AFib, Atrial Flutter in COVID-19, Influenza Patients Suggests Inflammatory Response

The incidence of atrial fibrillation (AFib) or flutter and associated mortality in patients with COVID-19 or influenza suggests AFib or atrial flutter may be a generalized response to inflammation of severe viral illness, according to a study published Feb. 24 in JACC: Clinical Electrophysiology.

In a retrospective analysis, Daniel R. Musikantow, MD, et al., looked at incidence, predictors and outcomes of AFib or atrial flutter in 3,970 patients hospitalized with PCR-positive COVID-19 and 1,420 patients hospitalized with influenza.

They found that among patients hospitalized with COVID-19, 375 (10%) had AFib or atrial flutter, including 146 patients (4%) with a history of atrial arrhythmias. Patients with new-onset AFib or atrial flutter were older and had increased inflammatory markers and more myocardial injury. AFib or atrial flutter were associated with increased mortality (46% vs. 26%). Among patients with influenza, 163 (12%) had AFib or atrial flutter. Mortality was lower in the influenza group than in the COVID-19 group (9% vs. 29%). Incidence of AFib or atrial flutter was associated with a similarly increased mortality for both COVID-19 and influenza patients.

According to the researchers, the "observation that [AFib] occurs in COVID-19 at a frequency similar to that in influenza argues against a unique effect of either virus on atrial rhythm." They note that in both COVID-19 and influenza patients, new-onset AFib or atrial flutter was associated with higher inflammation and disease severity, regardless of baseline characteristics. "These data suggest that these atrial arrhythmias are less likely specific to the COVID-19 viral infection but are rather a generalized response to the systemic inflammatory response of severe viral illness," they conclude.