In a previous trial (LOV111858/OM6), subjects received in a double-blind fashion either 4 g/day of Lovaza® (omega-3-ethyl esters) [formerly known as Omacor] co-administered with simvastatin 40 mg/day or placebo co-administered with simvastatin 40 mg/day for 8 weeks. This extension trial, LOV111818/OM6X assessed the continued efficacy and safety of Lovaza® (omega-3-ethyl esters) co-administered with simvastatin 40 mg vs. switching from simvastatin plus placebo to simvastatin plus Lovaza® for lowering non-High Density Lipoprotein-Cholesterol (non-HDL-C) levels at 4 months (primary endpoint) and additionally at 12 and 24 months.