High-risk plaque (HRP) criteria evaluated on computed tomography angiography (CTA) were found to provide added value for the prediction of long-term outcomes in patients with coronary artery disease (CAD), according to study results published in Atherosclerosis.
Evidence regarding long-term outcomes and prognoses in patients with CAD based on coronary CTA findings is lacking in the literature, particularly involving novel imaging biomarkers such as the HRP criteria.
In this study, 1430 patients with CAD (mean age, 57.9±11.1 years; 44.4% women) at low to intermediate risk for atherosclerotic cardiovascular (CV) disease were enrolled in a prospective cohort analysis and followed for a mean of 10.55±1.98 years. At baseline, all participants underwent coronary CTA imaging with coronary artery calcium (CAC) scoring.
CTA scans were evaluated for 3 parameters: severity of stenosis, rated on a 0 to 4 scale according to the Coronary Artery Disease – Recording and Data System (CAD-RADS); non-calcified plaque-weighted mixed plaque burden; and 3 HRP criteria — low-attenuation plaque (LAP), napkin-ring-sign, and remodeling index >1.1 or spotty calcifications <3 mm.
The study’s primary outcomes were rates of all-cause and CV mortality and a composite of fatal and nonfatal major adverse CV events (MACE) incidence.
During the follow-up period, 106 patients died from any cause (7.4%) and 25 patients died from CV events (1.75%). The MACE composite occurred in 57 patients (3.9%). In participants with a CTA negative for CAD, MACE and CV mortality occurred in 0.2% and 0.0%, respectively.
All 3 primary endpoints were found to be predicted by the CAD-RADS stenosis severity rating (P <.001), and all-cause mortality, but not the MACE composite, was found to be predicted by a CAC score >100 Agatston Units.
An LAP <60 Hounsfield units (hazard ratio [HR], 4.00; 95% CI, 1.52-10.52; P =.005) and the presence of the napkin-ring-sign (HR, 4.11; 95% CI, 1.77-9.52; P =.001) were both found to predicted the MACE composite, but not all-cause mortality. The other 2 HRP criteria — the remodeling index and spotty calcifications — were not found to predict MACE or all-cause mortality. Mixed plaque burden also predicted the occurrence of MACE (P <.0001).
The addition of the HRP criteria to CAD-RADS+CAC scoring was found to be superior to CAC scoring alone or with CAD-RADS in predicting MACE (area under the curve: c = 0.816 vs 0.716, respectively; P <.001). A total of 33.5% of patients with CAC scores =0 had non-calcified fibroatheromas detected.
Study limitations include a low CV mortality rate, the lack of inclusion of medication data, and a high percentage of patient loss to follow-up (30%).
“[O]ur study data indicate that total plaque burden weighted for the noncalcified plaque component and the ‘high-risk plaque’ imaging biomarkers LAP and [napkin-ring sign]are more specific and independent predictors of MACE,” noted the authors.
Senoner T, Plank F, Barbieri F, et al. Added value of high-risk plaque criteria by coronary CTA for prediction of long-term outcomes. Atherosclerosis. 2020;300:26-33. doi:10.1016/j.atherosclerosis.2020.03.019