Featured Research

from universities, journals, and other organizations

Study examines platelet function testing for guiding antithrombotic treatment before PCI procedures

Date:
September 20, 2011
Source:
JAMA and Archives Journals
Summary:
Among patients with acute coronary syndromes undergoing a procedure such as angioplasty, those who received platelet function tests before receiving antithrombotic therapy to determine appropriate clopidogrel dosing and who had high residual platelet reactivity (platelets resistant to antithrombotic therapy) were at an increased risk of an ischemic event at short- and long-term follow-up of up to two years, according to a new study.

Among patients with acute coronary syndromes undergoing a procedure such as angioplasty, those who received platelet function tests before receiving antithrombotic therapy to determine appropriate clopidogrel dosing and who had high residual platelet reactivity (platelets resistant to antithrombotic therapy) were at an increased risk of an ischemic event at short- and long-term follow-up of up to 2 years, according to a study in the Sept. 21 issue of JAMA.

Several studies have shown that high residual platelet reactivity during clopidogrel treatment is predictive of major cardiovascular events in patients undergoing percutaneous coronary intervention (PCI; procedures such as balloon angioplasty or stent placement used to open narrowed coronary arteries). However, it has not yet been proven that the risk of thrombotic events increases markedly above a critical cut point of platelet reactivity on in vitro platelet function tests, according background information in the article.

Guido Parodi, M.D., and colleagues of Careggi Hospital, Florence, Italy, conducted a study to examine whether high residual platelet reactivity (HRPR) after clopidogrel loading (a comparatively large dose of the drug given at the beginning of treatment) is an independent prognostic marker of risk of long-term thrombotic events in patients with acute coronary syndromes (ACS) undergoing an invasive procedure and receiving long-term antithrombotic treatment adjusted according to the results of platelet function tests. The study included 1,789 patients with ACS undergoing PCI from April 2005 to April 2009 and who had platelet reactivity assessed via testing. All patients received 325 mg of aspirin and a loading dose of 600 mg of clopidogrel followed by a maintenance dosage of 325 mg/d of aspirin and 75 mg/d of clopidogrel for at least 6 months. Patients with HRPR as assessed by adenosine diphosphate test (70 percent platelet aggregation or greater) received an increased dose of clopidogrel or switched to the antiplatelet drug ticlopidine under adenosine diphosphate test guidance. The primary outcome measure was a composite of cardiac death, heart attack, any urgent coronary revascularization, and stroke at 2-year follow-up. Secondary measured outcomes were stent thrombosis and each component of the primary end point.

The researchers found that the primary end point event rate was 14.6 percent (36/247) in the HRPR group and 8.7 percent (132/1,525) in the low residual platelet reactivity group (LRPR). The difference in the event rate was driven by the difference in cardiac mortality, which was 9.7 percent in the HRPR group and 4.3 percent in the LRPR group. The stent thrombosis rate was 2-fold higher in the HRPR group (6.1 percent [15/247] vs. 2.9 percent [44/1,525]). Additional analysis indicated that HRPR was independently associated with a 49 percent increased risk of the primary end point and a 81 percent increased risk of cardiac mortality.

The authors write that "the results of this study should be considered only as hypothesis generating for further studies of tailored therapy using new antithrombotic agents."

Editorial: Applying Platelet Function Testing in Clinical Practice

Dominick J. Angiolillo, M.D., Ph.D., of the University of Florida College of Medicine-Jacksonville, comments in an accompanying editorial on the use of platelet function testing.

"… despite promising research conducted to date, currently available evidence cannot support routine use of platelet function testing [PFT] in clinical practice. Until results of appropriately powered randomized controlled trials demonstrate efficacy and safety (in particular, low bleeding risk) of adjustment of antiplatelet treatment, PFT should be reserved mostly as a research tool."


Story Source:

The above story is based on materials provided by JAMA and Archives Journals. Note: Materials may be edited for content and length.


Journal References:

  1. G. Parodi, R. Marcucci, R. Valenti, A. M. Gori, A. Migliorini, B. Giusti, P. Buonamici, G. F. Gensini, R. Abbate, D. Antoniucci. High Residual Platelet Reactivity After Clopidogrel Loading and Long-term Cardiovascular Events Among Patients With Acute Coronary Syndromes Undergoing PCI. JAMA: The Journal of the American Medical Association, 2011; 306 (11): 1215 DOI: 10.1001/jama.2011.1332
  2. D. J. Angiolillo. Applying Platelet Function Testing in Clinical Practice: What Are the Unmet Needs? JAMA: The Journal of the American Medical Association, 2011; 306 (11): 1260 DOI: 10.1001/jama.2011.1349

Cite This Page:

JAMA and Archives Journals. "Study examines platelet function testing for guiding antithrombotic treatment before PCI procedures." ScienceDaily. ScienceDaily, 20 September 2011. <www.sciencedaily.com/releases/2011/09/110920163209.htm>.
JAMA and Archives Journals. (2011, September 20). Study examines platelet function testing for guiding antithrombotic treatment before PCI procedures. ScienceDaily. Retrieved July 22, 2014 from www.sciencedaily.com/releases/2011/09/110920163209.htm
JAMA and Archives Journals. "Study examines platelet function testing for guiding antithrombotic treatment before PCI procedures." ScienceDaily. www.sciencedaily.com/releases/2011/09/110920163209.htm (accessed July 22, 2014).

Share This




More Health & Medicine News

Tuesday, July 22, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

Courts Conflicted Over Healthcare Law

Courts Conflicted Over Healthcare Law

AP (July 22, 2014) Two federal appeals courts issued conflicting rulings Tuesday on the legality of the federally-run healthcare exchange that operates in 36 states. (July 22) Video provided by AP
Powered by NewsLook.com
Why Do People Believe We Only Use 10 Percent Of Our Brains?

Why Do People Believe We Only Use 10 Percent Of Our Brains?

Newsy (July 22, 2014) The new sci-fi thriller "Lucy" is making people question whether we really use all our brainpower. But, as scientists have insisted for years, we do. Video provided by Newsy
Powered by NewsLook.com
Scientists Find New Way To Make Human Platelets

Scientists Find New Way To Make Human Platelets

Newsy (July 22, 2014) Boston scientists have discovered a new way to create fully functioning human platelets using a bioreactor and human stem cells. Video provided by Newsy
Powered by NewsLook.com
Gilead's $1000-a-Pill Drug Could Cure Hep C in HIV-Positive People

Gilead's $1000-a-Pill Drug Could Cure Hep C in HIV-Positive People

TheStreet (July 21, 2014) New research shows Gilead Science's drug Sovaldi helps in curing hepatitis C in those who suffer from HIV. In a medical study, the combination of Gilead's Hep C drug with anti-viral drug Ribavirin cured 76% of HIV-positive patients suffering from the most common hepatitis C strain. Hepatitis C and related complications have been a top cause of death in HIV-positive patients. Typical medication used to treat the disease, including interferon proteins, tended to react badly with HIV drugs. However, Sovaldi's %1,000-a-pill price tag could limit the number of patients able to access the treatment. TheStreet's Keris Lahiff reports from New York. Video provided by TheStreet
Powered by NewsLook.com

Search ScienceDaily

Number of stories in archives: 140,361

Find with keyword(s):
Enter a keyword or phrase to search ScienceDaily for related topics and research stories.

Save/Print:
Share:

Breaking News:
from the past week

In Other News

... from NewsDaily.com

Science News

Health News

Environment News

Technology News



Save/Print:
Share:

Free Subscriptions


Get the latest science news with ScienceDaily's free email newsletters, updated daily and weekly. Or view hourly updated newsfeeds in your RSS reader:

Get Social & Mobile


Keep up to date with the latest news from ScienceDaily via social networks and mobile apps:

Have Feedback?


Tell us what you think of ScienceDaily -- we welcome both positive and negative comments. Have any problems using the site? Questions?
Mobile: iPhone Android Web
Follow: Facebook Twitter Google+
Subscribe: RSS Feeds Email Newsletters
Latest Headlines Health & Medicine Mind & Brain Space & Time Matter & Energy Computers & Math Plants & Animals Earth & Climate Fossils & Ruins