In a surprising setback, a big federal study testing prescription-strength niacin as an add-on to cholesterol-lowering statins to prevent heart disease was stopped early because the niacin didn't work.
Plus, more patients taking the drug Niaspan had strokes than those who got a placebo. That potential safety issue was another factor in the decision to halt the study 18 months early, doctors involved with the research said in a media conference call Thursday.
Niacin is the most effective treatment for raising HDL, or good cholesterol. And the study aimed to find out if raising HDL and lowering triglycerides (another consequence of niacin treatment) in addition to using a statin to control LDL, or bad cholesterol, would lead to better outcomes for patients.
The answer: Niaspan didn't reduce the risk of cardiovascular events, including heart attacks and strokes. There were 5.6 such events per year for the group that got placebo — compared with 5.8 per year for those who got Niaspan.
All of the more than 3,400 patients in the study took simvastatin, the cholesterol-lowering medicine sold under the brand-name Zocor. Some also got Zetia, another cholesterol-reducer.
The federally funded trial, called AIM-HIGH, was stopped because a scheduled review by an independent safety committee in April concluded the chances that the trial, started in early 2006, would ever show the expected benefit from niacin was less than 1 in 10,000. There was also that small but significant increase in stroke.
The results deal a blow to the so-called HDL hypothesis, which holds that raising good cholesterol should lower risk of heart disease. Epidemiological studies have suggested that's the case, but this test didn't bear it out.
Dr. William Boden, one of the lead investigators on the study, conceded the researchers were unable to show any additional benefit from raising HDL in patients whose bad cholesterol was controlled so well. Still, he didn't rule out the possibility of a positive HDL effect for different types of patients.
The Food and Drug Administration recommended no changes, for now, in the instructions or use of Niaspan. But the agency will analyze the data further.