For decades it’s been understood that certain risk factors explain the majority of cardiovascular events, until several recent studies claimed that coronary heart disease can develop without them. But a new large study calls this into question, finding that indeed 99% of all cardiac events resulted in patients with four modifiable risk factors.

In the study, published last month in The Journal of the American College of Cardiology, nearly all of the nine million participants had at least one traditional risk factor including high blood pressure, high cholesterol, prior tobacco use, or high blood sugar before having a heart attack, heart failure, or stroke.

The study authors considered suboptimal risk factors to be blood pressure > 120/80 mm Hg, total cholesterol > 200 mg/dL, fasting glucose > 100 mg/dL, as well as past or present tobacco use.

“The results were almost identical between the Korean and US cohorts in that traditional risk factors were universally present before cardiac events,” said Hokyou Lee, MD, PhD, lead study author and an associate professor of preventive medicine at Yonsei University College of Medicine in Seoul, Republic of Korea. “That consistency across very different populations and health systems makes our findings especially strong.”

Lee said high blood pressure stood out as the most common risk factor in patients followed by high cholesterol. Smoking was the most potent risk factor in that it seemed to cause the most damage. Additionally, risk factors often came in pairs: 93-97% of patients had two or more of them.

Controlling Risk Factors Before They Become a Problem

It’s not surprising that these risk factors cause heart attack, stroke, and heart failure because of what they do to the cardiovascular system, said Bharat Sangani, MD, a cardiologist with practices in Gulfport, Mississippi and Dallas.

Hypertension, for example, constantly elevates force against the blood vessel walls, which damages them and causes the heart to work harder pumping blood. High cholesterol forms plaque in the arteries which hardens and causes atherosclerosis. What’s more, tobacco is an irritant that damages the endothelium, the inner lining of the blood vessels, causing inflammation. Similarly, high blood sugar causes oxidative stress which also leads to inflammation.

“The blood vessels that supply blood to the heart muscle are 2-3 mm across — a small diameter on which your life depends,” said Sangani. This means that any irritant that causes the blood vessels to stiffen, harden, or become blocked can have a deadly impact on your cardiovascular system.

The study defined “suboptimal” as low enough that most people would have at least one risk factor. For example, stage I hypertension is 130-139 systolic or 80-89 diastolic and high cholesterol is 240 mg/dL, much higher than suboptimal levels listed in the study.

This makes the study slightly misleading because the levels only had to be minimally elevated, but it was also helpful because it can push younger patients or those with only minimally elevated risk factors to turn things around through diet and exercise, said Michael Joseph Blaha, MD, MPH, director of Clinical Research for the Ciccarone Center for the Prevention of Cardiovascular Disease, Johns Hopkins University School of Medicine, Baltimore.

“The important message here is that we should refrain from saying that your levels aren’t that elevated to instead tell patients that they should try and get them to optimal levels,” said Blaha. Making lifestyle changes before patients fall into a more dangerous cholesterol, glucose, and blood pressure range may stave off problems down the road.

While it isn’t included in the study, excess weight also makes a patient more prone to cardiac events because it causes the above risk factors to become elevated. A study published last year in the journal Circulation, found that deaths from obesity-related cardiovascular disease had increased in recent years.

The ability to manage stress may also affect the risk for cardiac events, said Sangani. A study published this year in the Journal of Psychosomatic Research found that a higher level of neuroticism, meaning patients who are more likely to experience negative emotions like anxiety, anger, and sadness, also put them at an increased risk of having a heart attack.

How to Help Patients Manage Risk Factors

The findings suggest that these risk factors are actually present most of the time and may go undiagnosed, especially if they’re just below the usual clinical thresholds.

“This means that checking blood pressure, cholesterol, and blood sugar at every medical visit and recognizing the gap between optimal and diagnostic levels is important,” said Lee.

The use of tobacco is an obvious risk factor and patients should be advised to abstain. Additionally, moderate exercise of at least 30-60 minutes per day and eating a heart healthy diet that’s low in saturated and trans-fats, sodium, highly processed foods, and alcohol is also key to heart.

Patients should maintain a healthy weight, manage stress, and manage genetic risk factors. Some patients are prone to having elevated cholesterol and blood pressure because of their family history and no matter what lifestyle changes they make, statins for hypertension as well as cholesterol-lowering medications may be required.

What’s more, getting vaccinated against infections like COVID-19, influenza, Tdap, and pneumococcal pneumonia is also important. Infections like COVID can damage heart cells, which in turn cause inflammation and lead to heart disease. According to a study published in the 2023 edition of the journal Circulation, “infectious diseases [are] short- and long-term risk factors for incidence of major cardiovascular events.”

While initially adopted for controlling blood sugar and weight loss, research has shown that GLP-1s can help reduce high blood pressure by suppressing the sympathetic nervous system and indirectly through increasing weight loss. They’ve proven to be a powerful weapon in controlling risk factors when patients can’t get them under control on their own, said Sangani. They may also help boost lipid metabolism in the liver and intestines which, along with weight loss, helps to lower cholesterol.

Taking steps early on to try and get your levels under control is the best tool for ensuring that patients don’t encounter cardiac events later on, said Blaha.

“Cardiovascular disease doesn’t come out of nowhere and patients should be aware of even suboptimal risk factors,” said Blaha.