There is documented data that there can be a family history or hereditary increase to the chances of heart attack.
For example my Grandfather died in the late 30's from a massive heart attack
. My Father Died at 41 with a massive heart attack and my younger brother died at 32 from a massive heart attack. Another problem has be found to be suffering from narrowing of the arteries in his heart and has just had stints placed to widen the arteries.
I also have dealt with people that have the same problem within their families.
Anyone that says that heart attacks are not hereditary are not necessarily wrong if they answer your question literally because it is not the heart attack that is hereditary it is the chance of having a heart attack that is hereditary.
There is a hereditary proneness to atherosclerosis
or hardening or the arteries. This is both genetic or dietary though in my family history my younger brother was a vegetarian and exercised daily and was careful about his diet and habits.
Check your families history and see a doctor if you are worried.