In- and out-of-hospital mortality for myocardial infarction during the first wave of the COVID-19 pandemic in Emilia-Romagna, Italy: A population-based observational study

Background: The COVID-19 pandemic has put several healthcare systems under severe pressure. The present analysis investigates how the first wave of the COVID-19 pandemic affected the myocardial infarction (MI) network of Emilia-Romagna (Italy). Methods: Based on Emilia-Romagna mortality registry and administrative data from all the hospitals from January 2017 to June 2020, we analysed: i) temporal trend in MI hospital admissions; ii) characteristics, management, and 30-day mortality of MI patients; iii) out-of-hospital mortality for cardiac cause. Findings: Admissions for MI declined on February 22, 2020 (IRR -19.5%, 95%CI from -8.4% to -29.3%, p = 0.001), and further on March 5, 2020 (IRR -21.6%, 95%CI from -9.0% to -32.5%, p = 0.001). The return to pre-COVID-19 MI-related admission levels was observed from May 13, 2020 (IRR 34.3%, 95%CI 20.0%-50.2%, p<0.001). As compared to those before the pandemic, MI patients admitted during and after the first wave were younger and with fewer risk factors. The 30-day mortality remained in line with that expected based on previous years (ratio observed/expected was 0.96, 95%CI 0.84–1.08). MI patients positive for SARS-CoV-2 were few (1.5%) but showed poor prognosis (around 5-fold increase in 30-day mortality). In 2020, the number of out-of-hospital cardiac deaths was significantly higher (ratio observed/expected 1.17, 95%CI 1.08–1.27). The peak was reached in April. Interpretation: In Emilia-Romagna, MI hospitalizations significantly decreased during the first wave of the COVID-19 pandemic. Management and outcomes of hospitalized MI patients remained unchanged, except for those with SARS-CoV-2 infection. A concomitant increase in the out-of-hospital cardiac mortality was observed. Funding: None.