{"id":791,"date":"2015-08-05T08:00:16","date_gmt":"2015-08-05T08:00:16","guid":{"rendered":"http:\/\/stg-blogs.bmj.com\/bmjebmspotlight\/?p=791"},"modified":"2017-08-21T11:36:07","modified_gmt":"2017-08-21T11:36:07","slug":"primary-care-corner-with-geoffrey-modest-md-comparison-of-the-2013-accaha-lipid-guidelines-to-atpiii","status":"publish","type":"post","link":"https:\/\/stg-blogs.bmj.com\/bmjebmspotlight\/2015\/08\/05\/primary-care-corner-with-geoffrey-modest-md-comparison-of-the-2013-accaha-lipid-guidelines-to-atpiii\/","title":{"rendered":"Primary Care Corner with Geoffrey Modest MD: Comparison of the 2013 ACC\/AHA lipid guidelines to ATPIII"},"content":{"rendered":"

By: Dr. Geoffrey Modest\u00a0<\/strong><\/p>\n

A recent study assessed the accuracy of the 2013 ACC\/AHA guidelines in identifying patients in the Framingham Study\u00a0who either developed cardiovascular disease (CVD) and\/or coronary artery calcification (CAC), comparing the results to that of the prior\u00a02004 ATPIII guidelines.\u00a0(see\u00a0JAMA.\u00a02015;314(2):134-141<\/strong>\u200b). <\/span><\/p>\n

Details:<\/span><\/p>\n

–2435 statin-naive participants (mean age 51.3, 56% female, mean Framingham Risk Score —\u00a0FRS —\u00a0of 6.7%, mean LDL 121 mg\/dL, mean CAC score of 95 with 42% having CAC score >0, overwhelmingly white population) were enrolled from the longitudinal offspring and third-generation cohorts of the Framingham Study.\u00a0median followup 9.4 years.<\/span><\/p>\n

Results:<\/span><\/p>\n

–39% of patients were deemed\u00a0statin-eligible by the 2013 guidelines vs 14% by ATPIII.<\/span><\/p>\n

–There were 74 (3.0%)\u00a0incident CVD events (40 nonfatal MIs, 31 nonfatal strokes, 3 fatal coronary artery disease\/ CAD events).<\/span><\/p>\n

–Those statin-eligible by 2013 guidelines had increased HR for incident CVD vs those eligible by ATP III:\u00a0HR 6.8 (3.8-11.9) vs 3.1 (1.9-5.0), with p<0.001<\/span><\/p>\n

–by the ATP III guidelines 6.9% of those statin-eligible vs 2.4% statin-ineligible had incident CVD event. by the 2013 guidelines, 6.3% of statin-eligible had CVD and 1.0% of those statin-ineligible<\/span><\/p>\n

–for women, the numbers were smaller than for men (2.0% vs 4.4% had incident CVD). There was\u00a0a nonsignificant difference between statin-eligible and statin-ineligible by\u00a0the ATPIII guidelines, though there was a significant (p<0.001) difference in those groups by the 2013 guidelines<\/span><\/p>\n

–there were\u00a0similar results in those at intermediate Framingham Risk Score (FRS),\u00a038% of the total population\u00a0(3.9% developing CVD), but the CAC score\u00a0was significantly higher in people with intermediate FRS who developed incident CVD. 80% of this intermediate group were statin-eligible by the 2013 guidelines vs 27% by ATP III [note: the definition of intermediate FRS is somewhat complex and depended on the LDL level and number of CAD risk factors]<\/span><\/p>\n

–those with CAC scores>0 were more likely to be statin-eligible by 2013 guidelines than\u00a0ATP III (all with p<0.001):<\/span><\/p>\n

–CAC score >0 (n=1015)\u00a063% vs 23%<\/span><\/p>\n

–CAC\u00a0score >100 (n=376)\u00a080% vs 32%<\/span><\/span><\/p>\n

–CAC\u00a0score >300 (n=186)\u00a085% vs 34%<\/span><\/span><\/p>\n

–CAC score of 0 was\u00a0associated with very low CVD risk in stain-eligible people by the 2013\u00a0new guidelines, comprising 33% of the cohort, and with a CVD rate of only\u00a01.6%<\/span><\/p>\n

–if all of the patients with CAC score of 0 were considered to be statin-ineligible (ie, this was a strong negative risk factor for starting statins), there was no difference in the % of incident CVD in the statin-ineligible groups by either the ATP III or 2013 guidelines, and\u00a0a much higher % incident\u00a0CVD in the statin-eligible group [which suggests\u00a0that those with CAC=0 really would\u00a0not benefit from statins, leaving even greater benefit for those with CAC>0 who were statin-eligible by either guideline]<\/span><\/p>\n

S<\/span>everal points:<\/span><\/p>\n

–FRS did not fare well in differentiating likely\u00a0statin benefit\u00a0as compared to\u00a0the 2013 guidelines. One suggestion from the data is that perhaps a large part of the reason is that the 2013 guidelines captured more people with CAC scores>0.<\/span><\/p>\n

–the 2013 guidelines cast a much wider\u00a0net in terms of those who would be statin-eligible, which I think include a lot of people at very low risk of cardiovascular disease (see prior blogs: here\u00a0<\/a>, here<\/a>,\u00a0and here<\/a>)\u200b For\u00a0example, using the 2013 guideline risk calculator, a 60 year old white male nonsmoker with systolic BP on 130 on meds and an LDL of 70 and an HDL of 70 should get a moderate intensity statin. Same\u00a0for a\u00a045 year old African-American with the same clinical picture. So, it is not surprising that adding an additional 12.8 million adults who would get statins by the 2013 guidelines over the ATP III guidelines would lead to less heart disease, but would also\u00a0treat lots of patients at very low risk<\/span><\/p>\n

–CAC is the one CAD marker which is felt to be the most useful\u00a0of the non-traditional ones (ie, better than C-Reactive Protein —\u00a0CRP, etc)\u00a0by the American Heart Assn. \u00a0Many studies have shown that low CAC scores nearly exclude clinically important CAD (as in\u00a0the current JAMA study, with other studies finding similarly about a 1% risk in 10 years). And those with extensive CAC have 10-fold increased risk after multivariate adjustment. This really is not so surprising: the existence of any atherosclerotic disease (eg peripheral artery disease) is associated with a significantly increased risk of CAD, so showing calcification of the coronaries themselves is at least as likely to predict risk of CAD…<\/span><\/p>\n

— the\u00a0Multi-Ethnic Study of Atherosclerosis\u00a0looked at the relative risks of CRP\u00a0vs CAC\u00a0(see\u00a0Lancet 2011; 378: 684\u201392<\/strong>), following 950 people for 5.8 years, finding no association of clinical events with CRP\u00a0levels, but<\/span><\/p>\n

–47% had initial CAC scores of 0 and had\u00a0CAD\u00a0event rate of 0.8\/1000 person-years<\/span><\/p>\n

–74% of all of the CAD events were in the 25% with CAC scores >100, at a rate of 20.2 events\/1000 person-years<\/span><\/p>\n

–for CAD, the\u00a05-year\u00a0NNT for CAC=0 score was 549, but was 94 for scores 1-100, and 24 for scores >100<\/span><\/p>\n

–for CVD, the\u00a05-year\u00a0NNT\u00a0for CAC=0 score was 124, but was 54 for scores 1-100, and 19\u00a0for scores >100<\/span><\/p>\n

S<\/span>o, this new JAMA\u00a0study by itself does not add much, other than that\u00a0by really spraying statins relatively indiscriminately\u00a0all over the place, there are fewer atherosclerotic events (this would likely happen by just lowering the threshold for treatment with the old ATP III guidelines). As a person who does prescribe lots of statins (always\u00a0reinforcing lifestyle changes as well)\u00a0to many more patients than those qualifying by ATPIII criteria (including those with PAD or any evidence of atherosclerotic disease, and often those with metabolic syndrome or glucose intolerance — as\u00a0noted in prior blogs), and as someone who is pretty strongly\u00a0anti-radiation exposure (eg, see\u00a0here<\/a>), I am leaning toward including CAC as part of my CAD risk assessment (i haven’t done so yet, but am thinking pretty strongly about doing so, if covered by insurance), since:<\/span><\/p>\n

–CAC pretty directly correlates with coronary atherosclerosis and ultimately with cardiac events (and a score of 0, present in a good proportion of patients even at intermediate CAD risk,\u00a0seems to render\u00a0CVD incidence miniscule)<\/span><\/p>\n

–the actual radiation exposure is only 0.89 mSv in the MESA study, well below both the\u00a0overall background radiation (3 mSv\/year) and\u00a0the average dose in the now-accepted low dose lung CT scans for smokers (1.5 mSv and this is annually<\/span><\/strong>, though really the average annual dose is\u00a08 mSv given the number of false positives leading to more intensive radiologic investigation: see\u00a0here<\/a>). And the cost\u00a0in 2011\u00a0was about $100 for the CAC scan.<\/span><\/p>\n

–and there really are harms to prescribing statins to those who do not need them: occasional really bad adverse events (I’ve seen a couple who have had bad rhabdo, renal failure, and prolonged dialysis), more frequent less bad events (diabetes, maybe cognitive decline), troublesome events (myalgias, bad dreams…), cost of meds, cost of followup exams and labs, and increasing the medicalization of the patients.<\/span><\/p>\n","protected":false},"excerpt":{"rendered":"

By: Dr. Geoffrey Modest\u00a0 A recent study assessed the accuracy of the 2013 ACC\/AHA guidelines in identifying patients in the Framingham Study\u00a0who either developed cardiovascular disease (CVD) and\/or coronary artery calcification (CAC), comparing the results to that of the prior\u00a02004 ATPIII guidelines.\u00a0(see\u00a0JAMA.\u00a02015;314(2):134-141\u200b). Details: –2435 statin-naive participants (mean age 51.3, 56% female, mean Framingham Risk Score […]<\/p>\n

Read More…<\/a><\/p>\n","protected":false},"author":148,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"_jetpack_memberships_contains_paid_content":false,"footnotes":""},"categories":[14283],"tags":[],"class_list":["post-791","post","type-post","status-publish","format-standard","hentry","category-archive"],"jetpack_featured_media_url":"","jetpack_sharing_enabled":true,"_links":{"self":[{"href":"https:\/\/stg-blogs.bmj.com\/bmjebmspotlight\/wp-json\/wp\/v2\/posts\/791","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/stg-blogs.bmj.com\/bmjebmspotlight\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/stg-blogs.bmj.com\/bmjebmspotlight\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/stg-blogs.bmj.com\/bmjebmspotlight\/wp-json\/wp\/v2\/users\/148"}],"replies":[{"embeddable":true,"href":"https:\/\/stg-blogs.bmj.com\/bmjebmspotlight\/wp-json\/wp\/v2\/comments?post=791"}],"version-history":[{"count":0,"href":"https:\/\/stg-blogs.bmj.com\/bmjebmspotlight\/wp-json\/wp\/v2\/posts\/791\/revisions"}],"wp:attachment":[{"href":"https:\/\/stg-blogs.bmj.com\/bmjebmspotlight\/wp-json\/wp\/v2\/media?parent=791"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/stg-blogs.bmj.com\/bmjebmspotlight\/wp-json\/wp\/v2\/categories?post=791"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/stg-blogs.bmj.com\/bmjebmspotlight\/wp-json\/wp\/v2\/tags?post=791"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}