{"id":14921,"date":"2011-12-27T16:13:33","date_gmt":"2011-12-27T21:13:33","guid":{"rendered":"http:\/\/blogs.nejm.org\/cardioexchange\/?post_type=news&#038;p=14921"},"modified":"2012-01-10T17:53:17","modified_gmt":"2012-01-10T22:53:17","slug":"clopidogrel-testing-comes-under-fire","status":"publish","type":"post","link":"https:\/\/blogs.nejm.org\/cardioexchange\/2011\/12\/27\/clopidogrel-testing-comes-under-fire\/","title":{"rendered":"Clopidogrel Testing Comes Under Fire"},"content":{"rendered":"<p>The phenomenon of clopidogrel resistance has been much discussed, but no consensus has emerged about the best, or any, response to the problem. Now <a title=\"Holmes_JAMA\" href=\"http:\/\/jama.ama-assn.org\/content\/306\/24\/2704.short\" target=\"_blank\">a review published in\u00a0<em>JAMA<\/em><\/a>\u00a0finds no clinically relevant relationship between the <em>CYP2C19<\/em> genotype\u00a0 and cardiovascular events.<\/p>\n<p>Michael Holmes and colleagues performed a meta-analysis of 32 studies involving <em>CYP 2C19<\/em> genotyping and more than 42,000 patients. In the observational studies of patients receiving clopidogrel, the investigators found an association between<em> CYP 2C19<\/em> alleles and outcomes. However, they also\u00a0found evidence of small-study bias, and when only larger studies were included the association was much diminished. In randomized trials, the clopidogrel genotype had no effect on outcome.<\/p>\n<p>In an <a title=\"Nissen_JAMA_Holmes\" href=\"http:\/\/jama.ama-assn.org\/content\/306\/24\/2727.extract\" target=\"_blank\">accompanying editorial<\/a>, Steven Nissen writes that attempts to integrate clopidogrel testing in clinical practice, including a\u00a0boxed warning about clopidogrel resistance from the FDA, have been premature:<\/p>\n<blockquote><p>No matter how promising, pharmacogenetic approaches to treatment must withstand the same scrutiny required of all therapeutic advances \u2014 careful evaluation through well-designed randomized clinical trials.<\/p><\/blockquote>\n<p>In the absence of a large randomized controlled trial demonstrating the benefits of the clopidogrel pharmacogenomics, writes Nissen, &#8220;physicians should use <em>CYP2C19<\/em> or platelet reactivity testing rarely, if ever, and interpret the results with caution.&#8221;<\/p>\n<p>[EDITOR&#8217;S NOTE: We&#8217;ve closed comments on this post to focus the discussion over at <a href=\"http:\/\/blogs.nejm.org\/cardioexchange\/interventional\/cyp2c19-genotyping-down-for-the-count\/\">this related piece by David Hillis and Rick Lange<\/a>. Please join the discussion there!]<\/p>\n","protected":false},"excerpt":{"rendered":"<p>The phenomenon of clopidogrel resistance has been much discussed, but no consensus has emerged about the best, or any, response to the problem. Now a review published in\u00a0JAMA\u00a0finds no clinically relevant relationship between the CYP2C19 genotype\u00a0 and cardiovascular events. Michael Holmes and colleagues performed a meta-analysis of 32 studies involving CYP 2C19 genotyping and more [&hellip;]<\/p>\n","protected":false},"author":196,"featured_media":0,"comment_status":"closed","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[1,9],"tags":[334,360,336,1086],"class_list":["post-14921","post","type-post","status-publish","format-standard","hentry","category-general","category-interventional-cardiology","tag-clopidogrel","tag-clopidogrel-genotyping","tag-cyp2c19","tag-fda-warning"],"_links":{"self":[{"href":"https:\/\/blogs.nejm.org\/cardioexchange\/wp-json\/wp\/v2\/posts\/14921","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/blogs.nejm.org\/cardioexchange\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/blogs.nejm.org\/cardioexchange\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/blogs.nejm.org\/cardioexchange\/wp-json\/wp\/v2\/users\/196"}],"replies":[{"embeddable":true,"href":"https:\/\/blogs.nejm.org\/cardioexchange\/wp-json\/wp\/v2\/comments?post=14921"}],"version-history":[{"count":0,"href":"https:\/\/blogs.nejm.org\/cardioexchange\/wp-json\/wp\/v2\/posts\/14921\/revisions"}],"wp:attachment":[{"href":"https:\/\/blogs.nejm.org\/cardioexchange\/wp-json\/wp\/v2\/media?parent=14921"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/blogs.nejm.org\/cardioexchange\/wp-json\/wp\/v2\/categories?post=14921"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/blogs.nejm.org\/cardioexchange\/wp-json\/wp\/v2\/tags?post=14921"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}