Genetics and Heart Disease: understanding personal risk

Most of us know someone who embraced a “healthy” life – ate a balanced diet, limited alcohol and tobacco usage, and regularly exercised – yet still faced heart problems. It can feel discouraging to find out that making all the right choices still may not be enough to keep heart disease from developing. If you’ve ever wondered why even healthy people go on to experience heart issues, clues may lie in their genes. Today researchers are learning more about how genetics can rather silently shape cardiovascular risk, even in fit individuals. 

Heart disease is a complex condition. It is influenced by many controllable factors like diet, physical activity and stress, as well as underlying medical conditions like diabetes or high blood pressure. But a person’s DNA also plays a part. Some people inherit gene variants that make them more likely to develop heart disease and other problems, even if they are known for a healthy lifestyle.

Inherited conditions

One of the most well-known genetic heart conditions is familial hypercholesterolemia (FH). This inherited disorder causes dangerously high levels of LDL (“the bad”) cholesterol. This may lead to coronary artery disease at a younger-than-usual age, as well as an early heart attack. FH affects about 1 in 250 people. In fact many people don’t even know they have it until a cardiac event occurs that prompts testing. If one parent has FH, there’s a 50% chance one of their biological child will inherit it.

Another inherited condition, hypertrophic cardiomyopathy (HCM), causes the heart muscle to thicken. This can lead to arrhythmias or sudden cardiac death; this is often the cause of cardiac arrest in young and seemingly healthy athletes. HCM affects roughly 1 in 500 people worldwide. It is often linked to mutations in genes like MYH7 and MYBPC3.  

Heart disease variants

Beyond inherited risk, scientists have identified other common genetic variants that may increase the chance of developing heart disease. These variants are not necessarily direct drivers of heart problems, but they instead influence body processes associated with heart issues. For example, how the body regulates blood pressure or responds to inflammation. It is estimated that there are over 175 genetic variants associated with heart failure; these affect metabolism, immune function, blood vessel health and more.

Researchers are now using something called a polygenic risk score to estimate a person’s genetic risk for disease (not just heart) based on the presence of small variants. In the realm of heart health, this score aims to help identify people who may benefit from lifestyle changes or more frequent cardiac screening even if they don’t have symptoms or a known family history.

Along with scoring, genetic counselling and testing are also available to understand risk. A trained genetic counselor can help assess family risk based on history, interpret test results, and guide decisions about surveillance programs for early identification of issues along with prevention. It’s important to remember that the presence of genetic risk does not mean a definite cardiac diagnosis. Even in the face of genetic risk, healthy habits like eating well, staying active, and managing stress can help lower the chances of a serious heart problem forming.

Looking ahead

As research continues to evolve and the understanding of cardiac genetics grows, genetic insights may help doctors personalize heart disease prevention. Instead of one-size-fits-all medical advice, tailored recommendations based on a person’s unique genetic profile are a likely outcome. This could mean earlier interventions and a more proactive approach to heart, and overall, health.

Anyone with a known family history of heart disease may want check to make sure their medical history is up-to-date in their records. It is important to share any changes in a blood relatives’ health status with one’s care team. This can help a cardiac specialist decide about ordering genetic testing along with what steps should be taken to protect the heart and circulatory system.