There was a time when heart attacks were thought to be a peril of old age.

Kannada actor Puneeth Rajkumar's death, unfortunately the latest in a long list of young, seemingly healthy individuals having fatal heart attacks, has once again reminded us that this is no longer the case.

Rajkumar was a fit 46-year-old, in his prime...who had a fatal cardiac arrest while working out.

The frenzy of fear that followed also spurred a sea of suggestions, tips, and preventive nuskas floating around the Interweb.

One such advice—coming from a health professional on a prime time news show — is that everyone over the age of 40 should get a CT scan, especially before taking on a workout regime.

This, in order to screen for and prevent ischaemic heart disease, because 'we Indians have a genetic predisposition for heart diseases'.

FIT spoke to Prof K Srinath Reddy, president of the Public Health Foundation of India, and formerly head of the Department of Cardiology at AIIMS, and Dr Ashwini Setya, Gastroenterologist, and Programme Director in Delhi’s Max Super Speciality Hospital, to get to the bottom of the claim, and to set the record straight on asymptomatic, healthy people needing CT scans.

To begin with, let's understand what exactly causes fatal cardiac arrests? It isn't always just heart attacks, says Dr Ashwini Setya.

"Cardiac deaths may be several other reasons including coronary artery anomalies, certain diseases of the heart muscles, certain congenital heart syndromes as also certain problems with the heart rhythm," says Dr Setya.

Explaining this, Prof Srinath Reddy says, "coronary arteries, which supplies blood to the heart can get disease with deposition of fat and that results in what is called plaque formation in the inside lining of the artery."

The predominant causes, he explains, come down to poor diet, lack of physical activity, and smoking.

What about some fit people who get heart attacks when they are exercising?

Explaining this, Prof Reddy says, 'excess of anything is bad, and it's important not to overdo it'.

"We don't know what that person had that day," he says, explaining, even a simple inflammation when combined with a sudden surge in blood pressure can lead to plaques rupturing.

For this reason, Prof Reddy warns against strenuous exercise when you have a cold, or your body is fighting off an infection.

So, does that mean that everyone should get a diagnostic screening done before they start working out just to be sure?

Can a CT scan prevent such a mishap?

"There are no large population-based studies from India, on the effectiveness of CT coronary angiography in asymptomatic patients in predicting heart attacks," says Dr Ashwini Setya.

He also adds that there is research–one from Johns Hopkins to be specific–that points to the contrary.

"The research paper from John Hopkins published a few years ago, has concluded that CT angiography screening in asymptomatic patients leads to more medicines, tests and procedures, without clear benefit."

Moreover, Prof Reddy explains that CT scans may not be able to pick up on soft plaque, which, like we said, can also lead to fatal cardiac arrests.

But it's not without its uses. Dr Setya talks about the specific circumstances under which a CT scan would prove useful.

However, he goes on to say, "because of the humongous cost involved in just doing a CTCA in the suggested population of over 40, it becomes a non-starter option," he adds.

"Therefore, while the recommendation of doing preventive cardiac tests may be true for a particular subset of those asymptomatic patients wanting to do high intensity exercise, it cannot be generalised as mandatory for public at large," Dr Setya concludes.

According to Prof Reddy, the idea that Indians have a higher genetic risk of heart attacks and coronary deaths comes from studies in other countries in the 50s.

"Then it was found that Indians are more likely to develop diabetes, more likely to have abdominal fat for the unit," he adds.

"We compare rural Indians to urban Indians, and urban India with migrant Indians. There is a definite gradient of risk," he says.

Prof Reddy also talks about studies that compared workers in factories who had recently moved to the city to their siblings who continued to live in villages, which threw up interesting results.

What About Genetics Then?

"At the same time, lots of genetic studies have been done. No single gene has been pointed out and even when a number of genes are clubbed together, they do not explain more than 10 percent of the risk," Prof Reddy explains.

He doesn't completely deny the causal link between genetics and heart diseases. "There may be susceptibility, even though it is not clearly defined," he says, adding, "but what we know is that environment, and our pattern of living is the main trigger."

"Everybody should do moderate levels of exercise. And if there is existing risk, you should get investigated with the routine tests and observe other precautions," he adds.

The main routine tests that Prof Reddy suggests are blood pressure, blood sugar and blood lipids tests.

"A yearly health check including a comprehensive cardiac check-up may be perfectly in order in those people who have definite high risk factors for cardiac disease. Managing these high-risk factors is the key," says Dr Setya.

Both Dr Setya and Prof Reddy emphasise on a healthy lifestyle being the best preventive for heart conditions.

Prof Reddy also points to another byproduct of the 'urban lifestyle' that is to blame. "We have realised that stress is one of the big factors that can raise your catecholamines in the blood and so on, and rupture the soft plaque," he says.