Relation between Progression and Regression of Atherosclerotic Left Main Coronary Artery Disease and Serum Cholesterol Levels as Assessed with Serial Long-Term (≥12 Months) Follow-Up Intravascular Ultrasound

Background - The relation between serum lipids and risk of coronary events has been established, but there are no data demonstrating directly the relation between serum low-density lipoprotein (LDL) cholesterol and high-density lipoprotein (HDL) cholesterol versus serial changes in coronary plaque dimensions. Methods and Results - We performed standard analyses of serial intravascular ultrasound (IVUS) studies of 60 left main coronary arteries obtained 18.3±9.4 months apart to evaluate progression and regression of mild atherosclerotic plaques in relation to serum cholesterol levels. Overall, there was (1) a positive linear relation between LDL cholesterol and the annual changes in plaque plus media (P&M) cross-sectional area (CSA) (r=0.41, P<0.0001) with (2) an LDL value of 75 mg/dL as the cutoff when regression analysis predicted on average no annual P&M CSA increase; (3) an inverse relation between HDL cholesterol and annual changes in P&M CSA (r=-0.30, P<0.02); (4) an inverse between LDL cholesterol and annual changes in lumen CSA (r=-0.32, P<0.01); and (5) no relation between LDL and HDL cholesterol and the annual changes in total arterial CSA (remodeling). Despite similar baseline IVUS characteristics, patients with an LDL cholesterol level ≥ 120 mg/dL showed more annual P&M CSA progression and lumen reduction than patients with lower LDL cholesterol. Conclusions - There is a positive linear relation between LDL cholesterol and annual changes in plaque size, with an LDL value of 75 mg/dL predicting, on average, no plaque progression. HDL cholesterol shows an inverse relation with annual changes in plaque size.