We evaluated coronary artery calcium (CAC) and exercise test results (cardiorespiratory fitness [CRF] and abnormal exercise tests) as predictors of coronary heart disease (CHD). We have nearly 5,000 persons with 2 electron beam tomography (EBT) scans, which allowed us to evaluate change in CAC as a predictor of incident CHD. Finally, we evaluated abdominal adiposity (visceral and subcutaneous fat) as predictors of CHD and diabetes. CAC and abdominal adiposity were assessed by EBT, and exercise test results were derived from a maximal treadmill exercise test.
The study group was approximately 35,000 women (n=12,250) and men (n=22,750) who had at least 1 EBT evaluation during 1995-2002. Follow-up is for an average of 3.1 yrs, with 38,548 woman-yrs and 70,654 man-yrs of observation by the end of the study. Primary outcomes were combined fatal and nonfatal CHD (MI, fatal CHD, and revascularization procedures) and diabetes. Secondary outcomes included all-cause mortality and stroke. All participants had CAC, abdominal adiposity, and outcome ascertainment, as mentioned above. An additional strength of the study was that more than 19,000 of the study participants received a comprehensive medical evaluation. This exam provided an extensive database of medical history, health habits, physical examination, and clinical variables including blood pressure, cholesterol, HDL-C, triglyceride, plasma glucose, and resting and exercise ECGs.
We evaluated whether medical history or measured conventional risk factors for CHD affect the association between the primary exposures and CHD or diabetes. We evaluated the independent predictive value of CAC, CRF, abnormal exercise test results, and the combination of these in relation to incident CHD. This study will make important contributions to the role of the primary exposures as predictors of CHD and diabetes, and implications for the prevention of these diseases.
|Cheng YJ, Church TS, Kimball TE et al.||Comparison of coronary artery calcium detected by electron beam tomography in patients with to those without symptomatic coronary heart disease. Am J Cardiol 2003;92:498-503.||Read Abstract|
|LaMonte MJ, FitzGerald SJ, Church TS et al.||Coronary artery calcium score and coronary heart disease events in a large cohort of asymptomatic men and women. Am J Epidemiol. 2005;162:421-429.||Read Abstract|
|LaMonte MJ, Fitzgerald SJ, Levine BD, Church TS, Kampert JB, Nichaman MZ, Gibbons LW, Blair SN.||Coronary artery calcium, exercise tolerance, and CHD events in asymptomatic men.Atherosclerosis. 2006 Nov;189(1):157-62.||Read Abstract|