Left Atrial Strain in Omicron-Type COVID-19 Patients

Information about left atrial (LA) 2-dimensional (2D) strain parameters in patients with the Omicron variant of COVID-19 is limited. The aim of this study is to evaluate LA strain (LAS) in COVID-19 patients with the Omicron variant and compare it to that of propensity-matched patients with the wild-type (WT) variant.

A total of 148 consecutive patients who were hospitalized with Omicron COVID-19 underwent an echocardiographic evaluation within the first day after hospital admission and were compared to propensity-matched patients (1:1) with the WT variant. LA 2D speckle tracking echocardiography parameters included the following: LAS, reservoir (LASr); LAS, conduit (LAScd); LAS, contraction (LASct); and LASr to the ratio between early mitral inflow velocity/mitral annular early diastolic velocity (E/e'). The values for the parameters that occurred during acute Omicron-type infection were compared with those found on historic examinations in 36 patients.

Compared to the matched WT cohort, patients with acute Omicron-type infection had similar LASr (31.3% ± 13.3% vs 33.0% ± 14.2%), LAScd (-18.7% ± 9.8% vs -18.6% ± 10.8%), and LASct (-12.5% ± 8.6% vs -13.6% ± 8.2%) values (P > 0.2 for all), but a higher E/e' ratio (11.8 ± 6 vs 10.1 ± 7; P = 0.03). Surprisingly, LASr (31.9% ± 13.7% vs 22.6% ± 13.9%; P = 0.04) and LAScd (-18.7% ± 9.7% vs -10.7% ± 6.6%; P < 0.001) improved in patients during acute infection. LASr, LAScd, and LASr/(E/e') were significantly associated with an increased risk of either in-hospital mortality, need for mechanical ventilation, or the combined event.

In hospitalized patients with an Omicron COVID-19 infection, LAS parameters are similar to those of matched patients with WT variant and are associated with mortality and respiratory deterioration. These abnormalities were recorded previously in the 36 patients with historical echocardiograms, suggesting that they are related to background cardiac disease.