Prediction of cardiovascular events with traditional risk equations and total plaque area of carotid atherosclerosis: The Arteris Cardiovascular Outcome (ARCO) cohort study

A large number of cardiovascular events occur in seemingly healthy individuals. Atherosclerosis imaging can improve the outcome and treatment regime of such subjects. We aim to assess the predictive value of atherosclerosis imaging beyond traditional risk calculators in subjects aged 40-65 years. We compared PROCAM, SCORE and FRAM with carotid ultrasound (total plaque area, TPA) and arterial age (AA) was calculated in subjects without known cardiovascular diseases. Follow-up was obtained by phone or mail. In 2842 subjects (age 50 ± 8, 38% women) 154 (5.4%) cardiovascular events occurred (ASCVD: 41 myocardial infarctions, 16 strokes or TIA, 21 CABG, 41 PTCA, 35 coronary artery disease defined by invasive angiography) during a mean follow-up time of 5.9 (1-12) years. PROCAM risk was 5 ± 6%, SCORE risk 1.3 ± 1.6% and FRAM 10 ± 6%. Both for the primary outcome (AMI, STROKE/TIA, CABG) and the secondary outcome (adding CAD and PTCA) hazards increased significantly for TPA tertiles and AA groups between 1.4 (0.1-16.1) and 21.4 (2.8-163.6) after adjustment for risk factors (age, smoke, sex, systolic BP, lipids, BMI, medication in Model 1) and after adjustment for results from PROCAM, SCORE and FRAM (Model 2). Model performance was statistically improved regarding model fit in all models using TPA and AA. Net reclassification improvement (NRI) for PROCAM and SCORE using TPA tertiles or AA age groups increased significantly between 30% to 48%. TPA and AA added prognostic information to conventional risk equations, supporting the assessment of ASCVD risk with carotid ultrasound in subjects aged 40-65 years.