CardioExchange Archive

March 28th, 2012

Proof-of-Concept for Bedside Rapid Genotyping Test of CYP2C19

Larry Husten, PHD

A new point-of-care test can rapidly identify people with a common genetic variant associated with impaired clopidogrel function. The authors claim that this is the first study to demonstrate the feasibility of delivering a genetic test at bedside. In an article published online in the Lancet, Jason Roberts and colleagues report on a new point-of-care test that can identify […]

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December 30th, 2011

CYP2C19 Genotyping: Down For The Count?

Richard A. Lange, MD, MBA and L. David Hillis, MD

The controversy over the use of genetic testing to guide antiplatelet therapy reminds us of a WWF (Worldwide Wrestling Federation) tag team match.   What we agree upon (the match rules): Clopidogrel is a prodrug activated by several enzymes, including CYP2C19, and common genetic variations alter CYP2C19 activity. Here’s where the wrestling match begins: Are the CYP2C19 genetic […]

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December 27th, 2011

Clopidogrel Testing Comes Under Fire

Larry Husten, PHD

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 JAMA finds no clinically relevant relationship between the CYP2C19 genotype  and cardiovascular events. Michael Holmes and colleagues performed a meta-analysis of 32 studies involving CYP 2C19 genotyping and more than […]

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October 25th, 2011

Genetic and Clinical Factors Linked to Stent Thrombosis

Larry Husten, PHD

French researchers have identified several genetic and clinical factors independently tied to early stent thrombosis. Writing in the Journal of the American Medical Association, Guillaume Cayla and colleagues report on their case-control study comparing 123 patients with definite early stent thrombosis with 246 matched controls without stent thrombosis. The researchers found three genes with variants that […]

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October 27th, 2010

Meta-Analysis Examines Risk Associated with CYP2C19 Genotypes

Larry Husten, PHD

There has been widespread debate and disagreement over the clinical significance of people with reduced function CYP2C19 genotypes who take clopidogrel. In an effort to shed light on the topic, Jessica Mega and colleagues analyzed data from 9685 patients enrolled in nine clinical trials. Some 26% of patients had 1 reduced-function allele, and 2% had […]

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August 29th, 2010

Genetic Substudies of Large Trials Question Value of Clopidogrel Genotyping

Larry Husten, PHD

Genetic substudies across a broad range of large clinical trials that used clopidogrel raise questions about the clinical utility of clopidogrel genotyping. The substudies come from large and important trials like PLATO, TRITON-TIMI 38, CURE, and ACTIVE A. A genetic substudy of PLATO finds that ticagrelor is superior to clopidogrel irrespective of genetic subtype. Therefore, according […]

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