Strong Legs Linked to Better Outcomes After Heart Attack

People with strong legs may be 41% less likely to develop heart failure after a heart attack, a new study finds.

Myocardial infarction, also called a heart attack, is the most common cause of heart failure. About 6% to 9% of heart attack patients develop this lifelong condition in which the heart muscle can't pump enough blood to meet the body's needs for blood and oxygen.

The new study presented at a scientific congress of the European Society of Cardiology (ESC) examined the hypothesis of whether leg strength can be associated with a lower risk of developing heart failure after acute myocardial infarction.

The researchers looked at the data of 932 patients hospitalized between 2007 to 2020 with acute myocardial infarction. The participants did not have a history of heart failure before the admission and did not develop heart failure complications during their hospital stay. The average age of the patients was 66 years, and most (81%) of them were men.

Leg strength was evaluated by measuring the patient's maximal quadriceps strength on each leg. They sat on a chair and contracted the quadriceps muscles as hard as possible for five seconds. Simultaneously, a handheld dynamometer attached to the ankle recorded the maximum value in kilograms. Strength was expressed relative to body weight.

A total of 451 patients had low quadriceps strength, and 481 had high strength. During an average follow-up of 4.5 years, the incidence of heart failure was 10.2 per 1,000 person-years in patients with high leg strength compared to 22.9 per 1,000 person-years in those with low strength.

After adjusting for factors linked with the development of heart failure following myocardial infarction, high leg strength was associated with a 41% lower risk of developing heart failure.

"Our study indicates that quadriceps strength could help to identify patients at a higher risk of developing heart failure after myocardial infarction who could then receive more intense surveillance. The findings need to be replicated in other studies, but they do suggest that strength training involving the quadriceps muscles should be recommended for patients who have experienced a heart attack to prevent heart failure," says study author Kensuke Ueno, a physical therapist at the Kitasato University Graduate School of Medical Sciences, Sagamihara, Japan.

Ways to prevent a heart attack

A heart attack occurs when a blocked artery prevents the blood flow that carries oxygen from reaching a heart muscle. About 805,000 people in the United States have a heart attack each year, with one in four happening to people who have already had a heart attack.

According to the American Heart Association, the key risk factors for a heart attack are:

• Increasing age. The average age for men at the time of their first heart attack is 65.5 years, and 72 years for women.
• Gender. Although men are at a higher risk of a heart attack and have attacks earlier in life, women are more likely to die.
• Heredity. Children of parents with heart disease are at a higher risk of developing the condition, which may lead to a heart attack.
• Race. In the U.S., heart disease disproportionately affects Black people, and the rates are also higher among Mexican American, American Indian, Native Hawaiian, and some Asian American people.

The good news is that some risk factors for heart attacks can be controlled. Such factors include:

• Tobacco smoke and vaping. Quit smoking and avoid exposure to secondary smoke.
• High blood cholesterol. Have your cholesterol checked every four to six years and follow the doctor's recommendations if the levels are elevated.
• High blood pressure. It can be managed by maintaining a healthy weight, exercising, following a healthy diet, managing stress, and following a balanced diet.
• Physical activity. Aim for at least 150 minutes a week of moderate-intensity physical activity or 75 minutes of vigorous-intensity physical activity.

Even though the study associates leg strength with better outcomes after myocardial infarction, heart health involves a combination of both hereditary factors and lifestyle choices.