Coronary CT Angiography and Carotid MRI Improve Phenotyping of Disease Extent Compared with ACC/AHA Risk Score Alone

Area of Science:

• Cardiovascular Imaging
• Atherosclerosis Research
• Risk Stratification

Background:

• Cardiovascular risk scores are crucial for guiding preventive therapies like statins.
• Accurate assessment of atherosclerotic plaque burden is essential for personalized risk management.
• Current risk scores may not fully capture individual disease extent.

Purpose of the Study:

• To evaluate the correlation between the ACC/AHA cardiovascular risk score and direct imaging measures of plaque phenotype.
• To compare risk score-based stratification with detailed plaque characterization in coronary and carotid arteries.

Main Methods:

• Prospective study of asymptomatic individuals eligible for statin therapy.
• Utilized coronary artery calcium (CAC) scoring, coronary CT angiography, and carotid MRI.
• Compared ACC/AHA risk quartiles with quartiles of noncalcified plaque, CAC, and carotid wall volume.

Main Results:

• Weak correlations were observed between ACC/AHA risk and carotid wall volume (τ=0.29), noncalcified plaque (τ=0.16), and CAC (τ=0.33).
• ACC/AHA risk score misclassified plaque extent in 22-30% of subjects compared to imaging findings.
• Approximately 13% of subjects were underclassified, and 12.5% were overclassified by the risk score.

Conclusions:

• Significant discrepancies exist between ACC/AHA risk scores and actual plaque burden in about 25% of individuals.
• Clinical risk models alone may not adequately represent the full extent of atherosclerotic disease.
• Direct imaging assessment offers a more precise evaluation of cardiovascular disease burden.