Comparison of coronary atherosclerotic plaque progression in East Asians and Caucasians by serial coronary computed tomographic angiography : A PARADIGM substudy

Objectives: To investigate potential differences in plaque progression (PP) between in East Asians and Caucasians as well as to determine clinical predictors of PP in East Asians. Background: Studies have demonstrated differences in cardiovascular risk factors as well as plaque burden and progression across different ethnic groups. Methods: The study comprised 955 East Asians (age 60.4 ​± ​9.3 years, 50.9% males) and 279 Caucasians (age 60.4 ​± ​8.6 years, 74.5% males) who underwent two serial coronary computed tomography angiography (CCTA) studies over a period of at least 24 months. Patients were enrolled and analyzed from the PARADIGM (Progression of AtheRosclerotic PlAque DetermIned by Computed TomoGraphic Angiography IMaging) registry. After propensity-score matching, plaque composition and progression were compared between East Asian and Caucasian patients. Within East Asians, the plaque progression group (defined as plaque volume at follow-up CCTA minus plaque volume at baseline CCTA> 0) was compared to the no PP group to determine clinical predictors for PP in East Asians. Results: In the matched cohort, baseline volumes of total plaque as well as all plaque subtypes were comparable. There was a trend towards increased annualized plaque progression among East Asians compared to Caucasians (18.3 ​± ​24.7 ​mm3/year vs 16.6 ​mm3/year, p ​= ​0.054). Among East Asians, 736 (77%) had PP. East Asians with PP had more clinical risk factors and higher plaque burden at baseline (normalized total plaque volume of144.9 ​± ​233.3 ​mm3 vs 36.6 ​± ​84.2 ​mm3 for PP and no PP, respectively, p ​< ​0.001). Multivariate logistic regression analysis showed that baseline normalized plaque volume (OR: 1.10, CI: 1.10–1.30, p ​< ​0.001), age (OR: 1.02, CI: 1.00–1.04, p ​= ​0.023) and body mass index (OR: 2.24, CI: 1.01–1.13, p ​= ​0.024) were all predictors of PP in East Asians. Clinical events, driven mainly by percutaneous coronary intervention, were higher among the PP group with a total of 124 (16.8%) events compared to 22 (10.0%) in the no PP group (p ​= ​0.014). Conclusion: East Asians and Caucasians had comparable plaque composition and progression. Among East Asians, the PP group had a higher baseline plaque burden which was associated with greater PP and increased clinical events.