This study had several limitations. Because the study was designed as a postmarketing observational study, only patients treated with prasugrel were evaluated. As this study aimed to assess the real clinical situation in Japan, patients were not subjected to strict exclusion criteria. The observation and follow-up periods varied for each patient. As this was a short-term study, the results are only applicable to patients treated during a short period. The length of the observational period was insufficient to collect an adequate number of cardiovascular events to thoroughly evaluate safety, especially in terms of risk factors. However, the long-term observational study “PRASFIT-Practice II” will address these issues.