Determining optimal poststroke exercise: Study protocol for a randomized controlled trial investigating therapeutic intensity and dose on functional recovery during stroke inpatient rehabilitation

Blood pressure trajectory of inpatient stroke rehabilitation patients from the Determining Optimal Post-Stroke Exercise (DOSE) trial over the first 12 months post-stroke

Background

High blood pressure (BP) is the primary risk factor for recurrent strokes. Despite established clinical guidelines, some stroke survivors exhibit uncontrolled BP over the first 12 months post-stroke. Furthermore, research on BP trajectories in stroke survivors admitted to inpatient rehabilitation hospitals is limited. Exercise is recommended to reduce BP after stroke. However, the effect of high repetition gait training at aerobic intensities (>40% heart rate reserve; HRR) during inpatient rehabilitation on BP is unclear. We aimed to determine the effect of an aerobic gait training intervention on BP trajectory over the first 12 months post-stroke.

Methods

This is a secondary analysis of the Determining Optimal Post-Stroke Exercise (DOSE) trial. Participants with stroke admitted to inpatient rehabilitation hospitals were recruited and randomized to usual care (n = 24), DOSE1 (n = 25; >2,000 steps, 40-60% HRR for >30 min/session, 20 sessions over 4 weeks), or DOSE2 (n = 25; additional DOSE1 session/day) groups. Resting BP [systolic (SBP) and diastolic (DBP)] was measured at baseline (inpatient rehabilitation admission), post-intervention (near inpatient discharge), 6- and 12-month post-stroke. Linear mixed-effects models were used to examine the effects of group and time (weeks post-stroke) on SBP, DBP and hypertension (≥140/90 mmHg; ≥130/80 mmHg, if diabetic), controlling for age, stroke type, and baseline history of hypertension.

Results

No effect of intervention group on SBP, DBP, or hypertension was observed. BP increased from baseline to 12-month post-stroke for SBP (from [mean ± standard deviation] 121.8 ± 15.0 to 131.8 ± 17.8 mmHg) and for DBP (74.4 ± 9.8 to 78.5 ± 10.1 mmHg). The proportion of hypertensive participants increased from 20.8% (n = 15/72) to 32.8% (n = 19/58). These increases in BP were statistically significant: an effect [estimation (95%CI), value of p] of time was observed on SBP [0.19 (0.12-0.26) mmHg/week, p < 0.001], DBP [0.09 (0.05-0.14) mmHg/week, p < 0.001], and hypertension [OR (95%CI): 1.03 (1.01-1.05), p = 0.010]. A baseline history of hypertension was associated with higher SBP by 13.45 (8.73-18.17) mmHg, higher DBP by 5.57 (2.02-9.12) mmHg, and 42.22 (6.60-270.08) times the odds of being hypertensive at each timepoint, compared to those without.

Conclusion

Blood pressure increased after inpatient rehabilitation over the first 12 months post-stroke, especially among those with a history of hypertension. The 4-week aerobic gait training intervention did not influence this trajectory.

Step Number and Aerobic Minute Exercise Prescription and Progression in Stroke: A Roadmap

Background

While higher therapeutic intensity improves motor recovery after stroke, translating findings from successful studies is challenging without clear exercise intensity targets. We show in the DOSE trial¹ more than double the steps and aerobic minutes within a session can be achieved compared with usual care and translates to improved long-term walking outcomes.

Objective

We modeled data from this successful higher intensity multi-site RCT to develop targets for prescribing and progressing exercise for varying levels of walking impairment after stroke.

Methods

In twenty-five individuals in inpatient rehabilitation, twenty sessions were monitored for a total of 500 one-hour physical therapy sessions. For the 500 sessions, step number and aerobic minute progression were modeled using linear mixed effects regression. Using formulas from the linear mixed effects regression, targets were calculated.

Results

The model for step number included session number and baseline walking speed, and for aerobic minutes, session number and age. For steps, there was an increase of 73 steps per session. With baseline walking speed, for every 0.1 m/s increase, a corresponding increase of 302 steps was predicted. For aerobic minutes, there was an increase of .56 minutes of aerobic activity (ie, 34 seconds) per session. For every year increase in age, a decrease of .39 minutes (ie, 23 seconds) was predicted.

Conclusions

Using data associated with better walking outcomes, we provide step number and aerobic minute targets that future studies can cross-validate. As walking speed and age are collected at admission, these models allow for uptake of routine measurement of therapeutic intensity.

Registration: www.clinicaltrials.gov; NCT01915368.

Higher Doses Improve Walking Recovery During Stroke Inpatient Rehabilitation

BACKGROUND AND PURPOSE

We investigated the effect of higher therapeutic exercise doses on walking during inpatient rehabilitation, typically commencing 1 to 4 weeks poststroke.

METHODS

This phase II, blinded-assessor, randomized controlled trial recruited from 6 Canadian inpatient rehabilitation units, between 2014 and 2018. Subjects (n=75; 25/group) were randomized into: control (usual care) physical therapy: typically, 1 hour, 5 days/week; Determining Optimal Post-Stroke Exercise (DOSE1): 1 hour, 5 days/week, more than double the intensity of Control (based on aerobic minutes and walking steps); and DOSE2: 2 hours, 5 days/week, more than quadruple the intensity of Control, each for 4 weeks duration. The primary outcome, walking endurance at completion of the 4-week intervention (post-evaluation), was compared across these groups using linear regression. Secondary outcomes at post-evaluation, and longitudinal outcomes at 6 and 12-month evaluations, were also analyzed.

RESULTS

Both DOSE1 (mean change 61 m [95% CI, 9-113], P=0.02) and DOSE2 (mean change 58 m, 6-110, P=0.03) demonstrated greater walking endurance compared with Control at the post-evaluation. Significant improvements were also observed with DOSE2 in gait speed (5-m walk), and both DOSE groups in quality of life (EQ-5D-5 L) compared with Control. Longitudinal analyses revealed that improvements in walking endurance from the DOSE intervention were retained during the 1-year follow-up period over usual care.

CONCLUSIONS

This study provides the first preliminary evidence that patients with stroke can improve their walking recovery and quality of life with higher doses of aerobic and stepping activity within a critical time period for neurological recovery. Furthermore, walking endurance benefits achieved from a 4-week intervention are retained over the first-year poststroke. Registration: URL: https://www.clinicaltrials.gov. Unique identifier: NCT01915368.

Factors Influencing the Delivery of Intensive Rehabilitation in Stroke: Patient Perceptions Versus Rehabilitation Therapist Perceptions

BACKGROUND

Despite increasing evidence regarding the benefit of intensive task-specific practice and aerobic exercise in stroke rehabilitation, implementation remains difficult. The factors influencing implementation have been explored from therapists' perspectives; however, despite an increased emphasis on patient involvement in research, patients' perceptions have not yet been investigated.

OBJECTIVE

The study aimed to investigate factors influencing implementation of higher intensity activity in people with stroke and to compare this with therapists' perspectives.

DESIGN

The design was a cross-sectional qualitative study.

METHODS

The study used semistructured interviews with people with stroke who were part of a randomized clinical trial, the Determining Optimal post-Stroke Exercise study, which delivered a higher intensity intervention. An interview guide was developed and data analyzed using implementation frameworks. Factors emerging from interviews with people with stroke were compared and contrasted with factors perceived by rehabilitation therapists.

RESULTS

Ten people with stroke were interviewed before data saturation was reached. Participants had a positive attitude regarding working hard and were satisfied with the graded exercise test, high intensity intervention, and the feedback-monitoring devices. Therapists and patients had contrasting perceptions about their beliefs regarding intensive exercise and the content of the intervention, with therapists more focused on the methods and patients more focused on the personal interactions stemming from the therapeutic relationship.

CONCLUSIONS

People with stroke perceived no barriers regarding the implementation of higher intensity rehabilitation in practice and were positive towards working at more intense levels. Contrastingly, from the therapists' perspective, therapists' beliefs about quality of movement and issues around staffing and resources were perceived to be barriers. In addition, therapists and people with stroke perceived the contents of the intervention differently, highlighting the importance of involving patients and clinicians in the development and evaluation of rehabilitation interventions.

Benefits of exercise training on cardiovascular dysfunction: molecular and integrative

Exercise training has been shown to ameliorate a wide variety of cardiovascular disorders. The mechanisms by which long-term benefits of exercise training are mediated remains incomplete, despite intense research in this area. Exactly how the act of chronic exercise improves function in every tissue is unknown, but many of the cellular, molecular, and genetic mechanisms are becoming progressively clearer. This "Perspectives" article reviews the contributions of 15 articles published in the American Journal of Physiology-Heart and Circulatory Physiology in response to a Call for Papers in this area. Here, we summarize the contributions of these studies at the cardiac, vascular, immune, and molecular levels. We discuss the translational benefit of these studies and conclude that the beneficial effects of exercise training in cardiovascular disease is due to a large interplay of cellular and molecular mediators in the heart and peripheral vasculature as well as changes in neural elements that regulate blood pressure and blood flow. Readers are encouraged to evaluate and learn from this collection of novel studies.