Switch to Prasugrel Safe After PCI in East Asian ACS Patients

Abdullah Hashmi, MD

June 30, 2022

The study covered in this summary was published on researchsquare.com as a preprint and has not yet been peer-reviewed.

Key Takeaways

  • Korean acute coronary syndrome (ACS) patients who were started and remained on prasugrel after percutaneous coronary intervention (PCI) did not have rates of major adverse cardiac and cerebrovascular events (MACCE) any different than those started on another P2Y12 inhibitor and switched to prasugrel.

  • The major cause of switches to prasugrel from other antiplatelet therapies, like clopidogrel, was the necessity for a more potent antiplatelet agent.

Why This Matter

  • Various P2Y12 inhibitors have different efficacies and bleeding risks, and patients are switched from one antiplatelet therapy to another on the basis of clinical scenarios. Clinical trials and guidelines do not elaborate on how to switch therapies in real-world practice.

  • East Asian patients are more prone to bleeding and might not achieve the benefit from dual antiplatelet therapy with potent P2Y12 inhibitors that other patients do. Many physicians in South Korea are reluctant to apply Western guidelines for antiplatelet agent use.

Study Design

  • The EFF-K registry was set up as a noninterventional prospective cohort study conducted in South Korea from March 2017 to November 2019. Data were collected 1, 3, 6, 9, and 12 months after PCI for ACS.

  • All patients 19 years and older who had been taking prasugrel for less than 6 months after PCI were screened for the study.

  • The naïve cohort was defined as patients who received only prasugrel before and after PCI. Patients whose antiplatelet therapy was changed within 6 months of PCI were defined as the switch cohort.

  • The study's primary endpoint was MACCE, defined as composite of cardiovascular death, non-fatal MI, non-fatal stroke, or Thrombolysis in Myocardial Infarction (TIMI) major bleeding unrelated to coronary artery bypass grafting (CABG).

  • Key secondary endpoints included a composite of cardiovascular death, non-fatal MI, and non-fatal stroke as the effectiveness endpoint, and a composite of TIMI major or minor bleeding unrelated to CABG as the safety endpoint.

  • Serious adverse events (SAE) and adverse events that caused the withdrawal of prasugrel were also analyzed as safety endpoints. Events that required hospitalization or caused disability, were life threatening, or resulted in death were considered a SAE.

Key Results

  • Of the 3077 patients involved in the analysis, 23.6% were in the naïve cohort and 76.4% were in the switch cohort. Mean age was 60.6 years, and 25.2% were diagnosed with ST-segment elevation MI (STEMI) at index PCI.

  • More than half (56.3%) of the switch cohort converted to prasugrel from clopidogrel because of the need for a more potent antiplatelet agent, and 27.7% switched from ticagrelor to prasugrel because of poor compliance with a twice-daily regimen.

  • At 1 year, 55 patients (1.8%) experienced at least once MACCE. The incidence of MACCE did not differ between the naïve and switch cohorts (1.7% vs 1.8%; P = .723).

  • In multivariate analysis, the switch cohort was not associated with a higher risk for MACCE (hazard ratio [HR], 1.14; P = .722), but STEMI was (HR, 2.30; P = .004).

  • There was no significant interaction between treatment strategy and the incidence of MACCE across various subgroups.

  • There were no significant differences between the naïve and switch cohorts in the rates of the effectiveness endpoint (0.7% vs 1.1%) and safety endpoint (3.7% vs 3.0%).

  • Comparative analysis of the results for the naïve and switch cohorts did not show significant differences in rates of adverse drug reactions, serious adverse drug reactions, and adverse events leading to prasugrel discontinuation.


  • The study lacked a control group.

  • Robust statistical analyses were not possible because some subgroups were small.


  • The study received no commercial funding.

  • None of the authors disclosed relevant financial relationships.

This is a summary of a preprint research study, Real-world evidence of switching P2Y12 receptor-inhibiting therapies to prasugrel after PCI in patients with ACS: results from EFF-K registry, written by Jeehoon Kang, Cardiovascular Center, Seoul National University Hospital, Seoul National College of Medicine, South Korea, and colleagues, on Research Square provided to you by Medscape. This study has not yet been peer-reviewed. The full text of the study can be found on researchsquare.com.


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