{"id":28342,"date":"2012-04-19T08:00:58","date_gmt":"2012-04-19T12:00:58","guid":{"rendered":"http:\/\/blogs.nejm.org\/cardioexchange\/?post_type=interventional&p=28342"},"modified":"2012-04-18T18:55:58","modified_gmt":"2012-04-18T22:55:58","slug":"should-we-pull-the-trigger-on-platelet-reactivity-testing-and-put-it-out-of-its-misery","status":"publish","type":"post","link":"https:\/\/blogs.nejm.org\/cardioexchange\/2012\/04\/19\/should-we-pull-the-trigger-on-platelet-reactivity-testing-and-put-it-out-of-its-misery\/","title":{"rendered":"Should We Pull the Trigger on Platelet Reactivity Testing (and Put It out of Its Misery)?"},"content":{"rendered":"

In a previous blog <\/a>about the GRAVITAS <\/a>trial —\u00a0 which showed that high-dose clopidogrel didn’t improve outcomes following PCI in patients with high on-treatment platelet reactivity (HTPR) when compared to clopidogrel given at conventional doses —\u00a0 we noted that an assessment of platelet reactivity by this method doesn\u2019t effectively identify individuals at high risk for a cardiovascular event following PCI.<\/em><\/strong>\u00a0 Although more than 40% of patients have HTPR (according to the VerifyNow P2Y12 Test), very few have a cardiovascular event in the 6 months following PCI.<\/p>\n

In the most recent issue of JACC<\/em><\/a>, the TRIGGER-PCI (T<\/em>esting Platelet R<\/em>eactivity i<\/em>n Patients Underg<\/em>oing Elective DES Placement on Clopidogrel to G<\/em>uide Alternative The<\/em>rapy with Pr<\/em>asugrel) trial investigated the effectiveness of prasugrel versus clopidogrel in 456 patients with HTPR undergoing elective PCI with DES.<\/p>\n

The results shown in the table below demonstrate (a) a low rate of ischemic events in patients with HTPR and (b) no demonstrable benefit to switching from clopidogrel to prasugrel when HPTR is detected.<\/p>\n\n\n\n\n\n\n\n\n\n\n\n\n
<\/td>\n\n

Prasugrel
\n(n=212)<\/strong><\/p>\n<\/td>\n

\n

Clopidogrel
\n(n=211)<\/strong><\/p>\n<\/td>\n

\n

P value<\/strong><\/p>\n<\/td>\n<\/tr>\n

PRU *<\/strong><\/td>\n<\/td>\n<\/td>\n<\/td>\n<\/tr>\n
\u00a0\u00a0 Baseline<\/td>\n\n

245<\/p>\n<\/td>\n

\n

249<\/p>\n<\/td>\n

\n

NS<\/p>\n<\/td>\n<\/tr>\n

\u00a0\u00a0 3 mos<\/td>\n\n

80<\/p>\n<\/td>\n

\n

241<\/p>\n<\/td>\n

\n

<0.001<\/p>\n<\/td>\n<\/tr>\n

Endpoints<\/strong><\/td>\n<\/td>\n<\/td>\n<\/td>\n<\/tr>\n
\u00a0\u00a0 CV death or MI<\/td>\n\n

0 (0%)<\/p>\n<\/td>\n

\n

1 (0.5%)<\/p>\n<\/td>\n

\n

NS<\/p>\n<\/td>\n<\/tr>\n

\u00a0\u00a0 CV death<\/td>\n\n

0 (0%)<\/p>\n<\/td>\n

\n

0 (0%)<\/p>\n<\/td>\n

\n

NS<\/p>\n<\/td>\n<\/tr>\n

\u00a0\u00a0 MI<\/td>\n\n

0 (0%)<\/p>\n<\/td>\n

\n

1 (0.5%)<\/p>\n<\/td>\n

\n

NS<\/p>\n<\/td>\n<\/tr>\n

\u00a0\u00a0 Urgent TVR<\/td>\n\n

2 (1.0%)<\/p>\n<\/td>\n

\n

1 (0.5%)<\/p>\n<\/td>\n

\n

NS<\/p>\n<\/td>\n<\/tr>\n

\u00a0\u00a0 Major bleeding<\/td>\n\n

3 (1.4%)<\/p>\n<\/td>\n

\n

1 (0.5%)<\/p>\n<\/td>\n

\n

NS<\/p>\n<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n

*PRU=P2Y12 reaction units, according to the VerfiyNow P2Y12 Test<\/em><\/p>\n

We said it before, and we\u2019ll say it again: an assessment of platelet reactivity by this method doesn\u2019t effectively identify individuals at high risk for a cardiovascular event following PCI.<\/em><\/strong><\/p>\n

We agree with the authors when they state, \u201cThe low observed ischemic event rate in the control group even without correction of HTPR demonstrates that testing platelet function in such patients for consideration of more intensive antiplatelet therapy is not warranted, especially given the potentially increased risk of bleeding.\u201d<\/p>\n

Critics of the GRAVITAS trial argued that the study may have been negative because the cut point for defining HTPR (P2Y12 reaction units [PRU] > 235<\/em>) may have been too high. \u00a0However, in Trigger-PCI, the cut point was much lower (PRU >208), yet switching to prasugrel yielded no improvement in clinical outcomes in patients with HTPR who were put on clopidogrel after elective PCI with DES.<\/p>\n

It appears that the utility of VerifyNow platelet testing is\u2026\u2026\u2026unverified.<\/p>\n

Should we be routinely testing platelet reactivity in our PCI patients? \u00a0If so, what should we do with that information?<\/strong><\/p>\n

 <\/p>\n","protected":false},"excerpt":{"rendered":"

“We said it before, and we\u2019ll say it again: an assessment of platelet reactivity by this method doesn\u2019t effectively identify individuals at high risk for a cardiovascular event following PCI.”<\/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":[334,1223,335],"class_list":["post-28342","post","type-post","status-publish","format-standard","hentry","category-interventional-cardiology","tag-clopidogrel","tag-platelet-reactivity","tag-prasugrel"],"_links":{"self":[{"href":"https:\/\/blogs.nejm.org\/cardioexchange\/wp-json\/wp\/v2\/posts\/28342","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=28342"}],"version-history":[{"count":0,"href":"https:\/\/blogs.nejm.org\/cardioexchange\/wp-json\/wp\/v2\/posts\/28342\/revisions"}],"wp:attachment":[{"href":"https:\/\/blogs.nejm.org\/cardioexchange\/wp-json\/wp\/v2\/media?parent=28342"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/blogs.nejm.org\/cardioexchange\/wp-json\/wp\/v2\/categories?post=28342"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/blogs.nejm.org\/cardioexchange\/wp-json\/wp\/v2\/tags?post=28342"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}