A first heart attack is a serious, life-changing event, although most people now survive them. But a new study underscores the importance of doing everything possible to avoid another one.

"It's like taking another hit," said Dr. Umesh Khot, a cardiologist at the Cleveland Clinic in Ohio. "One heart attack is a lot, and having another one is a big hit on the heart."

Khot is lead author of a study that examined the outcomes of patients who suffered a second heart attack – formally known as recurrent myocardial infarction – within 90 days of being discharged from the hospital after the first heart attack. The study was published Aug. 2 in the Journal of the American Heart Association.

Khot's team examined the data from 6,626 admissions for heart attack at the Cleveland Clinic from 2010 through 2017. While only about 2.5% of them were readmitted within 90 days with another heart attack, nearly 50% of those people would die within five years.

"What we've done for the first time is to analyze a large population of patients to find this uncommon recurrence and describe it," he said. "It's important for the cardiology community to understand that this phenomenon happens, and when it does it has significant implications for long-term mortality."

One surprise in the results, Khot said, was that the greatest risk of an early recurrent heart attack occurred in the first two weeks, "which means you have to really get on top of this early on in terms of treatment."

Heart disease is the leading cause of death in the United States and worldwide. About 805,000 people in the United States have a heart attack each year – one-fourth of which are recurrent heart attacks, according to statistics from the American Heart Association.

A heart attack occurs when blood flow to the heart is blocked, damaging or destroying part of the heart muscle. Survival can depend on how much damage is done, and how quickly it can be treated with medication and surgical procedures.

To prevent a recurrent heart attack, experts recommend following professional advice regarding medication and making lifestyle changes to reduce risk factors, including exercising, eating a heart-healthy diet, losing weight, controlling blood pressure and quitting smoking.

The new study is observational, calculating the frequency and dangers of early recurrent heart attacks.

"We didn't answer the question of whether we can change this beyond the regular care that we do," Khot said. "But it helps us emphasize key messages in terms of adherence to medicines, following up with your care team and good [health] practices in general."

Dr. Nieca Goldberg, a cardiologist and clinical associate professor at the New York University Grossman School of Medicine, agreed.

"This is an important reminder," said Goldberg, who was not involved in the study. "I think all of us in the cardiology community have to be a little more vigilant about reminding people the importance of following through with these lifestyle changes and medications, so we reduce the risk of recurrent heart attacks."

Both doctors acknowledge the changes aren't always easy.

"Some people are dramatic in terms of the changes they make, some are middle of the road and some people don't change anything," Khot said. "And now with COVID-19, we're very concerned that some patients have left the health care system and are not getting follow-up care."

After a first heart attack, Goldberg said, "Some people feel a little overwhelmed with all the things that are thrown at them – procedures, cardiac rehab, their diet, even coping with anxiety over this sudden illness."

"It's a lot to handle," she said. "Maybe we need to do better to explain why these things are so important. With a heart attack, it's not necessarily one and done."