Impact of the COVID-19 pandemic on the hospitalizations, time course, presenting symptoms, and mid-term outcomes in patients with myocardial infarctions in a Japanese multi-center registry

To investigate the impact of the coronavirus disease 2019 (COVID-19) pandemic on myocardial infarctions (MIs), consecutive MI patients were retrospectively reviewed in a multi-center registry. The patient characteristics and 180-day mortality for both ST-segment elevation myocardial infarctions (STEMIs) and non-STEMIs (NSTEMIs) in the after-pandemic period (7 April 2020-6 April 2021) were compared to the pre-pandemic period (7 April 2019-6 April 2020). Inpatients with MIs, STEMIs, and NSTEMIs decreased by 9.5%, 12.5%, and 4.1% in the after-pandemic period. The type of the presenting symptoms (as classified as typical symptoms, atypical symptoms, and out-of-hospital cardiac arrests [OHCAs]) did not differ between the two time periods for both STEMIs and NSTEMIs, while the rate of OHCAs was numerically higher in the after-pandemic period for the STEMIs (12.1% vs. 8.0%, p = 0.30). The symptom-to-admission time (STAT) did not differ between the two time periods for both STEMIs and NSTEMIs, but the door-to-balloon time (DTBT) for STEMIs was significantly longer in the after-pandemic period (83.0 [67.0-100.7] min vs. 70.0 [59.0-88.7] min, p = 0.004). The 180-day mortality did not significantly differ between the two time periods for both STEMIs (15.9% vs. 11.4%, p = 0.14) and NSTEMIs (9.9% vs. 8.0%, p = 0.59). In conclusion, hospitalizations for MIs decreased after the COVID-19 pandemic. Although the DTBTs were significantly longer in the after-pandemic period, the mid-term outcomes for MIs were preserved.