Cholesterol-lowering statin drugs are already blockbuster medicines taken by 30 million people around the world. Now it turns out you still might need them if you have normal cholesterol. There’s a new risk factor in town: A protein associated with inflammation.

Taking the statin Crestor, also known as rosuvastatin, slashed the risk of heart attack by more than half in nearly 18,000 people with increased levels of the protein, called high-sensitivity C-reactive protein (CRP), according to research presented yesterday at the annual American Heart Association meeting in New Orleans. The drug reduced the chance of stroke and the need for a stent – a mesh tube propping open the heart’s blood vessels — by nearly 50 percent. It also lowered the risk of death by 20 percent. The research, funded by Crestor maker AstraZeneca, is in this week's New England Journal of Medicine.

Previous work on statins has shown the drugs reduce heart attacks and strokes, but don’t increase life span or better its quality. The JUPITER study may challenge that idea. (JUPITER stands for Justification for the Use of Statins in Primary Prevention: an Intervention Trial Evaluating Rosuvastatin.) "JUPITER should dramatically change prevention guidelines," study co-author James Willerson said in a statement. "If your high-sensitivity CRP is high, you should be on statin therapy regardless of your cholesterol level. This is an approach we can start using tomorrow."

Not so fast, says Mark Hlatky, a Stanford University health-policy professor. Hlatky criticizes JUPITER in an editorial accompanying the paper, saying the study was poorly controlled and excluded people with diabetes and uncontrolled high blood pressure. It also failed to explain how heart disease risk changed for particular groups, such as women, Hlatky writes. Crestor can cause headache, muscle and abdominal pain, weakness and nausea, according to AstraZeneca.

The study attempts to solve one piece of a vexing problem: Not everyone who suffers a heart attack has high cholesterol, and it's next to impossible to predict who's most likely to suffer from one imminently, even among people with some risks. (Remember Tim Russert’s sudden death from a heart attack? “His total cholesterol was not high, nor was his LDL, the bad type of cholesterol, or his C-reactive protein,” the New York Times reported at the time.) The Journal is polling doctors on whether the new study will change their practice.

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