Abstract:
Aspirin resistance is an emerging clinical entity. However the data available on aspirin resistance in Asian
population is scarce. This study was initiated to prospectively evaluate the frequency of aspirin resistance in
patients with stable coronary artery disease (CAD) in Pakistan. A cross sectional prospective study was
conducted in cardiology and hematology departments at Shifa International Hospital, Islamabad from January to
December 2007. Two hundred and fifty patients were enrolled from cardiology out patient department having
met the specific inclusion criteria. Details were entered on a pre-designed questionnaire and aspirin response
assay was performed on IMPACT–R (Dia Med AG 1785 Cressier Morat, Switzerland). Data was analyzed
using SPSS V12. Aspirin resistance was observed in 12% of patients. 73.2% of study population were male and
26.8% were female, with a mean age of 57.2 years. There was no significant correlation of aspirin resistance
with traditional risk factors like Diabetes Mellitus (DM), Hypertension or Dyslipidemia. 84% of Aspirin non
responders were taking 75mg per day and 16% were on 150mg per day. A positive trend was noted between
aspirin resistance and cigarette smoking. Aspirin resistance is a real phenomenon in Pakistani population with
an estimated frequency of 12%. Large scale prospective randomized trials with long term follow up are needed
to assess the impact of different doses and the clinical significance of this biochemical entity.
