AHA lipid guidelines, again
as per several prior blogs, there are (to me) significant problems with the new AHA guidelines for assessment/treatment of lipid abnormalities. one of my concerns is the very large number of people (esp men) over the age of 60 who meet criteria for statin therapy by these guidelines. i gave the following examples:
--60 yo white male, no known atherosclerotic disease, systolic blood pressure of 130 on meds, total cholesterol 130, HDL 70 (so LDL around 70) would qualify for moderate intensity statins
--60 yo african-american with same risk factors qualifies for high intensity
--all men age 70 would qualify for high intensity statins, including a white male nonsmoker with syst blood pressure of 130 and the same pristine lipids
--a 70 yo woman with similar risk profile qualifies for moderate intensity statins.
an assessment was just published of the difference between the old and new guidelines, looking at baseline data from the NHANES database of 3773 people aged 40-75 (see chol guideline AHA NHANES nejm 2014 in dropbox, or DOI: 10.1056/NEJMoa1315665). results:
--by the old guidelines (ATP-III), 42% would be eligible for statins. for the new ones, 56.6%
--this extrapolates to the 40-75 yo US population as 43.2 M adults (37.5% of the population aged 40-75) by the old guidelines qualify for statins. 56M (48.6% of the population) qualify by the new guidelines
--for adults 60-75: 30.4% of men and 21.2% of women are eligible by old guidelines; 87.4% of men and 53.6% of women by the new ones
--applying the Framingham Risk Calculator to the NHANES dataset, over 10 years we would expect 11.4M cases of cardiovasc disease (CVD) among 103.5M adults aged 40-75 without known prior CVD. by the new guidelines, 16.8% of these 11.4M adults not eligible for statins by ATPIII would now be eligible per the new AHA recs (1.9M people). if, as per the primary prevention studies, there would be 25% relative risk reduction by using statins, 475K future cardiovasc events would be avoided, 90% of which would be among older adults within this age range. (of course, this is a rough estimate, based on different sources of info, using primary prevention studies which had patients at much higher risk than in my above examples and scaling up from NHANES to the full population).
so, bottom line: the new guidelines would dramatically overtreat older people without significant atherosclerotic risk factors. on the one hand, statins are well-tolerated and perhaps it is better to overtreat in order to avoid undertreating a minority of people (increased sensitivity, decreased specificity). on the other hand, treatment is expensive, leads to medicalization/blood tests/office visits and is associated with some potentially serious adverse events (rhabdo/acute renal failure, diabetes, ???dementia, etc) as well as more common annoying effects (myalgias), which also increase health care utilization. as i have mentioned in the past, i am pretty aggressive in treating lipids in primary prevention, first by aggressive lifestyle modification if appropriate, then by statins. i have always felt that the ATPIII did not go far enough in the risk assessment [i always included periph art dz, stroke, chronic inflammatory conditions such as HIV/lupus..., A1c (which despite a recent negative study, there have been 2 dramatically positive ones over the past decade) in my gestalt risk assessment, meaning that someone with lipid abnormalities which placed them at a framingham score in the 5+% range and nonresponsive to lifestyle changes would get statins]. that being said, it is hard for me to justify using a statin on a 60-70yo man with no risk factors and an LDL of 70 and HDL of 70!!!! and my guess is that this person has a much lower relative risk reduction by statins than the high-risk patients in the primary prevention studies.
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