Dr. Terje Pedersen, the Norwegian cardiologist who conducted the trial, said he also doubted that Vytorin caused the excess of cancers seen in the study.

People who have trouble getting a decent night's sleep may also face a higher risk of heart attack, Norwegian researchers report.

Researchers examined hospital records and Norway's National Cause of Death Registry to identify 2, 368 people who had first-time heart attacks during the following 11 years.