Long-term trends in cardiovascular disease mortality and association with respiratory disease

The recent decline in cardiovascular disease mortality in Western countries has been linked with changes in life style and treatment. This study considers periods of decline before effective medical interventions or knowledge about risk factors. Trends in annual age-standardized death rates from cerebrovascular disease, heart disease and circulatory disease, and all cardiovascular disease are reviewed for three phases, 1881-1916, 1920-1939, and 1940-2000. There was a consistent decline in the cerebrovascular disease death rate between 1891 and 2000, apart from brief increases after the two world wars. The heart disease and circulatory disease death rate was declining between 1891 and 1910 before cigarette smoking became prevalent. The early peak in cardiovascular mortality in 1891 coincided with an influenza pandemic and a peak in the death rate from bronchitis, pneumonia and influenza. There is also correspondence between short-term fluctuations in the death rates from these respiratory diseases and cardiovascular disease. This evidence of ecological association is consistent with the findings of many studies that seasonal influenza can trigger acute myocardial infarction and episodes of respiratory infection are followed by increased risk of cardiovascular events. Vaccination studies could provide more definitive evidence of the role in cardiovascular disease and mortality of influenza, other viruses, and common bacterial agents of respiratory infection.