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Updated: May 11, 2026
Microfluidics in Assessing Platelet Function
Published on: November 8, 2024
Platelet function testing to predict hyporesponsiveness to clopidogrel in patients with chest pain seen in the
Rakesh K Sharma1, Stephen W Erickson, Rohit Sharma
1Division of Cardiovascular Medicine, University of Arkansas for Medical Sciences, Little Rock, AR, USA. rsharma@uams.edu
Insights
A significant number of patients with coronary stents show reduced response to clopidogrel, increasing cardiovascular risk. African Americans, type 2 diabetics, women, and older individuals are more prone to this hyporesponsiveness.
Area of Science:
- Cardiology
- Pharmacology
- Clinical Medicine
Background:
- Dual antiplatelet therapy is standard after percutaneous coronary intervention to prevent cardiovascular events.
- Limited data exists on clopidogrel's effectiveness in patients with prior coronary stents presenting with chest pain.
- This study investigates clopidogrel hyporesponsiveness in stented patients with chest pain.
Purpose of the Study:
- To determine the prevalence of clopidogrel hyporesponsiveness in patients with prior coronary stents presenting with chest pain.
- To identify factors associated with clopidogrel hyporesponsiveness in this patient population.
Main Methods:
- Evaluated clopidogrel responsiveness in 533 stented patients presenting with chest pain.
- Measured P2Y12 reaction units (PRU) and percent P2Y12 inhibition.
- Used multivariate logistic regression to identify risk factors for hyporesponsiveness (defined as PRU ≥ 230).
Main Results:
- 41.6% of patients exhibited clopidogrel hyporesponsiveness (PRU ≥ 230).
- Higher risk of hyporesponsiveness was observed in African Americans (aOR=2.165), type 2 diabetics (aOR=2.109), and women (aOR=1.813).
- Increasing age was also associated with a greater risk of hyporesponsiveness (aOR=1.167 per decade).
Conclusions:
- High prevalence of clopidogrel hyporesponsiveness exists in stented patients with chest pain.
- Non-insulin-dependent diabetes mellitus and African American race are significant predictors.
- Gender and age are also important factors associated with clopidogrel hyporesponsiveness.
Background:
A dual antiplatelet regimen has been shown to reduce the risk of major adverse cardiovascular events after percutaneous coronary intervention. However, there is little information available on inhibition of platelet aggregation in patients with a prior coronary stent presenting with chest pain. This study evaluated the prevalence of hyporesponsiveness to clopidogrel and factors associated with this in patients presenting to our emergency department with chest pain who had previously undergone coronary stent placement and were prescribed dual antiplatelet therapy.
Methods:
Responsiveness to clopidogrel was evaluated in a cohort of 533 consecutive stented patients presenting to the emergency department with chest pain. P2Y12 reaction units (PRU) and percent P2Y12 inhibition with clopidogrel were measured in all patients. Of 533 patients, 221 (41.6%) had PRU ≥ 230. A multivariate logistic regression model was used to determine the relationship between hyporesponsiveness to clopidogrel (defined as PRU ≥ 230) and several potential risk factors, ie, gender, age, race, type 1 or type 2 diabetes, hypertension, smoking, chronic renal failure, and obesity.
Results:
There was a greater risk of hyporesponsiveness in African Americans than in non-African American patients (adjusted odds ratio [OR] = 2.165), in patients with type 2 diabetes than in those without (adjusted OR = 2.109), and in women than in men (adjusted OR = 1.813), as well as a greater risk of hyporesponsiveness with increasing age (adjusted OR = 1.167 per decade).
Conclusion:
There was a high prevalence of hyporesponsiveness to clopidogrel in patients presenting with chest pain and a prior coronary stent. Non-insulin-dependent diabetes mellitus and African American race were the strongest predictors of hyporesponsiveness to clopidogrel, followed by gender and age.
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