A large new study suggests that millions more people could benefit from taking the cholesterol-lowering drugs known as statins, even if they have low cholesterol.
The drugs can halve the risk of heart attacks, strokes and death in seemingly healthy patients, and a simple blood test can spot those who appear healthy but are at increased risk.
The study, involving nearly 18,000 people worldwide, could dramatically change the treatment of cardiovascular disease. The effects were so beneficial that the planned four-year study was halted after less than two years, researchers said Sunday.
"These are very, very dramatic findings," said Dr. Elizabeth Nabel, director of the National Heart, Lung and Blood Institute.
The study, presented Sunday at an American Heart Association convention in New Orleans, tested statin treatment in men 50 and older and in women 60 and older who did not have high cholesterol or histories of heart disease. What they did have was high levels of a protein called high-sensitivity C-reactive protein, or CRP, which indicates inflammation in the body.
The study found that the risk of heart attack was more than cut in half for people who took statins.
Those people were also almost 50 percent less likely to suffer a stroke or need angioplasty or bypass surgery, and they were 20 percent less likely to die.
Scientists said the research could provide clues on how to address a long-confounding statistic: that half of heart attacks and strokes occur in people without high cholesterol.
"These are findings that are really going to impact the practice of cardiology in the country," said Nabel, whose institute was not involved in the research.
Several leading authorities predicted the findings would prompt many doctors to start routinely screening middle-aged patients for inflammation with the $20 test and begin prescribing the statin used in the study, or one of the less expensive generic versions, to those who get worrisome results. All such drugs reduce inflammation.
The traditional model for how heart attacks and strokes occur is that high cholesterol causes fatty buildups to slowly accumulate inside arteries supplying blood to the heart and brain, but about half of all heart attacks and strokes occur in people whose cholesterol is normal. That has raised questions about what other factors may be involved and how more deaths could be prevented.
"This has been the puzzle," said the leader of the study, Dr. Paul Ridker. "How do we identify these people and prevent disease in these folks?"
Evidence has been building that inflammation, part of the body's defense against infection and injuries, may play a crucial role by causing the most vulnerable plaques inside arteries to rupture, triggering blood clots that finally block blood flow. The blood test detects inflammation by measuring CRP, which statins drive down.
Some experts, however, worried about rushing millions of healthy people onto powerful drugs.
"This would be a huge expansion of the boundaries of drug therapy," said Mark Hlatky of Stanford University, who wrote an editorial that will accompany a paper describing the findings in the New England Journal of Medicine. "I think we need to be careful before we radically change what we do. Nothing is risk-free."
Because heart disease is a complex illness affected by many risk factors — including smoking, hypertension, being overweight and a family history of heart disease — most researchers said high CRP alone should not justify prescribing statins to people who have never had heart problems.
Some experts cautioned against testing people for CRP unless they had other indications of being at risk for heart disease, and they said more research was needed to pinpoint the patients for whom the benefit of statins outweighs the risks. Others recommended testing more frequently and using statins for people with low cholesterol if they have high CRP and some other risk factors.
Nabel said national panels were likely to revise their official guidelines for doctors, which she described as "silent on CRP," to recommend CRP testing and statin therapy for some people not previously considered candidates.
Current practice, she said, is to treat people with high cholesterol with statins, and to counsel people at low risk for heart disease about diet and exercise.
"What cardiologists have never known what to do about is the intermediate range" of patients, Nabel said, who may be overweight, smoke or have hypertension, but do not have the most serious red flags of high cholesterol or diabetes. "I think CRP will emerge as a new risk factor added to traditional risk factors."
Ridker, director of the Center for Cardiovascular Disease Prevention at Brigham and Women's Hospital in Boston, said his team estimated that expanding statin use to the types of patients he studied could prevent about 250,000 heart attacks, strokes, vascular procedures or cardiac deaths over five years.
Some experts not involved in the Jupiter study said several million more Americans should probably be taking statins. About 16-million to 20-million Americans are taking statins.
Several experts said that although the research was significant and would affect clinical practice, the study as published in the journal did not give enough detailed information to indicate exactly which patients should be tested for CRP or given statins.
The trial was one of the few to test statins that included many women, Hispanics and blacks, groups that all showed similar benefit from statins.
Like many clinical trials, Jupiter was sponsored by a pharmaceutical company, in this case AstraZeneca. It makes the drug in the trial, rosuvastatin, which is sold as Crestor. The most potent statin on the market, Crestor has been criticized by consumer health advocates who say it is more likely to cause some rare side effects of statins — muscle deterioration and kidney problems.
But in the Jupiter study, people who got rosuvastatin, showed no increase in muscle or kidney problems. There was a small increase in diabetes.
Dr. Timothy Gardner, president of the American Heart Association, said some recent statin trials "have been either negative or in some ways concerning in terms of complications," but, he added, "this one is pretty clearly a winner for statin therapy."
Dr. Ridker, a co-inventor of a CRP test, has consulted for or received research money from companies that make statins.
Although Crestor, which has 9 percent of the American cholesterol-lowering market, was used in this study, several experts said it seemed likely that the effect would be the same for other statins in appropriate doses, including much cheaper generics.
Information from the Associated Press and New York Times was used in this report.