Has the recent US decline in coronary heart disease (CHD) mortality increased life expectancy? The authors estimated the number of life-years gained from CHD treatments and changes in the prevalence of cardiovascular disease risk factors for the US population between 1980 and 2000. The previously validated IMPACT model was used to integrate data on numbers of CHD patients, treatment uptake, treatment effectiveness, population risk factor trends, and median survival among US adults. There were 308,900 fewer CHD deaths in 2000 among Americans aged 25-84 years than if 1980 mortality rates had applied. These 308,900 fewer deaths represented approximately 3,147,800 life-years gained (sensitivity analysis range, 2,448,900-3,744,900). Treatments for patients accounted for approximately 1,092,400 (751,700-1,387,000) life-years gained, whereas changes in the prevalence of population risk factors accounted for a gain of 2,055,500 (1,697,200-2,346,300) life-years. However, the 2,770,500 life-years gained through decreased levels of smoking, cholesterol, blood pressure, and physical inactivity were diminished by a loss of 715,000 life-years attributable to increased rates of obesity and diabetes. Therefore, modest reductions in the prevalence of several major cardiovascular disease risk factors accounted for more than twice as many life-years gained as did treatments. Unfortunately, these gains were partially offset by substantial increases in obesity and diabetes.