The Retrospective Analysis of Clopidogrel Resistance Tests

Background: Clopidogrel binds to P2Y12 and inhibits platelet aggregation. Clopidogrel resistance can be categorized into two main categories: laboratory clopidogrel resistance and clinical clopidogrel resistance. Laboratory clopidogrel resistance refers to the inadequate in vitro antiplatelet effects of clopidogrel. In the present study, we aimed to evaluate the clopidogrel resistance test results from the perspective of laboratory specialists. Methods: All clopidogrel resistance test results from the Bilkent City Hospital laboratory information system, between February 1, 2019, and May 31, 2025, were collected. Clopidogrel resistance tests were performed using the adenosine diphosphate-induced platelet aggregation method using an aggreometer device (Stago Chrono-Log Model 700). Data were expressed as mean, minimum, and maximum levels, numerically and as percentages. The Chi-square test was performed a categorical data comparison between the created groups. IBM SPSS Statistics performed statistical analyses for Windows, Version 27.0 (IBM Corp., Armonk, NY, USA). Results: A total of 285 clopidogrel resistance test results were included. Negative and positive clopidogrel test results were as follows: 95 (33.3 %) and 190 (66.7 %). The present study consisted of 98 (34.4 %) females, 187 (65.6 %) males’ clopidogrel resistance tests. There were 107 (37.5 %) clopidogrel resistance test results in the under 65 years old group, while there were 178 (62.5 %) in the 65 and older years group. The neurology clinic requested clopidogrel resistance tests mostly (N:72, 62.5 %). No statistical differences were found in gender among age intervals (p>0.05), in clopidogrel resistance tests among gender (p>0.05), and in clopidogrel resistance tests among age intervals (p>0.05). Conclusion: The most appropriate laboratory test to assess clopidogrel resistance has not yet been determined. The present study, evaluated from a laboratory perspective, may be useful for future research; however, prospective studies combining laboratory and clinical findings may be more effective.