Profile and prevalence of clopidogrel resistance in patients of acute coronary syndrome

Sandeep Kumar, Ram K. Saran, Aniket Puri, Nishant Gupta, Rishi Sethi, W. R. Surin, Madhu Dikshit, Sudhanshu K. Dwivedi, Varun S. Narain, Vijay K. Puri

Research output: Contribution to journalArticlepeer-review

16 Scopus citations

Abstract

Recently reports of a variable platelet response to aspirin and potential resistance to therapy have emerged with thienopyridines group of drugs. However the data available on clopidogrel resistance is scarce. The present study was initiated to prospectively evaluate the prevalence of clopidogrel resistance in patients of acute coronary syndrome (ACS) presently on dual anti platelet therapy by using an established method of optical platelet aggregation. We studied 39 patients of ACS, who were on clopidogrel 300 mg bolus followed by 75 mg per day for 3 days along with aspirin 325 mg per day. Fasting blood samples were assessed using optical platelet aggregation (Chronolog Corp, USA). Clopidogrel resistance was defined as <10% decrease from baseline in platelet aggregation. Clopidogrel semi-responders were defined as 10-29% (<30%) decrease from baseline in platelet aggregation. Clopidogrel non-responders were defined as a composite of resistant and semi-responders. A baseline mean platelet aggregation obtained from 18 healthy subjects was 63.8 ± 14.75% with 5 μM and 68.8 ± 13.91% with 10 μM of Adenosine Diphosphate. Hence, the definition of clopidogrel resistance was set as aggregation of >57% with 5 μm ADP and >61.9% with 10 μm ADP (<10% decrease from baseline). The definition of clopidogrel semi-responder was set as aggregation of 45% with 5 μm ADP and 48% with 10 μm ADP (10-29% decrease from baseline). The mean platelet aggregation with 5 μM and 10 μM of Adenosine Diphosphate in the patient group was 30.77 ± 17.19% and 35.71 ± 17.0% respectively. Based on these criteria, 2.54% patients were found to be clopidogrel resistant, 12.7% were clopidogrel semi-responders and 84.7% were clopidogrel responders. On comparison of clopidogrel responders with non-responders, females (p = 0.07) and patients with higher serum triglyceride levels (p = 0.08), had a trend to be more inclined towards clopidogrel non-responders. All other parameters tested namely age, smoking, diabetes, hypertension, obesity, cholesterol, hemoglobin, platelet count, ejection fraction and concurrent drug intake did not show any statistically significant difference among the groups. CONCLUSIONS This study shows that clopidogrel resistant and clopidogrel semi-responders do occur in Indian patients with ACS and there are no reliable clinical predictors for this condition. The diagnosis therefore relies primarily on laboratory tests.

Original languageEnglish
Pages (from-to)152-156
Number of pages5
JournalIndian Heart Journal
Volume59
Issue number2
StatePublished - 2007
Externally publishedYes

Keywords

  • Acute coronary syndrome
  • Clopidogrel resistance
  • Platelet aggregation

Fingerprint

Dive into the research topics of 'Profile and prevalence of clopidogrel resistance in patients of acute coronary syndrome'. Together they form a unique fingerprint.

Cite this