High On-Clopidogrel Treatment Platelet Reactivity in
Thai Patients with Chronic Stable Angina Scheduled
for Percutaneous Coronary Intervention
Rewat Phankingthongkum MD*, Pradit Panchavinnin MD*, Yingyong Chinthammitr MD**,
Damras Tresukosol MD*, Chunhakasem Chotinaiwattarakul MD*, Wiwun Tungsubutra MD*,
Nattawut Wongpraparut MD*, Bussakorn Kitrattana RN*, Piyachat Leewanun RN***
Affiliation :
* Division of Cardiology, Department of Medicine Siriraj Hospital, Mahidol University, Bangkok, Thailand
** Division of Hematology, Department of Medicine Siriraj Hospital, Mahidol University, Bangkok, Thailand
*** Her Majestry’s Cardiac Center, Faculty of Medicine Siriraj Hospital, Mahidol University, Bangkok, Thailand
Objective : To determine the prevalence, clinical profile, and risk factors of high on-clopidogrel treatment platelet reactivity
in Thai patients with chronic stable angina scheduled for percutaneous coronary intervention.
Material and Method: The patients were prospectively recruited from the consecutive patients undergoing coronary
angiography and planned for elective percutaneous coronary intervention (PCI). Ten ml of blood samples were cautiously
drawn from the antecubital vein of the patients to determine the hemoglobin and platelet count. Platelet aggregation test
was performed by light transmittance aggregometry using platelet-rich plasma. Platelets were stimulated with 5 μM
adenosine diphosphate (ADP). Platelet aggregation was expressed as the maximal percent change in light transmittance
from baseline. High on-clopidogrel treatment platelet reactivity was defined as post treatment maximal platelet aggregation
>46% with 5 μmol/l ADP used as agonist.
Results : The present study consecutively enrolled two hundred four patients diagnosed with chronic stable angina planned
for PCI. Seventy-nine patients demonstrated the high on-clopidogrel treatment platelet reactivity (38.7%). Among these
patients, 48% were men with a mean age of 66 years. Diabetes mellitus and chronic kidney disease were detected in 34.2%.
Original clopidogrel (Plavix®) was prescribed in 72% of the patients and 28% received generic clopidogrel (Apolets®). The
prevalence of high on-clopidogrel treatment platelet reactivity increased in the older patients, patients with CKD and patients
receiving angiotensin receptor blockers (ARB). However, from multivariate analysis, none of the risk factors, including age,
BMI, diabetes mellitus, smoking, CKD, ARB use, and type of clopidogrel (Plavix® versus Apolets®) had a statistically
significant association with the high on-clopidogrel treatment platelet reactivity.
Conclusion : The prevalence of high on-clopidogrel treatment platelet reactivity in the present study was 38.7%. No significant
association was demonstrated between age, BMI, diabetes mellitus, smoking, CKD, ARB use, type of clopidogrel, and high
on-clopidogrel treatment platelet reactivity.
Keywords : High on-clopidogrel treatment platelet reactivity, Clopidogrel resistance, Clopidogrel non-responsiveness,
Clopidogrel, Platelet aggregation
All Articles
Download