Impact of Comorbidities on the Prognosis of Pediatric Postural Tachycardia Syndrome

OBJECTIVE: To investigate the influence of comorbidities on the prognosis of pediatric postural tachycardia syndrome (POTS). METHODS: In this retrospective cohort study, 275 children with POTS admitted to the Department of Pediatrics at Peking University First Hospital were recruited from 2016 to 2019 and followed up. The participants were divided into simple POTS (S-POTS, n=156 cases) and POTS with comorbidities (Co-POTS, n=119 cases) groups according to whether they were complicated with comorbidities. A Cox regression analysis was used to identify the prognostic risk factors for children with POTS, while Kaplan–Meier curves were applied to compare the cumulative symptom remission rate (CSRR) between the two groups. The rehospitalization of the children between the two groups was also compared to explore the influence of comorbidities. RESULTS: Twenty-one participants (7.6%) were lost during a median follow-up of 24 months. The Cox regression model showed that comorbidities and body mass index (BMI) were associated with the CSRR of the children with POTS. The CSRR of pediatric POTS alone was 1.748 times higher than that of patients with comorbidities, and the CSRR was decreased by 5.1% for each 1 kg/m(2) increase in BMI. The most common comorbidity in children with POTS in this study was allergic disorders, followed by the psychological diseases. The patients in the Co-POTS group had a lower CSRR than those in the S-POTS group (log rank P=0.0001). In addition, compared with those of the S-POTS group, the total number of rehospitalizations was high (P=0.001), and the total hospital stays were long in the Co-POTS group (P<0.001). CONCLUSION: Complicating with comorbidities, pediatric patients with POTS had lower CSRR and more rehospitalizations than those without comorbidities. More attention should be given to comorbidities when managing pediatric POTS.