Coronary Artery Disease and Carotid Artery Disease Progress Despite Normal Lipid Levels by Standard Statin Therapy in Asymptomatic Patients without Known Coronary Artery Disease: Implications for Statin Therapy

Many mega-trials of statin therapy demonstrate that a 28% drop in LDL-cholesterol (LDL-C) in 5-year statin trial is associated with a 25% to 35% drop in CAD risk, leaving a substantial residual risk. We studied whether standard statin therapy would prevent progression of coronary artery disease (CAD) and carotid artery disease in asymptomatic patients without known CAD. We retrospectively selected 45 patients who continued statin therapy for one year and underwent multidetector computed tomography and carotid ultrasound measurement one year apart. Follow-up period was 1.37±0.49 (1.0 to 2.5) years. Total cholesterol changed from 213.2±46.2mg/dl to 196.0±34.3mg/dl (p=0.045). Triglyceride changed from 125.5±72.3mg/ dl to 107.1±58.2mg/dl (p=0.184). HDL-cholesterol changed from 60.8±15.8mg/dl to 60.0±12.3mg/dl (p=0.789). LDL-cholesterol changed from 101.7±25.2mg/dl to 102.7±23.0mg/dl (p=0.844). However coronary calcium score significantly increased (230.1±414.5 to 298.3±479.2, p=0.009) and the number of coronary plaques significantly increased (2.5±1.7 to 3.0±1.7, p=0.001). Also carotid IMT significantly increased (1.42±0.81 to 1.78±0.92, p=0.049) and the number of carotid plaques significantly increased (0.5±1.1 to 1.1±1.5, p=0.001). In conclusion, our results showed that CAD and carotid artery disease progressed significantly despite normal lipid values using standard statin therapy in asymptomatic patients without known CAD. This suggests that more intense lipid lowering will be needed to prevent progression of CAD and carotid artery disease.