CONTEMPORARY ANTIPLATELET THERAPY IN MODERATE TO HIGH-RISK PATIENTS WITH NON-ST-SEGMENT ELEVATION MYOCARDIAL INFARCTION: INSIGHTS FROM THE CANADIAN ACS REFLECTIVE II STUDY

Abstract

Among patients with myocardial infarction (MI), higher potency ADP receptor inhibitors (ADPri) (e.g. ticagrelor) are associated with greater reduction in events compared with clopidogrel. The ongoing ACS Reflective II, an observational, quality enhancement research initiative was initiated to identify moderate to high-risk non-ST elevation MI (NSTEMI) patients who do and do not receive guideline-recommended dual antiplatelet therapy (DAPT) and potential reasons why not. Cardiologists enrolled patients 18 years presenting with moderate-to-high risk NSTEMI. Demographic, presentation and treatment data was captured through a standardized data collection form (DCF). Since September 2016, 512 patients have been enrolled by 52 cardiologists in 13 hospitals across Canada. The median (25th, 75th percentile) age is 68 (60, 75) years, 70% are male, 36% have diabetes, 8% have atrial fibrillation (AF), and 5% had prior stroke. Coronary angiography was performed in 85%; 63% were treated with percutaneous coronary intervention (PCI) and 18% underwent coronary artery bypass grafting (CABG). In the first 24 hours of hospitalization, 98% received aspirin and 92% received an ADPri (54% ticagrelor, 1% prasugrel, 43% clopidogrel). The most common reasons (not mutually exclusive) for not receiving ticagrelor in the first 24 hours included physician preference (31%), perceived high risk for bleeding (25%) and plan for coronary artery bypass grafting (CABG) (15%) (Figure 1). Three in-hospital deaths were observed. At the time of hospital discharge, 97% of the patients were on aspirin, 79% received an ADPri (46% ticagrelor, 1% prasugrel, 33% clopidogrel), and 11% an oral anticoagulant (OAC), including 9% on a non-vitamin K antagonist (NOAC). The most common reasons for not receiving ticagrelor at discharge (not mutually exclusive) included physician preference (28%), perceived high risk for bleeding (28%) and need for OAC (14%) (Figure 1). Among patients discharged on clopidogrel, 13% had atrial fibrillation, 18% were treated with oral anticoagulant, and 8% had prior stroke (Table 1). In contemporary Canadian practice, approximately one third of moderate to high-risk NSTEMI patients are still treated acutely in hospital and on discharge with clopidogrel. Physician preference for clopidogrel and avoidance of bleeding in the setting of advanced age are the most frequently cited reasons for avoiding ticagrelor. Only a minority of patients discharged on clopidogrel have an absolute or relative contraindication to higher potency ADPri. Opportunities remain for further optimization of evidence-based, guideline-recommended antiplatelet therapy use in NSTEMI patients in Canada.View Large Image Figure ViewerDownload Hi-res image Download (PPT)