Protocol for a randomised controlled feasibility trial of exercise rehabilitation for people with POTS: the PULSE study (2020) MacGregor et al

[Milo]

Abstract:

Background

Postural orthostatic tachycardia syndrome (POTS) is an autonomic nervous system disorder causing an abnormal cardiovascular response to upright posture.

It affects around 0.2% of the population, most commonly women aged 13 to 50 years.

POTS can be debilitating; prolonged episodes of pre-syncope and fatigue can severely affect activities of daily living and health-related quality of life (HRQoL).

Medical treatment is limited and not supported by randomised controlled trial (RCT) evidence.

Lifestyle interventions are first-line treatment, including increased fluid and salt intake, compression tights and isometric counter-pressure manoeuvres to prevent fainting.

Observational studies and small RCTs suggest exercise training may improve symptoms and HRQoL in POTS, but evidence quality is low.

Methods

Sixty-two people (aged 18–40 years) with a confirmed diagnosis of POTS will be invited to enrol on a feasibility RCT with embedded qualitative study.

The primary outcome will be feasibility; process-related measures will include the number of people eligible, recruited, randomised and withdrawn, along with indicators of exercise programme adherence and acceptability.

Secondary physiological, clinical and health-related outcomes including sub-maximal recumbent bike exercise test, active stand test and HRQoL will be measured at 4 and 7 months post-randomisation by researchers blinded to treatment allocation.

The PostUraL tachycardia Syndrome Exercise (PULSE) intervention consists of (1) individual assessment; (2) 12-week, once to twice-weekly, supervised out-patient exercise training; (3) behavioural and motivational support; and (4) guided lifestyle physical activity.

The control intervention will be best-practice usual care with a single 30-min, one-to-one practitioner appointment, and general advice on safe and effective physical activity.

For the embedded qualitative study, participants (n = 10 intervention, n = 10 control) will be interviewed at baseline and 4 months post-randomisation to assess acceptability and the feasibility of progressing to a definitive trial.

Discussion

There is very little high-quality research investigating exercise rehabilitation for people with POTS.

The PULSE study will be the first randomised trial to assess the feasibility of conducting a definitive multicentre RCT testing supervised exercise rehabilitation with behavioural and motivational support, compared to best-practice usual care, for people with POTS.

Trial registration
ISRCTN45323485 registered on 7 April 2020.


Link to paper here

 

[James Morris-Lent]

Looks like all the usual problems.

They do include two physical performance tests in the outcomes; however no critical observer could consider that greater gains on these metrics in the treatment group would constitute reliable and convincing evidence of real improvement. Especially when the trial is so transparently uncontrolled - the 'controls' get shooed out while the treatment group is getting pretty well buttered up from all angles.

The 'Feasibility'+R(notC)T thing looks quite shifty. Perhaps if results are 'positive' (technically not possible the way they've designed the study, but oh well) they say you have positive RCT evidence; if results are null they say that everybody liked the treatment very much and the RCT outcomes weren't what was important - more study needed and in the meantime they'll 'optimize' the treatment to try to manufacture a p = <.05 next time.

 

[Trish]

If it's really just a feasibility study, why do they even need 62 people, and why do they need controls. Surely all they need to do is recruit 10 people and see if they are willing and able to comply with the program.

 

[Hoopoe]

My experience with POTS is that exercise has a weak positive effect on what is clearly a very abnormal state not primarily caused by deconditioning. When I had regular short walks it seemed to help a little with POTS.

Too much exercise paradoxically appears to make orthostatic intolerance worse, presumably due to PEM.

 

[Mithriel]

POTS is a symptom that some people with ME get because of what is gong wrong in the body with ME. People can also get POTS as a result of another disease. Even if exercise helps everyone with POTS who does not have ME it will make us worse because we have a problem with exercise.

 

[Mij]

Patients may develop POTS after a viral illness, serious infections, medical illness, pregnancy and trauma such as head injury. Not all post-infectious patients develop ME.

 

[rvallee]

POTS can be debilitating; simple activities may result in persistent orthostatic intolerance. This can lead to poor concentration, palpitations, nausea, ‘brain fog’ and exercise intolerance

A constellation of symptoms can initiate a negative feedback loop by which enforced inactivity further precipitates orthostatic intolerance, immobility and deconditioning [6, 7].

So they have no idea what POTS is, what dysautonomia is, what PEM or exertion intolerance are. Basically a PACE protocol. Ugh.

 

[Milo]

It is a CBT/GET program, and there is a chance that a few patients who also happen to have ME will be harmed by this kind of program. I am not sure whether this team is even aware of this.

Personally the cardiologist i saw for POTS recommended i enter their in-house exercise program. It was nearby and i could hear the loud music playing from there, and could only imagine what it would sound like if I was actually in the room.

Another cardiologist also recommended exercise. They do not seem to be aware of the problems related to exercise at least with those with ME.