OBJECTIVES: To explore the association between baseline Lp (a) levels and high-risk plaques, plaque volume, and plaque progression in patients with diabetes mellitus. METHODS: Patients with diabetes mellitus and intermediate pretest probability of coronary artery disease (CAD) were prospectively enrolled. All patients underwent baseline coronary computed tomography angiography (CCTA), and patients with recurrent symptoms underwent mid-term follow-up CCTA. Plaque quantification and qualification were performed to compare coronary atherosclerosis features and plaque progression between the elevated and normal Lp (a) groups. RESULTS: In this study, 1694 subjects (mean age: 62.0 ± 7.0 years
1031 males) were enrolled for baseline analysis, and 246 subjects with repeat CCTA (mean interval of 2.3 ± 0.74 years) were included for follow-up analysis. The total plaque volume, noncalcified plaque volume, low attenuation plaque (LAP) volume, fibro-fatty plaque volume, and fibrotic plaque volume were higher in the elevated Lp (a) group than in the normal Lp (a) group at baseline (all p <
0.001). At follow-up, the elevated Lp (a) group showed a higher mean annual increase in LAP volume than the normal Lp (a) group (3.03 ± 22.26 mm CONCLUSION: Elevated Lp (a) level in patients with diabetes mellitus was associated with high coronary artery plaque burden at baseline and LAP volume progression at follow-up. KEY POINTS: Question The relationship between Lp (a) levels and coronary artery plaque volume and progression in patients with diabetes mellitus remains unclear. Findings Elevated Lp (a) level was associated with high total coronary plaque volume at baseline and low-attenuation plaque (LAP) volume progression at follow-up. Clinical relevance Elevated Lp (a) level in patients with diabetes mellitus was associated with high coronary artery plaque burden at baseline and LAP volume progression at follow-up, which supports the modulation of LAP level to improve prognosis.