Genetics at the heart of it

Cardiovascular diseases (CVDs) have emerged as the leading cause of mortality worldwide, surpassing even cancer and respiratory illnesses. Alarming data suggests that in India, one in four individuals who suffer a heart attack is younger than 45 years of age. While well-known culprits like smoking, high cholesterol, diabetes, hypertension, and family history continue to play a major role, research has increasingly highlighted the genetic underpinnings of early-onset cardiovascular diseases.

What is early-onset cardiovascular disease?

Early-onset cardiovascular disease refers to heart-related conditions that manifest at an unusually young age, often before the age of 40. Unlike the traditional perception of heart disease as a condition of middle-aged or elderly individuals, these cases affect otherwise young and active people, sometimes leading to devastating consequences such as sudden cardiac arrest or premature death.

One of the most concerning conditions in this group is hypertrophic cardiomyopathy (HCM), a genetic cardiac disorder that affects around 1 in 500 individuals. This genetic disorder is not only the most common genetic heart condition but also a leading cause of sudden cardiac death in children, teenagers, and young adults.

Risk factors: modifiable vs non-modifiable

Like most chronic diseases, early-onset CVDs result from a mix of modifiable and non-modifiable risk factors.

 Modifiable risk factors: Smoking, obesity, diabetes, hypertension, and sedentary lifestyles are widely prevalent among young Indians. Substance abuse, particularly the use of opioids and anabolic steroids, further adds to cardiovascular risk in this age group.

 Non-modifiable risk factors: Genetics play a crucial role. In many cases, a family history of premature heart disease significantly increases the risk, even when lifestyle habits are relatively healthy.

The genetic connection

The role of genetics in heart disease was first recognised in specific inherited conditions such as:
Hypertrophic cardiomyopathy (HCM) – leading cause of sudden cardiac death among the young.
Familial hypercholesterolemia (FH) – a disorder that causes dangerously high cholesterol levels from an early age, dramatically raising the risk of premature coronary artery disease.

Beyond these, genetic variants in cardiac ion channels have also been linked to life-threatening arrhythmias such as ventricular tachycardia and ventricular fibrillation. Mutations in the SCN5A gene, for instance, are implicated in Long QT syndrome, a condition that predisposes one to early onset heart disease.

Cardiogenetics: pathway to prevention

The emerging field of cardiogenetics offers new hope in addressing early-onset CVDs. By focusing on the genetic basis of heart disease, it enables early diagnosis, risk prediction, and personalized interventions.

For example:

 Familial hypercholesterolemia (FH): In individuals with FH and a family history of premature coronary deaths, starting cholesterol-lowering therapy early can significantly cut the risk of heart attacks.

 Cardiomyopathies: Families with a history of hypertrophic or dilated cardiomyopathy can benefit from genetic testing, which allows for early diagnosis, timely monitoring, and targeted interventions to prevent heart failure or sudden death.

Genetic screening, therefore, becomes a powerful preventive tool. For at-risk individuals, it allows doctors to predict the likelihood of certain conditions before symptoms appear, giving them the opportunity to act proactively. Preventive strategies may include lifestyle modifications, regular monitoring, medications, or in some cases, advanced therapies and devices to reduce the risk of sudden cardiac events.

Way forward

The rising burden of early-onset cardiovascular disease, particularly in India, highlights the urgent need for awareness about both lifestyle risks and genetic factors. While healthy habits such as avoiding tobacco, eating a balanced diet, staying physically active, and managing stress remain essential, they may not be enough for those with a strong genetic predisposition.

(The author is a cardiology consultant at a leading Bengaluru hospital.)