Detailed causality between coronavirus disease-2019 and atrial fibrillation

Niu et al. investigated the clinical implication of atrial fibrillation (AF) in patients with coronavirus disease-2019 (COVID-19).¹ According to their findings, AF was prevalent in patients hospitalized for COVID-19 and was associated with worse in-hospital mortality, more disease-related complication, and increased healthcare utilization. Several concerns have been raised.

COVID-19 is a systemic inflammatory disease that induces various cardiovascular conditions.² AF may be triggered by this inflammatory cascade. Consequently, the presence of AF may be a confounding factor for in-hospital mortality rather than a prognostic factor. Did the authors observe obvious differences in the severity and inflammatory status of COVID-19 between those with and without AF?

It is widely acknowledged that AF is a robust predictor of cardiovascular diseases and mortality.³ Did the authors identify any distinct profiles in individuals who had both COVID-19 and AF when compared to those with AF alone?

In the authors' study, the incidence of ventricular arrhythmia was higher in individuals with AF.¹ However, the detailed types of ventricular arrhythmia remain uncertain. For instance, did the authors include premature ventricular contractions? It is plausible that the dominant causes of in-hospital cardiac arrest were ventricular tachycardia and ventricular fibrillation. Ventricular fibrillation is often encountered in younger patients with acute coronary syndrome, while extra-cardiac abnormalities such as anemia and advanced age are associated with pulseless electrical activity.⁴ Could the authors provide more clarity on the relationship between COVID-19, AF, and cardiac arrest?