Aerobic Fitness Training: No Benefit in Early Subacute Stroke

June 12, 2018

GOTHENBURG, Sweden — Aerobic physical fitness training in early subacute stroke patients did not lead to improvement in activities of daily living or walking speed and was associated with some safety concerns in a new study.

"Our results do not support the use of aerobic fitness training in moderately to severely affected patients in the sub-acute phase of stroke," concluded lead investigator Agnes Floel, MD, University Medicine Greifswald, Germany.

Floel presented results of the PHYS-STROKE study here at the recent 4th European Stroke Organisation Conference (ESOC) 2018.

She explained that although there have been some exciting new developments for acute stroke, about one third of stroke patients still experience chronic impairments in daily life and 20% need help with walking.

Preliminary studies have suggested that fitness training may improve walking ability and ability to perform activities of daily living. In addition, it has been suggested that fitness training after stroke could increase blood flow and neuroplasticity in the brain, leading to enhanced motor, language, and cognitive function, Floel noted.

To look at this issue further, she and her colleagues conducted the PHYS-STROKE study — an investigator-initiated, multicenter, randomized clinical trial in Germany that included 200 patients with subacute stroke, defined as days 5 to 45 after stroke, and a Barthel index less than 65 who were unable to sit unsupported for 30 seconds. 

They were randomly assigned to participate in 50 minutes of treadmill-based, aerobic physical exercise (study intervention) or relaxation sessions (control) five times per week for 4 weeks (a total of 20 sessions), in addition to standard rehabilitative therapy.

The co-primary outcomes were change of gait speed and the Barthel index at 3 months after stroke (co-primary endpoint).

Results showed no benefit in the aerobic exercise training group on either primary endpoint.

Table. PHYS-STROKE Co-Primary Outcomes

Endpoint Aerobic Exercise Relaxation Treatment Effect (95% Confidence Interval) P Value
Mean change in gait speed (m/s) 0.4 0.3 0.1 (–0.1 to 0.2) .40
Mean change in Barthel index 29 30 –0.3 (–5.2 to 4.5) .89


Key secondary endpoints, which included change in 6-minute walk test and change in Rivermead Mobility Index, were also nonsignificant.

The safety analysis showed a strong trend toward an increase in serious adverse events in the aerobic exercise group, which had higher rates of acute hospital referrals and recurrent strokes. The exercise group also experienced more falls and more pain.

Floel noted that the PHYS-STROKE results concurred with findings of larger rehabilitation studies, such as AVERT (2015), which suggested that very early rehabilitation could be harmful, and LEAPS (2011), which showed show similar gains in walking ability with home rehab as locomotor training but with fewer risks.similar gains with home physical therapy as locomotor treadmill training but with fewer risks.  show similar gains in walking ability with home rehab as locomotor training but with fewer risks.

Further analyses will explore effects on cognition and quality of life, but for the time being "our results do not support such aerobic exercise intervention," Floel said. 

However, other experts did not seem totally convinced by the researchers' conclusions.

Co-chair of the ESOC session at which the PHYS- STROKE study was presented, Philip Bath, MD, University of Nottingham, United Kingdom, pointed out that the study was smaller than planned because of a shortage of funding, and he wondered whether the results might have been better if the original planned sample size of 450 had been achieved.  

And during the discussion, it was noted that previous trials have shown benefits of exercise in subacute stroke on subsequent walking speed, raising the question of why this study was different.

Floel pointed out that their trial was "larger and better controlled than previous studies so the results are probably more reliable. However, at baseline the exercise group were a little bit worse than the control patients — that might be an issue, she said.

The per protocol analysis came close to showing a significant effect in gait performance, "so there may be something there," she added. "But still, if you take everything together, including adverse events, you might wonder if this is the right way to go."

Commenting on the findings for Medscape Medical News, Alistair Webb, MD, University of Oxford, United Kingdom, said, "Finding the right intervention and outcome to assess in rehabilitation trials is very difficult. It's hard to pin down the best study design."  

"My feeling is that the negative results of recent trials have probably done a disservice to rehabilitation," he said.   

4th European Stroke Organisation Conference (ESOC) 2018. Presented May 18, 2018. Abstract

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