Lowering apolipoprotein C-III associates with regression of lipidic plaque materials in type 2 DM patients with coronary artery disease: the pre-specified analysis from the OPTIMAL trial

Abstract

Introduction: Apolipoprotein CIII (ApoC-III) is a circulating lipoprotein which affects triglyceride-rich lipoprotein metabolism and functionality of high-density lipoproteins. These properties indicate ApoC-III as a potential contributor to atherosclerosis. The OPTIMAL randomized controlled trial (jRCT1052180152) compared the efficacy of continuous glucose monitoring guided versus HbA1c-guided glycemic control on coronary atherosclerosis in Type 2 Diabetes (T2DM) patients by using serial near-infrared spectroscopy/intravascular ultrasound (NIRS/IVUS). Given that NIRS/IVUS imaging enables to quantitatively evaluate plaque burden and its lipidic component in vivo, the OPTIMAL study provides an opportunity to elucidate the association of ApoC-III with change in quantity and quality of coronary plaques. Purpose: To elucidate whether serial change in ApoC-III affects the degree of atheroma progression and lipidic plaque materials on NIRS/IVUS imaging. Methods: The OPTIMAL trial has serially monitored non-culprit lesions in 94 T2DM patients receiving PCI by NIRS/IVUS imaging. Of these, 46 patients (73 lesions) were included into the current analysis. Circulating ApoC-III levels were measured at both baseline and 48 weeks. The relationships of serial change in ApoC-III with NIRS/IVUS-derived measures [total atheroma volume (TAV) and maximum lipid core burden index in a 4-mm segment (maxLCBI4mm)] were analyzed. Results: All of study subjects received a statin, and high-intensity statin was used in 65.2% of them. On-treatment LDL-C and HbA1c levels were 1.9±0.5mmol/L and 7.2±0.7%, respectively. On NIRS/IVUS analysis, any regression of TAV and maxLCBI4mm was observed in 71.2 and 38.4% of analyzed lesions, respectively (Table). There was no significant relationship between change in ApoC-III and TAV regression (r=0.02, p=0.89). However, a reduction of ApoC-III was significantly associated with a greater regression of maxLCBI4mm (r=0.26, p=0.03) (Figure). Furthermore, multivariate analysis adjusting for LDL-C and high-intensity statin use demonstrated lowering ApoC-III level as an independent predictor of maxLCBI4mm regression (OR=0.83, 95%CI=0.69-0.99, p=0.04) (Table). Even in patients receiving high-intensity statin, the relationship of change in ApoC-III with regression of maxLCBI4mm still existed (Figure). Conclusion: Serial NIRS/IVUS imaging revealed that a reduction of circulating ApoC-III was associated with a greater regression of maxLCBI4mm. Our findings suggest ApoC-III as an important therapeutic target to modulate lipidic plaque materials in T2DM receiving a statin.