A risk factor indicates a higher probability of a heart attack, but it does not make a heart attack inevitable. In general, however, the more risk factors you have, the greater your vulnerability. If you have already had a heart attack, have diabetes, or have atherosclerosis elsewhere in your body —a previous stroke or peripheral arterial disease (narrowing of arteries in the legs) —you are at particularly high risk for a heart attack. Heart attack risk factors can be divided into two groups: those that cannot be changed and those that can. Here, we take a look at risk factors that cannot be changed:
Heart Attack Risk Factors That Cannot Be Changed
Even though nothing can be done to alter the following risk factors, their presence means that you should make an extra effort to control the risk factors that are preventable or treatable.
Age and Heart Attack
Your heart attack risk increases with age, especially after age 45 in men and after age 55 in women. The average age for a first heart attack is age 65 for men and age 70 for women.
Gender and Heart Attack
Before age 50, heart attacks are far more common in men than in women, largely because of the protective effect of the female hormone estrogen. After menopause, however, naturally decreasing levels of estrogen lead to an increase in LDL cholesterol levels, a drop in HDL cholesterol, and thus a rise in a woman’s risk of a heart attack. If a woman experiences menopause before age 40, because she has had her ovaries removed or has experienced spontaneous ovarian failure, she is at much higher risk for a heart attack than the average woman her age. After age 65, heart attacks occur in one in four women, affecting many more women than breast cancer. In fact, just as many postmenopausal women as men die of a heart attack each year.
Family History and Race
If your father, brother(s), or son(s) had a heart attack before age 55 or your mother, sister(s), or daughter(s) had one before age 65, you are at increased risk for a heart attack. A positive family history is an indication that you may have a genetic tendency to develop high blood pressure or high cholesterol or triglyceride levels. It also means that you have an increased risk of plaque buildup in the coronary arteries. Race affects your heart attack risk as well. In general, blacks have a greater chance of a heart attack than whites, mostly because of higher rates of elevated blood pressure, diabetes, and obesity. The risk of a heart attack also is generally higher in Latinos, Native Americans, and Native Hawaiians than in whites.
Personal History of Cardiovascular Disease
If you have already had a heart attack, your risk of having another is substantial. About 20% of men and 25% of women suffer a second heart attack within five years of their first attack. Even if you have not had a heart attack, being diagnosed with coronary heart disease —the buildup of plaques in the coronary arteries —raises your risk. These plaques can rupture, triggering the formation of a blood clot that could lead to a heart attack.
Atherosclerosis can also occur in other arteries of the body. For example, atherosclerosis in the carotid arteries, which supply blood to the brain, can lead to a stroke. Plaques in the arteries of the legs can cause peripheral arterial disease, an illness that results in intermittent claudication (painful leg cramps during physical exertion). In addition, atherosclerosis in the aorta can produce an abdominal aortic aneurysm (enlargement or weakening of the wall of the abdominal aorta). Individuals with these conditions invariably have significant atherosclerosis in their coronary arteries as well, and thus they are also at heightened risk for a heart attack.
Blood-clotting Factors and Heart Attack
The formation of a blood clot is a complex process that involves a large number of proteins called clotting factors. High blood levels of two of these clotting factors —fibrinogen and factor VII —are associated with an increased risk of a heart attack. Elevated levels of other substances involved in blood clotting also can increase your heart attack risk. One of these substances is plasminogen activator inhibitor type 1 (PAI-1), which interferes with the breakdown of blood clots.
Certain variant forms of genes also can increase heart attack risk. Individuals with an inherited variation of a platelet antigen gene — called the PLA2 variant —tend to have heart attacks at an earlier age than people who do not have this gene variant. The PLA2 variant is also known as the Grinkov risk factor, named after Olympic skater Sergei Grinkov, who died in 1995 at age 28 of a massive heart attack and was found to have the PLA2 variant.
Kidney Disease and Heart Attack
Adults with kidney disease have a high risk of heart attacks. In fact, if you have kidney disease you’re more likely to die of a heart attack than of kidney disease itself. One reason is that people with kidney disease are likely to have other heart attack risk factors, such as high blood pressure, elevated cholesterol and triglyceride levels, diabetes, a sedentary lifestyle, and older age. They also tend to have high levels of homocysteine, an amino acid that promotes atherosclerosis. In addition, their blood platelets tend to clump and form clots. Kidney disease also seems to elevate the risk of a heart attack independent of these other risk factors. The National Kidney Foundation recommends screening people with kidney disease for other heart attack risk factors and treating these risk factors aggressively.