Abstract Number: Esoc2026a338 Incidence of Recurrent Strokes in Patients on Clopidogrel in South Asians vs Other Ethnic Groups in Tia Clinic – Evaluating Need for Targeted Cyp2c19 Testing

Abstract Background and aims A significant proportion of the population has loss of function of the CYP2C19 gene allele, which is essential to convert clopidogrel, a pro-drug, to its active form. This loss of function is more common in South Asians. We wanted to establish if there was a correlation between ethnic background and risk of recurrent strokes while on clopidogrel in TIA clinic. Methods TIA clinic data was reviewed for the past 2 years. The total number of patients seen in TIA clinic was 7249. Of these, 1169 had a diagnosis of ischaemic stroke. We excluded patients who had atrial fibrillation (n:99) and who were on anticoagulation for other indications (n:36). Patients were divided by ethnicity; those with recurrent strokes on who were already on clopidogrel as secondary prevention were noted. Results South Asian patients with strokes (without atrial fibrillation and anticoagulation) were 187. Of these, patients with recurrent strokes who were on clopidogrel were 30 (16%). All other ethnic groups with strokes (without atrial fibrillation and anticoagulation) were 847. Of these, patients with recurrent strokes on clopidogrel were 111 (13%). The difference of incidence of strokes in South Asians and other ethnic groups was 3% (p=0.289), with a 22.4% increased relative risk of recurrent stroke. Conclusions Although the difference is not statistically significant, the importance of CYP2C19 testing with recurrent strokes cannot be understated, including in South Asians due to increased incidence of loss of function. Larger trials would be suitable in investigating this further. Conflict of interest Fahad Musarrat: nothing to disclose, Safia Mohammed: nothing to disclose, Mohammed Moqsith: nothing to disclose