Abstract Introduction Despite guideline-recommended control of LDL-C with a statin, type 2 diabetic patients more likely cause cardiovascular events. This indicates the need to identify additional therapeutic targets in those patients. Angioprotein-like 3 (ANGPTL3) is an inhibitor of lipoprotein and endothelial lipase, which increases the levels of LDL-C and other atherogenic lipoproteins. These properties suggest ANGPTL3 as a potential driver associated with diabetic atherosclerosis. The OPTIMAL randomized controlled trial (jRCT1052180152) compared the efficacy of continuous glucose monitoring-guided versus HbA1c-guided glycemic control on coronary atherosclerosis in statin-treated type 2 diabetic patients by using serial intravascular ultrasound (IVUS) imaging. This pre-specified analysis of the OPTIMAL study was designed to evaluate whether ANGPTL3 affects progression of coronary atheroma in statin-treated type 2 diabetic patients. Purpose To elucidate the association of serial change in ANGPTL3 with the degree of atheroma progression in statin-treated type 2 diabetic patients. Methods 59 patients (59 lesions) with serial ANGPTL3 levels at baseline and week 48 were included into the current analysis. Clinical demographics and IVUS-derived measure were compared in patients with and without any increase in ANGPTL3. Results All of study subjects received a statin, and over 60% of them were treated with high-intensity statin. Under these lipid-lowering therapies, any increase in ANGPTL3 levels at week 48 was observed in 52.5% of study participants. Patients with any increase in ANGPTL3 were more likely to have a history of hypertension (90.0% vs. 64.3%, p=0.02), whereas there was no significant difference in on-treatment LDL-C levels between the two groups (1.8 ± 0.4 vs. 1.6 ± 0.6 mmol/L, p=0.25) (Table). On IVUS imaging analysis, baseline percent atheroma volume (PAV) did not differ in those with and without any increase in ANGPTL3. However, patients with any increase in ANGPTL3 presented a greater progression of PAV (0.08 ± 0.28 vs. -0.74 ± 0.29, p=0.04). There was a trend toward a lower frequency of PAV regression in those exhibiting any increase in ANGPTL3 (48.4% vs. 57.1%), but this comparison did not meet statistical significance (p=0.50) (Figure). Multivariate analysis adjusting clinical characteristics demonstrated that any increase in ANGPTL3 level was not independently associated with PAV progression (β=0.16, 95%CI=-0.01 – 0.18, p=0.27). Conclusion Over 50% of statin-treated type 2 diabetic patients with coronary atherosclerosis showed any increase in ANGPTL3 levels at week 48. Serial IVUS imaging revealed that patients with any increase in ANGPTL3 more likely presented a greater atheroma progression. However, this relationship did not exist after adjusting clinical characteristics. Our findings suggest that ANGPTL3 may not be a pivotal driver associated with atheroma progression in statin-treated type 2 diabetic patients.