May 27, 2011
Heart Risk Not Reduced After Taking Niacin
U.S. government researchers said on Thursday that giving a high dose of niacin to people with heart disease who are already taking a cholesterol-lowering statin does nothing more to prevent heart attacks and strokes.
The findings challenge the notion that raising high-density lipoprotein (HDL) can further reduce heart risks in people who already have their low-density lipoprotein (LDL) under control.
Patients in the study who had a history of heart disease were treated with Abbott Laboratories' Niaspan and Merck & Co Inc.'s Zocor.
Researchers said Niaspan raised levels of HDL, but that did not translate into fewer fatal and non-fatal heart problems.
"Although we did not see the expected clinical benefit, we have answered an important scientific question about treatment for cardiovascular disease," Dr. Susan Shurin, acting director of the National Heart, Lung, and Blood Institute, part of the National Institutes of Health, said in a statement.
Niacin has been known to raise HDL and lower triglycerides, which is another type of blood fat that raises heart risks.
Millions of heart patients taking niacin to raise HDL and lower triglycerides do so on the assumption that this will reduce heart attacks.
"This sends us back to the drawing board," Shurin said during a conference call.
"Either the approach to raise HDL was not effective, or HDL is not a good target," she said.
The study involved 3,414 volunteers in the U.S. and Canada who were taking a statin to keep their LDL cholesterol low. Over half had suffered a heart attack before entering the trial.
The volunteers were given Zocor, and 515 patients were given a second LDL cholesterol-lowering drug to ensure their LDL stayed in low levels.
Researchers said the drug performed as expected by raising HDL by about 28 percent and lowering triglycerides by about 25 percent.
An independent panel looked at the interim results of the study last month and found that high-dose niacin offered no benefits beyond statins alone in reducing heart complications.
Abbott said the relevance of the findings outside the type of patients in the study "is currently unknown and it would be premature to extrapolate these results to a broader patient population at this time."
The U.S. Food and Drug Administration (FDA) said it will review the study but has made no new recommendations about niacin alone or in combination with statins.
The study is the latest to raise questions about whether increasing HDL helps prevent heart problems.
Study co-leader Dr. William Boden of the University at Buffalo said it is not clear if niacin would have any effect on people at higher risk of those who do not have a diagnosis of heart disease yet but take niacin as a preventive.
"We can't generalize these findings ... to patients that we didn't study," he said in a statement.
On the Net:
- Abbott Laboratories
- Merck & Co Inc
- National Heart, Lung, and Blood Institute
- University at Buffalo