LAUSR

Since the outbreak of the pandemic until early 2022, SARSCoV2 infection (COVID19) has affected more than 410 million individuals worldwide, and of those almost 5.9 million people have died. COVID19 mortality is strongly associated with advanced age, comorbidities, thromboembolism and vaccination status ( www.COVID-19.who.int). Atrial fibrillation (AF) is the most common sustained arrhythmia. Globally, more than 37 million patients have AF, and its prevalence is forecasted to increase more than twofold by 2060. Mortality in patients with AF is closely related to the same comorbidities as in COVID19 including congestive heart failure (CHF) and thromboembolic complications. The risk of AF is elevated among patients with COVID19, and vice versa. In the study published in this issue of Heart, Handy et al evaluated antithrombotic use and the impact of various antithrombotic agents on the outcomes of patients with AF and COVID19. Using routinely updated, linked populationscale electronic health records for 56 million people in England, they found 972 971 individuals with AF and CHA2DS2VASc score ≥2. Due to the massive sample size, it was possible to control for a wide range of confounding variables without losing statistical power.