Featured Research

from universities, journals, and other organizations

Global platelet reactivity identifies high risk ACS patients more effectively than responsiveness to clopidogrel

Date:
August 27, 2012
Source:
European Society of Cardiology (ESC)
Summary:
Global platelet reactivity is more effective than responsiveness to clopidogrel in identifying acute coronary syndrome (ACS) patients at high risk of ischemic events, according to new research.

Global platelet reactivity is more effective than responsiveness to clopidogrel in identifying acute coronary syndrome (ACS) patients at high risk of ischemic events, according to research presented at the ESC Congress today. The results from the RECLOSE 2-ACS study were presented by Dr Rossella Marcucci from Italy.

Related Articles


The Responsiveness to Clopidogrel and Stent thrombosis 2 -- ACS (RECLOSE 2-ACS) study is a prospective, observational, referral center cohort study of 1,789 patients with acute coronary syndromes undergoing percutaneous coronary intervention (PCI) at the Division of Cardiology, Careggi Hospital, Florence, Italy.

Dual antiplatelet therapy with aspirin and clopidogrel is the cornerstone of therapy in these patients to improve prognosis and reduce adverse cardiovascular events, stent thrombosis and cardiovascular death.

"In recent years, we and other groups have focused our attention on the role of platelet inhibition," said Dr Marcucci. "We found that a significant percentage of patients on clopidogrel therapy -- the so-called nonresponders to clopidogrel -- had a high platelet reactivity (HPR) on clopidogrel and a significantly higher risk of developing an adverse ischemic event at a follow-up of 2 years."

A number of genetic and acquired conditions are associated with a high platelet reactivity on clopidogrel. Carriers of a genetic variant (the CYP2C19*2 polymorphism), diabetics, older patients, females and patients with a reduced renal and cardiac function have a higher risk of maintaining a high platelet reactivity on clopidogrel. In addition, the concomitant use of drugs such as proton pump inhibitors (PPIs) is associated with a reduced metabolization of clopidogrel (which is a prodrug and needs to be metabolized to the active drug by the liver) and a high risk of high platelet reactivity.

The aim of the current study was to evaluate whether a high platelet reactivity due to nonresponsiveness to aspirin could also identify ACS patients at high risk of ischemic events. The investigators also evaluated whether the combination of aspirin and clopidogrel nonresponsiveness could identify high risk patients more effectively than one measure alone.

The researchers measured platelet reactivity in response to aspirin and clopidogrel in patients enrolled in the RECLOSE 2-ACS study. They found that approximately 20% of patients had a high platelet reactivity to aspirin and were therefore nonresponders. These patients had a significantly higher prevalence of an ischemic event or cardiac death at the 2 year follow-up (major adverse cardiac events [MACE]: Hazard Ratio [HR]=1.4 [1.0-1.8], p<0.04; Cardiac death: HR=1.7 [1.2-2.6],p=0.004).

The researchers calculated the net reclassification index (NRI), which is a method to define whether the addition of a new parameter increases the predictive value. Dr Marcucci said: "We found that adding the response to aspirin to the response to clopidogrel enabled us to recognize a higher number of patients at risk of ischemic events and cardiac events."

Approximately 9% of patients had high platelet reactivity (ie were nonresponders) to both clopidogrel and aspirin. This phenotype is known as global high platelet reactivity (GHPR).

GHPR was significantly associated with cardiovascular ischemic events and cardiac death in a Cox regression analysis (MACE: HR=1.5[1.0-2.2], p=0.02; cardiac death: HR= 1.9[1.2-3.2], p=0.008). The analysis was adjusted for age, sex, body mass index, smoking, diabetes, hypertension, hypercholesterolemia, history of myocardial infarction, serum creatinine higher than 1.5 mg/dl, left ventricular ejection fraction <40%, Killip class III or IV at admission, 3-vessel coronary disease, use of drug eluting stents, total stent length, multivessel PCI and use of abciximab.

The figures below show that patients with GHPR have lower survival rates from MACE (p=0.001) and cardiac death (p<0.0001) than patients without GHPR.

Dr Marcucci said: "These results show that global high platelet reactivity is the most effective parameter for identifying ACS patients at high risk of ischemic events."

She added: "This shifts the focus of risk stratification from response to clopidogrel to assessing response to both clopidogrel and aspirin. Responsiveness to both antiplatelet drugs should be assessed in all patients with ACS in order to identify and reduce their risk of ischemic events."


Story Source:

The above story is based on materials provided by European Society of Cardiology (ESC). Note: Materials may be edited for content and length.


Cite This Page:

European Society of Cardiology (ESC). "Global platelet reactivity identifies high risk ACS patients more effectively than responsiveness to clopidogrel." ScienceDaily. ScienceDaily, 27 August 2012. <www.sciencedaily.com/releases/2012/08/120827104954.htm>.
European Society of Cardiology (ESC). (2012, August 27). Global platelet reactivity identifies high risk ACS patients more effectively than responsiveness to clopidogrel. ScienceDaily. Retrieved December 22, 2014 from www.sciencedaily.com/releases/2012/08/120827104954.htm
European Society of Cardiology (ESC). "Global platelet reactivity identifies high risk ACS patients more effectively than responsiveness to clopidogrel." ScienceDaily. www.sciencedaily.com/releases/2012/08/120827104954.htm (accessed December 22, 2014).

Share This


More From ScienceDaily



More Health & Medicine News

Monday, December 22, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

Touch-Free Smart Phone Empowers Mobility-Impaired

Touch-Free Smart Phone Empowers Mobility-Impaired

Reuters - Innovations Video Online (Dec. 21, 2014) A touch-free phone developed in Israel enables the mobility-impaired to operate smart phones with just a movement of the head. Suzannah Butcher reports. Video provided by Reuters
Powered by NewsLook.com
Earthworms Provide Cancer-Fighting Bacteria

Earthworms Provide Cancer-Fighting Bacteria

Reuters - Innovations Video Online (Dec. 21, 2014) Polish scientists isolate bacteria from earthworm intestines which they say may be used in antibiotics and cancer treatments. Suzannah Butcher reports. Video provided by Reuters
Powered by NewsLook.com
Existing Chemical Compounds Could Revive Failing Antibiotics, Says Danish Scientist

Existing Chemical Compounds Could Revive Failing Antibiotics, Says Danish Scientist

Reuters - Innovations Video Online (Dec. 21, 2014) A team of scientists led by Danish chemist Jorn Christensen says they have isolated two chemical compounds within an existing antipsychotic medication that could be used to help a range of failing antibiotics work against killer bacterial infections, such as Tuberculosis. Jim Drury went to meet him. Video provided by Reuters
Powered by NewsLook.com
Hugging It Out Could Help You Ward Off A Cold

Hugging It Out Could Help You Ward Off A Cold

Newsy (Dec. 21, 2014) Carnegie Mellon researchers found frequent hugs can help people avoid stress-related illnesses. Video provided by Newsy
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:

Strange & Offbeat Stories


Health & Medicine

Mind & Brain

Living & Well

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