A heart scan that checks for hardening of the arteries is a better way to predict who will benefit from cholesterol-fighting statin drugs, U.S. researchers said on Tuesday in a finding that could reduce the number of people who take statins.
The researchers said the vast majority of heart attacks, strokes and deaths occur in people who have a measurable buildup of artery-hardening calcium in their blood vessels.
Only those patients are likely to need to take statins — the world's top-selling prescribed drugs — to protect them from an impending heart attack.
"Our results tell us that only those with calcium buildup in their arteries have a clear benefit from statin therapy," said Dr. Michael Blaha of Johns Hopkins University School of Medicine, who presented his findings at the American Heart Association meeting in Chicago.
The study vastly rolls back the number of people who should be treated with statins. Statins lower low-density lipoprotein or LDL, the bad kind of cholesterol, and a steady drumbeat of studies in recent years have expanded the potential pool of people who might benefit from taking them.
A major heart study two years ago dubbed Jupiter found giving the AstraZeneca drug Crestor or rosuvastatin to people with average to low cholesterol but other heart risks cut the risk of heart attacks and strokes by half.
In that study, patients had low cholesterol but high levels of C-reactive protein, or CRP, a sign of inflammation that could mean a higher risk of heart attacks or strokes.
WHO WILL BENEFIT MOST FROM STATINS?
Blaha said his team had been working on ways to narrow down who will really benefit from taking a statin.
For their study, they identified a group of nearly 1,500 patients who were similar to the Jupiter population -- people with normal cholesterol and high CRP levels. They gave those patients a CT heart scan to check for calcium buildup and followed them for about five years.
They found most heart attacks — 75 percent — occurred in people with a high buildup of calcium in their arteries — the top 25 percent in the study.
"We think we've shown it's very unlikely for someone with no coronary calcium to get any benefit in the near-term from taking statins," Blaha said.
He said with the CRP test, doctors would have to treat 94 people to prevent one heart attack. But in the group with high calcium buildup in their arteries, doctors only need to treat 24 patients for one person to benefit.
Blaha said measuring calcium buildup in the arteries costs about $200 per scan and delivers a relatively low radiation dose — about the same amount as 10 chest X-rays.
Dr. Robert Bonow of Northwestern University in Chicago and past president of the American Heart Association said the study confirmed earlier findings that calcium scores can help identify who will benefit from taking statins.
"You would not want to do this to everyone in the world," he said. "You would first do a risk assessment, and then target it to that group of people."
Coronary heart disease is the leading cause of death in the United States, killing one in five adults.
Pfizer's Lipitor or atorvastatin has global sales of more than $10 billion while AstraZeneca's Crestor has global sales of more than $5 billion.