LOS ANGELES -- A major new study of a cholesterol-lowering drug has found that it can shrink the fatty deposits in coronary arteries that are linked to heart attacks.
The findings, in a study of the drug lovastatin, hold the promise that significant progress can ultimately be made in reducing the toll from heart disease, the leading killer in the United States and most developed countries.
The results of the study add to the evidence that a low-fat diet and drugs can halt and reverse the buildup of fatty deposits, or plaque, in arteries in a process known as atherosclerosis, but it is the first suggestion that a single drug could have that effect.
The benefits of the drug, in combination with diet changes, were so readily apparent that the study, a two-year project with an optional two-year extension, was not continued after the first phase. An independent safety monitoring committee said it would not be ethical to continue to give some participants a placebo rather than lovastatin. One million Americans are already taking the drug, sold by prescription under the name Mevacor, to lower blood levels of cholesterol.
The researchers from the University of Southern California here, who conducted the study for Merck & Co. of Rahway, N.J., the drug's maker, refused to discuss the new findings in detail other than to confirm them. A part of the study was also conducted at the University of Wisconsin in Madison.
In an interview, the head of the research team, Dr. David H. Blankenhorn of the University of Southern California, said he was withholding details for fear of jeopardizing his chances of reporting the findings in a scientific journal. He had been scheduled to make a presentation last week to the annual meeting of the American Heart Association in Anaheim. But he canceled his presentation in August after learning that there were strong hints of favorable results from the study.
The final recommendation to stop the study was not made until the eve of last week's meeting, leaving him too little time to prepare adequately, he said.
Many doctors believed until recent years that the buildup of plaque advanced inexorably to its conclusion, blocked coronary and other arteries. The deposits build up over years to narrow the arteries and promote the formation of blockages that impede and eventually stop blood flow, killing heart muscle cells and causing a heart attack.
Since 1967, more than 20 studies from centers in the United States and Europe have indicated that diet and drugs tailored to the needs of a patient can shrink plaque deposits in coronary and other arteries.
"The evidence is beginning to be compelling," Dr. Burton Sobel of Washington University in St. Louis said at a session at the meeting in Anaheim. Dr. Blankenhorn spoke at the session but did not mention the new lovastatin study.
Like many of the earlier efforts, the new study relied on angiography, in which a tube is inserted into an artery in the leg and guided to the arteries that feed the heart, to detect changes. As a radio-opaque chemical is injected, X-rays are taken in rapid sequence to get an image of the coronary arteries.
Dr. Daniel Steinberg of the University of California at San Diego, who headed the monitoring committee, said the panel had recommended that the study be stopped because "there were clearly positive results by angiography."
In the interview, Dr. Blankenhorn cautioned against premature optimism that drugs like lovastatin will have lasting benefits in preventing heart attacks and other serious ailments of the circulatory system.
"The enthusiasm for the results from the first couple of years in all of these studies has got to be tempered with long-range evaluations," he said.