FRIDAY, Sept. 24, 2004 (HealthDay News) -- Heart attack prevention has just taken another step with the U.S. Food and Drug Administration's go-ahead for one of the nation's best-selling cholesterol-lowering drugs to be used by people whose cholesterol levels are not elevated.
Why would anyone without an overt cholesterol problem want to take a statin, the class of drugs that Pfizer Pharmaceutical's Lipitor falls under? The reason, researchers say, is because there are a great number of people who have other health problems that indicate higher-than-average heart attack risk, and statins may help reduce that risk.
The FDA approval opened the door for Pfizer to label and market atorvastatin (Lipitor's generic name) for individuals whose near-normal cholesterol levels may be offset by high blood pressure. They may also exhibit other risk factors that include obesity, smoking, diabetes or a family history of cardiovascular disease.
"This use for statins represents a significant advance in preventing individuals from having a first heart attack," said Dr. Jerome D. Cohen, a professor of internal medicine and cardiology at the St. Louis University School of Medicine. "It's evident that statins are even more powerful than we originally thought, including having benefits for individuals whose cholesterol levels are not elevated, but who have other risk factors that may contribute to a heart attack, stroke or other cardiovascular condition."
Atorvastatin is one of five statins presently approved for the U.S. market. The others are lovastatin (Mevacor), simvastatin (Zocor), pravastatin (Pravachol) and fluvastatin (Lescol). The newest drug in the field is a combination of ezetimibe and simvastatin (Vytorin).
All statins work about the same -- by inhibiting an enzyme that controls the rate of cholesterol production and increasing the liver's ability to remove LDL cholesterol already in the blood.
LDL is the so-called "bad" cholesterol. When too much of it circulates in the blood, it can build up in arteries that feed the heart and brain. Together with other substances it forms plaque, a thick, hard deposit that clogs the arteries -- a condition known as atherosclerosis. When a clot blocks a narrowed artery, a heart attack or stroke often follows.
LDL cholesterol of less than 100 milligrams per deciliter (mg/dL) is considered the best level; the National Cholesterol Education Program's new guidelines recommend the option of reducing LDL cholesterol to less than 70 mg/dL for those at high risk of heart attack or death.
"High" LDL level is defined as more than 160 mg/dL for individuals with no more than one risk factor for cardiovascular disease; or 130 mg/dL for individuals with at least two risk factors, with the option of reducing that to 100 mg/dL.
In clinical trials during the 1990s, statins were demonstrated to significantly reduce high levels of total and LDL cholesterol. In addition, their use was linked to lower triglyceride levels and to modest increases in HDL cholesterol, often called the "good cholesterol." These effects translated into significant reductions in heart attacks and heart disease deaths. As a result, statins quickly became the drug of choice when individuals at risk for heart disease needed a cholesterol-lowering medication.
The early August 2004 FDA approval of statins for those whose cholesterol levels are essentially normal was based on evidence from an extensive clinical trial in England that followed about 10,300 patients with normal or borderline high cholesterol levels. That study was originally published in the June 2003 issue of the The Lancet.
That research shows that lowering cholesterol levels -- even in those whose cholesterol levels were not high enough to be a medical concern -- can reduce the risk of heart attacks and strokes, said Dr. David Waters, chief of cardiology at the University of California, San Francisco. "When a person's overall risk for a heart attack is high, for whatever reason, this suggests that it's wise to treat all of the factors we know are associated with coronary disease, including achieving a reduction in their cholesterol levels."
Cohen and Waters agree that statins are well tolerated by most patients, and that serious side effects are rare.
The American Heart Association has a wealth of information about cholesterol and cholesterol measures, including statins.