Cardiac Function and Functional Capacity in Patients With Long COVID: A Comparison to Propensity-Matched Community Controls

Background: Cardiac impairment has been associated with acute COVID-19 since the earliest reports of the pandemic. However, its role in postacute sequelae of COVID-19 ("long COVID") is undefined, and many existing observations about cardiovascular involvement in postacute sequelae of COVID-19 are uncontrolled.

Objective: To compare the prevalence of cardiac dysfunction in patients with long COVID and noninfected controls from the same community and explore their association with functional capacity.

Methods: Echocardiography was used to assess cardiac structure and function, including the measurement of global longitudinal strain (GLS), in 190 participants with long COVID. All underwent assessment of functional impairment by subjective (Duke Activity Status Index) and objective tests (6-minute walk test). The 190 participants from the long COVID group were matched with those from 979 patients who underwent the same tests in the pre-COVID-19 era, using a propensity score.

Results: The 190 patients with long COVID had similar age and risk factor profiles to those of their matched controls. Left ventricular dimensions and geometry, but not diastolic parameters, were significantly altered in the long COVID group. The long COVID group had subclinical systolic dysfunction (GLS 18.5% ± 2.6% vs 19.3% ± 2.7%, P = .005), and more long COVID patients had abnormal (<16%) GLS (13% vs 8%, P = .035). The association of long COVID with abnormal GLS (odds ratio, 1.49 [1.04, 2.45]) was independent of-and had a similar or greater effect size than-age and risk factors. There was no interaction of long COVID with the association of risk factors with GLS. As expected, the long COVID group had significant subjective (<85% predicted METS; 72% vs 5%, P < .001) and objective functional impairment (29% vs 24%, P = .026), but GLS was only weakly associated with both subjective (r = 0.30, P = .005) and objective (r = 0.21, P = .05) functional impairment. The presence of long COVID was independently associated with subjective (odds ratio = 159.7 [95% CI, 61.6-414.2]) and objective functional impairment (odds ratio = 2.8 [95% CI, 1.5-5.2]).

Conclusions: Impaired GLS and left ventricular dimensions are the echocardiographic features that are overrepresented in long COVID, and this association is similar to and independent of other risk factors. Impaired GLS is weakly associated with functional impairment.