The effect of continuous glucose monitoring-guided glycemic control on progression of coronary atherosclerosis in type 2 diabetic patients with coronary artery disease: The OPTIMAL randomized clinical trial

Background: Continuous glucose monitoring (CGM) improves glycemic fluctuation and reduces hypoglycemic risk. Whether CGM-guided glycemic control favorably modulates coronary atherosclerosis in patients with type 2 diabetes (T2DM) remains unknown. Methods: The OPTIMAL trial was a prospective, randomized, single-center trial in which 94 T2DM patients with CAD were randomized to CGM- or HbA1c-guided glycemic control for 48 weeks (jRCT1052180152). The primary endpoint was the nominal change in total atheroma volume (TAV) measured by serial IVUS. The secondary efficacy measure was the nominal change in maxLCBI4mm on near-infrared spectroscopy imaging. Results: Among the 94 randomized patients, 82 had evaluable images at 48 weeks. Compared to HbA1c-guided glycemic control, CGM-guided control achieved a greater reduction in %coefficient of variation [-0.1 % (-1.8 to 1.6) vs. -3.3 % (-5.1 to -1.5), p = 0.01] and a greater increase in the duration with glucose between 70 and 180 mg/dL [-1.5 % (-6.0 to 2.9) vs. 6.7 % (1.9 to 11.5), p = 0.02]. TAV increased by 0.11 +/- 1.9 mm3 in the HbA1c-guided group and decreased by -3.29 +/- 2.00 mm3 in the CGM-guided group [difference = -3.4 mm3 (95%CI: -8.9 to 2.0 mm3), p = 0.22]. MaxLCBI4mm, increased by 90.1 +/- 25.6 in the HbA1c-guided group and by 50.6 +/- 25.6 in the CGM-guided group (difference = -45.6 (95%CI: -118.1 to 26.7) p = 0.21]. A post-hoc exploratory analysis showed a greater regression of maxLCBI4mm in the CGM-guided group [difference = 20.4 % (95%CI:1.3 to 39.5 %), p = 0.03]. Conclusions: CGM-guided control for 48 weeks did not slow disease progression in T2DM patients with CAD. A greater regression of lipidic plaque under CGM-guided glycemic control in the post-hoc analysis requires further investigation.