Some of the top cardiologists in the country are having a public disagreement about who should take statin drugs and how to calculate the risk of heart attack or stroke - but local doctors say there's no need for panic.

The American Heart Association and the American College of Cardiology recently issued new guidelines for the prescription of statins, that potentially could double the number of Americans taking Crestor, Lipitor and similar drugs. Heart specialists called the new guidelines a "paradigm shift" because the groups' risk calculator pushed about 15 million more people into the at-risk pool for heart attack and stroke.

"If the public isn't confused, they aren't reading the newspapers," said Dr. Jim Willerson, president and medical director of the Texas Heart Institute at St. Luke's Hospital. Qualified doctors, he said, won't reactively upend the way they're treating patients anyway.Then things broke down. Two Harvard Medical School professors denounced the guidelines saying the risk assessment tool vastly exaggerates the risk pool. Officials from the two associations, however, defended their calculator and their recommendations at the American Heart Associations' annual meeting in Dallas. The result of this back and forth? A lot of confusion about statins and heart attack risk.

"I'm not interested in some calculator," Willerson said. "I don't need a calculator, and neither does any heart doctor who's had reasonable experience in caring for patients."

For years, he said, he's looked at a patient's LDL cholesterol levels, family history, blood pressure, smoking and diabetes as a combination of risk factors.

And, in fact, that's the heart of the new guidelines released last week. Until now, a patient's LDL cholesterol level (that's the bad one) was designated the sole focus for doctors prescribing statins; if your LDL was high, your doctor might put you on one of the drugs. But last week's guidelines urged doctors to weigh a number of risk factors - including overall health, personal habits and family history - to determine whether a patient might need medicine to prevent heart attack or stroke.

"The major recommendations are still valid," said Dr. William A. Zoghbi, director of cardiovascular imaging at Houston Methodist DeBakey Heart & Vascular Center. "Where some of the controversy came is in the risk calculator for people who have no symptoms or no evidence of coronary disease yet."

And while the researchers' risk calculator is under fire, Zoghbi says it will be improved.

"This is a living document," he said, designed to be updated and overhauled as new and better research comes along.

Zogbhi, who was president of the American College of Cardiology last year, said the risk calculator is really just a "risk estimator." Predicting who'll have a stroke or heart attack, he said, is similar to predicting whether it'll rain or where a hurricane will hit the coast. And the risk assessment tool, he said - flawed though it may be - wasn't designed to immediately make doctors write 15 million more prescriptions for Lipitor, no questions asked.

Ideally, Zoghbi said, the calculator simply "sparks a conversation with patients regarding the risk."

Beyond the calculator controversy, the new guidelines have drawn criticism from people who believe statins are overprescribed. Just after the guidelines became public, a New York Times editorial argued that by expanding the patient base for statins, they immediately and primarily benefit the pharmaceutical industry.

"I think that we want to have a sense of vigilance in the way that we prescribe them," said Ali Miller, a registered dietitian and certified diabetes educator. Miller owns Naturally Nourished, a Houston company that uses food and lifestyle, not medicine, to prevent and manage disease. She doesn't want to see millions of people getting new prescriptions for drugs they may take for decades.

While statins may lower cholesterol, they create other deficiencies in the body, Miller said - "deficiencies that throw everything into imbalance."

Statins work by inhibiting the enzyme HMG-CoA reductase in the liver, she said. That lowers cholesterol levels, but it also limits the body's ability to produce necessities such as serotonin and testosterone.

"I always make the joke that, yeah, your doctor pats you on the back and says, 'Good job, your cholesterol went down,'" Miller said. "But now you're getting a prescription for an antidepressant and you have erectile dysfunction."

Zoghbi, too, doesn't see statins as a cure-all. While they can help prevent heart disease, they aren't a substitute for healthy living, he said.

"Unfortunately, we have an obesity epidemic in this country," he said, and millions of people are developing risk factors for heart attack and stroke. Statins can't take the place of eating well and staying fit.

"I really think we have to go back to basics and emphasize diet, exercise, good lifestyle," Zoghbi said. "And if needed, obviously, we will use medications - including statins."