Neurofilament Light Chain as a Biomarker of Global Cognition in Individuals With Possible Vascular Mild Cognitive Impairment.

BACKGROUND: Neurofilament Light Chain (NfL) is a biomarker of axonal injury elevated in mild cognitive impairment (MCI) and Alzheimer's disease dementia. Blood NfL also inversely correlates with cognitive performance in those conditions. However, few studies have assessed NfL as a biomarker of global cognition in individuals demonstrating mild cognitive deficits who are at risk for vascular-related cognitive decline. OBJECTIVE: To assess the relationship between blood NfL and global cognition in individuals with possible vascular MCI (vMCI) throughout cardiac rehabilitation (CR). Additionally, NfL levels were compared to age/sex-matched cognitively unimpaired (CU) controls. METHOD: Participants with coronary artery disease (vMCI or CU) were recruited at entry to a 24-week CR program. Global cognition was measured using the Montreal Cognitive Assessment (MoCA) and plasma NfL level (pg/ml) was quantified using a highly sensitive enzyme-linked immunosorbent assay. RESULTS: Higher plasma NfL was correlated with worse MoCA scores at baseline (ß = -.352, P = .029) in 43 individuals with vMCI after adjusting for age, sex, and education. An increase in NfL was associated with worse global cognition (b[SE] = -4.81[2.06], P = .023) over time, however baseline NfL did not predict a decline in global cognition. NfL levels did not differ between the vMCI (n = 39) and CU (n = 39) groups (F(1, 76) = 1.37, P = .245). CONCLUSION: Plasma NfL correlates with global cognition at baseline in individuals with vMCI, and is associated with decline in global cognition during CR. Our findings increase understanding of NfL and neurobiological mechanisms associated with cognitive decline in vMCI.

Patients' Perceptions of Hybrid and Virtual-Only Care Models During the Cardiac Rehabilitation Patient Journey: A Qualitative Study.

BACKGROUND: The COVID-19 pandemic initially led to discontinuation of the "traditional" center-based cardiac rehabilitation (CR) model. Virtual models emerged as an opportunity to deliver care, with many programs continuing to offer these models. OBJECTIVE: The aim of this study was to explore patients' perceptions of virtual models of either hybrid (combining center-based and virtual) or virtual-only CR since the pandemic. METHODS: Men and women who chose to participate in hybrid or virtual CR models between January 2022 and January 2023 were invited to attend 1 of 8 focus group sessions. Focus groups were conducted online until thematic saturation was reached. Transcripts were analyzed using thematic analysis. RESULTS: Twenty-three patients (48% female; 83% attending hybrid CR) participated in the study. Analysis revealed 12 overarching themes associated with the CR patient journey: pre-CR, namely, (1) importance of endorsement from healthcare providers and (2) need for education/communication while waiting for program initiation; during CR, namely, (3) preference for class composition/structure, (4) need to enhance peer support in the virtual environment, (5) convenience and concerns with virtual sessions, (6) necessity of on-site sessions, (7) safety of the exercise prescription, (8) requirement/obligation for allied health offerings, (9) satisfaction with virtual education, and (10) use of technology to facilitate CR participation; and post-CR, namely, (11) acknowledgment of program completion and (12) need for support/education after program graduation. CONCLUSIONS: Patients require ongoing support from time of referral to beyond CR program completion. Physical, psychosocial, nutritional, and educational supports are needed. Perceptions expressed by patients related to the program model are modifiable, and strategies to address these perceptions should be explored.

Sex differences and predictors of completion of a 6-month exercise-based cardiac rehabilitation program in 1,536 people following stroke.

OBJECTIVE: To retrospectively examine sex-differences and predictors of completion in consecutively-referred patients to a 6-month exercise-based cardiac rehabilitation program (CRP) from 2006 to 2017. MATERIALS/METHODS: People with hemiplegic gait participated in stroke-adapted-CRP; otherwise, traditional-CRP. Reasons for non-completion were ascertained by interview. Regression-analyses were conducted to determine non-completion in all patients and women and men separately. RESULTS: There were 1536 patients (30.3% women), mean age 64.5 ± 12.5 with 23% initiating the stroke-adapted-CRP. Overall, 75.1% completed the CRP (87.3% stroke-adapted-CRP vs 71.5% traditional-CRP; p < .001). There was no difference in completion between women and men (74.5% vs 75.4%; p=0.7), or in attendance to pre-scheduled sessions (p=0.6) or reasons for non-completion (p > .05, all). The only sex difference in completion by age (decade) occurred in those <41 years (59% women vs 85% men; p=.02). Baseline predictors of non-completion among all patients included not being enrolled in the stroke-adapted-CRP, lower V̇O2peak, smoking, diabetes (prescribed insulin) and depression but not sex (p=.5) or age (p=.15). Unique predictors in women vs men were younger age, lower V̇O2peak, smoking, diabetes (prescribed insulin), depression, and cancer diagnoses. Unique to men was having >1 stroke and diabetes (any anti-diabetes medication). The strongest predictor of non-completion among all models was not being enrolled in stroke-adapted-CRP. CONCLUSIONS: While there were no sex-differences in adherence to the CRP, women and men have mostly unique predictors of non-completion. Younger women are at greatest risk for non-completion. Practitioners should provide sex-specific, tailored strategies for enhancing completion with a focus on younger women and offering a stroke-adapted-CRP with close attention to those with diabetes.

Profile of women choosing mixed-sex, women-only, and home-based cardiac rehabilitation models and impact on utilization.

This study compared characteristics and program utilization in women electing to participate in mixed-sex, women-only, or home-based cardiac rehabilitation (CR). In this retrospective cohort study, electronic records of CR participants in Toronto who were offered the choice of program model between January 2017-February 2020 were analyzed. There were 727 women (74.7% mixed, 22.0% women-only, 3.3% home-based) who initiated CR. There were significantly more women who were not working in women-only than mixed-sex (80.4% vs 64.1%; P = .009). Session adherence was significantly greater with mixed-sex (58.8 ± 28.9% sessions attended/25) than women-only (54.3 ± 26.3% sessions attended/25; P = .046); program completion was significantly lower with home-based (33.3%) than either supervised model (59.7%; P = .035). Participation in women-only CR may be less accessible. Further research is needed to investigate offering remote women-focused sessions or peer support.

Muscle Oxygenation of the Paretic and Nonparetic Legs During and After Arterial Occlusion in Chronic Stroke.

Oxygen delivery and demand are reduced in the paretic leg post-stroke, reflecting decreased vascular function and reduced muscle quantity and quality. However, it is unknown how muscle oxygenation, the balance between muscle oxygen delivery and utilization, is altered in chronic stroke during and after occlusion-induced ischemia. OBJECTIVES: The objective was to determine muscle oxygen consumption rate, microvascular responsiveness and reactive hyperemia in the paretic and nonparetic legs during and after arterial occlusion post-stroke. MATERIALS AND METHODS: Muscle oxygen saturation was measured with near-infrared spectroscopy on the vastus lateralis of each leg during 3-minute arterial occlusion and recovery (3 min). Muscle oxygen consumption was derived from the desaturation slope during ischemia, microvascular responsiveness was derived from the resaturation slope after ischemia and reactive hyperemia was derived from the area under the curve above baseline after ischemia. RESULTS: Eleven subjects (91% male; 32.2±6.1 months post-stroke; age 62.9±13.6 years) with a hemiparetic gait pattern participated. There was no significant between-leg muscle oxygenation difference at rest (paretic: 64.9±16.6%; nonparetic: 70.6±15.6%, p = 0.13). Muscle oxygen consumption in the paretic leg (-0.53±0.24%/s) was significantly reduced compared to the nonparetic leg (-0.70±0.36%/s; p = 0.03). Microvascular responsiveness was significantly reduced in the paretic leg compared to the nonparetic leg (paretic: 4.6±1.8%/s; nonparetic: 5.7±1.6%/s, p = 0.04). Reactive hyperemia was not significantly different between legs (paretic:4384±2341%·s; nonparetic: 3040±2216%·s, p = 0.07). CONCLUSION: Muscle oxygen consumption and microvascular responsiveness are impaired in the paretic compared to the nonparetic leg, suggesting both reduced skeletal muscle aerobic function and reduced ability to maximally perfuse muscle tissue.

Validity of Bioelectric Impedance in Relation to Dual-Energy X-Ray Absorptiometry for Measuring Baseline and Change in Body Composition After an Exercise Program in Stroke.

ABSTRACT: Vanzella, LM, Lawand, R, Shuaib, M, Oh, P, Corbett, D, and Marzolini, S. Validity of bioelectric impedance in relation to dual-energy x-ray absorptiometry for measuring baseline and change in body composition after an exercise program in stroke. J Strength Cond Res 36(12): 3273-3279, 2022-Exercise is an important strategy to improve fat-free mass (FFM) and reduce percent fat mass (FM%). However, no study has reported on a valid, cost-effective method to measure changes in body composition after stroke. The purpose of the study is to determine the level of agreement between bioelectrical impedance analysis (BIA) and dual-energy x-ray absorptiometry (DXA) for assessing baseline and change in FFM and FM% after an exercise training intervention for individuals with mobility deficits after stroke. Fat-free mass and FM% were measured by BIA and DXA at the beginning and after 6 months of participation in an exercise program for individuals with mobility deficits after stroke. Forty-two subjects after stroke were included. Overall, Bland-Altman plots revealed that BIA overestimated the baseline FFM and FM% by only -0.4 ± 1.8 kg and -2.8 ± 1.8%, respectively. BIA underestimated changes in FFM by 0.33 ± 0.45 kg and overestimated changes in FM% by -0.40 ± 0.68%. The 95% CI of the mean bias for baseline FFM was -7.1 to 6.3 kg and -11.8 to 6.0% for FM%, demonstrating good agreement. The 95% CI for the change in FFM was -3.8 to 4.5 kg and -5.0 to 4.2% for FM%, which reflected good agreement. BIA is a good tool for assessing qualitative baseline and change in FFM and FM%. Body composition is important for the prescription and evaluation of rehabilitation programs designed for individuals after stroke. Our results provide clinicians and researchers with a better understanding of the utility of BIA to measure body composition at baseline and in response to exercise interventions in this population.

A Gap in Post-Stroke Blood Pressure Target Attainment at Entry to Cardiac Rehabilitation.

BACKGROUND: Recurrent events account for approximately one-third of all strokes and are associated with greater disability and mortality than first-time strokes. Blood pressure (BP) is the most important modifiable risk factor. Objectives were to determine the proportion of post-stroke patients enrolled in cardiac rehabilitation (CR) meeting systolic and diastolic BP (SBP/DBP) targets and to determine correlates of meeting these targets. METHODS: A retrospective study of 1,804 consecutively enrolled post-stroke patients in a CR program was conducted. Baseline data (database records 2006-2017) included demographics, anthropometrics, clinical/medication history, and resting BP. Multivariate analyses determined predictors of achieving BP targets. RESULTS: Mean age was 64.1 ± 12.7 years, median days from stroke 210 (IQR 392), with most patients being male (70.6%; n = 1273), overweight (66.8%; n = 1196), and 64.2% diagnosed with hypertension (n = 1159), and 11.8% (n = 213) with sleep apnea. A mean of 1.69 ± 1.2 antihypertensives were prescribed, with 26% (n = 469) of patients prescribed 3-4 antihypertensives. SBP target was met by 71% (n = 1281) of patients, 83.3% (n = 1502) met DBP target, and 64.3% (n = 1160) met both targets. Correlates of meeting SBP target were not having diabetes, younger age, fewer prescribed antihypertensives, and more recent program entry. Correlates of meeting DBP target were not having diabetes, older age, fewer prescribed antihypertensives, and more recent stroke. CONCLUSIONS: Up to one-third of patients were not meeting BP targets. Patients with diabetes, and those prescribed multiple antihypertensives are at greater risk for poorly controlled SBP and DBP. Reasons for poor BP control such as untreated sleep apnea and medication non-adherence need to be investigated.

Women's outcomes following mixed-sex, women-only, and home-based cardiac rehabilitation participation and comparison by sex.

BACKGROUND: Despite women's greater need for cardiac rehabilitation (CR), they are less likely to utilize it. Innovative CR models have been developed to better meet women's needs, yet there is little controlled, comparative data assessing the effects of these models for women. This study compared outcomes in women electing to participate in mixed-sex, women-only, or home-based CR, and a matched sample of men. METHODS: In this retrospective study, electronic records of CR participants in Toronto who were offered the choice of program model between January 2017 and July 2019 were analyzed; clinical outcomes comprised cardiorespiratory fitness, risk factors and psychosocial well-being. These were assessed at intake and post-6-month program and analyzed using general linear mixed models. RESULTS: There were 1181 patients (727 women [74.7% mixed, 22.0% women-only, 3.3% home-based]; 454 age and diagnosis-matched men) who initiated CR; Cardiorespiratory fitness among women was higher at initiation of mixed-sex than women-only (METs 5.1 ± 1.5 vs 4.6 ± 1.3; P = .007), but no other outcome differences were observed. 428 (58.9%) women completed the programs, with few women retained in the home-based model limiting comparisons. There were significant improvements in high-density lipoprotein cholesterol (P = .001) and quality of life (P = .001), and lower depressive symptoms (P = .030) as well as waist circumference (P = .001) with mixed-sex only. VO2peak was significantly higher at discharge in mixed-sex than women-only (estimate = 1.67, standard error = 0.63, 95% confidence interval = 0.43-2.91). CONCLUSION: Participation in non-gender-tailored women-only CR was not advantageous as expected. More research is needed, particularly including women participating in home-based programs.

Exercise priming with transcranial direct current stimulation: a study protocol for a randomized, parallel-design, sham-controlled trial in mild cognitive impairment and Alzheimer's disease.

BACKGROUND: Transcranial direct current stimulation (tDCS) is a non-invasive type of brain stimulation that uses electrical currents to modulate neuronal activity. A small number of studies have investigated the effects of tDCS on cognition in patients with Mild Cognitive Impairment (MCI) and Alzheimer's disease (AD), and have demonstrated variable effects. Emerging evidence suggests that tDCS is most effective when applied to active brain circuits. Aerobic exercise is known to increase cortical excitability and improve brain network connectivity. Exercise may therefore be an effective, yet previously unexplored primer for tDCS to improve cognition in MCI and mild AD. METHODS: Participants with MCI or AD will be randomized to receive 10 sessions over 2 weeks of either exercise primed tDCS, exercise primed sham tDCS, or tDCS alone in a blinded, parallel-design trial. Those randomized to an exercise intervention will receive individualized 30-min aerobic exercise prescriptions to achieve a moderate-intensity dosage, equivalent to the ventilatory anaerobic threshold determined by cardiopulmonary assessment, to sufficiently increase cortical excitability. The tDCS protocol consists of 20 min sessions at 2 mA, 5 times per week for 2 weeks applied through 35 cm2 bitemporal electrodes. Our primary aim is to assess the efficacy of exercise primed tDCS for improving global cognition using the Montreal Cognitive Assessment (MoCA). Our secondary aims are to evaluate the efficacy of exercise primed tDCS for improving specific cognitive domains using various cognitive tests (n-back, Word Recall and Word Recognition Tasks from the Alzheimer's Disease Assessment Scale-Cognitive subscale) and neuropsychiatric symptoms (Neuropsychiatric Inventory). We will also explore whether exercise primed tDCS is associated with an increase in markers of neurogenesis, oxidative stress and angiogenesis, and if changes in these markers are correlated with cognitive improvement. DISCUSSION: We describe a novel clinical trial to investigate the effects of exercise priming before tDCS in patients with MCI or mild AD. This proof-of-concept study may identify a previously unexplored, non-invasive, non-pharmacological combination intervention that improves cognitive symptoms in patients. Findings from this study may also identify potential mechanistic actions of tDCS in MCI and mild AD. TRIAL REGISTRATION: Clinicaltrials.gov, NCT03670615 . Registered on September 13, 2018.

Inclusion of People With Peripheral Artery Disease in Cardiac Rehabilitation Programs: A Pan-Canadian Survey.

PURPOSE: To determine the proportion of cardiac rehabilitation programs (CRPs) in Canada that accept referrals for individuals with peripheral artery disease (PAD), eligibility criteria, and barriers/facilitators to inclusion. METHODS: CRPs across Canada were sent a web-based questionnaire. RESULTS: Of 180 questionnaires sent, 98 CRP managers representing 114 CRPs (62.6% of CRPs in Canada) responded. Of respondents, 81.6% accepted referrals for people with PAD; however 44.6% reported that ≤10 patients participated in the previous calendar year; two CRPs had no participants. Of CRPs accepting PAD, 23.7% accepted patients only with coexisting cardiac disease, 68.4% accepted post-lower limb amputees with prosthesis and 53.9% without prosthesis (non-ambulatory). Further, 32.2% did not provide formal/informal PAD-specific education to patients and only 14.3% provided education to staff regarding PAD in the previous 3 years. Three (3) numerical pain scales were used to guide exercise intensity. Within these scales up to four pain thresholds were used. Most frequently cited barriers to participation included lack of referrals (61.6%), and programs being at capacity (59.3%). Frequently cited facilitators were providing information on benefits of CRPs to referral sources (88.3%) and patients (88.3%), providing PAD-specific education to staff (85.5%), and PAD-toolkits for prescribing aerobic/resistance training (81.5%, both). CONCLUSION: Most CRPs accept individuals with PAD, however, few are referred. Inclusion of PAD with and without cardiac disease, collaboration between referral source and CRPs to improve the referral process, and PAD-specific education for staff and information/brochures on benefits of CRPs for patients and referral sources should improve participation and delivery of secondary prevention strategies.

Cardiac-Related Pulsatility in the Insula Is Directly Associated With Middle Cerebral Artery Pulsatility Index.

BACKGROUND: Arterial stiffness in large arteries is a risk factor for cerebral small vessel disease and neurodegeneration. The challenge of accessing intracranial pulsatility noninvasively is one reason few studies provide empirical insight on the relationship between large artery and tissue pulsatility in the human brain. PURPOSE: To investigate the association between the functional magnetic resonance imaging (fMRI)-derived cardiac-related pulsatility in the insular cortex and the ultrasound-derived pulsatility index in the middle cerebral artery (MCA-PI). STUDY TYPE: Cross-sectional. POPULATION: Younger adults (11; 25 ± 4 years) and older adults with and without cardiovascular risk factors (44; 70 ± 6 years). FIELD STRENGTH/SEQUENCE: T1 -weighted, fluid attenuated inversion recovery, and T2 *-weighted blood oxygenation level-dependent (BOLD) sequences at 3T. ASSESSMENT: MCA-PI and cardiac-related pulsatility were assessed at rest by transcranial Doppler ultrasound and BOLD fMRI, respectively. STATISTICAL TESTS: Multivariate analyses of covariance between MCA-PI and cardiac-related pulsatility. Analysis of variance was used to assess regional differences. RESULTS: MCA-PI was associated with cardiac-related insular pulsatility (P = 0.037), but not whole-brain pulsatility (P = 0.81). Left insular pulsatility was higher than right insular pulsatility (P < 0.01) and was associated with diastolic blood pressure (P = 0.028). DATA CONCLUSION: We show a correlation between ultrasound and fMRI measures of cerebrovascular pulsatility. This association provides insight into the transmission of pulsatile energy from large basal arteries at the Circle of Willis to downstream cerebrovascular beds and has implications for the utility of cardiac-related pulsatility as a potential marker for cerebral small vessel disease. LEVEL OF EVIDENCE: 4 Technical Efficacy: Stage 3 J. Magn. Reson. Imaging 2020;51:1454-1462.

Training heart failure patients with reduced ejection fraction attenuates muscle sympathetic nerve activation during mild dynamic exercise.

Muscle sympathetic nerve activity (MSNA) decreases during low-intensity dynamic one-leg exercise in healthy subjects but increases in patients with heart failure with reduced ejection fraction (HFrEF). We hypothesized that increased peak oxygen uptake (V̇o2peak) after aerobic training would be accompanied by less sympathoexcitation during both mild and moderate one-leg dynamic cycling, an attenuated muscle metaboreflex, and greater skin vasodilation. We studied 27 stable, treated HFrEF patients (6 women; mean age: 65 ± 2 SE yr; mean left ventricular ejection fraction: 30 ± 1%) and 18 healthy age-matched volunteers (6 women; mean age: 57 ± 2 yr). We assessed V̇o2peak (open-circuit spirometry) and the skin microcirculatory response to reactive hyperemia (laser flowmetry). Fibular MSNA (microneurography) was recorded before and during one-leg cycling (2 min unloaded and 2 min at 50% of V̇o2peak) and, to assess the muscle metaboreflex, during posthandgrip ischemia (PHGI). HFrEF patients were evaluated before and after 6 mo of exercise-based cardiac rehabilitation. Pretraining V̇o2peak and skin vasodilatation were lower (P < 0.001) and resting MSNA higher (P = 0.01) in HFrEF than control subjects. Training improved V̇o2peak (+3.0 ± 1.0 mL·kg-1·min-1; P < 0.001) and cutaneous vasodilation and diminished resting MSNA (-6.0 ± 2.0, P = 0.01) plus exercise MSNA during unloaded (-4.0 ± 2.5, P = 0.04) but not loaded cycling (-1.0 ± 4.0 bursts/min, P = 0.34) and MSNA during PHGI (P < 0.05). In HFrEF patients, exercise training lowers MSNA at rest, desensitizes the sympathoexcitatory metaboreflex, and diminishes MSNA elicited by mild but not moderate cycling. Training-induced downregulation of resting MSNA and attenuated reflex sympathetic excitation may improve exercise capacity and survival.

Aerobic Training in Canadian Stroke Rehabilitation Programs.

BACKGROUND AND PURPOSE: Aerobic training (AT) is recommended for people after stroke, yet uptake and operationalization of AT in clinical practice in Canada have not been measured. We surveyed inclusion of structured AT and barriers to implementation in public inpatient/outpatient stroke rehabilitation programs across Canada. METHODS: A Web-based questionnaire was sent to 89 stroke rehabilitation program leads. RESULTS: Forty-six programs from 7 of 9 eligible Canadian provinces/territories completed the questionnaire. Seventy-eight percent of programs reported including AT, with most (75%) excluding participants with severe physical impairments, and 28% excluding those with coexisting cardiac conditions. A greater proportion of dedicated stroke rehabilitation programs prescribed AT, compared to nondedicated stroke units (68.8% vs 31.3%, P = 0.02). The top 2 challenges for programs that included and did not include AT were "insufficient time within therapy sessions" and "length of stay in rehabilitation." Programs that did not include AT ranked "not a goal of most patients" and "not an organizational/program priority" as third and fourth, whereas they were ranked eighth and thirteenth by programs with AT. Best practice recommendations were inconsistently followed for conducting preparticipation exercise testing (36.1%) and for monitoring patients from higher-risk populations, specifically people with diabetes at risk for hypoglycemia (78.8%) and hypertension (36.6%). Of programs conducting preparticipation exercise testing, 91% did not monitor electrocardiography. DISCUSSION AND CONCLUSIONS: Most stroke rehabilitation programs across Canada include AT. People with severe physical impairment and those with cardiac, metabolic, and hemodynamic comorbidities may be excluded or not appropriately monitored during exercise. More detailed guidelines and training practices are needed to address these challenges.Video Abstract available for more insights from the authors (see Video, Supplemental Digital Content 1, available at: http://links.lww.com/JNPT/A233).

Does limb partitioning and positioning affect acute cardiorespiratory responses during strength exercises in patients with COPD?

BACKGROUND AND OBJECTIVE: Cardiorespiratory responses and symptoms in response to endurance exercise in patients with COPD vary with the number and position of involved limbs. Responses to such variations have never been quantified for strength exercises. We therefore assessed acute cardiorespiratory responses during brief bouts of weight lifting exercises. METHODS: We compared double- versus single-limb leg extensions and arm elevations, as well as arm elevation done above or below shoulder level in patients with moderate to severe COPD (n = 10, 6 males, 66 (8.1 years), forced expiratory volume on 1 s (FEV1 ) % predicted = 34% (14%)). Minute ventilation, oxygen uptake, oxygen saturation, heart rate (HR), blood pressure (BP), rate of perceived exertion (RPE) and recovery time were collected during single sets of each exercise (10 repetitions at 80% of one repetition maximum). RESULTS: Ventilatory and gas exchange responses were not affected by the number of exercising limbs. Changes in HR, BP and RPE scores during arm elevation above shoulder level were greater after double- compared with single-arm elevation (P ≤ 0.001) and greater when exercising above compared with below shoulder level (P ≤ 0.01). Double-arm elevation above shoulder level required 1.5 min longer HR recovery time (P ≤ 0.041) compared with other exercises. CONCLUSION: Double-arm elevation above shoulder level appears to be more challenging than other strength exercise variations. Partitioning exercises and limb position may reduce perceived exertion during training.

Feasibility and Effects of Cardiac Rehabilitation for Individuals after Transient Ischemic Attack.

BACKGROUND AND OBJECTIVE: Cardiac rehabilitation programs (CRPs) are common for cardiac patients; however, most individuals post transient ischemic attack (TIA) receive no rehabilitation despite similar pathologies. The objective of this study is to determine effects of cardiac rehabilitation (CR) on cardiovascular fitness (peak oxygen uptake [VO2peak]) and 6-minute walk distance (6MWD) post TIA. Secondary outcomes included other clinical and process indicators. METHODS: Eighty-five people post TIA (mean age 67.5 ± 10.7, 47% female) were referred to CR (2006-2014). The retro-TIA cohort included 65 consecutively enrolled individuals who were evaluated retrospectively. To collect additional measures, the pro-TIA cohort included 20 participants who were followed prospectively with a 3-month nonintervention period followed by 6-months of CR with 6MWD, cognition, depression score, and anthropometrics measured at each time point. Baseline, 6-month cardiopulmonary exercise test results, depression score, and anthropometrics were examined separately for both cohorts. RESULTS: Among all participants, 62% completed CR with 72.8 ± 17.7% attendance to prescheduled classes. CR resulted in improvements in VO2peak for both cohorts (both, P < .02). In the retro-TIA cohort, there were improvements in resting heart rate and body mass index, with reductions in the proportion of people with obesity and abdominal obesity (all, P < .04). In the pro-TIA cohort, compared to the stable baseline period there was a significant improvement with the CR intervention in the depression score (Δ1.1 ± 4.3 and Δ-3.3 ± 3.9, respectively; P = .04) but not in 6MWD (Δ4.8 ± 42 m and Δ61.0 ± 73.5 m, respectively; P = .06). For all participants, regression analysis revealed a higher depression score (ß = 1.10, P = .02), male sex (ß = 4.932, P = .02), and less social support (ß = 4.085, P = .04) as predictors of dropout. CONCLUSIONS: A CRP is feasible and effective for improving cardiovascular health. Strategies to promote adherence in men, in those with depressive symptoms, and in those with less social support require investigation.

Prescribing Aerobic Exercise Intensity without a Cardiopulmonary Exercise Test Post Stroke: Utility of the Six-Minute Walk Test.

BACKGROUND: The cardiopulmonary exercise test (CPET) is an established method for determining target exercise training intensity (ventilatory threshold [VAT]) and cardiovascular risk; unfortunately, CPET is not readily accessible to people post stroke. The objective of this study was to determine the utility of the 6-minute walk test (6MWT) as a less resource-intensive alternative to CPET for prescribing exercise intensity to people post stroke with motor impairments. METHODS: Sixty participants (male, 71.7%; 13.5 ± 22.5 [mean ± standard deviation] months post stroke; age 64.5 ± 12.5 years, with a Chedoke-McMaster Stroke Assessment score of 4.9 ± .9 of the leg) underwent 6MWT, CPET, balance, strength, and cognition assessments. RESULTS: 6MWT heart rate (hr) was significantly lower than VAT-hr (92.3 ± 14.8 beats⋅min(-1) versus 99.8 ± 15.7 beats⋅min(-1), respectively, P < .001; correlation r = .7, P < .001). Bland-Altman analysis revealed that the 6MWT underestimated the VAT-hr by 7.7 ± 11.5%. The 95% confidence interval of the mean bias was large (14.8% and -30.3%), reflecting poor agreement, with 71.7% (n = 43) of the participants unable to reach a walking intensity at or above the VAT-hr. Lower oxygen uptake at the VAT (ß = .655, P = .004), higher 6MWT-hr (ß = 1.07, P = .01), and better balance (ß = 1.128, P = .04) were associated with greater utility of the 6MWT for prescribing exercise. CONCLUSIONS: The 6MWT-hr was not interchangeable with the target training VAT-hr determined by CPET. However, in combination with CPET, the 6MWT will indicate when deficits preclude walking alone as the primary exercise modality for optimizing cardiovascular fitness. Future studies to develop a less resource-intensive, multimodal alternative to the CPET for prescribing exercise are needed. A modality that minimizes the effect of stroke deficits, specifically poor balance, should be included.

Factors Affecting Attendance at an Adapted Cardiac Rehabilitation Exercise Program for Individuals with Mobility Deficits Poststroke.

OBJECTIVE: The aim of this study was to determine the factors affecting attendance at an adapted cardiac rehabilitation program for individuals poststroke. METHODS: A convenience sample of ambulatory patients with hemiparetic gait rated 20 potential barriers to attendance on a 5-point Likert scale upon completion of a 6-month program of 24 prescheduled weekly sessions. Sociodemographic characteristics, depressive symptoms, cardiovascular fitness, and comorbidities were collected by questionnaire or medical chart. RESULTS: Sixty-one patients attended 77.3 ± 12% of the classes. The longer the elapsed time from stroke, the lower the attendance rate (r = -.34, P = .02). The 4 greatest barriers influencing attendance were severe weather, transportation problems, health problems, and traveling distance. Health problems included hospital readmissions (n = 6), influenza/colds (n = 6), diabetes and cardiac complications (n = 4), and musculoskeletal issues (n = 2). Of the top 4 barriers, people with lower compared to higher income had greater transportation issues (P = .004). Greater motor deficits of the stroke-affected leg were associated with greater barriers related to health issues (r = .7, P = .001). The only sociodemographic factor associated with a higher total mean barrier score was non-English as the primary language spoken at home (P = .002); this factor was specifically related to the barriers of cost (P = .007), family responsibilities (P = .018), and lack of social support (P = .001). No other associations were observed. CONCLUSION: Barriers to attendance were predominantly related to logistic/transportation and health issues. People who were more disadvantaged socioeconomically (language, finances), and physically (stroke-related deficits) were more affected by these barriers. Strategies to reduce these barriers, including timely referral to exercise programs, need to be investigated.

Divergent muscle sympathetic responses to dynamic leg exercise in heart failure and age-matched healthy subjects.

KEY POINTS: People with diminished ventricular contraction who develop heart failure have higher sympathetic nerve firing rates at rest compared with healthy individuals of a similar age and this is associated with less exercise capacity. During handgrip exercise, sympathetic nerve activity to muscle is higher in patients with heart failure but the response to leg exercise is unknown because its recording requires stillness. We measured sympathetic activity from one leg while the other leg cycled at a moderate level and observed a decrease in nerve firing rate in healthy subjects but an increase in subjects with heart failure. Because these nerves release noradrenaline, which can restrict muscle blood flow, this observation helps explain the limited exercise capacity of patients with heart failure. Lower nerve traffic during exercise was associated with greater peak oxygen uptake, suggesting that if exercise training attenuated sympathetic outflow functional capacity in heart failure would improve. ABSTRACT: The reflex fibular muscle sympathetic nerve (MSNA) response to dynamic handgrip exercise is elicited at a lower threshold in heart failure with reduced ejection fraction (HFrEF). The present aim was to test the hypothesis that the contralateral MSNA response to mild to moderate dynamic one-legged exercise is augmented in HFrEF relative to age- and sex-matched controls. Heart rate (HR), blood pressure and MSNA were recorded in 16 patients with HFrEF (left ventricular ejection fraction = 31 ± 2%; age 62 ± 3 years, mean ± SE) and 13 healthy control subjects (56 ± 2 years) before and during 2 min of upright one-legged unloaded cycling followed by 2 min at 50% of peak oxygen uptake (V̇O2,peak). Resting HR and blood pressure were similar between groups whereas MSNA burst frequency was higher (50.0 ± 2.0 vs. 42.3 ± 2.7 bursts min(-1), P = 0.03) and V̇O2,peak lower (18.0 ± 2.0 vs. 32.6 ± 2.8 ml kg(-1) min(-1), P < 0.001) in HFrEF. Exercise increased HR (P < 0.001) with no group difference (P = 0.1). MSNA burst frequency decreased during mild to moderate dynamic exercise in the healthy controls but increased in HFrEF (-5.5 ± 2.0 vs. 6.9 ± 1.8 bursts min(-1), P < 0.001). Exercise capacity correlated inversely with MSNA burst frequency at 50% V̇O2,peak (n = 29; r = -0.64; P < 0.001). At the same relative workload, one-legged dynamic exercise elicited a fall in MSNA burst frequency in healthy subjects but sympathoexcitation in HFrEF, a divergence probably reflecting between-group differences in reflexes engaged by cycling. This finding, coupled with an inverse relationship between MSNA burst frequency during loaded cycling and subjects' V̇O2,peak, is consistent with a neurogenic determinant of exercise capacity in HFrEF.

Exercise intensity modulates the change in cerebral blood flow following aerobic exercise in chronic stroke.

The mechanisms supporting functional improvement by aerobic exercise following stroke remain incompletely understood. This study investigated how cycling intensity and aerobic fitness influence cerebral blood flow (CBF) following a single exercise session. Thirteen community-living stroke survivors performed 20 min of semi-recumbent cycling at low and moderate intensities (40-50 and 60-70 % of heart rate reserve, respectively) as determined from an exercise stress test. CBF was quantified by arterial spin labeling MRI at baseline, as well as 30 and 50 min post-exercise. An intensity-dependent effect was observed in the right post-central and supramarginal gyri up to 50 min after exercise (uncorrected p < 0.005, cluster size ≥10). Regional CBF was increased 18 ± 17 % and reduced 8 ± 12 % following moderate- and low-intensity cycling, respectively. In contrast, CBF changes were similar between sessions in the right lentiform nucleus and mid-frontal gyrus, as well as the left temporal and parietal gyri. Aerobic fitness was directly related to posterior cingulate and thalamic CBF, and inversely related to precuneal CBF at rest (R (2) ≥ 0.75); however, no relationship between fitness and the post-exercise change in CBF was observed. Divergent changes in regional CBF were observed in the right parietal cortex following low- and moderate-intensity exercise, which suggests that intensity of prescribed exercise may be useful in optimizing rehabilitation.

"I'm No Superman": Understanding Diabetic Men, Masculinity, and Cardiac Rehabilitation.

Exercise-based cardiac rehabilitation (CR) programs help patients with coronary heart disease (CHD) reduce their risk of recurrent cardiac illness, disability, and death. However, men with CHD and Type 2 diabetes mellitus (T2DM) demonstrate lower attendance and completion of CR despite having a poor prognosis. Drawing on gender and masculinity theory, we report on a qualitative study of 16 Canadian diabetic men recently enrolled in CR. Major findings reflect two discursive positions men assumed to regain a sense of competency lost in illness: (a) working with the experts, or (b) rejection of biomedical knowledge. These positions underscore the varied and sometimes contradictory responses of seriously ill men to health guidance. Findings emphasize the priority given to the rehabilitation of a positive masculine identity. The analysis argues that gender, age, and employment status are powerful mechanisms of variable CR participation.