Clinical and biochemical aspirin resistance in patients with recurrent cerebral ischemia

Stroke recurrence is an important public health concern. One half of survivors remain disabled, and one seventh requires institutional care. Aspirin remains the cornerstone of primary and secondary stroke prevention; meanwhile, aspirin resistance is one of the possible causes of stroke recurrence. We aimed to evaluate the clinical and biochemical aspirin resistance in patients with recurrent ischemic stroke.

We studied demographic characteristics, vascular risk factors, stroke subtypes, radiologic findings and biochemical aspirin resistance tests using both arachidonic acid (AA) and adenosine diphosphate (ADP)-induced light transmittance aggregometry (LTA) on admission and 24 h after observed aspirin ingestion.

Of the 82 patients with recurrent cerebral ischemia included in this study, 37 (45%) patients were poor compliant with aspirin. There were no statistically significant differences between the two groups regarding the demographic characteristics, stroke severity, laboratory tests, radiological findings or vascular risk factors. On admission, 19.6% and 4.8% of patients showed aspirin resistance, while 24 h after supervised 300 mg single aspirin dose ingestion, it was 9.8% and 2.4% using ADP and AA-induced LTA respectively. Of the eight aspirin resistant patients, two only showed resistance using both AA and ADP. Aspirin resistance was statistically significantly higher in the male gender, older age, hyperlipidemia, smokers and in all lacunar strokes using AA.

Biochemical aspirin resistance in one's series was rather rare (2.4%) and was more prevalent in patients with lacunar strokes. Clinical aspirin failure may often be contributed to poor compliance with aspirin intake.