Thromb Haemost 2013; 109(04): 744-754
DOI: 10.1160/TH12-05-0336
New Technologies, Diagnostic Tools and Drugs
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Cardiovascular risk among patients on clopidogrel anti-platelet therapy after placement of drug-eluting stents is modified by genetic variants in both the CYP2C19 and ABCB1 genes

John F. Carlquist
1   Intermountain Heart Institute, Intermountain Healthcare, Murray, Utah, USA
2   Department of Internal Medicine, Cardiology Division, University of Utah School of Medicine, Salt Lake City, Utah, USA
,
Stacey Knight
1   Intermountain Heart Institute, Intermountain Healthcare, Murray, Utah, USA
3   Department of Internal Medicine, Genetic Epidemiology Division, University of Utah School of Medicine, Salt Lake City, Utah, USA
,
Benjamin D. Horne
1   Intermountain Heart Institute, Intermountain Healthcare, Murray, Utah, USA
3   Department of Internal Medicine, Genetic Epidemiology Division, University of Utah School of Medicine, Salt Lake City, Utah, USA
,
John A. Huntinghouse
1   Intermountain Heart Institute, Intermountain Healthcare, Murray, Utah, USA
,
Jeffrey S. Rollo
1   Intermountain Heart Institute, Intermountain Healthcare, Murray, Utah, USA
,
J. Brent Muhlestein
1   Intermountain Heart Institute, Intermountain Healthcare, Murray, Utah, USA
2   Department of Internal Medicine, Cardiology Division, University of Utah School of Medicine, Salt Lake City, Utah, USA
,
Heidi May
1   Intermountain Heart Institute, Intermountain Healthcare, Murray, Utah, USA
,
Jeffrey L. Anderson
1   Intermountain Heart Institute, Intermountain Healthcare, Murray, Utah, USA
2   Department of Internal Medicine, Cardiology Division, University of Utah School of Medicine, Salt Lake City, Utah, USA
› Author Affiliations

Financial support: This study was funded in part by the Intermountain Research and Medical Foundation, formerly the Deseret Foundation, and by the Dell Loy Hansen Heart Foundation, Inc.
Further Information

Publication History

Received: 21 May 2012

Accepted after major revision: 12 January 2013

Publication Date:
22 November 2017 (online)

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Summary

Long-term (at least one year) dual anti-platelet therapy incorporating aspirin and clopidogrel is currently recommended following percutaneous coronary intervention with placement of a drug-eluting stent (DES). Genetic variants in both the ABCB1 and CYP2C19 genes have been associated with cardiovascular events among patients on clopidogrel. We examined the concurrent contribution of the CYP2C19 *2 and *17 alleles and the ABCB1 3435 alleles to one-year clinical risk among patients (n=1,034 on clopidogrel therapy following the placement of a DES. For CYP2C19*2, event rates were 8.4%, 10.9% and 44.4% for patients with 0, 1 and 2 *2 alleles, respectively (p=0.016). ABCB1 3435 was not associated with events in univariate analysis. However, 72% of patients with a *2 variant also possessed the ABCB1 3435 C allele; among these patients (*2/C genotype) the event rate for myocardial infarction (MI) was 14.2% vs. 6.9% for those lacking both *2 and C alleles (p=0.027) and for MI/death, 16.9% vs. 9.6% (p=0.046). Overall for all genotypes, the presence of the gain-of-function (protective) *17 allele significantly reduced the one-year rate of MI from 11.1% to 7.0% (p=0.045) and trended to reduce the combined rate of MI/death from 13.8% to 10.5% (p=0.182). In conclusion, the ABCB1 3435 locus and the *2 allele combine to impart a significant trend toward increased risk. This trend was largely reversed by the simultaneous carriage of one or two *17 alleles. These findings suggest that assessment of a combined genotype may improve risk assessment.