Response to the letter regarding the article “Do East Asians have different hypercoagulable states compared with Western population?”
Article Outline
To the Editor:
We appreciate Dr Jeong's interest and comment to our work. In our registry study,1 compared with high-dose clopidogrel loading (600 mg), standard-dose clopidogrel loading (300 mg) showed similar rates of ischemic and bleeding events up to 12 months after primary percutaneous coronary intervention (PCI) in patients with ST-segment elevation myocardial infarction (STEMI). Although we suggested that Asians could achieve adequate platelet inhibition by standard-dose clopidogrel because of lower body mass index, several studies already have shown high levels of postclopidogrel platelet reactivity in Asians. Therefore, we agreed with Dr Jeong's opinion that different levels of thrombogenicity and inflammation across the ethnicity can make the different cutoff for predicting post-PCI ischemic events, and the concept of “one-size-fit-all-races” is questionable.
In 2009 focused update on their STEMI and PCI guidelines, 60-mg prasugrel loading and 10-mg prasugrel maintenance at least 12 months was added as a class I recommendation in American patients with STEMI undergoing primary PCI.2 TRITON-TIMI 38 enrolled the small number of Asians (~1%),3 and pharmacokinetics and pharmacodynamics of prasugrel seem different between Asians and whites4: in healthy volunteers receiving prasugrel, Asians showed significantly greater levels of active metabolite (~29%) and platelet inhibition (~10%) compared with whites, despite no difference in age, sex, and body weight. Overall, Asians appeared to show a higher bleeding rate compared with other races, even on the same antiplatelet therapy.5 Therefore, among Asian patients with STEMI, the required dose of prasugrel to balance clinical efficacy and safety can be different compared with whites.
Our data may raise the investigators' enthusiasm for this unmet need. Future clinical trials regarding antithrombotic regimen should enroll the convincing number of each race to suggest the rational guideline of “personalized anti-thrombotic therapy.”
Acknowledgements
This program was supported by a Korea University Grant, and we appreciated the help of all KAMIR investigators.
References
- Standard versus high loading doses of clopidogrel in Asian ST-segment elevation myocardial infarction patients undergoing percutaneous coronary intervention: insights from the Korea Acute Myocardial Infarction Registry. Am Heart J. 2011;161:373–382.e3
- Focused updates: ACC/AHA guidelines for the management of patients with ST-elevation myocardial infarction (updating the 2004 guideline and 2007 focused update) and ACC/AHA/SCAI guidelines on percutaneous coronary intervention (updating the 2005 guideline and 2007 focused update): a report of the American College of Cardiology Foundation/American Heart Association Task Force on Practice Guidelines. Circulation. 2009;120:2271–2306
- Prasugrel versus clopidogrel in patients with acute coronary syndromes. N Engl J Med. 2007;357:2001–2015
- Effect of intrinsic and extrinsic factors on the clinical pharmacokinetics and pharmacodynamics of prasugrel. Clin Pharmacokinet. 2010;49:777–798
- Ethnic variation in adverse cardiovascular outcomes and bleeding complications in the Clopidogrel for High Atherothrombotic Risk and Ischemic Stabilization, Management, and Avoidance (CHARISMA) study. Am Heart J. 2009;157:658–665
Disclosures: The authors have no conflicts of interest to disclose with regard to the work reported herein.
PII: S0002-8703(11)00345-0
doi:10.1016/j.ahj.2011.05.002
© 2011 Mosby, Inc. All rights reserved.
Refers to article:
- Do East Asians have different hypercoagulable states compared with Western population? , 13 June 2011
