High-Dose Niacin Did Not Reduce Rate of Cardiovascular Events in Patients Also Taking Statins

The purpose of the trial was to discover if, in the setting of well-treated LDL (or “bad”cholesterol) and low HDL (“good” cholesterol)/elevated triglycerides, there was an incremental benefit of adding extended-release niacin.

 Niacin has long been known to raise patients’ good (HDL) cholesterol while lowering triglycerides, both factors that reduce the risk of cardiovascular disease.

William E. Boden, MD, professor of medicine in the School of Medicine and Biomedical Sciences and professor of social and preventive medicine in the School of Public Health and Health Professions, is co-principal investigator of the AIM-HIGH clinical trial with Jeffrey Probstfield, MD, professor of medicine and cardiology at the University of Washington, Seattle.

A press release issued by the NIH explains that the AIM-HIGH trial was stopped because it found that adding high dose, extended-release niacin to statin treatment in these patients with heart and cardiovascular disease, who had low HDL and elevated triglycerides, did not reduce the risk of cardiovascular events, including heart attacks and stroke.

Participants in the AIM-HIGH clinical trial were selected because even though their bad (LDL) cholesterol levels were very well controlled by statins, they were at high risk for cardiovascular events due to low levels of good (HDL) cholesterol and high levels of triglycerides.

The AIM-HIGH (Atherothrombosis Intervention in Metabolic Syndrome with Low HDL/High Triglycerides: Impact on Global Health) trial showed that while high-dose niacin (approximately 100 times greater than the recommended daily dose) raised patients’ good (HDL) cholesterol levels, it did not reduce overall cardiovascular events in this patient population.

“We now have an answer to what has been one of the most important, unanswered scientific questions about patients with high blood cholesterol and triglycerides and low levels of HDL cholesterol,” Boden explains. “The AIM-HIGH trial was stopped because it found that adding high dose, extended-release niacin to statin treatment in these patients with heart and cardiovascular disease, who had low HDL and elevated triglycerides, did not reduce the risk of cardiovascular events, including heart attacks and stroke. This is precisely why we do randomized, placebo-controlled, clinical trials. We have advanced the science of lipid management and now we have new questions to answer in the aftermath of this trial.”

The recommendation to stop the trial was made by the independent Data Safety and Monitoring Board overseeing the conduct and safety of participants in the AIM-HIGH clinical research trial.

Early data from the AIM-HIGH trial also suggest that there were more strokes in the group taking niacin, which also contributed to the decision to stop the trial, although the risk of stroke among participants in both the niacin and the placebo group was small, less than 1 percent a year.

“No previous clinical studies with niacin have shown an increased stroke risk,” says Boden, “thus, the significance of this finding is uncertain and could be due to chance.”

A specific cause for this imbalance has not been identified and the data are now being analyzed.

“The results of AIM-HIGH cannot be extrapolated to apply to a broader patient population, especially higher-risk patients admitted for heart attack or acute coronary syndrome, for example, or those whose LDL, or bad, cholesterol is not as well controlled as those in AIM-HIGH,” Boden explains.

He adds that people who are not AIM-HIGH participants who have been taking prescription niacin should not stop taking it without first consulting with their physicians.

The study findings also are not relevant to consumers who take niacin in multivitamin formulations that they purchase without a prescription.

Patient recruitment for AIM-HIGH began in early 2006. The study was scheduled to finish in late 2012. Patients were randomly assigned to receive either a prescription-level dose (up to 2,000 mg/day) of niacin or a placebo. Both groups continued to take statins.

A total of 3,414 participants were enrolled in the AIM-HIGH trial from among 95 U.S. and Canadian research centers. Sixteen patients were enrolled through the Diabetes Endocrinology Center of Western New York.

All patients have been notified that the clinical trial has been stopped and they have been directed to stop taking the medication labelled “extended release niacin or placebo.”

The AIM-HIGH investigators, sponsors and local clinic staff have expressed their sincere appreciation to participants for their dedication to this critically important study for helping answer important questions about the treatment of patients with cardiovascular disease.

The principal investigators will now complete data collection and analysis. They plan to report preliminary study outcomes at the upcoming annual scientific sessions of the American Heart Association in November 2011.