Interaction between risk factors, coronary calcium, and CCTA plaque characteristics in patients aged 18-45 years

Aims: The atherosclerotic profile and advanced plaque subtype burden in symptomatic patients ≤45 years old have not been established. This study aimed to assess the prevalence and predictors of coronary artery calcium (CAC), plaque subtypes, and plaque burden by coronary computed tomography angiography (CCTA) in symptomatic young patients. Methods and results: We included 907 symptomatic young patients (18-45 years) from Montefiore undergoing CCTA for chest pain evaluation. Prevalence and predictors of CAC, plaque subtypes, and burden were evaluated using semi-automated software. In the overall population (55% female and 44% Hispanic), 89% had CAC = 0. The likelihood of CAC or any plaque by CCTA increased with >3 risk factors {RFs, odds ratio [OR] 7.13 (2.14-23.7) and OR 10.26 (3.36-31.2), respectively. Any plaque by CCTA was present in 137 (15%); the strongest independent predictors were age ≥35 years [OR 3.62 (2.05-6.41)] and family history of premature coronary artery disease (FHx) [OR 2.76 (1.67-4.58)]. Stenosis ≥50% was rare (1.8%), with 31% of those having CAC = 0. Significant non-calcified plaque (NCP, 37.2%) and low-attenuation plaque (LAP, 4.24%) burdens were seen, even in those with non-obstructive stenosis. Among patients with CAC = 0, 5% had plaque, and the only predictor of exclusively NCP was FHx [OR 2.29 (1.08-4.86)]. Conclusion: In symptomatic young patients undergoing CCTA, the prevalence of CAC or any coronary atherosclerosis was not negligible, and the likelihood increased with RF burden. The presence of coronary stenosis ≥50% was rare and most often accompanied by CAC >0, but there was a significant burden of NCP and LAP even within the non-obstructive group.