Report: frequency of aspirin resistance in patients with coronory artery disease in Pakistan.

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 75 mg per day and 16% were on 150 mg 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.