Super-Low Cholesterol Stops Heart Disease

A new study suggests that getting cholesterol to super-low levels can actually stop progression of heart disease.

A new study suggests that getting cholesterol to super-low levels can actually stop progression of heart disease. The study compared two cholesterol-lowering drugs, Lipitor and Pravachol, in more than 500 patients with heart disease. Among those taking 80 mg of Lipitor, lowering LDL “bad” cholesterol to an average of 79 mg/dL stopped progression of clogged arteries, says Steven E. Nissen, MD, the Cleveland Clinic cardiologist who headed the study. But taking 40 mg of Pravachol did not offer the same slowing effect on heart disease even though some patients were able to achieve the same super-low LDL levels. Heart disease in the Pravachol-treated patients was about 3% worse after 18 months of treatment. Lipitor’s manufacturer, Pfizer, sponsored the study. Current recommendations are to lower LDL cholesterol to less than 100 mg/dL in people with heart disease. Nissen says the results apply only to people already diagnosed with heart disease and not to persons who are taking either Lipitor or Pravacol to lower cholesterol but are otherwise healthy. Nissen says that when the study was initiated, “I was quoted as saying, ‘It’s the LDL, stupid.’ I was only partly right, it was the drug as well.” And to emphasize that point, he notes that Lipitor stopped progression of plaque in a variety of patient groups including younger and older patients as well as people with diabetes and high blood pressure. But for Pravachol it was a different story: “We were unable to stop progression in any of the subgroups in the Pravachol group,” he says. But though the study results were hailed by heart specialists gathered at the American Heart Association’s annual meeting here, the kudos were mixed with words of caution. The stunning results presented by Nissen are based on ultrasound images of the inside of arteries in beating hearts. Nissen’s study did not show that super-low cholesterol levels decreased deaths from heart disease or lowered the likelihood of having a heart attack or stroke. Nor did the study show that Lipitor is more likely to save lives than Pravachol. This ultrasound technique is still in its infancy, and no one has proved that a good result on artery ultrasound translates into a good clinical result, says Raymond J. Gibbons, MD, professor of medicine at the Mayo Clinic Medical School in Rochester, Minn. Gibbons tells WebMD that it is too soon to change clinical practice based on this one study. Both Lipitor and Pravachol are members of a class of drugs called statins, and Gibbons says that evidence-based medicine tells us that all statins reduce deaths and complications from heart disease. He says there is no need for patients taking Pravachol to change their current treatment. Other statins include Lescol, Mevacor, and Zocor. Some statins have a more powerful cholesterol-lowering effect than others. In addition to bigger drops in LDL cholesterol with Lipitor, patients taking Lipitor also had much greater reductions in C-reactive protein: 36% vs. 5%. C-reactive protein, CRP, is an inflammatory marker found in the blood. High levels of CRP have recently been identified as a heart disease risk factor. The potent anti-inflammatory effect seen with Lipitor might be a factor in the observed differences between the two treatments, says Nissen. The study results have prompted Nissen to change the way he practices medicine. He tells WebMD that he is now switching to more aggressive cholesterol-lowering treatment with Lipitor. But he says it is too soon to make general recommendations about treatment changes. Christopher Cannon, MD, associate physician in the cardiovascular division of Brigham & Women’s Hospital and an investigator in a study sponsored by Bristol-Myers Squibb, maker of Pravachol, says the study results from Nissen “are wonderful because they show that lowering LDL does appear to stop progression of the disease.” But he cautions using the ultrasound technique to measure benefit, noting that clinical results often don’t look as good as these imaging results. For example, he says that clinical studies of some anti-clotting treatments showed no benefit even though the drugs looked great on earlier imaging studies. Cannon says he is also studying Lipitor and Pravachol at the same dose but with several thousand patients. The results of his study will be presented next spring at the American College of Cardiology meeting. He says his study is one of several that are comparing clinical outcomes in patients taking different statins. (Source: American Heart Association Scientific Sessions 2003, Orlando, Fla., Nov 9-12, 2003. Steven Nissen, MD, The Cleveland Clinic. Christopher Cannon, MD, associate physician, cardiovascular division, Brigham & Women’s Hospital; assistant professor of medicine, Harvard Medical School, Boston: WebMD Health News: November 2003)