Heart Disease : How To Tell if You Should Get a Polygenic Risk Test
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Heart Disease : How To Tell if You Should Get a Polygenic Risk Test

Aug 30, 2023

Medical professionals can use a number of approaches to determine a person's heart disease risk — including blood tests, CT scans, and electrocardiograms.

But there's another test that's rising in popularity: polygenic risk scores.

Polygenic risk scores involves analyzing a person's genes to see if there are any variants, as variations can indicate their likelihood of developing a certain disease.

In addition to heart disease, polygenic risk scores can be used in determining concerns such as cancer, diabetes, and Alzheimer's.

This type of testing is relatively new, first coming into use during the mid-2000s.

But what exactly does polygenic risk scores involve, and who should consider this type of testing?

Undergoing polygenic risk scores is (relatively) painless, involving either a simple blood test or swab from the inside of your cheek.

The DNA in this sample is then analyzed for variants — resulting in "a score that tells you how high your risk is for getting heart disease, or if you have an increased risk for it," explained Dr. Christie Ballantyne, a cardiologist at Baylor College of Medicine and Texas Heart Institute and director of the Center for Cardiometabolic Disease Prevention at BCM.

Depending on the health concern under investigation, the number of genes assessed can range from hundreds to thousands, said Dr. Geoffrey D. Barnes, a cardiologist and vascular medicine specialist at the University of Michigan Health System, a spokesperson for World Thrombosis Day, and consultant at several pharmaceutical companies.

"Each genetic variant may only contribute a small fraction to the risk of heart disease," he stated. "But, when combined, these genes can help explain a significant degree of risk for developing blockages in the coronary arteries of the heart."

Medical professionals can use polygenic risk score data in several key ways.

"The idea is to utilize the information derived from PRS testing to usher in a better-tailored management plan, taking into account an individual's unique genetic signature," explained Dr. Rigved Tadwalkar, a board-certified cardiologist at Providence Saint John's Health Center in Santa Monica, CA.

Physicians might advise closer or more frequent monitoring if an individual has a high polygenic risk score for heart disease. "Increased points of contact allow for greater detection of heart disease at an earlier stage," Tadwalkar said.

Furthermore, if a polygenic risk score shows someone has a higher likelihood of cardiac arrest in the future, their score can help doctors determine the timing and intensity of preventative efforts, Ballantyne told Healthline.

For instance, when lifestyle measures (such as improved diet) aren't helping improve high blood pressure in patients with a high PRS [polygenic risk score,] data "may be useful to decide when to add a medication," he added.

If you’re a patient, undergoing polygenic risk scores and learning your risk for heart disease can assist you in making lifestyle-related decisions that may aid in reducing your risk of developing issues later on.

"We’ve seen individuals with bad PRS [polygenic risk scores] who have changed their lifestyles to have a better diet, exercise more, or quit smoking to help their chances of having fewer heart events," said Ballantyne.

Polygenic risk scores can be beneficial in helping both patients and medical staff make more informed decisions. However, the tool isn't 100% perfect, and experts agree it has downsides.

For starters, polygenic risk scores isn't a magic ball and the results aren't definitive. "A high PRS does not guarantee that someone will develop heart disease," said Tadwalkar. "And, conversely, a low score does not mean that they will not."

He continued: "For this reason, it is necessary to interpret the results cautiously and in the context of other risk factors."

As such, the jury is out on where it sits alongside other predictor tests. While some studies have shown polygenic risk scores to be a reliable indicator, others have had less positive results.

"Recent studies have suggested that other tests (e.g., a coronary artery calcium score) may be more useful in predicting who is at risk of heart attack and stroke," Barnes noted to Healthline.

Tadwalkar added that these findings "highlight the need for caution and continued research to better understand the performance, clinical utility, and limitations of PRS in cardiovascular risk assessment."

Another element to consider is that — while scientists’ understanding of genetics is advanced — "interpreting PRS results can be complex in its current form," said Tadwalkar.

However, as our understanding of genetic variants and their relationship with diseases continues to develop, he explained that interpreting PRS results should become easier.

But these aren't the only limitations to consider.

"We do not know how race and ethnicity affect PRS scores," stated Ballantyne. Furthermore, "there is not a large consensus within the medical community of what the best PRS score is, as many different PRS scores are available."

Finally, from a patient's perspective, it's vital to consider the potential psychological outcomes (such as anxiety) that can arise from discovering you’re at high risk of serious disease.

In light of this, Tadwalkar asserted that "proper counseling should be coupled with PRS testing to help individuals make informed decisions about their health."

Essentially, PRS testing isn't something to enter into lightly. "It should only be done after consulting with your doctor," said Barnes.

Barnes revealed "there is no consensus as to when PRS should be used for assessing heart disease risk."

However, certain people may benefit more than others.

If you’re a younger individual with a family history of heart disease, you might undergo PRS to understand your risk better and start working with your doctor earlier on tailored preventative strategies, said Tadwalkar.

But, Barnes explained, it's not only those without signs of heart disease who can undergo PRS testing. The results can be used to help establish treatment and management plans to help slow disease progression.

As an example, patients who already have related concerns, such as high levels of ‘bad’ LDL cholesterol, may use PRS to help them and their doctor decide when to introduce medications, he said.

It's worth noting that polygenic risk score testing isn't currently available to many people. Furthermore, for those who can access this testing, Barnes revealed that it isn't free and insurance doesn't cover the costs.

If you go down the polygenic risk score route, it shouldn't be used as the sole method to determine your risk level and potential treatment plan.

Instead, this testing should be conducted as part of a more comprehensive evaluation, Tadwalkar said, also involving traditional risk factors, clinical history, and other diagnostic tests.

Using a polygenic risk score "is more commonly used in research settings and specialized clinics," said Tadwalkar. However, it will likely play a much larger role in clinical settings in the future, "especially as the technology is further refined and validated," he added.

As research continues to explore its reliability — particularly compared to other testing approaches — experts will better understand precisely how polygenic risk scores might contribute to diagnosing and treating heart disease.

Plus, "as new therapies that target cholesterol and help to reduce the risk of heart attack or stroke become available, the role of PRS [polygenic risk score] testing may become clearer," Barnes added.

Further improvements are undoubtedly needed in various aspects of polygenic risk scores testing before it can become a mainstream approach.

But, "in theory, the integration of PRS [polygenic risk score] testing into routine clinical practice has the potential to revolutionize cardiovascular risk assessment," concluded Tadwalkar.

Physicians are looking at a new tactic to determine a person's risk of heart disease. They are now considering if more people should undergo polygenic risk score testing, which analyzes a person's DNA. Experts say people with a family history of heart disease or high cholesterol levels may want to get tested.