Before 1900, infectious diseases and malnutrition were the most common causes of death. However, as robust economies developed, the common causes of death in these economies shifted to cardiovascular diseases and cancer. This shift was largely due to improved nutrition and public health measures. At the same time, easier access to less expensive foods with a higher fat content has led to an increase in total caloric intake and continued mechanization has resulted in a lower daily caloric expenditure. This combination has produced a more sedentary lifestyle leading to a higher mean body mass index, blood pressure, serum lipid levels, and blood sugar. In 2000, cardiovascular disease accounted for nearly half of all deaths in developed countries and 25% of the deaths in developing countries. As this trend continues in developing countries, cardiovascular disease will become the dominant cause of death by 2020, accounting for at least one in every three deaths worldwide. By 2020, it is predicted that cardiovascular disease will claim 25 million lives annually and that coronary artery disease (CAD) will surpass infectious disease as the worldÔÇÖs number one cause of death and disability.
Because the prevalence of CAD is so high, preventing even a small proportion of cases could save lives, avoid considerable disability, and substantially reduce healthcare expenditures. In addition, measures that prevent CAD may diminish other manifestations of atherosclerosis, such as stroke and peripheral artery disease, and may have a favorable impact on hypertension, diabetes, cancer, cognitive function, depression, and other chronic conditions. Thus, the use of affordable preventive strategies should have high priority in both developed and developing countries.
Efforts to prevent cardiovascular disease are commonly classified into primary or secondary prevention. Primary prevention refers to therapeutic interventions applied to individuals without overt manifestations of disease although individuals may be classified as low- or high-risk individuals. In this circumstance, the goal is to lower the individualÔÇÖs risk of suffering a future cardiovascular event. Secondary prevention refers to therapeutic interventions applied to individuals who have already experienced some clinical manifestation of disease, such as a myocardial infarction. In this circumstance, the goal is to reduce the individualÔÇÖs risk of suffering a second cardiovascular event.