Last update and review: October 30, 2020.
A short summary.
CAC score can decrease over time in a notable proportion of people. In a study by Lee et al. 2009 (1), CAC score decreased in about 20% of the subjects during the 24 months of the observation period.
Interventions capable of decreasing CAC score should, therefore, exist. The goal is to identify them.
CAC progression during 24 months in a community-based sample of 869 healthy adults aged 60 to 72 years who were free of clinical CAD.
Lee et al., 2009 (1):
We measured CAC at enrollment and after 24 months in a community-based sample of 869 healthy adults aged 60 to 72 years who were free of clinical CAD. We assessed predictors of the progression of CAC using univariate and multivariate models after square root transformation of the Agatston scores. Predictors tested included age, sex, race/ethnicity, smoking status, body mass index, family history of CAD, C-reactive protein and several measures of diabetes, insulin levels, blood pressure, and lipids.
The follow-up CAC measurements were performed at a median of 23.7 months.
Mean age 66, 62% men, 10% African American.
At the time of enrollment, the mean age of the subjects was 66 years, 62% were men, 76% were white, and 10% were African American.
“CAC progression was associated with (the usual culprits) white race, diabetes, dyslipidemia, hypertension”, BUT ALSO: “lower diastolic blood pressure, and higher pulse pressure.”
Adapted from lee et al., 2009.
The median CAC at entry was 38.6 Agatston units and increased to 53.3 Agatston units over 24 months.
Lee et al., 2009 (1):
The median CAC at entry was 38.6 Agatston units and increased to 53.3 Agatston units over 24 months (P<0.01).
The median change in CAC was of 3.3 Agatston units over 24 months.
Lee et al., 2009 (1):
The distribution of change scores was skewed (Figure 1), with a median change in CAC of 3.3 Agatston units.
Repeatability of CAC measurements: 96% of the 2 values acquired during each visit to the CT scanner were withing 2 standard deviations.
Lee et al., 2009 (1):
We assessed the repeatability of CAC measurements by generating Bland-Altman plots to analyze the differences in the 2 values acquired during each visit to the CT scanner. Greater than 96% of the differences in the repeated measurements were within 2 standard deviations, indicating adequate measurement repeatability.
African American patients had a lower rate of CAC progression as compared with whites.
Lee et al., 2009 (1):
African American patients had a lower rate of CAC progression as compared with whites, which was significant even after adjusting for all other variables.
African Americans may have either less calcification despite similar degrees of atherosclerosis or less underlying CAD. In light of the high cardiac event rates in African Americans, the former possibility seems more likely. If so, CAC scores and CAC progression may need to be interpreted differently in African Americans.
Dyslipidemia was a strong predictor of CAC progression in multivariate models.
Lee et al., 2009 (1):
A diagnosis of dyslipidemia was a strong predictor of CAC progression in both the univariate and multivariate models.
Hypertension was a predictor of CAC progression after adjustment for other variables.
Lee et al., 2009 (1):
The diagnosis of hypertension, lower diastolic blood pressure, and higher pulse pressure were all significant predictors of CAC progression after adjustment for other variables. None of the other risk factors, including body mass index, smoking history, C-reactive protein, and family history of CAD, were associated with CAC progression after adjustment for other variables.
Arterial stiffness.
Lee et al., 2009 (1):
A diagnosis of hypertension in this study was a strong and independent predictor of CAC progression. Even after controlling for hypertension, age, sex, and other factors, we found that a higher pulse pressure and lower diastolic pressure were independently associated with increased CAC progression. Because increased arterial stiffness is associated with both a higher pulse pressure and a lower diastolic blood pressure, 33,34 this finding suggests that more rapid progression of CAC and increased stiffness of the arterial system are associated with one another.
In about 20% of the subjects, CAC score decreased during the 24 months of the observation period.
Lee et al., 2009 (1), do not mention at all the remarkable fact that in a notable proportion of their subjects, CAC score decreased during the 24 months of the observation period. We can calculate their proportion form the Figure 1 above. If we add the number of subjects represented by each bar with negative CAC score progression, we arrive at approximately 170 subjects. Thus, 170 out of 869 subjects, or about 20%, had no progression or a decrease in CAC score.
Conclusions: Interventions capable of decreasing CAC score should exist. The goal is to identify them.
The fact that CAC score can remain unchanged or slightly regress in as much as 20% of a community-based sample of people is quite remarkable. It tells us that interventions that decrease CAC score should exist.
Our Working Group on reducing coronary artery calcium (CAC) score.
If you are a medical practitioner, a person interested in optimizing your health, or a patient/consulting client, you may want to collaborate with us in our Working Group on reducing CAC score. In our groups, we share our ideas and different interventions or “protocols” that address a particular area. The goal in the case of CAC score is to identify interventions capable of reducing CAC score.
Selected references:
1. Lee et al. Am Heart J. 2009 May;157(5):939-45.
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