Schering-Plough Corp., File, Associated Press
FILE - This 2004 file photo provided by Schering-Plough Corp. shows the cholesterol-lowering drug Vytorin. A major study gives a long-awaited answer on whether the blockbuster drugs Vytorin and Zetia lower the risk of heart problems.

CHICAGO — Drugmaker Merck & Co. says its cholesterol-lowering medicine ezetimibe met its main goal in a study testing whether adding it to an older type of cholesterol medicine could reduce heart risks. The drug is sold as Zetia and in combination with the statin drug Zocor as Vytorin.

Zetia and Vytorin have racked up billions of dollars in sales over more than a decade without evidence they help prevent heart attacks and strokes. The study of 18,000 people tested Vytorin versus a statin alone in people who had recently had a heart attack or worsening chest pain from a severely blocked artery. About 1.1 million people face this situation in the United States alone each year.

Doctors have long focused on lowering LDL, or bad cholesterol, to prevent heart disease. Statins like Lipitor, Crestor and Zocor are the main medicines for this, and lots of research shows they work.

Zetia, which went on sale in 2002, lowers cholesterol in a different way. It won Food and Drug Administration approval for lowering LDL, but some studies suggested that might not translate to lower risks of heart attacks and strokes. One study even questioned its safety.

Full results were to be released later Monday at an American Heart Association conference in Chicago.

Merck is based in Whitehouse Station, New Jersey.

Online:

Cholesterol info: http://tinyurl.com/2dtc5vy

Heart facts: http://circ.ahajournals.org/content/127/1/e6

Marilynn Marchione can be followed at http://twitter.com/MMarchioneAP