Abstract Body: Introduction: Guidelines recommend higher-potency P2Y12 receptor inhibitors over clopidogrel in ACS patients undergoing PCI. Real-world adoption varies. A protocol favoring higher-potency P2Y12 inhibitors was implemented at a high-volume tertiary PCI center serving a catchment population of approximately 2.2 million people.

Hypothesis: We assessed the hypothesis that protocol implementation would increase discharge prescription of higher-potency P2Y12 inhibitors among ACS patients treated with PCI.

Methods: We conducted a retrospective single-center audit of consecutive adults with ACS undergoing PCI before and after protocol implementation. Patients were assigned to pre-implementation (February 2020 to May 15, 2021; 254 patients) or post-implementation (May 16 to November 2021; 251 patients) cohorts. Patients with stable coronary disease or requiring anticoagulation were excluded. Ticagrelor was the only higher-potency P2Y12 inhibitor available in Canada at the time. The primary outcome was discharge prescription of higher-potency P2Y12 inhibitors.

Results: Among 505 patients (mean age 69.4 ± 11.1 years; 351 [69.5%] men), discharge prescription of higher-potency P2Y12 inhibitors was 37.4% (95/254) pre- and 36.3% (91/251) post-implementation. Patients receiving higher-potency therapy were younger (66.0 vs 71.4 years; p<0.0001), more often men (75.8% vs 65.8%; p=0.021), and more likely to present with STEMI (48.4% vs 22.9%; p<0.0001). Traditional cardiovascular risk factors such as hypertension (60.2% vs 77.7%; p<0.0001), dyslipidemia (59.1% vs 77.1%; p<0.0001), and anemia (14.0% vs 27.0%; p=0.0008) were less common among higher-potency recipients. Baseline laboratory values showed higher eGFR (80.1 ± 19.9 vs 75.1 ± 20.5 mL/min/1.73 m2; p=0.0068) and hemoglobin (142.7 ± 15.7 vs 135.2 ± 17.8 g/L; p<0.0001) in the higher-potency P2Y12 inhibitor group. Other comorbidities—including prior MI, PCI, CABG, stroke, COPD, heart failure, prior stent thrombosis, prior bleeding, and AV block—were comparable between groups.

Conclusions: Protocol implementation did not increase use of higher-potency P2Y12 inhibitors at discharge after PCI for ACS. These findings suggest that the perceived risk of adverse outcomes is a key determinant of clinical decision-making and warrants further investigation. In this assessment of contemporary practice in a tertiary care center, opportunities remain to further optimize evidence-based antiplatelet therapy.