Frequency of aspirin non responsiveness in patients of ischemic heart disease

Abstract

Aspirin is widely used as an antiplatelet agent. Many patients have been noticed with recurrence of major ischemic events in- spite of antiplatelet therapy. The objective of this study was to determine frequency of aspirin nonresponsiveness /resistance in patients of ischemic heart disease. Seventy one patients of IHD were selected from outpatient department of Punjab Institute of Cardiology Lahore. Whole Blood Platelet aggregation studies were performed on Diamed Impact R. Aspirin response assay was performed with DiaChidon (Arachidoinc Acid 16mmol/L). Non responders to aspirin were assessed on the basis of software generated results: Surface covered (SC) ≥2.5% was considered as response to aspirin and SC <2.5% was considered as no response (or resistance) to Aspirin. Chi-square test was applied to measure statistical significance. Non-response to Aspirin was observed in 11% (8 out of 71). There was significant association (p=0.045) between resistance to aspirin and Diabetes mellitus. Treatment resistance was also significantly associated with female gender (p=0.015). We concluded that non response to Aspirin is seen in significant number of patients of IHD. Diabetes mellitus and female gender are strong risk factors of developing failure to aspirin therapy.