Prognostic value of CT-derived coronary artery disease characteristics varies by ASCVD risk: insights from the PROMISE trial.

OBJECTIVES

To compare the prognostic value of individual CT-derived coronary artery disease (CAD) characteristics across categories of clinical cardiovascular risk.

METHODS

The central core laboratory assessed coronary artery calcium (CAC), obstructive CAD (stenosis ≥ 50%), and high-risk plaque (HRP) in stable outpatients with suspected CAD enrolled in the PROMISE trial. Multivariable Cox regression models (endpoint: unstable angina, nonfatal myocardial infarction, or all-cause mortality; median follow-up: 2 years) were used to compare hazard ratios (HR) of the CT measures between low-borderline (< 7.5%) and moderate-high (≥ 7.5%) atherosclerotic cardiovascular disease (ASCVD) risk based on the pooled cohort equation.

RESULTS

Among 4356 included patients (aged 61 ± 8 years, 52% women), 67% had ASCVD risk ≥ 7.5%. Stratified by ASCVD risk, CAD ≥ 50% had nearly threefold greater HR in individuals with ASCVD < 7.5% (aHR, 6.85; 95% CI, 2.33-20.15; p < 0.001) vs. ASCVD ≥ 7.5% (aHR: 2.66, 95% CI: 1.67-4.25, p < 0.001; interaction p = 0.041). CAC predicted events solely in ASCVD ≥ 7.5% patients (aHR: 1.92, 95% CI: 1.01-3.63, p = 0.045; interaction p = 0.571), while HRP predicted events only in ASCVD < 7.5% (aHR: 3.11, 95% CI: 1.09-8.85, p = 0.034; interaction p = 0.034).

CONCLUSIONS

Prognostic values of CT-derived CAD characteristics differ by ASCVD risk categories. While CAD ≥ 50% has the highest prognostic value regardless of ASCVD risk, CAC is prognostic in high and HRP in low ASCVD risk. These findings suggest that CAD ≥ 50% and HRP detection rather than CAC scoring may better risk-stratify symptomatic low-risk patients and thus potentially improve downstream care.

KEY POINTS: • Prognostic value of individual CT-derived CAD characteristics differs by categories of cardiovascular risk. • Presence of obstructive coronary artery stenosis ≥ 50% has the highest prognostic value regardless of cardiovascular risk. • Coronary artery calcium is independently prognostic in high and high-risk plaque features in low cardiovascular risk.