A clinical trial which compared statin only treatment versus niacin combined with statins was stopped 18 months early because the combination treatment made no difference to the risk of cardiovascular events, including stroke and heart attacks, the National Heart, Lung, and Blood Institute informed today.
Niacin is also known as Vitamin B3.
The trial, called AIM-HIGH (Atherothrombosis Intervention in Metabolic Syndrome with Low HDL/High Triglycerides), specifically wanted to determine whether patients with heart and vascular disease might benefit from high dose, extended-release niacin treatment added to their statin therapy.
The trial selected patients who were still at risk of having a cardiovascular event despite well-controlled LDL (low-density lipoprotein). Their risk was already higher because they had a history of cardiovascular disease, as well as high triglycerides and high HDL levels.
Low HDL levels combined with high triglycerides are linked to a higher chance of having a cardiovascular event. However, it has never been shown that raising HDL levels lowers cardiovascular events risk.
In the trial, those on the high dose, extended release niacin plus statin treatment had higher HDL cholesterol and lower triglyceride levels compared to those on just stains. Even so, the combination-treatment patients did not experience any reduction in fatal or non-fatal heart attacks, strokes or hospitalizations. Neither were their risk of needing a revascularization procedure reduced.
Susan B. Shurin, M.D., acting director of the NHLBI, said:
“Seeking new and improved ways to manage cholesterol levels is vital in the battle against cardiovascular disease. This study sought to confirm earlier and smaller studies. Although we did not see the expected clinical benefit, we have answered an important scientific question about treatment for cardiovascular disease. We thank the research volunteers whose participation is key in advancing our knowledge in this critical public health area, and the dedicated investigators who conducted the study.”
The trial involved 3,414 American and Canadian patients, all of them with a history of cardiovascular disease and were taking a statin medication to control their LDL cholesterol levels. They also had low HDL cholesterol and high triglycerides, meaning they were at high risk of future cardiovascular events.
Niacin raises HDL and lowers triglycerides, this has been known for a while. 1,718 participants were randomly selected to either receive high dose, extended-release Niaspan (niacin) in doses that gradually increased to 2,000 mg per day and another 1,696 received a placebo treatment. All of them were prescribed Zocor (simvastatin), and 595 were given ezetimibe (Zetia) as a second LDL cholesterol lowering drug, so as to keep LDL cholesterol levels at the target range between 40 and 80 mg/dL.
Recruitment started in 2006 and the trial was to last until 2012. Patients had an average age of 64. 92% already had coronary artery disease, 81% metabolic syndrome, 71% hypertension, and 34% diabetes. Over 50% had had a heart attack before the study began.
Jeffrey Probstfield, M.D., AIM-HIGH co-principal investigator and professor of medicine and epidemiology at the University of Washington, Seattle, said:
“The lack of effect on cardiovascular events is unexpected and a striking contrast to the results of previous trials and observational studies. The AIM-HIGH findings do not support the trial’s hypothesis that, in the population studied, adding extended-release niacin to simvastatin in participants with well-controlled LDL cholesterol can provide additional clinical benefit.”
William E. Boden, M.D., AIM-HIGH co-principal investigator and professor of medicine and preventive medicine at the University at Buffalo, N.Y., said:
“The results from AIM-HIGH should not be extrapolated to apply to potentially higher-risk patients such as those with acute heart attack or acute coronary syndromes, or in patients whose LDL cholesterol is not as well-controlled as those in AIM-HIGH.”
Written by Christian Nordqvist