Giving statin drugs within 24 hours of a heart attack decreases the short-term death rate by more than 50%, according to a study published Monday.
The study suggested that statins, now widely used to lower cholesterol levels, might have a powerful effect in decreasing the inflammation of heart muscle that occurs immediately after an attack.
But several experts expressed doubt about the dramatic results, arguing that the study was poorly conceived.
“The idea that you would see such a huge benefit so quickly is hard to accept,” said Dr. Steven E. Nissen, a statin expert at the Cleveland Clinic Foundation in Ohio and a well-known advocate of the drugs.
Lead researcher Dr. Gregg C. Fonarow, a professor of cardiology at UCLA, said he also was surprised at the results, but “this is what we observed in 170,000 patients.”
“This is the first large-scale study looking at this protective effect,” he said.
Fonarow said a controlled clinical trial would be needed to confirm the findings, which were published in the American Journal of Cardiology.
The researchers analyzed data from 174,635 heart attacks compiled as part of a national registry from July 2000 to January 2002.
Compared with patients who never took the drugs, heart attack victims who had been on statins and continued them without interruption had a 54% lower death rate.
The reduction was 58% for patients who started taking the drugs within 24 hours of their attacks.
For patients who had been on the drugs but did not take them immediately after their attacks, the death rate rose 25% over patients who had never been on statins.
Dr. P.K. Shah, a UCLA professor and director of cardiology at Cedars-Sinai Medical Center in Los Angeles, called the results “almost too good to be true.”
He questioned the mechanism that the authors proposed to explain their findings.
“Whether you get a benefit in the first 24 hours is pretty dubious,” Shah said.
Dr. Bruce M. Psaty, a University of Washington epidemiologist, said he thought that the results were flawed because too many factors complicated the analysis.
For example, the most critically ill patients, whose treatment is focused on preventing imminent death, were probably the least likely to be prescribed a pill immediately after admission to the hospital, he said.
Known as an observational study, the new research relies on an analysis of previously collected data. The gold standard for drug tests are placebo-controlled clinical trials.
“We’ve been misled many times by observational studies like this,” Nissen said.
Both Fonarow and the study’s critics said they could see no downside to starting the drugs early, a practice that is already employed at some hospitals as a way of conditioning patients to take the drugs for their long-term cholesterol-lowering benefits.