The prognosis of patients with acute myocardial infarction (AMI) in the setting of coronavirus disease 2019 (COVID-19) remains uncertain.

To evaluate patients’ prognosis after an AMI concomitant with COVID-19.

This retrospective nationwide observational cohort study was based on the French administrative hospital discharge database. Primary outcomes were incidences of all-cause death, cardiovascular death, heart failure (HF), recurrence of AMI, ischaemic stroke, incident atrial fibrillation (AF), ventricular tachycardia/ventricular fibrillation (VT/VF) and cardiac arrest. Patients with AMI and COVID-19 were matched to those without COVID-19 (using propensity score matching techniques) to account for differences between the two populations.

A total of 288,408 patients hospitalized for AMI in France from March 2020 to January 2023 were included; 26,879 had a COVID-19-positive test between 15 days before to 5 days after admission. Patients with COVID-19 were older, more frequently had diabetes mellitus and obesity but less frequently smoked. They more frequently had non-ST-segment elevation myocardial infarction presentation and more often had lung disease. After matching, patients with COVID-19 had higher risks of all-cause death (hazard ratio [HR] 1.255; 95% confidence interval [CI] 1.203–1.308; P<0.0001), HF (HR 1.205; 95% CI 1.159–1.254; P<0.0001), ischaemic stroke (HR 1.237; 95% CI 1.084–1.411; P=0.002), incident AF (HR 1.160; 95% CI 1.070–1.258; P=0.0003) and VT/VF (1.360; 95% CI 1.200–1.540; P<0.0001). Surprisingly, cardiovascular death risk was lower in patients with COVID-19 (HR 0.932; 95% CI 0.879–0.988; P=0.02) as a result of competition with non-cardiovascular death. No statistical difference was found for cardiac arrest or recurrent AMI.

In this French nationwide cohort study, AMI in patients infected with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) increased all-cause death incidence compared to non-infected AMI, but this poorer prognosis was not due to cardiovascular death. Further investigations are needed to elucidate the aetiologies of death.