COVID-19 pandemic is associated with mechanical complications in patients with ST-elevation myocardial infarction

Objective Although there are regional reports that the COVID-19 pandemic is associated with a reduction in acute myocardial infarction presentations and primary percutaneous coronary intervention (PCI) procedures, little is known about the impact of the COVID-19 pandemic on mechanical complications resulting from ST-segment elevation myocardial infarction (STEMI) and mortality.Methods This single-centre retrospective cohort study analysed presentations, incidence of mechanical complications, and mortality in patients with STEMI before and after a state of emergency was declared due to the COVID-19 pandemic by the Japanese government on 7 April 2020.Results We analysed 359 patients with STEMI hospitalised before the declaration and 63 patients hospitalised after the declaration. The proportion of patients with late presentation was significantly higher after the declaration than before (25.4% vs 14.2%, p=0.03). The incidence of late presentation was significantly higher during the COVID-19 pandemic than before (incidence rate ratio (IRR), 2.41; 95% CI, 1.37 to 4.05; p=0.001, even after adjusting for month (IRR, 2.61; 95% CI, 1.33 to 5.13; p