Does the PFA-100 identify varying responses to daily 75 mg aspirin in patients with ischemic heart disease?
The PFA-100 can identify varying degrees of aspirin responsiveness, which could help tailor pre-operative aspirin continuation strategies to avoid bleeding risks.
Continuing aspirin up until surgery in cardiac surgical patients may increase peri-operative blood loss. It is possible that there is a subset of patients particularly sensitive to aspirin. The platelet function analyser (PFA-100) can demonstrate the antiplatelet effect of aspirin. This study was designed to assess the effect of daily 75 mg aspirin on platelet function, as measured by the PFA-100, in 92 patients with ischaemic heart disease. Patients were classified into three groups according to their PFA-100 results; aspirin hyper-responders (16%), aspirin normal responders (33%) and aspirin non-responders (51%). The PFA-100 has potential as a screening tool to identify patients who are either hyper-responsive or resistant to aspirin. Pre-operative PFA-100 screening to isolate aspirin hyper-responders could enable the vast majority of patients to continue with aspirin therapy pre-operatively, avoiding the risks of stopping treatment.
Coakley et al. (2005) studied this question.