The Long-Term Impact of the COVID-19 Pandemic on the Prognosis of Patients With Acute Myocardial Infarction in Japan

BACKGROUND: The prognosis of patients with acute myocardial infarction (AMI) in the initial stage of the coronavirus disease 2019 (COVID-19) outbreak has been reported globally. However, the reports on the prognosis of patients with AMI after the initial stage of the pandemic are limited worldwide. METHODS: This retrospective observational study utilized data from the electronic medical records system of the Oita University Hospital. This study encompassed patients who were hospitalized at our hospital for AMI treatment between April 2018 and June 2022. The study period was categorized into the following three periods: the pre-pandemic period (April 2018 to March 2020), the first phase of the pandemic (April 2020 to March 2021), and the second phase of the pandemic (April 2021 to June 2022). The primary outcome was the duration from the initial admission for AMI treatment to the onset of major adverse cardiac events (MACE). The secondary outcome was the duration from the initial admission for AMI treatment to death from any cause. These outcomes were compared among patients with AMI admitted during the three periods. RESULTS: The one-year MACE-free survival rates did not differ significantly among the three periods (p = 0.146), whereas the one-year overall survival rates were significantly different (p = 0.022). Univariate Cox regression analysis showed that patients with AMI had poorer overall survival in the second phase of the COVID-19 pandemic compared to the pre-pandemic period (hazard ratio {HR}: 4.92, 95% confidence interval {CI}: 1.27-19.09, p = 0.021). However, multiple regression analysis did not show significant differences in the overall survival of patients with AMI across the three periods (HR: 2.77, 95% CI: 0.59-12.96, p = 0.196). CONCLUSION: The long-term impact of the COVID-19 pandemic on the prognosis of patients with AMI remains unclear. Further research is required to clarify the long-term impact by using larger cohorts that include pre-hospital data.