Background: The incidence of postural orthostatic tachycardia syndrome (POTS) in long COVID has been a growing concern since the first cases were reported in 2021. The aim of this study was to assess the prevalence and clinical impact of POTS in a series of well-characterized patients with long COVID.
Methods: We prospectively analyzed 467 nonhospitalized, highly symptomatic (sick leave ≥50%) patients with long COVID, and studied differences in demographics and clinical assessment outcomes between those diagnosed with POTS and the remaining long COVID patients. Examinations were performed at a median of 12 months after acute COVID-19, followed by a cardiologist evaluation with 48-hour ECG, head-up tilt test, and Active Stand Test for those with clinically suspected POTS.
Results: Of all long COVID patients, 143 (31%) were diagnosed with POTS, 128 (27%) did not fulfill POTS criteria, while 196 (42%) had no clinical signs of POTS. Patients with POTS were younger (mean age, 40.0 versus 44.0 versus 47.0 years, respectively; P≤0.001) and predominantly female (91%). They had significantly lower physical activity compared with the other 2 groups, as measured with the Frändin-Grimby scale (P=0.001). Heart rates during the 6-minute walk test were significantly higher in the POTS group, both during walking and at rest afterward, with a significantly shorter walking distance (448 m versus 472 m versus 509 m, respectively; P≤0.001). However, the distribution of symptoms showed no significant differences between the groups.
Conclusions: In this cohort of predominantly younger women with highly symptomatic long COVID, POTS is common and presents with overlapping symptoms between POTS and non-POTS patients. Long COVID POTS confers lower physical activity and capacity compared with non-POTS long COVID and should be systematically assessed in this condition.
Keywords: exercise test; long COVID; orthostatic intolerance; postural orthostatic tachycardia syndrome; sick leave; symptom burden; tilt-table test.