Background: Throughout the past 50 years, heart disease has been the leading cause of death in the United States. Although declines in coronary heart disease (CHD) mortality have been noted, there is still uncertainty about the magnitude of the decline and whether the trend is similar for sudden cardiac death (SCD).
Methods and results: We examined temporal trends in SCD and nonsudden CHD death in the Framingham Heart Study original and offspring cohorts from 1950 to 1999. SCD was defined as a death attributed to CHD with preceding symptoms that lasted less than 1 hour; all deaths were adjudicated by a physician panel. Log-linear Poisson regression was used to estimate CHD mortality and SCD risk ratios (RRs); RRs were adjusted for age and gender. There were 811 CHD deaths: 453 nonsudden and 358 SCDs. Ninety-one (20%) of nonsudden CHD deaths and 173 (48%) of SCDs were in subjects free of antecedent CHD. From 1950-1969 to 1990-1999, overall CHD death rates decreased by 59% (95% CI 47% to 68%, P(trend)<0.001). Nonsudden CHD death decreased by 64% (95% CI 50% to 74%, P(trend)<0.001), and SCD rates decreased by 49% (95% CI 28% to 64%, P(trend)<0.001). These trends were seen in men and women, in subjects with and without a prior history of CHD, and in smokers and nonsmokers.
Conclusions: The risks of SCD and nonsudden CHD mortality have decreased by 49% to 64% over the past 50 years. These trends were evident in subjects with and without heart disease, which suggests important contributions of primary and secondary prevention to the decreasing risk of CHD death and SCD.