Basingstoke Team Parish

Exercise for PoTS - What's the Evidence?

8th September 2018

Soldiering on

An early study on exercise for orthostatic intolerance was done in 2005 on 27 Austrian soldiers [1]. The subjects were selected from nearly 3,000 healthy young male new recruits who reported symptoms of dizziness on a questionnaire, and had a heart rate rise of more than 30 beats per minute (bpm) on a tilt table test. These individuals had not previously had a clinical diagnosis of PoTS, and all were healthy enough to join the army. 

After a three-month jogging programme, ten out of 16 soldiers no longer had orthostatic intolerance on the tilt table test, while only one out of 11 soldiers allocated to a comparison group (known as a control group) who did not jog, recovered.

At the time, little notice was taken of this study partly because it was done in men, while the typical PoTS patient is a young woman. Also the participants were not patients with a syndrome of chronic orthostatic intolerance, but were well enough to be soldiers.   

 

A cardiologist who works with astronauts

Since then studies of exercise in patients with PoTS have been led by Professor Benjamin Levine, Director of the Institute for Exercise and Environmental Medicine at Texas Health Presbyterian Hospital and Distinguished Professor of Exercise Sciences at UT Southwestern Medical Center, Dallas, USA. 

He’s a cardiologist whose work with NASA astronauts led him to develop an exercise programme for PoTS.

He and his team have studied two groups of patients. First they carried out extensive studies on 27 PoTS patients from Professor Levine’s clinic in Dallas, and then they did another ‘registry’ study on 250 PoTS patients worldwide.

The Dallas Studies

Fifty-four consecutive patients with PoTS referred to Professor Levine’s clinic over a roughly three year period were invited to take part in the study. Eight were not interested in participating, 18 were not prepared to go without their medications or do the extensive assessments required, and one took part but their results were excluded from the published journal article at the request of a reviewer because the participant had Ehlers-Danlos Syndrome. 

This left 27 patients (26 women and 1 man) in the study [2].

In the study, for a patient to be classified as having PoTS they must have had a clinical syndrome of orthostatic intolerance for at least 6 months. They also either had to have a rise in heart rate of more than 30 bpm while standing for ten minutes, or their heart rate had to exceed 120bpm with no significant drop in blood pressure while standing for that period.

Professor Levine and colleagues published the results from research on these 27 individuals in a series of papers between 2010 and 2015 [2, 3, 4, 5, 6].

Twenty-five of the patients took part in a three-month daily exercise programme doing three to five sessions of 30-45 minutes endurance training plus strength training per week. 

Only sitting or horizontal exercises such as rowing, swimming or recumbent cycling were used in the first month to six weeks [2, 3]. Upright exercise was gradually included in the second half of the programme.

In addition, participants were encouraged to drink 3L of water a day, eat 7-10g of salt and to elevate the heads of their beds by 10-15cm.

The patients were assessed for signs of PoTS and also completed a health questionnaire known as the SF-36 (the 36-item short form health survey) before and after the exercise training.

Nineteen of them (76%) managed to complete the exercise programme. Before the programme their heart rates rose by an average of 36 beats per minute during a ten-minute stand, but after the exercise programme the average rise was only 22 bpm [7]. 

All 19 patients showed improved scores on the physical function section of the health questionnaire [2].

In fact, after the exercise training, ten of them no longer met the criteria for PoTS, and so were effectively in remission, and able to live normal lives, according to Professor Levine [2]. 

The average age of participants was 26 years [2]. They had had PoTS for between six months and five years, with an average duration of 28 months [3].

When assessing whether an intervention (such as exercise) works, it has to be compared with something. This is usually done by comparing the treatment group with a ‘control’ group. The control group could be people with PoTS who carry on as usual and don’t do the exercise programme for example, or they could be given a different treatment for PoTS.

In this study the patients doing the exercise programme were compared with two other groups: ten patients who took a common medication for PoTS for a month (the beta blocker, propranolol slow release 80mg/day) and nine patients who took a placebo tablet for a month [4]. All of these same patients then went on to do the exercise programme.

Initially – before any interventions- the patients scored an average of 33 on the physical functioning section of the health questionnaire [4]. (The average score for a healthy person is 50 [7]).

Although propranolol lowered their heart rates, patients taking the medicine did not report feeling any better – their scores on the health questionnaire after a month of treatment were not improved [4]. Patients taking the placebo did not report improvement either [4].

But after the three months’ exercise training the average score on the physical function section of the questionnaire was 50 - at the level of a healthy person [4,7]. 

The international registry study

In his next study Professor Levine and his colleagues wanted to test whether the exercise programme could be delivered to patients in the community without his supervision.

People with PoTS anywhere in the world were invited to do the programme under the supervision of their own doctor with minimal contact with the research team in Texas [8].  

To take part, their doctor had to consider it safe for the patient to do so.

The diagnosis of PoTS had to be confirmed by measuring heart rate during a 10 minute standing test, using the same criteria as in the Dallas studies.

The SF-36 health questionnaire was also completed before starting the programme.

Over 250 people with PoTS enrolled in the study. Of these, 103 (41%) completed the exercise training and 78 (31%) completed all the data requirements and so were included in the analysis of results [8]. 

Forty percent of the people who dropped out did so because they considered the training was “too difficult.” A further 24% dropped out because of other medical problems including Lyme disease, epilepsy and chronic migraines. 

Although the drop-out rate (59%) may seem high, Professor Levine says it is similar to drop-out rates for many medical treatments including cardiac rehabilitation after a heart attack, or even for something as simple as taking medications as prescribed for high blood pressure. 

Before exercise training the average increase in heart rate while standing for the 78 participants with full data sets was 46 bpm. After the training it was 23 bpm on average [8].  

Scores on all eight sections of the SF-36 health questionnaire improved after the programme.

The majority (71%) of the 78 patients who completed the programme no longer met the classification for PoTS. 

About 30 patients carried on exercising and submitted results to Professor Levine’s team after six or 12 months of exercise. The benefits persisted [8]. 

A limitation of this study was that it had no control group [8].

 

Exercise in medical guidelines for treating PoTS

Based on the results of Professor Levine’s Dallas studies [2] and the Austrian soldier study [1], the Heart Rhythm Society recommended exercise for PoTS patients in an 2015 expert consensus statement [9].

The class of recommendation is ‘IIa’, which is not the strongest level of recommendation available (class I). It means that the experts consider that the benefit to the patient ‘probably exceeds the risk’ [9]. 

The guidelines say the quality of the evidence used to come to this recommendation is ‘moderate’. 

 

What other experts say

Consultant cardiologist Dr Boon Lim, who specialises in conditions such as PoTS, welcomes Professor Levine’s research on exercise.

“It’s great work, and Professor Levine needs to be given credit for conducting the research showing that his patients can improve with exercise,” says Dr Lim who is an honorary senior lecturer at Imperial College, London.

He is surprised, however, that based on such a small randomised-controlled trial, exercise has been recommended in the Heart Rhythm Society guidelines.

Dr Lim has concerns that the patients who agreed to take part in or managed to complete the exercise training in the Dallas and international registry studies may not have been representative of all PoTS patients and may perhaps have had milder disease.

“I think it was a self-selected group. You can see how a patient who was wheelchair-bound or found it difficult to stand for more than a few minutes might look at the planned programme and opt out because it looked impossible. This could explain the 18 out of 57 who declined to take part in the Dallas studies,” says Dr Lim, who also leads the Imperial Syncope Diagnostic Unit at Hammersmith Hospital in London.

“In my experience PoTS patients vary greatly. Some are clearly the type of patient that would benefit from Professor Levine’s programme. But others are not, especially if they have Ehlers-Danlos Syndrome or chronic gut and bladder issues.” 

He says when he treats patients with PoTS, he recommends exercise to all patients, but finds only a proportion (estimated 70%) are able to do regular sustained exercise. However, in his experience, when patients are able to exercise, they do manifest an improvement in symptoms within 3-6 months. 

 

Meanwhile Dr Gordon McGregor, a clinical exercise physiologist, says that the current evidence for exercise as a treatment for PoTS would not be sufficient to persuade the UK’s National Health Service to commission the treatment.

“I think there are limitations with Professor Levine’s studies, because the population was very carefully selected, the numbers were pretty small, and the study design not particularly strong - particularly in the registry study, where there was no control group,” says Dr McGregor, who works at University Hospital, Coventry and is a Clinical Research Fellow at Coventry University.

“There is absolutely no way the NHS would pay for a treatment that is based on that kind of evidence. They demand evidence based on high quality randomised controlled trials, carried out at several centres, with patients that are representative of the demographics and diversity of people with PoTS,” he added.

“But that doesn’t mean that patients with POTS can’t pursue physical activity goals. The studies provide some evidence and the 2015 Heart Rhythm Society guidelines say the benefit exceeds the risk - though to be honest I think that is a bit of a stretch.

“Physiologically the rationale is sound. If you were to ask me whether I think exercise could improve POTS, then I would definitely say ‘yes’, because of the physical deconditioning component that’s involved for some people with POTS.

“My belief strongly is that exercise can work. Whether or not we have the definitive evidence yet to prove that is questionable, I think.” 

 

5 'practical pearls' from Dr Satish Raj

Dr Satish Raj, a cardiologist and PoTS expert based at the University of Calgary, Canada, wrote a commentary on Professor Levine’s worldwide exercise study [10].”

In the commentary he gave five “practical pearls” for exercise training in PoTS [10]:

  1. Exercise is a treatment not a cure. Symptoms can return if you stop exercising.
  2. The key is to avoid upright exercise at first.
  3. Some PoTS patients may have other conditions that make exercising difficult. For people with joint hypermobility, swimming may be the best choice.
  4. Exercise duration and consistency is important. Patients should be doing 30 minutes of continuous training early in the programme. They need to exercise at least every other day.
  5. Many PoTS patients will feel worse (more fatigued) before they start to feel better. It can take 4-6 weeks before an improvement is noticed. It’s important to be aware of this, or patients may drop out of the programme before it has had time to work.  

 

How to do Professor Levine's programme

People with PoTS wanting to do the programme should ask their doctor to get in touch with Professor Levine by emailing:  benjaminelevine@texashealth.org.

There is a link to a video of an exercise physiologist explaining Dr Levine’s programme to a patient here.

©Clare Pain 2018

 

References

  1. Robert Winker et al. Endurance exercise training in orthostatic intolerance. A randomised controlled trial. Hypertension, 2005. http://hyper.ahajournals.org/content/45/3/391.long
  2. Qi Fu et al. Cardiac origins of the postural orthostatic tachycardia syndrome. Journal of the American College of Cardiology, 2010. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2914315/
  3. Shigeki Shibata et al. Short-term exercise training improves the cardiovascular response to exercise in the postural orthostatic tachycardia syndrome. Journal of Physiology2012. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3547265/
  4. Qi Fu et al. Exercise Training versus Propranolol in the Treatment of the Postural Orthostatic Tachycardia Syndrome. Hypertension, 2011. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3142863/
  5. M Melyn Galbreath et al. Effects of exercise training on arterial-cardiac baroreflex function in POTS. Clinical Autonomic Research, 2011. https://link.springer.com/article/10.1007%2Fs10286-010-0091- 5
  6. Qi Fu et al. Exercise in the Postural Orthostatic Tachycardia Syndrome. Autonomic Neuroscience, 2015. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4336603/
  7. Personal communication from Professor Levine
  8. Stephen A George et al. The international POTS registry: Evaluating the efficacy of an exercise training intervention in a community setting. Heart Rhythm 2016. https://www.heartrhythmjournal.com/article/S1547-5271(15)01527-1/fulltext
  9. 2015 Heart Rhythm Society Expert Consensus Statement on the Diagnosis and Treatment of Postural Tachycardia Syndrome, Inappropriate Sinus Tachycardia, and Vasovagal Syncope. https://www.hrsonline.org/Policy-Payment/Clinical-Guidelines-Documents/2015-HRS-Document-on-POTS-IST-VVS
  10. Satish R Raj. Row, row, row your way to treating postural tachycardia syndrome. Heart Rhythm, 2016. https://linkinghub.elsevier.com/retrieve/pii/S1547-5271(15)01674-4

 

 


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