The AIM-HIGH trial was looking at the effect of adding long acting Niacin therapy to well controlled ldl statin therapy in people with vascular disease and high triglycerides. The trial was stopped early (May 2011) by the NHLBI due to lack of efficacy. Two other earlier trials (HATS and ARBITER 2) showed that Niacin was beneficial in patients with low hdl and near or sub-optimal ldl on (presumably) max statin therapy. HATS and ARBITER 2 both showed reduction in endpoint pathology with combo Niacin and statin therapy. The bottom line appears to be for now that Niacin is not beneficial when added to already aggressively controlled ldl by statin. There seems to still be a niche for Niacin when added to max tolerated statin where ldl is still not at goal and hdl is low. The results of a Niacin hdl raising treatment trial called HPS2-THRIVE is forthcoming. There is also a role for Niacin mono therapy in the setting of statin intolerance and/or very high triglyceride patients. See the link below for a summary of these issues.