How to Prevent a Heart Attack (In Those with Heart Disease)

Posted By Donna Alvarado, Medical Editor

Presented by David J. Maron, MD
Director, Stanford Prevention Research Center
Director, Preventive Cardiology

January 23, 2020

You might feel pretty good, at least for someone your age. But when you climb the stairs, you feel a tightness, a squeezing, a heaviness in your chest. It’s not exactly pain, but it’s uncomfortable.

That could be the tipoff to the discovery that you have heart disease. At that point, there’s still time to keep it from leading to a heart attack.

That’s where David J. Maron, MD, comes in. He helps people figure out the most important steps to prevent a heart attack even if they already have heart disease. The steps can also help those who have already had a heart attack and want to prevent a second one.

Early warning

Many people don’t realize they have heart disease until they have an episode of chest tightness or heaviness. It can come from climbing the stairs, walking up a hill, or when they get upset emotionally. The chest symptoms are called angina.

Angina is the symptom that arteries leading to your heart have become clogged, slowing down the blood flow. The process causing the narrowed arteries is called atherosclerosis. It’s one of the most common conditions linked to aging.

Unless you take steps to stop atherosclerosis from getting worse, your risk for a heart attack may rise. Studies show people can turn that around with the right medical help.

“If you put it all together with lifestyle and the right medicines, you can do quite a lot to prevent having a heart attack,” Dr. Maron said at a presentation to the Stanford Health Library.

How disease starts

As people age, often the lining of their blood vessels changes. The lining accumulates material called plaque, consisting of lipid (fat) particles, cholesterol, inflammatory cells, and perhaps some calcium. Over time, that narrows the arteries and limits blood flow.

If someone also has risks from other health problems or from the way they live, that can aggravate the plaque buildup. Over time, the plaque develops a fibrous cap that encapsulates it and acts as a barrier between the fatty buildup and the inside of the artery.

If the fibrous cap ruptures, blood mixes with the plaque and can form a blood clot. If the blood clot is small, it may eventually dissolve and heal on its own. If not, the clot can grow bigger and blocks the inside of the blood vessel so blood can’t flow to the heart. That causes a heart attack.


Angina is a symptom that a blood vessel is at least partly clogged with plaque and that’s limiting blood flow to the heart. At that point, a person still has multiple ways to reverse that condition.

Anyone who has symptoms of a heart attack should see a doctor immediately. “You go to the hospital as fast as you can,” Dr. Maron said. Your doctors may recommend getting a stent, which is a small device inserted inside an artery. The stent props open the artery and gets the blood flowing to reduce damage to the heart.

Those who haven’t yet had a heart attack, but have symptoms of angina, should see a doctor soon, Dr. Maron said. Getting good medical help is important for people who want to prevent a first — or a second — heart attack.

Stress test

Your doctor’s first step in medical care is often to do a stress test. For anyone with significant heart disease, the results are going to be abnormal, Dr. Maron said. If so, your doctor may send you for a next step, a procedure that opens up a blocked artery.

First the doctor gets pictures of the artery to see if it is narrowed. This procedure is called a coronary angiogram. If a narrowing is seen, a stent is often inserted into the artery to widen the inside. That usually relieves angina symptoms.

Over time, the spot that was treated begins to heal. Sometimes that leaves an area that is scarred, but is less likely to cause any clogging in the future. Your doctor should prescribe high-intensity statins, to limit future deposits and strengthen the fibrous cap so it doesn’t rupture.

Next steps

Whether you’ve gotten a stent to ease angina, or recovered from a heart attack, there are things you can do to prevent a heart attack in the future. The “preventive interventions” fall into 2 categories: changing the way you live and taking medicine to lower “risk factors” like smoking, high cholesterol, and high blood pressure.

Both steps are important. According to a study that Dr. Maron published, people with heart disease who reach all of their risk factor goals after an average 7 years of follow-up have about a 70 percent lower risk of dying than people who don’t.

“What you can’t change are things like your age and your sex, and your history and your family,” Dr. Maron said. Those factors may raise your risk for heart attack, but there are still ways you can reduce your overall risk.

The things you can change, with medicine or by the way you live, are:

  • Smoking
  • High blood pressure: Get it to 130/80 or less
  • High cholesterol or triglycerides: Lower them with nutrition, exercise, and medicine
  • Diabetes: Control it with medicine and good health habits
  • Eating habits: Have plenty of fruits and vegetables with a Mediterranean food plan
  • Exercise: Be active at least 30 minutes a day, at least 5 times a week

Extra weight: Lose those extra pounds with diet and exercise

Stents not superior

Although many people get stents in their arteries to treat heart disease, the COURAGE trial followed people for 4.5 years and found that stents weren’t any better than lifestyle change and medicine to prevent heart attacks or death.

However, COURAGE found that people who change their health habits and controlled their risk factors — to start exercise, lose weight, lower cholesterol or blood pressure, stop smoking, and control diabetes — also lowered their risk for dying. Each “risk factor goal,” or health habit improved, made a difference.

“For every risk factor goal attained, there was a 16 percent further reduction in the risk of dying,” Dr. Maron said.

Exercise benefit

“Physical activity had the greatest benefit” after smoking cessation, Dr. Maron said. “After that came lowering blood pressure below 130.”

Having said that, Dr. Maron said, there are also 2 kinds of drugs that all people with heart disease should take: low-dose aspirin (to prevent blood clots), and statins (to lower cholesterol).

Many patients ask whether taking fish oil supplements — or a prescription drug with fish oil — can help. Dr. Maron said there are 2 studies that found a specific type of fish oil contained in a prescription drug are effective in preventing heart disease.

This specific medication is called icosapent ethyl. The benefit was found in people who didn’t have heart disease as well as those who did.

Prescription vs non-prescription

That doesn’t mean that non-prescription fish oil supplements found on the shelves in many drugstores have the same benefit. “It’s anyone’s guess if over-the-counter fish oil is as good,” Dr. Maron said.

“I can’t in good conscience say it’s just as good to take over-the-counter fish oil. Unfortunately, I would say you might be wasting your money.”

Dr. Maron summarized the best strategy known to date for preventing heart attacks and early deaths:

Walking, if you can, or other exercise with moderate intensity

  • Taking medicine to control blood pressure
  • Taking medicine to lower cholesterol
  • Eating healthy food
  • Not smoking

“Those simple things can dramatically reduce the chances of dying if you have heart disease,” he said.

“None of us gets out of here alive, ultimately,” Dr. Maron said. “But we want to be as healthy as we can, and be as free of symptoms for as long as we can.”

For more information:

Stanford Prevention Research Center

David J. Maron, MD

Stanford Health Library can do the searching for you. Send us your medical questions.