{"id":6856,"date":"2011-03-15T16:00:59","date_gmt":"2011-03-15T20:00:59","guid":{"rendered":"http:\/\/blogs.nejm.org\/cardioexchange\/?p=6856"},"modified":"2011-07-19T17:44:14","modified_gmt":"2011-07-19T21:44:14","slug":"gravitas-editorial-why-invite-the-fox-into-the-henhouse","status":"publish","type":"post","link":"https:\/\/blogs.nejm.org\/cardioexchange\/2011\/03\/15\/gravitas-editorial-why-invite-the-fox-into-the-henhouse\/","title":{"rendered":"GRAVITAS Editorial: Why Invite the Fox into the Henhouse?"},"content":{"rendered":"<p>Results from the\u00a0GRAVITAS\u00a0randomized trial, presented at the 2010 American Heart Association conference, have just been <a href=\"http:\/\/jama.ama-assn.org\/content\/305\/11\/1097.short\">published in <em>JAMA<\/em><\/a>. They show that high-dose clopidogrel did <em>not<\/em> improve outcomes after percutaneous coronary intervention (PCI) in patients with \u201chigh on-treatment platelet reactivity\u201d (i.e., during clopidogrel therapy), compared with clopidogrel given at conventional doses.<\/p>\n<p>Our interpretation at CardioExchange, <a href=\"http:\/\/blogs.nejm.org\/cardioexchange\/gravitas-no-benefit-for-clopidogrel-dosing-based-on-platelet-function-test\/\">reported at the time of the AHA conference<\/a><em>, <\/em>was that assessing platelet reactivity doesn\u2019t effectively identify individuals who are at high risk for a cardiovascular event after PCI.<em> <\/em>Although 41% of patients were reported to have had high on-treatment platelet reactivity (according to the VerifyNow P2Y<sub>12<\/sub> test), only 2.3% of them had a cardiovascular event in the 6 months after PCI.<\/p>\n<p>In a comment on our post, <a href=\"http:\/\/blogs.nejm.org\/cardioexchange\/members\/sanjaykaul\/\">Dr. Sanjay Kaul<\/a> bolstered our explanation by noting that 25 of 1080 patients (2.3%) with and 8 of 586 (1.4%) without high on-treatment platelet reactivity had adverse cardiac events. He calculated these statistics:<\/p>\n<ul>\n<li>sensitivity: 76%<\/li>\n<li>specificity: 35%<\/li>\n<li>positive predictive value: 2%<\/li>\n<li>negative predictive value: 99%<\/li>\n<li>positive likelihood ratio: 1.17<\/li>\n<li>negative likelihood ratio: 0.69<\/li>\n<li>area under the curve: 0.59<\/li>\n<\/ul>\n<p>In this week\u2019s <em>JAMA,<\/em> the GRAVITAS article is accompanied by <a href=\"http:\/\/cardiobrief.wordpress.com\/wp-admin\/post-new.php\">an editorial<\/a> suggesting<strong> <\/strong>that personalized therapy with high-dose clopidogrel was not effective because<em> <\/em>the cutpoint for defining high on-treatment platelet reactivity (P2Y<sub>12<\/sub> reaction units \u2265230) may have been too high. On the contrary, multiple studies have shown that <a href=\"http:\/\/eurheartj.oxfordjournals.org\/content\/29\/8\/992.full.pdf+html\">this cutpoint provides the best predictive value<\/a> of post-PCI ischemic complications, according to receiver-operating-characteristic analysis, and identifies the top tertile of post-treatment reactivity.<\/p>\n<p>Notably, the lead author\u00a0of the editorial receives grant support from Accumetrics, manufacturer of the VerifyNow P2Y<sub>12<\/sub> test, and is an advocate for its use. We commend the author for disclosing his potential conflict of interest but have difficulty understanding why <em>JAMA<\/em> invited a major proponent of this platelet-reactivity test to write the editorial. Rather than acknowledging that the test has a negligible impact on risk prediction, the editorial simply calls for different platelet-function cutpoints to be used.<\/p>\n<p><em>Do you consider this to be a real or merely a perceived conflict of interest? Do you routinely look at the COI disclosures that accompany published studies and editorials?<\/em><\/p>\n","protected":false},"excerpt":{"rendered":"<p>Results from the\u00a0GRAVITAS\u00a0randomized trial, presented at the 2010 American Heart Association conference, have just been published in JAMA. They show that high-dose clopidogrel did not improve outcomes after percutaneous coronary intervention (PCI) in patients with \u201chigh on-treatment platelet reactivity\u201d (i.e., during clopidogrel therapy), compared with clopidogrel given at conventional doses. Our interpretation at CardioExchange, reported [&hellip;]<\/p>\n","protected":false},"author":214,"featured_media":0,"comment_status":"open","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[9],"tags":[334,301,564,738],"class_list":["post-6856","post","type-post","status-publish","format-standard","hentry","category-interventional-cardiology","tag-clopidogrel","tag-pci","tag-platelet-function-testing","tag-platelets"],"_links":{"self":[{"href":"https:\/\/blogs.nejm.org\/cardioexchange\/wp-json\/wp\/v2\/posts\/6856","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\/214"}],"replies":[{"embeddable":true,"href":"https:\/\/blogs.nejm.org\/cardioexchange\/wp-json\/wp\/v2\/comments?post=6856"}],"version-history":[{"count":0,"href":"https:\/\/blogs.nejm.org\/cardioexchange\/wp-json\/wp\/v2\/posts\/6856\/revisions"}],"wp:attachment":[{"href":"https:\/\/blogs.nejm.org\/cardioexchange\/wp-json\/wp\/v2\/media?parent=6856"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/blogs.nejm.org\/cardioexchange\/wp-json\/wp\/v2\/categories?post=6856"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/blogs.nejm.org\/cardioexchange\/wp-json\/wp\/v2\/tags?post=6856"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}