Risk factors

Risk factors for atherosclerosis are generally risk factors for myocardial infarction:^{[citation needed]}

• Diabetes (with or without insulin resistance) - the single most important risk factor for ischaemic heart disease (IHD)
• Tobacco smoking
• Hypercholesterolemia (more accurately hyperlipoproteinemia, especially high low density lipoprotein and low high density lipoprotein)
• Low HDL
• High Triglycerides
• High blood pressure
• Family history of ischaemic heart disease (IHD)
• Obesity^[27] (defined by a body mass index of more than 30 kg/m², or alternatively by waist circumference or waist-hip ratio).
• Age: Men acquire an independent risk factor at age 45, Women acquire an independent risk factor at age 55; in addition individuals acquire another independent risk factor if they have a first-degree male relative (brother, father) who suffered a coronary vascular event at or before age 55. Another independent risk factor is acquired if one has a first-degree female relative (mother, sister) who suffered a coronary vascular event at age 65 or younger.
• Hyperhomocysteinemia (high homocysteine, a toxic blood amino acid that is elevated when intakes of vitamins B₂, B₆, B₁₂ and folic acid are insufficient)
• Stress (occupations with high stress index are known to have susceptibility for atherosclerosis)
• Alcohol Studies show that prolonged exposure to high quantities of alcohol can increase the risk of heart attack
• Males are more at risk than females.^[20]

Many of these risk factors are modifiable, so many heart attacks can be prevented by maintaining a healthier lifestyle. Physical activity, for example, is associated with a lower risk profile.^[28] Non-modifiable risk factors include age, sex, and family history of an early heart attack (before the age of 60), which is thought of as reflecting a genetic predisposition.^[20]
Socioeconomic factors such as a shorter education and lower income (particularly in women), and unmarried cohabitation may also contribute to the risk of MI.^[29] To understand epidemiological study results, it's important to note that many factors associated with MI mediate their risk via other factors. For example, the effect of education is partially based on its effect on income and marital status.^[29]
Women who use combined oral contraceptive pills have a modestly increased risk of myocardial infarction, especially in the presence of other risk factors, such as smoking.^[30]
Inflammation is known to be an important step in the process of atherosclerotic plaque formation.^[31] C-reactive protein (CRP) is a sensitive but non-specific marker for inflammation. Elevated CRP blood levels, especially measured with high sensitivity assays, can predict the risk of MI, as well as stroke and development of diabetes.^[31] Moreover, some drugs for MI might also reduce CRP levels.^[31] The use of high sensitivity CRP assays as a means of screening the general population is advised against, but it may be used optionally at the physician's discretion, in patients who already present with other risk factors or known coronary artery disease.^[32] Whether CRP plays a direct role in atherosclerosis remains uncertain.^[31]
Inflammation in periodontal disease may be linked coronary heart disease, and since periodontitis is very common, this could have great consequences for public health.^[33] Serological studies measuring antibody levels against typical periodontitis-causing bacteria found that such antibodies were more present in subjects with coronary heart disease.^[34] Periodontitis tends to increase blood levels of CRP, fibrinogen and cytokines;^[35] thus, periodontitis may mediate its effect on MI risk via other risk factors.^[36] Preclinical research suggests that periodontal bacteria can promote aggregation of platelets and promote the formation of foam cells.^[37][38] A role for specific periodontal bacteria has been suggested but remains to be established.^[39] There is some evidence that influenza may trigger a acute myocardial infarction.^[40]
Baldness, hair greying, a diagonal earlobe crease (Frank's sign^[41]) and possibly other skin features have been suggested as independent risk factors for MI.^[42] Their role remains controversial; a common denominator of these signs and the risk of MI is supposed, possibly genetic.^[43]
Calcium deposition is another part of atherosclerotic plaque formation. Calcium deposits in the coronary arteries can be detected with CT scans. Several studies have shown that coronary calcium can provide predictive information beyond that of classical risk factors.^[44][45][46]
The European Society of Cardiology and the European Association for Cardiovascular Prevention and Rehabilitation have developed an interactive tool for prediction and managing the risk of heart attack and stroke in Europe. HeartScore is aimed at supporting clinicians in optimising individual cardiovascular risk reduction. The Heartscore Programme is available in 12 languages and offers web based or PC version.^[47]