The cholesterol/statin story starts in the early 1980s. Here’s a quick summary:
By 1985, studies showed conclusively that statins (the best known one then was Mevacor/lovastatin) substantially reduced the risk of another heart attack in people who had already had one. Into the 1990s, further research found that people who were at high risk of a heart attack (smokers, overweight, diabetes, family history, etc.) but who had not yet had a heart attack also benefited from taking statins, in terms of a reduced risk of both fatal and non-fatal heart attacks and strokes.
The pinpointed mechanism: statins reduced the levels in the blood of so-called “bad” cholesterol (low-density lipoprotein, or LDL, cholesterol). Levels of LDL and total cholesterol were linked to dietary intake of high fat and cholesterol-rich foods such as meat, eggs, and high fat dairy products. All this led to broad public health advice to get your blood cholesterol levels checked regularly, lower the amount of fat and cholesterol in your diet, and exercise regularly.
A whole generation paid attention.
These developments also triggered an explosion of statin prescriptions, with new statins emerging, such as Lipitor, which—aided by aggressive marketing—soon became one of the most widely prescribed drugs in the country.
In the late 1990s and into the 2000s, studies began to show that even people who were not at particularly high risk but who had one or two risk factors (especially high blood pressure and diabetes) had their chances of having a heart attack or stroke reduced by taking statins.
As a result, health officials and medical groups from 2002 to 2007 issued treatment guidelines that everyone aim to lower their LDL to certain target levels, mainly through diet, exercise, and life style changes. In addition, they advised that people with an LDL above a certain level and at least one risk factor (especially diabetes) take a statin.
Doctors embraced the guidelines with near religious fervor. But they also went further, again with a marketing push from drug companies. They began to prescribe statins to millions of people who had marginally higher-than-desired LDL and no risk factors, other than perhaps age. Some even prescribed the drugs to men whose LDLs were in the normal range but perhaps were a bit overweight. After all, the drugs looked very safe to use long-term, and all the studies indicated that the lower your LDL the better in terms of heart disease risk.
By 2008, one in four people over age 50 were taking a statin.
Lo and behold, it wasn’t long before studies (some funded by drug companies) backed up the practice of prescribing statins to people over age 50 even if they didn’t have any other risk factors. Doctors call this “primary prevention.”
That brings us to 2013 when the American Heart Association and American College of Cardiology changed the game in a highly publicized and somewhat controversial guideline. Instead of basing statin treatment somewhat arbitrary LDL levels, they recommended basing the decision on a simple assessment of heart disease and stroke risk. That would be assessed via an online tool that factors in age and just a few other risk factors, and then spits out a 10-year risk. If the risk is 7.5 percent or higher over a 10-year period, a statin is in order.
The new guideline drew praise and criticism. Subsequent analyses showed it meant that 8 to 13 million more people aged 40 to 75 should take statins compared to under the old guidelines. That would bring the total to 56 million people, or half the people in that age range.
Yikes, could that be right? Front line doctors were skeptical and cautious, fearing that the drugs were perhaps now truly being oversold. And prescription data for 2014 show doctors didn’t jump on the bandwagon this time; statin prescriptions were fairly flat from 2013 to 2014.
That brings us to this month, with the publication of two studies in the Journal of the American Medical Association. Both lend pretty strong support to the 2013 guidelines, and confirm other recent findings. One of the studies looked at about 2,400 people who were not taking statins between 2002 and 2005 but who had a test for calcium build-up in their coronary arteries. Looking back at their risks then and what happened to them over the next nine years, the researchers concluded that the online risk calculator and the 7.5 percent cut-off did a better job than the old guidelines of predicting who would have developed cardiovascular problems. One metric: Only one percent of people deemed ineligible for statin treatment under the new guidelines had a heart attack or stroke over the nine years versus 2.4 percent deemed ineligible under the old guidelines. When applied to the population at large, that difference is pretty big.
The second study was a simulation focused on the cost effectiveness of treating so many more people with statins. It calculated the cost and outcome if everyone aged 40 to 75 who fit the 7.5 percent-or-higher risk cutoff were put on statins, most of which are available as inexpensive generics. Yes, it’s cost effective, very much so. In fact, statin treatment is cost-effective, the researchers concluded, even if you reduce the treatment guideline cut-off to a 3 percent risk of heart attack or stroke over 10 years (which would mean about two-thirds of people aged 40 to 75 would be taking the drugs). Doing so would cost about four times more but prevent 161,500 heart attacks and other heart disease events over 10 years—an acceptable benefit for the money.
Part of the explanation for the benefits of the new statin guidelines is simple math: there are far more people at the low end of the heart disease risk scale than at the high end, such that shear volume means they’ll have more cardiovascular events that higher-risk people. Thus identifying and treating them holds potential for preventing more heart attacks than previously thought.
The limiting factor as a matter of public policy is cost effectiveness. It’s critical that statins are now available as inexpensive generics. But the calculus is also driven by risk statistics and volume of people. For example, if statin treatment was initiated at a 2 percent chance of a cardiovascular event over 10 years, the population cost skyrockets and it’s is not worth it.
What should you do? I’m not a doc but I spoke to a couple for this piece and the bottom line is this:
(a) The benefits of statins are very clear but the drugs do pose some side effect risk (of muscle weakness and diabetes, for example, but those are associated mostly with higher doses)
(b) Do the online risk calculator questionnaire– it only takes a few minutes but you’ll need your latest blood test results and blood pressure reading
(c) Discuss the results and the issue with your doctor. The decision is still an individual one based on your preferences, general health, feelings about taking a pill everyday for the rest of your life, etc.
(d) Bear in mind that statins don’t eliminate the risk of heart attacks or strokes. For example, just over 3 percent of men and 1.8 percent of women aged 40 to 59 will have a heart attack. The numbers rise with age, to 10 percent of men and 4 percent of women aged 60 to 79. Taking a statin might lower than chance by 20 to 40 percent.
(e) Consider diet and lifestyle changes first if your 10-year risk is lower than 10 percent, especially if you are overweight. And read this Consumer Reports for overall guidance and an assessment of the statin drugs.
My result on the risk calculator was 7.7 percent. I’ve been taking a low dose generic statin for 10 years. My total cholesterol was 177 in 2014. I don’t have high blood pressure or diabetes. I exercise regularly. Still, I plan to continue taking the pill for now, though I do have occasional mild muscle weakness some mornings.
Steven Findlay is an independent journalist who covers medicine and healthcare policy and technology.
No comments:
Post a Comment