Aims: To use the Global Registry of Acute Coronary Events (GRACE) and Can Rapid risk stratification of Unstable angina patients Suppress ADverse outcomes with Early implementation of the ACC/AHA guidelines (CRUSADE) scores to risk stratify antiplatelet treatment post-acute coronary syndrome (ACS).
Methods and results: This was a prospective registry of 3374 patients undergoing percutaneous coronary intervention for ACS between 2013 and 2015 at a UK cardiac centre. Patients with either low GRACE or high CRUSADE risk scores were stratified either to clopidogrel therapy or ticagrelor was used. The primary endpoint was major adverse cardiac events (MACE) defined as death, non-fatal myocardial infarction, stroke, or target vessel revascularization with bleeding rates as a secondary outcome, assessed at a median follow-up of 1.8 years (interquartile range 0.8-3.4 years). A total of 1723 (51.1%) patients were risk stratified to either clopidogrel (n = 520) or ticagrelor treatment (n = 1203), with the remaining 1651 not risk scored and treated with clopidogrel therapy. Patients in the risk score stratified group were older than the control group otherwise the groups were similar. Over the follow-up period, a significant reduction in MACE rates between the patients' risk score stratified and control (clopidogrel therapy) (13.7% vs. 19.7%, P < 0.0001) was seen [hazard ratio (HR) 0.61, 95% confidence interval (CI) 0.31-0.86]. This persisted after adjusting for baseline variables (HR 0.65, 95% CI 0.37-0.89) and propensity matching (HR = 0.63, 95% CI 0.27-0.93; P = 0.0015) No significant differences in the rate of major bleeding were seen between the groups (5.3% vs. 5.1%, P = 0.86). In the risk-stratified group, no difference in outcome (ischaemic/bleeding) was seen between clopidogrel and ticagrelor.
Conclusion: Our registry data suggest that using appropriate risk scoring to guide antiplatelet therapy after ACS is safe and can result in improved clinical outcomes.