CAC scoring helps identify which CVD patients will benefit from statin therapy: JAMA
USA: CT coronary artery calcium (CAC) scoring can be used as an adjunct to risk-enhancing factor assessment to allow the health professionals to confirm more accurately whether a patient is at moderate risk for atherosclerotic cardiovascular disease (ASCVD) would benefit from statin therapy, suggests a study published JAMA Cardiology journal.
According to the results from the cross-sectional study, in people with coronary artery calcium (CAC) scores of 0, the presence of risk-enhancing factors did not lead to overall atherosclerotic cardiovascular disease (ASCVD) risk that was higher than the recommended treatment threshold for the initiation of statin therapy. The use of calcium scores significantly improved reclassification and discrimination of incident ASCVD.
The 2018 guideline by the American Heart Association/American College of Cardiology on the management of blood cholesterol recommends the use of risk-enhancing factor assessment and the selective use of CAC scoring to guide statin treatment among people with an intermediate risk of ASCVD. Considering this, Jaideep Patel, Virginia Commonwealth University Medical Center, Richmond, and colleagues aimed to examine the association between risk-enhancing factors and incident ASCVD by CAC burden among those at intermediate risk of ASCVD in the Multi-Ethnic Study of Atherosclerosis -- a multicenter population-based prospective cross-sectional study conducted in the US.
For this purpose, the researchers collected baseline data between July 15, 2000, and July 14, 2002, and ascertained follow-up for incident ASCVD events through August 20, 2015. It included patients aged 45 to 75 years with no clinical ASCVD or diabetes at baseline, were at intermediate risk of ASCVD (≥7.5% to <20.0%), and had a low-density lipoprotein cholesterol level of 70 to 189 mg/dL.
A total of 1688 participants (mean age, 65 years; 57.8% were men). A total of 722 participants (42.8%) had a CAC score of 0.
The research revealed following findings:
- Among those with 1 to 2 risk-enhancing factors vs those with 3 or more risk-enhancing factors, the prevalence of a CAC score of 0 was 45.7% vs 40.3%, respectively.
- Over a median follow-up of 12.0 years (interquartile range [IQR], 11.5-12.6 years), the unadjusted incidence rate of ASCVD among those with a CAC score of 0 was less than 7.5 events per 1000 person-years for all individual risk-enhancing factors (with the exception of ankle-brachial index, for which the incidence rate was 10.4 events per 1000 person-years) and combinations of risk-enhancing factors, including participants with 3 or more risk-enhancing factors.
- Although the individual and composite addition of risk-enhancing factors to the traditional risk factors was associated with improvement in the area under the receiver operating curve, the use of CAC scoring was associated with the greatest improvement in the C statistic (0.633 vs 0.678) for ASCVD events.
- For incident ASCVD, the net reclassification improvement for CAC was 0.067.
The results of our study support the utility of CAC scoring as an adjunct to risk-enhancing factor assessment to more accurately classify individuals with an intermediate risk of ASCVD who might benefit from statin therapy, the authors concluded.
The study titled, "Assessment of Coronary Artery Calcium Scoring to Guide Statin Therapy Allocation According to Risk-Enhancing Factors: The Multi-Ethnic Study of Atherosclerosis," is published in the journal JAMA Cardiology.