Objective: Aspirin resistance is described as the failure of aspirin to decrease the production of thromboxane A2 by platelets, which is the mechanism by which aspirin decreases platelet activation and aggregation. This study was performed to assess the prevalence of aspirin resistance among cardiovascular patients in al-Qassim, Saudi Arabia.
Patients and methods: The study used a survey of patients with first and recurrent attacks of ischemic heart disease (IHD) and available data from blood samples processed using a VerifyNow® kit, which measures aspirin reaction units (ARUs).
Results: A total of 119 patients were included: 45 with their first IHD episodes and 74 with recurrent episodes. Of the surveyed patients, 40% with a first episode were younger than 50 years old, and 75.6% of them have been diagnosed with IHD during the previous 5 years. Of the patients with recurrent attacks, 45.9% were older than 60 years, and 54.1% of them have been diagnosed more than 5 years before. The group with first episodes of IHD had 133.2 ARUs, whereas the group with recurrent episodes had 168.5 ARUs (p=0.105). In the recurrent-episode group, 77% had diabetes; in the first-episode group, only 37.8% had diabetes (p≤0.001). Overall, 46.2% were overweight, 54.6% were nonsmokers, and 82.4% underwent percutaneous coronary intervention.
Conclusions: The study participants in both the new and recurrent IHD groups showed no sign of aspirin resistance. The presence of cardiovascular risk factors increased the likelihood of episode recurrence.