Our state of health is subject to an intricate interplay between “nature and nurture.” Whereas you cannot alter your heredity, studies are convincing that proper environmental factors, especially lifestyle habits, can significantly impact the expression (i.e. activating vs. silencing) of one's genes.
For example, the U.S. population has not undergone a massive genetic mutation in the past 25 years, and yet poor lifestyle choices have doubled our obesity rate. In you case, there is a very good chance you can overcome your genetics. You can even be healthier than one without the heart disease genes. The choice is yours.