Atrial fibrillation (AF) is the most documented arrhythmia in COVID-19 pneumonia. Left atrial (LA) strain analysis, assessing LA contractility have been associated with the development of new-onset atrial fibrillation (NOAF) in several clinical situations. We aimed to assess the diagnostic ability of LA strain parameters to predict NOAF in patients with severe hypoxemic COVID-19 pneumonia.

We conducted a prospective single center study at Amiens Hospital University (NCT04354558). The population study was composed of adult patients with a severe or critical Covid-19 pneumonia in sinus rhythm at inclusion. Transthoracic echocardiography was performed within 48hours of admission. LA strain analysis was performed by an automated software. The following LA strain parameters were recorded: LA strain during reservoir phase (LASr), LA strain during conduit phase (LAScd) and LA strain during contraction phase (LASct). The primary endpoint was the occurrence of NOAF during the intensive care unit (ICU) stay.

From March 2020 to February 2021, 79 patients were included. Sixteen patients (18%) developed NOAF in ICU. LAScd and LASr were significantly reduced in the NOAF group compared to the other group (8.1[6.3-10.9] vs. 17.2[5.0-10.2]%; P<0.001 and 20.2 [12.3-27.3] % vs. 30.5 [23.8-36.2] %; P=0.002 respectively). After adjustment, only LAScd remained independently predictive of NOAF (OR:2.43; 95%CI:1.18-3.37). A LAScd cut-off value of 11.1% had a sensitivity of 76% and a specificity of 75% to identify patients with NOAF. The 30-day cumulative risk of NOAF was 42±9% with LAScd <11% and 8±4% with LAScd >11% (log rank test P value<0.0001) (Figure 1).

In patients with severe hypoxemic COVID-19 pneumonia, LAScd ≤11% at admission is a strong risk factor of NOAF development during critical care.