Read more...