Supplementary Material for: Cardiac Characteristics of the First Two Waves of COVID-19 in Denmark and the Prognostic Value of Echocardiography: The ECHOVID-19 Study

Introduction: COVID-19 has spread globally in waves, and Danish treatment guidelines have been updated following the first wave. We sought to investigate whether the prognostic values of echocardiographic parameters changed with updates in treatment guidelines and the emergence of novel severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) variants, 20E (EU1) and Alpha (B.1.1.7), and further to compare cardiac parameters between patients from the first and second wave. Methods: A total of 305 patients hospitalised with COVID-19 were prospectively included, 215 and 90 during the first and second wave, respectively. Treatment in the study was defined as treatment with remdesivir, dexamethasone, or both. Patients were assumed to be infected with the dominant SARS-CoV-2 variant at the time of their hospitalisation. Results: Mean age for the first vs. second wave was 68.7±13.6 vs. 69.7±15.8 years and 55% vs. 62% were male. Left ventricular (LV) systolic and diastolic function was worse in patients hospitalised during the second wave (LV ejection fraction (LVEF) for first vs. second wave = 58.5±8.1% vs. 52.4±10.6%, p