The reasons for switching from prasugrel back to clopidogrel after percutaneous coronary intervention (PCI) in acute myocardial infarction (AMI) are unclear, but are frequently practiced. The study aims to compare the characteristics and in-hospital outcomes of patients initially given prasugrel but was switched back to clopidogrel versus those who were continued on prasugrel on discharge.

The study included a cohort of 152 consecutive AMI patients who were first loaded with prasugrel and underwent PCI. Patients were categorized into switched therapy to clopidogrel on discharge (Switched, n=58) and continued therapy on prasugrel on discharge (Continued, n=94). Patient and procedural characteristics, as well as PCI-related complications and in-hospital outcomes were evaluated.

Baseline demographics and procedural characteristics of both groups were similar. Patients who switched to clopidogrel on discharge had significantly longer hospital stay, and intensive care unit stay trended longer. Switched patients had significantly higher incidence of blood transfusions. Major bleeding, hematocrit drop, hematoma and urgent coronary artery bypass grafting (CABG) also trended higher in patients who switched therapy.

Concomitant coumadin therapy was significantly higher in the switched therapy group, whereas aspirin therapy was similar in both groups. No in-hospital mortality or myocardial infarction occurred in either groups (05).

In-hospital bleeding complications requiring blood transfusion, need for urgent CABG and concomitant coumadin therapy are the main reasons for switching of antiplatelet therapy from prasugrel to clopidogrel prior to discharge.