Dr. Kilmer S. McCully says in his book, The Heart Revolution, that B12 methylcobalamin vitamin B6 and methylfolate are absolute preventives for heart disease.
Now Dr. James Braly and Patrick Holford in their book, The H-factor Solution, say that homocysteine levels can be kept in safe parameters with B6, folate and B12 methylcobalamin. Homocysteine levels are a marker for heart disease.
I will add that potassium chloride salt, using it as daily salt, is also essential. Many grocery stores have it. If not, health food stores do.