BACKGROUND:

Coronary heart disease (CHD) and other thrombosis related disorders are a major source of morbidity and mortality in the United States and the world. To a certain extent they are diseases of the elderly, with the majority of overt CHD occurring in persons over the age of 65. Recently, fibrinogen and factor VII have been implicated as independent CHD risk factors in middle age populations, although causative roles have not been established. These studies increased understanding of the relationship of thrombosis to cardiovascular risk.

DESIGN NARRATIVE:

Beginning in 1992, the study tested the hypothesis that measures of coagulation and fibrinolysis correlated with the incidence of coronary heart disease (CHD) and other thrombosis related disorders, and identified those individuals at greatest risk, using the Cardiovascular Health Study (CHS) and Honolulu Heart Program (HHP) populations. These two genetically distinct populations had different event rates for CHD, and offered a unique opportunity to test associations that were uncovered by comparing results across populations. The study examined selected measures of coagulation and fibrinolysis in individuals 65 years and older: measures of pro-coagulation (factor antigen VII, prothrombin fragment 1.2, fibrinopeptide A and thrombin

• antithrombin III complex), measures of coagulation inhibition (protein C and protein S, antithrombin III, and the lipoprotein associated coagulation inhibitor (LACI), and measures of fibrinolysis (plasminogen activator inhibitor-1 (PAI-1), tissue plasminogen activator-PAI-1 complex, plasmin-alpha-2 antiplasmin complex, and Lp(a).

A case/control design was used to determine the relationship between the above measurements and the incidence of CHD (and other thrombosis related disorders). The short and medium term biological variability of the above measures was determined to aid in interpretation of observed differences.

Finally, the distribution of the above measurements was established in both cohorts and their relationships to other variables in the extensive CHS and HHP data bases ascertained.

The study was renewed in 1999 to determine inflammation markers over time in cardiovascular disease.