Combination therapy in dyslipidemia: where are we now?

Lowering low-density lipoprotein cholesterol (LDL-C) reduces the risk of cardiovascular disease: each 1.0 mmol/L (38.7 mg/dL) reduction in LDL-C reduces the incidence of major coronary events, coronary revascularizations, and ischemic stroke by approximately 20%. Statins are a well-established treatment option for dyslipidemia, with LDL-C reduction in the range of 27-55%. Several lipid goal-driven guidelines recommend reducing LDL-C to <2.59 mmol/L (100 mg/dL) or <1.81 mmol/L (70 mg/dL) in very high-risk patients. Many patients treated with statins do not reach these goals, and remain at risk of future cardiovascular events. The 2013 American College of Cardiology/American Heart Association guidelines move away from advocating LDL-C treatment targets with focus placed on identifying patients most likely to benefit from high-intensity or moderate-intensity statin therapy. While increasing the statin dose can prove efficacious in some patients, this approach typically offers limited additional LDL-C lowering, and is associated with increased incidence of adverse side effects. Indeed, this has led to the investigation of statins in combination with other lipid-modifying agents for the treatment of dyslipidemia. This review of the evidence for statin use in combination with fibrates, niacin, bile acid sequestrants, and the cholesterol absorption inhibitor, ezetimibe, in dyslipidemic patients at increased risk of cardiovascular disease, explores the impact of such combination therapies on lipids, attainment of lipid targets, inflammatory markers, and on cardiovascular outcomes and pathology. Additionally, new and emerging dyslipidemia treatments are summarized.