OBJECTIVES: Numerous trials have shown that lowering LDL cholesterol (LDL-C) reduces CVD events; however, at any LDL-C level, residual risk remains. LDL particle concentration (LDL-P) may be a better predictor of events, but no studies have evaluated its cost-effectiveness. We used the Archimedes model to evaluate the cost-effectiveness of using LDL-C or LDL-P in preventing cardiovascular disease in dyslipidemic patients. METHODS: Archimedes is a highly detailed, large-scale simulation model of physiology, disease and health care systems. We created a simulated population of 1,000,000 individuals age 20-84 reflective of real subjects in the NHANES dataset. Because NHANES does not contain LDL-P values, they were imputed maintaining covariance with other biomarkers. The study had three arms:

• Control: subjects evaluated for therapy for elevated LDL-C and treated with statins to LDL-C goals outlined in ATP-III;
• LDL-P Alone: subjects evaluated and treated based solely on their LDL-P values;
• Dual Arm: subjects evaluated by LDL-C but treated to both LDL-C and LPL-P recommended goals.

RESULTS: In the general population, the costs per quality-adjusted life year (QALY) associated with the use of LDL-P alone were $76,052 at 5 years and $8,913 at 20 years and with the use of both markers were $142,825 at 5 years and $25,505 at 20 years. In high-risk subpopulations, the use of LDL-P alone was cost-saving at 5 years; whereas the cost per QALY for the use of both markers was $14,250 at 5 years and $859 at 20 years for high-risk dyslipidemics, $19,192 at 5 years and $649 at 20 years for diabetics, and $9,030 at 5 years and $7,268 at 20 years for patients with prior CHD. CONCLUSIONS: Utilizing LDL-P to guide statin therapy is cost-effective in the long term for the general population, and cost-saving or cost-effective in the short term for high-risk patients.