Abstract 4022: Aspirin responsiveness/resistance and Diabetes in an Acute Coronary Syndrome Population
Background: The relationship between aspirin responsiveness/resistance and diabetic outcomes in patients with Acute Coronary Syndrome (ACS), has not been well characterised. This study assessed this relationship in an Australian ACS population.
Methods: The CARS- (Clopidogrel and Aspirin Resistance Study), is a prospective, multicentre Australian registry of 520 consecutive patients with ST-elevation myocardial infarction or high risk non-ST-elevation ACS. Patients were either loaded with aspirin(300mg) or taking chronic aspirin(100mg) for >1 week. Data collected included demographics, clinical risk stratification, in-hospital management and death, stroke, re-myocardial infarction and unplanned revascularisation (MACE). We characterised the responsiveness to aspirin in diabetic and non-diabetic patients, as a continuous variable, using the Verify Now System, aspirin resistance unit(ARU). Aspirin resistance has been defined as an ARU>550. We explored the interaction between diabetes and aspirin resistance and MACE through a stratified analysis
Results: Diabetic patients have a lower responsiveness to aspirin [450(IQR:402– 469) vs 422(IQR:414 – 494), p<0.001]. Diabetes was not associated with an increase in MACE (OR=1.6, p=0.30, CI: 0.57 – 4.2). Aspirin resistance(ARU>550) is associated with an increase in MACE overall (OR=7.0, p<0.001, CI: 2.2–20.0). The impact of aspirin resistance on MACE was similar regardless of diabetic status (OR in diabetics: 3.9, OR in non-diabetics: 9.2, p=0.41)
Conclusion: Aspirin resistance appears to be associated with an increase in adverse ischemic events among patients presenting with ACS. Despite a lower responsiveness to aspirin in diabetic patients, the relationship between aspirin resistance and adverse ischaemic outcomes did not differ between diabetic and non-diabetic patients.