Comorbidities and risk factors
Although 41% of patients with POTS report some health event preceding onset of symptoms, it’s unclear which, if any, of these events may be related to the condition. The most common antecedent event is infection, reported by 41% of patients in the “Big POTS Survey” conducted by Dysautonomia International, Dr. Vernino said. Other antecedent events reported included surgery (12%), pregnancy (9%), an accident (6%), vaccination (6%), puberty (5%), concussion (4%), and emotional trauma (3%). Research has found associations with migraine, concussion, and infection.
Comorbidities are also common, reported by 84% of patients in the same survey. Migraine, vitamin D deficiency, and joint hypermobility (Ehlers-Danlos syndrome type 3) top the list of comorbidities, and various autoimmune conditions, particularly Sjögren’s syndrome, may co-occur with POTS. Other comorbidities include small fiber neuropathy, mast-cell activation syndrome, chronic fatigue, gastrointestinal problems, vasovagal syncope, and sleeping difficulties.
Joint hypermobility appears to be a “pretty strong risk factor for development” of POTS, Dr. Vernino said, and patients may even be involved in activities where that’s helpful, such as gymnastics. “You can make this diagnosis clinically – there isn’t a genetic test for joint hypermobility syndrome – and you usually don’t have the other features of Marfan syndrome,” he told attendees.
Other risk factors include low body mass, mitral valve prolapse, migraine, anxiety, irritable bowel syndrome, prolonged bed rest after an illness, and mast-cell activation syndrome.
Prognosis and treatment
POTS is very common but often still unrecognized, Dr. Vernino said, “because the symptoms are somewhat diverse and broad and vague.” Even providers who recognize POTS can become preoccupied with “the heart rate increase being the whole picture, but there are many other symptoms, and that leads to a significant impact on the quality of life of these patients.”
The course of POTS varies across patients. In about half of patients, symptoms persist but the severity improves, and one in five patients fully resolve. Severity only tends to worsen over time in about 3.5% of patients, and severity remains constant in 8.7% (J Pediatr. 2016 Jun;173:149-53. doi: 10.1016/j.jpeds.2016.02.035).
“It would probably be simpler if POTS was a single entity that had a single etiology that we could target,” Dr. Vernino said. But its heterogeneity means “we have to investigate patients individually and understand their particular situation, individualize their treatment, whether it be nonpharmacological or pharmacological, to their particular potential etiologies.”
Dr. Vernino has received research support from Genentech, Grifols, Athena/Quest, Biohaven Pharmaceutical, Dysautonomia International, and the Rex Griswold Foundation.