Winnie Chia-hsuan Chi, MS

To assess if coronary artery calcium (CAC) scans influence treatment 

patterns as reflected by subsequent rates of cardiac imaging 

and therapeutic interventions, and their effect on ischemic 

Longitudinal observational study from January 1, 2005, through 

August 31, 2011, using a large managed-care medical and pharmacy 

Two cohorts were evaluated: CAC patients who received CAC 

testing, and Reference patients, subject to preauthorization, who 

were denied CAC scans. Patients were adults less than 65 years 

old. Index date was CAC scan date for CAC and pre-authorization 

request date for Reference. Patients were stratified into high-risk 

and non—high-risk categories; outcomes were analyzed only for 

non—high-risk where CAC scores could potentially modify risk 

classification. Cardiac imaging, coronary revascularizations, and 

pharmaceutical interventions were evaluated for 6 months post 

index and adverse ischemic events were assessed using all available 

The study included 2679 CAC and 1135 Reference patients. 

Among non—high-risk patients, similar proportions of both 

groups received an imaging test within 6 months (23.2% vs 

= .5); revascularization rates and pharmaceutical 

utilization were similar. Adverse events were rare. Age-sex 

adjusted incidence rate ratio for adverse events was 1.1 (95% 

CI, 0.36-3.38) among CAC relative to Reference. High-risk patients, 

considered inappropriate for CAC testing, represented 20.2% and 

23.5% of CAC and Reference, respectively (

Patients having CAC scans were not associated with fewer downstream 

ischemic events nor with reduced subsequent imaging 

and therapeutic interventions among non—high-risk patients. 

Results also indicated inappropriate testing of high-risk patients.

This is the first study to compare downstream differences post scan in the rates of 

additional diagnostic testing, therapeutic interventions, and ischemic events between 

patients who received coronary artery calcium (CAC) scans, and controls, who were denied 

CAC scans because their health plans did not cover the procedure, within a large, 

The findings in this study, consistent with those of prior, largely clinical studies, 

indicated that there were no significant differences in treatment patterns or ischemic 

events during the post scan, follow-up period.

While questions about the value of CAC scans persist, they are still being ordered 

for asymptomatic patients, raising policy questions that may be resolved by additional 

studies in larger patient populations and for longer durations.

An estimated 33% of the adults in the United States 

are affected by coronary artery disease (CAD),

and along with such high prevalence have come 

substantial and increasing rates of morbidity.

relative mortality rates attributable to cardiovascular 

disease (CVD) declined 33% in the United States from 

1999 to 2009, disease burden remained high. CVD was 

associated with 1 of every 3 United States deaths in 2009, 

32% of the 2.4 million overall. Of 2009 deaths, coronary 

heart disease alone caused approximately 1 in every 6, and 

stroke 1 in every 19. The total direct and indirect cost 

of CVD and stroke was estimated at $312.6 billion in 

 These sizable and growing burdens have driven 

efforts to evaluate and better understand cardiac risks in 

Coronary artery calcium (CAC) scanning, a screening 

tool that detects subclinical coronary disease in asymptomatic 

populations, is noninvasive; it can be performed in a few 

minutes while the patient is fully dressed.

older studies suggest that CAC scores are directly correlated 

with coronary atherosclerosis, and may represent a marker 

and CAC score is considered a predictor of coronary death 

Articles

This article provides an assessment of the downstream impact of coronary artery calcium scanning on the subsequent treatment patterns of non—high-risk patients.

Winnie Chia-hsuan Chi, MS

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Does CAC Testing Alter Downstream Treatment Patterns for Cardiovascular Disease?