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Tuesday, March 09, 2004The findings should prompt doctors to give much higher doses of drugs known as statins to hundreds of thousands of patients who already have severe heart problems, experts said. In addition, it will probably encourage physicians to start giving the medications to millions of healthy people who are not yet on them, and to boost dosages for some of those already taking them to lower their cholesterol even more, they said. ...."This is a sea change, and I don't use that term lightly," Topol repeated in a telephone interview. "This is big. This will mean a major change in the daily practice of medicine." Maybe Dr. Topol should take a closer look at that study. (Available for free, in in its entirety here, albeit in pdf form.) The study looked at 4162 patients from around the world who were hospitalized within ten days of enrollment for an acute coronary syndrome - that is they were admitted with chest pain that ended up being caused by heart disease. Half were put on 40 mg of Pravachol (whose maker sponsored the study) and half were placed on 80 mg of Lipitor. The Pravachol dose is a commonly used dose, the Lipitor dose is much higher than routinely used. They followed the patients for 18 to 36 months, looking to see how many would die (of any cause), have a heart attack, a stroke, or have to be admitted again for unstable angina. The results are more notable for what they don't tell us than what they tell us. Rather than following patients over a given period of time and tallying the number of events each group had, they stopped the study when they had 925 events, then relied on statistics to estimate the rates. As a result, the paper deals not with actual event rates but with Kaplan-Meier event rates. A far better study would have been to look at the actual rates. But then, the significance of the findings might not have been as impressive. That is, it would have been harder to present their statistically significant findings as equally clinically significant. But even using the statistical mill, the difference between the Pravachol group and the Lipitor group wasn't that impressive. Twenty-six percent in the Pravachol group had bad outcomes compared to and twenty-two percent in the Lipitor group. (Keep in mind that those aren't acutal outcomes, just "estimated" outcomes), for a whopping 4 percent difference. Now, consider the risks of achieving that four percent estimated improvement in outcome. The authors were kind enough to present the adverse events in terms of real rates, so they're worth noting. Twenty-one percent of the patient's on Pravachol discontinued the drug during the study compared to 23 percent of those taking Lipitor. Even more worrisome, three percent of the high dose Lipitor group had to stop it because their liver enzymes were elevated above three times the normal level, compared to one percent of those in the Pravachol group. There's no mention of how many patients in each group had mildly elevated or moderately elevated liver enzymes. It's common among cardiologists to insist that patients remain on statins even if their liver enzymes are elevated, unless they're elevated above three times normal. Their world revolves around the heart, all other organs be damned. But elevated liver enzymes are a sign of liver inflammation. And chronic liver inflammation, even if mild, increases the risk of liver cancer and cirrhosis. That's why we worry about alcoholics and chronic hepatitis victims. And although there's no evidence - yet - that statins are associated with higher rates of liver cancer, we need to remember that they've only been in widespread use for the past ten years or so. There just hasn't been time to find out yet what the long term consequences of taking statins might be. Those consequences could just end up outweighing the marginal benefits that pushing the cholesterol to ever lower limits conveys. posted by Sydney on 3/09/2004 08:46:00 AM 0 comments 0 Comments: |
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