Immediate release niacin effect at stratified lipid levels

BackgroundThe Coronary Drug Project demonstrated a significant decrease in non-fatal myocardial infarction, and total mortality using immediate release niacin (IRN). However, AIM-HIGH and HPS-2-THRIVE showed no additional benefit from adding niacin to statin therapy.ObjectiveTo evaluate the efficacy and tolerability of IRN on low-density-lipoprotein-cholesterol (LDL-C), high-density-lipoprotein-cholesterol (HDL-C), triglycerides, and lipoprotein (a) (Lpa) at stratified lipid levels in a monotherapy IRN group (MTG) and a combined therapy group (CTG) statin + IRN.MethodsWe retrospectively studied 185 patients who were prescribed IRN for elevated LDL-C, triglycerides, lipoprotein a (Lpa), or low HDL-C. All patients used the same IRN products.Results157 patients had complete records. (MTG = 74 patients, CTG = 83 patients with 68 combined with statins). Mean IRN dose = 2474 mg. Mean duration = 3.05 years.If initial LDL-C was < 130, LDL-C did not decrease significantly with IRN. If initial LDL-C > = 130, LDL-C decreased 35% in MTG vs. 32% decrease in CTG. If initial HDL-C < 40, there was a 40% increase in MTG vs. 61% increase in CTG. If initial triglycerides > 150, there was a 48% decrease in MTG vs. 54% decrease in CTG. Lpa decreased 49% for all patients with initially elevated Lpa. Data except for LDL-C < 130 were significant (p < .001).ConclusionLowering LDL-C is the corner stone for decreasing cardiovascular events. IRN reduces LDL-C significantly when initial LDL-C > 130, but not significantly when LDL-C < 130. Patients in AIM-HIGH and HPS-2-THIRVE received statin therapy causing very low initial LDL-C. Our results may explain why adding niacin to statin therapy failed in AIM-HIGH and HPS-2-THRIVE since niacin did not further lower LDL-C.