Spatially Weighted Coronary Artery Calcium Score and Coronary Heart Disease Events in the Multi-Ethnic Study of Atherosclerosis.
BACKGROUND
A limitation of the Agatston coronary artery calcium (CAC) score is that it does not use all of the calcium density information in the computed tomography scan such that many individuals have a score of zero. We examined the predictive validity for incident coronary heart disease (CHD) events of the spatially weighted coronary calcium score (SWCS), an alternative scoring method for CAC that assigns scores to individuals with Agatston CAC=0.


METHODS
The MESA (Multi-Ethnic Study of Atherosclerosis) is a longitudinal study that conducted a baseline exam from 2000 to 2002 in 6814 participants including computed tomography scanning for CAC. Subsequent exams and systematic follow-up of the cohort for outcomes were performed. Statistical models were adjusted using the MESA risk score based on age, sex, race/ethnicity, systolic blood pressure, use of hypertension medications, diabetes, total and HDL (high-density lipoprotein) cholesterol, use of lipid-lowering medications, smoking status, and family history of heart attack.


RESULTS
In the 3286 participants with Agatston CAC=0 at baseline and for whom SWCS was computed, 98 incident CHD events defined as definite or probably myocardial infarction or definite CHD death occurred during a median follow-up of 15.1 years. In this group, SWCS predicted incident CHD events after multivariable adjustment (hazard ratio=1.30 per SD of natural logarithm [SWCS] [95% CI, 1.04-1.60]; P=0.005); and progression from Agatston CAC=0 at baseline to CAC>0 at subsequent exams (multivariable-adjusted incidence rate difference per SD of natural logarithm [SWCS] per 100 person-years 1.68 [95% CI, 1.03-2.33]; P<0.0001).


CONCLUSIONS
SWCS predicts incident CHD events in individuals with Agatston CAC score=0 as well as conversion to Agatston CAC>0 at repeat computed tomography scanning at later exams. SWCS has predictive validity as a subclinical phenotype and marker of CHD risk in individuals with Agatston CAC=0.
['Shea|Steven|S|', 'Navas-Acien|Ana|A|', 'Shimbo|Daichi|D|', 'Brown|Elizabeth R|ER|', 'Budoff|Matthew|M|', 'Bancks|Michael P|MP|', 'Barr|R Graham|RG|', 'Kronmal|Richard|R|']
D000368:Aged D050197:Atherosclerosis D002118:Calcium D017023:Coronary Angiography D003324:Coronary Artery Disease D003331:Coronary Vessels D005006:Ethnicity D005260:Female D006801:Humans D015994:Incidence D008297:Male D008875:Middle Aged D011237:Predictive Value of Tests D018570:Risk Assessment D014057:Tomography, X-Ray Computed D014481:United States
calcium heart diseases atherosclerosis blood pressure hypertension