Contemporary use of guideline-based higher potency P2Y12 receptor inhibitor therapy in patients with moderate-to-high risk non-ST-segment elevation myocardial infarction: Results from the Canadian ACS reflective II cross-sectional study.

BACKGROUND: After myocardial infarction, guidelines recommend higher-potency P2Y12 receptor inhibitors, namely ticagrelor and prasugrel, over clopidogrel. HYPOTHESIS: We aimed to determine the contemporary use of higher-potency antiplatelet therapy in Canadian patients with non-ST-elevation myocardial infarction (NSTEMI). METHODS: A total of 684 moderate-to-high risk NSTEMI patients were enrolled in the prospective Canadian ACS Reflective II registry at 12 Canadian hospitals and three clinics in five provinces between July 2016 and May 2018. Multivariable logistic regression modeling was performed to assess factors independently associated with higher-potency P2Y12 receptor inhibitor use at discharge. RESULTS: At hospital discharge, 78.3% of patients were treated with a P2Y12 receptor inhibitor. Among patients discharged on a P2Y12 receptor inhibitor, use of higher-potency P2Y12 receptor inhibitor was 61.4%. After adjustment, treatment in-hospital with PCI (OR 4.48, 95%CI 3.34-6.03, p < .0001) was most strongly associated with higher use of higher-potency P2Y12 receptor inhibitor, while oral anticoagulant use at discharge (OR 0.03, 95%CI 0.01-0.12, p < .0001), and atrial fibrillation (OR 0.40, 95%CI 0.17-0.98, p = .046) were most strongly associated with lower use of higher-potency P2Y12 receptor inhibitor. Use of higher-potency P2Y12 receptor inhibitor varied across provinces (range, 21.6%-78.9%). DISCUSSION: In contemporary Canadian practice, approximately 60% of moderate-to-high risk NSTEMI patients discharged on a P2Y12 receptor inhibitor are treated with a higher-potency P2Y12 receptor inhibitor. In addition to factors that increase risk of bleeding, interprovincial differences in practice patterns were associated with use of higher-potency P2Y12 receptor inhibitor at discharge. Opportunities remain for further optimization of evidence-based, guideline-recommended antiplatelet therapy use.

Longitudinal treatment patterns with ADP receptor inhibitors after myocardial infarction: Insights from the Canadian Observational AntiPlatelet sTudy.

BACKGROUND: After myocardial infarction (MI) treated with percutaneous coronary intervention (PCI), guidelines recommend dual antiplatelet therapy (DAPT) with aspirin and an ADP receptor inhibitor (ADPri) for at least 1year. However, whether real-world Canadian practice patterns reflect this recommendation is unknown. METHODS: We studied 2175 MI patients treated with PCI and discharged from 26 Canadian hospitals between 12/2011 and 05/2013 in the Canadian Observational Antiplatelet sTudy (COAPT). Hierarchical Cox proportional hazard regression modeling was used to determine baseline demographic and clinical factors associated with duration of ADPri therapy post-discharge. RESULTS: At index-hospitalization discharge, 1597 (73%) patients were treated with clopidogrel, 220 (10%) with prasugrel, and 358 (17%) with ticagrelor. ADPri was discontinued prior to 1year in 474 (21.8%) patients; discontinuation rates were lowest for patients discharged on prasugrel (17.7%), compared with clopidogrel (22.5%) or ticagrelor (21.0%), (log rank test, p=0.03). In addition to regional variability, factors associated with shorter ADPri duration included older age, low body weight, Killip III/IV heart failure, atrial fibrillation, ticagrelor on discharge, and bare metal stent use, while longer ADPri duration was associated with history of prior MI. CONCLUSIONS: One in five PCI-treated MI patients did not complete Canadian guideline-recommended 1-year course of ADPri treatment. Premature ADPri discontinuation was most strongly associated with factors that increase the risk of bleeding. Further study is required to assess the clinical implications of premature ADPri discontinuation on patient outcomes.

Radial versus femoral access for emergent percutaneous coronary intervention with adjunct glycoprotein IIb/IIIa inhibition in acute myocardial infarction--the RADIAL-AMI pilot randomized trial.

BACKGROUND: Transradial percutaneous coronary intervention (PCI) results in fewer vascular complications, earlier ambulation, and improved patient comfort. Limited data exist for radial access in acute myocardial infarction, where reperfusion must occur quickly. METHODS: In a multicenter pilot trial, 50 patients with myocardial infarction requiring either primary or rescue PCI were randomized to radial or femoral access. All operators had previously performed at least 100 transradial cases. Procedure times were prospectively recorded. RESULTS: Thrombolysis was used in 66% of the cases and glycoprotein IIb/IIIa inhibitors in 94%. Crossover from radial to femoral access was required in one case. Percutaneous coronary intervention was performed in 47 patients, with stenting in 45. One procedural failure occurred with radial access because of inability to cross the occlusion. The time from local anesthesia to first balloon inflation was 32 (25th percentile 26, 75th percentile 38) minutes for radial access and 26 (22, 33) minutes for femoral access (P = .04). There were no significant differences in contrast use or fluoroscopy time. No patient experienced major bleeding or required transfusion. Doppler studies demonstrated 2 asymptomatic radial occlusions and 2 pseudoaneurysms (1 from each group). One patient in the femoral group died 2 days after PCI. At 30 days, there were no strokes or reinfarctions and no patient required bypass surgery or repeat PCI. CONCLUSIONS: Primary and rescue PCI can be performed with high success rates using either radial or femoral access. Although radial access was associated with a longer time to first balloon inflation, the difference was small and likely not clinically significant. In patients without shock, major bleeding and vascular complications are infrequent with either access site despite the high use of thrombolysis and glycoprotein IIb/IIIa inhibitors.