Individual tailored physical training in patients with postural orthostatic tachycardia syndrome associated with post-acute COVID-19 syndrome - a feasibility study

Abstract Funding Acknowledgements Type of funding sources: Public grant(s) – National budget only. Main funding source(s): Hjärt-Lungfonden Vetenskapsrådet Background The number of people that has been affected by COVID-19 is high and has continued to increase throughout the pandemic. A significant proportion of patients with COVID-19 have developed persistent symptoms, described as post-acute COVID-19 syndrome (PACS). A specific PACS variant is the postural orthostatic tachycardia syndrome (POTS). POTS is a cardiovascular dysautonomia characterized by an excessive increase in heart rate in standing and deconditioning. Studies evaluating effect and feasibility of individual tailored physical exercises in POTS associated with PACS are sparse. Purpose To evaluate the effects and feasibility of a individually tailored exercise on physical and psychological function in patients with POTS associated with PACS. Method Patients with POTS + PACS and diagnosed between Dec 2021-Sep 2022 were enrolled. Measurements were carried out at baseline and after intervention: 6-minute walking test (6MWT), Active Standing Test (AST) and self-assessment of symptoms through forms; Malmö POTS scale (MaPs), Vanderbilt Orthostatic Symptom Score (VOSS), health-related quality of life (EQ-5D-5L), anxiety (GAD) and depression (PHQ-9). Physical activity and time in different positions (lying, sitting, standing and walking) were measured using accelerometers (ActivPAL). The intervention consisted of 12 weeks individually tailored training, including both endurance and muscle-strengthening exercises with a gradual progression of time, dose, and position (supine-upright). The training was adapted based on the study subject's heart rate and/or self-estimated exertion using BORG reported perceived excertion. Progression of the exercise was halted if the study subject described increased symptoms >24h after the last exercise session indicating post exertional malaise (PEM). Recruitment rate, compliance and adverse events was registered. Results A total of 15 patients were enrolled and 14 patients completed the intervention (9 women; mean age, 41.6 years (SD 12.3). No severe adverse events occurred however some of the patients’ described PEM. After completing the intervention period, patients demonstrated improvement in physical (6MWT p<0.004) and psychological functions (PHQ-9 p<0.001) and less symptoms related to POTS (MaPS p<0.03) (Table 1). The primary outcome, time spent in upright position increased by 1.5h/day (Figure 1). Conclusion In patients with COVID-19-related POTS, individually tailored exercise was associated with increased time in upright position, reduction of POTS-specific symptoms and improved function. The intervention seems to be feasible in terms of recruitment, compliance and safety. Further studies are needed to verify these results and compare disease progression with and without intervention.