May 2009

Document Type


Degree Name



Dept. of Public Health and Preventive Medicine


Oregon Health & Science University


Background: Coronary Artery Disease (CAD) is highly prevalent in the the United States and involves the progression of calcified atherosclerotic plaque in patients’ coronary arteries.1 Although many people adopt lifestyle changes to reduce CAD risk factors, the ability to alter calcified plaque burden is not well understood. Recent studies find Multidetector Computed Tomography (MDCT) to be an accurate and non-invasive method for CAD imaging and quantification of calcified atheroslcerotic plaque, measured as a Coronary Atery Caclium (CAC) score. Objectives: this study aims 1) to determine the magnitude and direction of CAC score change using 64-MDCT cardiac scans at baseline and 1-year post lifestyle modification, 2) to determine whether CAC progression is associated with the lowering of known CAD risk factors, including LDL cholesterol, systolic blood pressure, diastolic blood pressure, BMI, and functional capacity and 3) to determine which CAD risk factors are most predictive of CAC score changes through multivariable analysis. Methods: Baseline and 1-year MDCT cardiac scans measured participant CAC progression and CAD risk factors were assessed at baseline and 12-weeks. The relationship between change in CAD risk factors and change in CAC were evaluated through multivariable regression analyses. Results: Among participants with complete follow-up (n=22), 2 (9.1%) participants experienced reductions of CAC, and nearly 60% experienced greater than 20% CAC progression. None of the variables of interest was found to be significantly predictive of CAC progression in either multivariable linear or logistic regresison. Age was found to significantly predict CAC progression and a significant interaction between age and gender was observed. When assessing predictors of 1-year CAC score, baseline CAC score was statisitcally significant (p<0.001). Conclusion: Age, gender and baseline CAC score are most significantly predictive of CAC progression and future CAC scores. Future studies involving Wellspring Heart may find significant associations between improvements in other CAD risk factors and CAC progression when larger datasets are available and participants are followed for a longer periods of time.




School of Medicine



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