Tuesday June 17 2014
An alternative diagnosis could provide new treatment options
“ME: one third of patients ‘wrongly diagnosed’,” says The Daily Telegraph, which has reported on a new study of a condition called postural tachycardia syndrome (PoTS).
In PoTS, the heart rate increases by over 30 beats per minute when standing, causing dizziness, fatigue and other symptoms that impact a person’s quality of life (for a full list, read the PoTS UK advice on PoTS symptoms).
Researchers wanted to find out some of the characteristics of people who had PoTS, and whether the condition has any similar characteristics to chronic fatigue syndrome (CFS). The media headlines have used this latest study to focus on previous research that found around a third of people with a diagnosis of CFS/myalgic encephalitis (ME) actually had PoTS.
It is unclear from this latest report whether these people had been “wrongly diagnosed”, or whether they had both PoTS and CFS. In the new study, 20% of people with PoTS also had a diagnosis of CFS.
Unfortunately, there are no cures for either condition – instead, doctors help people to manage their symptoms and reduce the impact on their quality of life. Beta-blockers were the most commonly used treatment for the symptoms of PoTS in this study, but there were a total of 21 (of a possible 136) different treatments used, and some patients received no treatment at all.
The researchers speculate that those who did not have any treatment may have experienced side effects or no improvement, compared to those who did have treatment. The results also showed very little difference in symptoms, regardless of whether medication was taken.
Where did the story come from?
The study was carried out by researchers from Newcastle University and was funded by the UK National Institute for Health Research (NIHR) Biomedical Research Centre in Ageing.
The study was published in the peer-reviewed medical journal BMJ Open. The article is open-access, meaning the research is free to view and download online.
The media reported that a third of people are being wrongly diagnosed with CFS when they have PoTS, which is “treatable”. However, this is not what the latest study found. Instead, it highlights that very little is known about both conditions, although it did find that there is a degree of crossover between PoTS and CFS/ME. Both are difficult to manage with current treatment options.
However, The Independent did correctly cover the results of this latest study.
What kind of research was this?
This was a cross-sectional survey of people with a diagnosis of PoTS and people with CFS.
The aim was to raise awareness of PoTS in health professionals, and to see if there were any differences between people with PoTS seen in one centre, compared to those who were members of the largest UK support group for people with PoTS – PoTS UK.
The researchers compared all of these people with PoTS to people with CFS who did not have PoTS. A previous cross-sectional study in 2008 found that 27% of those with a diagnosis of CFS also had PoTS.
What did the research involve?
The researchers sent questionnaires to:
- people diagnosed with PoTS who had attended their clinics
- all members of the support group PoTS UK
- people with CFS without PoTS
The researchers looked for differences in demographics, time taken for a diagnosis to be made, symptoms and treatments. The participants with PoTS were asked to complete two initial questionnaires about:
- background details, including education level, age of symptom onset, age at diagnosis of PoTS and current medication
- symptoms of PoTS, potential precipitants to the illness and any other illnesses
All of the participants, those with PoTS and those with CFS, were sent the following six validated symptom assessment tools:
- fatigue impact scale
- Epworth sleepiness scale
- orthostatic grading scale
- hospital anxiety and depression scale
- patient-reported outcomes measurement information system, health assessment questionnaire (PHAQ)
- cognitive failures questionnaire
What were the basic results?
The researchers recruited 136 people with PoTS (52 out of 87 from the clinics and 84 of the 170 members of PoTS UK).
The researchers found that patients with PoTS are predominantly women, young, well-educated and have significant and debilitating symptoms that considerably impact a person's quality of life.
The researchers noted several differences between their cohort of patients and all members of the support group. There were differences in:
- working hours
20% of the total sample of people with PoTS also had a diagnosis of CFS (27 out of the 136 participants), and this went up to 42% in those recruited from the clinic (22 out of 52). Of people with PoTS who did not report CFS, 43% of them would have met the diagnostic criteria.
Compared to those with both PoTS and CFS, people diagnosed only with PoTS:
- had significantly more symptoms before diagnosis, the majority of which were palpitations, dizziness, memory impairment, breathlessness, lightheadedness and muscle aches
- were more likely to receive disability benefits
The researchers also compared people with PoTS to people who had CFS. It is not known how many people with CFS completed the questionnaires, but the study reports that they were matched to the people with PoTS in terms of age and gender.
Comparing all people with PoTS (with and without CFS) to people with just CFS, it was found that:
- there were similar high levels of symptom burden in each group
- the symptoms related to low blood pressure, such as dizziness, were more severe in the PoTS group
- anxiety and depression scores were significantly higher in the CFS group
On analysing the questionnaire responses from people with PoTS, the researchers found that:
- there were 21 different treatment “regimes” for PoTS
- the most common treatment was beta-blockers
- 27% of people were receiving no treatment for their PoTS
- there was no difference in fatigue severity, daytime sleepiness, cognitive or autonomic symptoms or level of functional impairment between those being treated and those having no treatment
- people without medication scored slightly higher on the anxiety and depression scale
How did the researchers interpret the results?
The researchers concluded that postural tachycardia syndrome (PoTS) “is a condition that is associated with significant symptoms that impact on quality of life. Currently, there are no evidence-based treatments for PoTS, and its underlying pathogenesis [reason for disease development], natural history and associated features are not fully understood.
“We would suggest that increasing awareness of this debilitating disease is important to improve understanding, diagnosis and management of PoTS”.
This study has described some of the demographics and symptoms of people with PoTS and has also shown that there is a degree of overlap in people diagnosed with CFS and PoTS.
However, in contrast to the media's coverage, this study does not show whether patients were misdiagnosed. It also does not show that there are effective treatments for PoTS. In fact, very little difference was found in symptoms between people having treatment compared to those that were having none.
There are several other limitations to this study. These were the fact that:
- it was based on a small number of participants
- there was a low response rate to the questionnaires, which could bias results, either because people were too ill to respond or were too busy
- it is unclear how well people with PoTS were matched to people with CFS; 20% of the people with PoTS also had a diagnosis of CFS, which would compromise the results
However, the researchers set out to raise awareness of PoTS in health professionals. This was done to increase its recognition, so that further research can be conducted in order to improve treatment options, which from the media coverage garnered, they have almost certainly achieved.
Analysis by Bazian. Edited by NHS Choices. Follow Behind the Headlines on Twitter. Join the Healthy Evidence forum.