Effects of Combining Coronary Calcium Score With Treatment on Plaque Progression in Familial Coronary Artery Disease: A Randomized Clinical Trial

Abstract

Importance: Coronary artery calcium (CAC) scoring provides prognostic information, especially in patients at intermediate risk for coronary artery disease (CAD). However, the benefit of combining CAC score with a primary prevention strategy has not been tested in a randomized trial. Objective: To assess whether combining the CAC score with a prevention strategy can be used to limit plaque progression in intermediate-risk patients with a family history of premature CAD. Design, Setting, and Participants: Prospective, randomized, open-blinded end point clinical trial in 7 hospitals across Australia (between 2013 and 2020; the last date of follow-up was June 5, 2021). Asymptomatic people aged 40 to 70 years with a first-degree relative with CAD onset at younger than 60 years old or second-degree relative with onset at younger than 50 years old were recruited from the community. Interventions: Intermediate-risk participants underwent CAC scoring. Those with a CAC score greater than 0 but less than 400 underwent coronary computed tomography angiography (CCTA) and were randomized to CAC score-informed prevention or usual care. Main Outcomes and Measures: Follow-up CCTA was obtained at 3 years, with plaque volume measured by an independent core laboratory. The primary outcome was total plaque volume, with further analysis for calcified and noncalcified plaque volume. Results: This study included 365 participants (mean [SD] age, 58 [6] years; 57.5% male); 179 in the CAC score-informed and 186 in the usual care groups. Compared with usual care, the CAC score-informed group showed a sustained reduction in total (mean [SD], -3 [31] mg/dL vs -56 [38] mg/dL; P