Niacin AIM HIGH study


 * Associate Editor(s)-In-Chief: Priyamvada Singh, M.B.B.S. [mailto:psingh@perfuse.org]

Overview
The results of the AIM HIGH study were recently presented in AHA 2011 held at Orlando, Florida. The study hypothesis was that raising HDL cholesterol by adding Niaspan (extended release niacin) to simvastatin would provide an additional 25% reduction in cardiovascular events in patients with established cardiovascular disease and well-controlled LDL cholesterol levels. However, an early termination of the study was done as an interim analysis found that combination therapy do not result in an additional reduction in cardiovascular events beyond treatment with simvastatin in the patients with well-controlled LDL cholesterol. The inclusion criteria was very tight (small % of high-risk patients who reach their guideline-recommended lipid treatment goals) thus decreasing the external validity or generalizability. Thus, the results from the study should not be applied beyond the patient population studied.

==AIM HIGH study ==


 * Funding - National Heart, Lung and Blood Institute (NHLBI) funded study.


 * Hypothesis - Raising HDL cholesterol by adding Niaspan to simvastatin would provide an additional 25% reduction in cardiovascular outcomes in patients with established cardiovascular disease and well-controlled LDL cholesterol levels.


 * Study design
 * Patient population
 * Approximately 3000 patients
 * Randomized placebo controlled
 * Duration of study - 3 years
 * Intervention - Extended-release niacin, 1.5 to 2g / day, or active placebo (very low doses of niacin) + all patients received simvastatin, (40 to 80 mg / day), + ezetimibe, 10 mg / day, if needed, to maintain an LDL cholesterol level of 40 to 80 mg/dL
 * Primary end point - MACE, composite of death from coronary heart disease, nonfatal myocardial infarction, ischemic stroke, hospitalization for an acute coronary syndrome, or coronary or cerebral revascularization.
 * Patients with stable established cardiovascular disease with well-controlled lipid levels at the start of the study. Current treatment guidelines would not recommended additional lipid therapy for these patents.


 * Limitations
 * The inclusion criteria was very narrow (small percentage of high-risk patients who reach their guideline-recommended lipid treatment goals) thus decreasing the external validity or generalizability. Thus, the results from the study should not be applied beyond the patient population studied.


 * Results - Early termination of the study as an interim analysis showed lack of efficacy due to the intervention (it found that combination therapy did not result in an additional reduction in cardiovascular events beyond treatment with simvastatin in the patients with well-controlled LDL cholesterol and non-HDL-cholesterol).

In a narrow cohort of patients with cardiovascular disease and well controlled LDL cholesterol levels (< 70 mg per dL), there was no statistically significant clinical benefits from the addition of niacin to statin therapy.
 * Conclusions

Heart Protection Study 2 Treatment of HDL to Reduce the Incidence of Vascular Events (HPS2-THRIVE)
Failure and early termination of the AIM-HIGH study has raised curiosity towards this ongoing clinical trial called (HPS2-THRIVE) which is trying to assess whether a combination of extended-release niacin and a prostaglandin D2 blocker will be successful in preventing myocardial infarction, stroke, or revascularization in cardiovascular patients. Approximately, 20,000 patients are planned to be enrolled in this study.