New atherosclerotic plaque formation by coronary CTA in suspected coronary artery disease patients: Results from the PARADIGM Registry

Abstract Background The natural history of new atherosclerotic lesion formation in humans has not been described morphologically in primary prevention populations by direct anatomical visualization. Purpose To compare new atherosclerotic plaque formation prevalence and characteristics among patients with and without prior plaque by coronary CTA (CCTA). Methods We performed a sub-analysis of the PARADIGM registry which consecutively enrolled 2252 patients with suspected CAD undergoing serial CCTA at a scan interval of ≥2 years. Patients were excluded for noninterpretable scans, prior CAD, and interval major adverse cardiac events. Quantitative CCTA was performed and patients with and without plaque at baseline scan were compared for presence of new lesions (NLs) and differences in plaque characteristics including location, percent diameter stenosis (%DS) severity, total and compositional plaque volume and presence of high-risk plaque (HRP) on follow-up. Results Of 1343 patients (age 60.4±9.4 years, 42.8% females), 334 (24.9%) patients had no baseline plaque (BP). Over 3.3 years (IQR 2.6, 4.8), NLs developed in 35% of patients without and 46.7% of patients with BP (p=0.0003). New obstructive lesions ≥50% were rare, observed in 3(0.9%) in those without and 7(0.7%) in those with BP. Among patients with NLs (n=588), those developing in patients without BP had higher %DS (median=17.2% (IQR 11.3, 25.7) vs. 15.8% (IQR 8.8, 23.2), p=0.013), higher PV (21.8mm3 (IQR 9.54, 41.7) vs. 16.1mm3 (IQR 6.70, 31.5), p=0.008), higher fibrofatty composition of 30-130 HU (10.7% (IQR 1, 29.9) vs. 3.1% (IQR 0.04, 17.4), p