Implementation of prasugrel and prognostic outcomes after percutaneous coronary intervention for myocardial infarction: a nationwide observational study

Abstract Background Prasugrel has shown superior efficacy and similar safety compared to ticagrelor for patients with acute coronary syndrome treated with percutaneous coronary intervention (PCI) in a randomised setting. Since 2020, prasugrel has been recommended over ticagrelor in our country. It remains unknown if these recommendations have been implemented, and if the findings from the randomised trial can be expanded to an all-comer population. Purpose To assess the implementation of prasugrel and compare effectiveness and safety between prasugrel and ticagrelor in PCI-treated, all-comer patients with myocardial infarction (MI). Methods From January 1st, 2019, to December 31st, 2021 patients with MI treated with PCI were identified by use of nationwide health registries. We included patients who were alive and claimed a prescription of prasugrel or ticagrelor within 7 days from discharge. Incidence rates per 100 person-years (IRs) 6 months from discharge were calculated for a composite outcome of all-cause mortality, recurrent MI (>28 days after index MI), and stroke (MACE), all-cause mortality alone, ischaemic events (a composite of recurrent MI and stroke) and bleeding leading to hospitalisation. We illustrated a Kaplan Meier curve with log-rank test and a cumulative incidence curve with Gray’s test and performed Cox models to assess adjusted comparative differences of the outcomes between prasugrel and ticagrelor after adjusting for age, sex, relevant comorbidities, and calendar year. Results We identified 14,365 PCI-treated patients with MI, of whom 13,887 (96.7%) were alive 7 days from discharge. After excluding patients who did not collect a P2Y12 inhibitor (n=1097 [7.9%]) or collected clopidogrel within 7 days from discharge (n=2696 [21.1%]), the final study population counted 10,094 patients of whom 2045 (20.3%) patients collected prasugrel and 8049 (79.7%) ticagrelor. Figure 1 shows the temporal use of P2Y12 inhibitors. The mean age was 64.4 (±11.7) years and 23.9% were female. Patients with prasugrel were less often ≥75 years old (16.3% vs. 23.2%), female (22.1% vs. 24.3%), and had fewer comorbidities (hypertension, hypercholesterolemia, diabetes, stroke or transient ischaemic attack, bleeding, and prior PCI) than ticagrelor-treated patients. Figure 2 illustrates IRs of the outcomes and Kaplan Meier and cumulative incidence curves. Prasugrel treatment was associated with reduced risk of MACE (HR 0.67 [95% CI 0.47-0.95]) and ischaemic events (HR 0.68 [0.47-0.97]) compared with ticagrelor after adjustment, and there were no differences in all-cause mortality or bleeding (Figure 2). Conclusion Prasugrel use increased from 1% to 44% from 2019 to 2021, but most all-comer patients with MI were treated with ticagrelor after PCI. Prasugrel showed lower risk of MACE and ischaemic events without excess in bleeding 6 months post-discharge compared to ticagrelor, consistent with the findings of a previous randomised trial.Temporal use of potent P2Y12 inhibitorsSix-months outcomes of potent P2Y12i