Aspirin Resistance in Different Doses by Bleeding Time and Urinary 11-dehydro-thromboxane B2

The aim of the present study was the evaluation bleeding time (BT) in comparison to Urinary 11-dehydro thromboxane B2 (TXB2) regarding different ASA frequent dosages used in Borujerd city. This is a double blind randomized clinical trial on 370 subjects aged 35 years and older, referred to clinical offices in Borujerd. All ischemic heart disease’s patients were randomly assigned to 4 ASA dose groups (80 mg, 81 mg, 100 mg and 325 mg) and one group-matched control group without any IHD. BT was measured by Ivy method; TXB2 was measured in a urine sample, both at least 5 days after ASA consumption. Probale AR was indicated if TXB2 was normal or higher than normal higher limit values, or BT was normal or lower than normal higher values. (IRCT201202026958N3) Probale AR was present in 37.6% and 64% resistance by BT and TXB2, respectively. All 4 treated groups had higher TXB2 levels than the control group/normal values (p>0.05). Also, urinary TXB2 level correlated positively with BT. Given the simplicity and low costs of its performance it might be of some potential use in developing countries. However, due to IVY method limitations it cannot be perceived as a tool to assess such specific aspects of platlat function or aspirin resistance.