Heart failure patients demonstrate impaired changes in brachial artery blood flow and shear rate pattern during moderate-intensity cycle exercise

New Findings What is the central question of this study? We explored whether heart failure (HF) patients demonstrate different exercise-induced brachial artery shear rate patterns compared with control subjects. What is the main finding and its importance? Moderate-intensity cycle exercise in HF patients is associated with an attenuated increase in brachial artery anterograde and mean shear rate and skin temperature. Differences between HF patients and control subjects cannot be explained fully by differences in workload. HF patients demonstrate a less favourable shear rate pattern during cycle exercise compared with control subjects. Repeated elevations in shear rate (SR) in conduit arteries, which occur during exercise, represent a key stimulus to improve vascular function. We explored whether heart failure (HF) patients demonstrate distinct changes in SR in response to moderate-intensity cycle exercise compared with healthy control subjects. We examined brachial artery SR during 40 min of cycle exercise at a work rate equivalent to 65% peak oxygen uptake in 14 HF patients (65 ± 7 years old, 13 men and one woman) and 14 control subjects (61 ± 5 years old, 12 men and two women). Brachial artery diameter, SR and oscillatory shear index (OSI) were assessed using ultrasound at baseline and during exercise. The HF patients demonstrated an attenuated increase in mean and anterograde brachial artery SR during exercise compared with control subjects (time × group interaction, P = 0.003 and P 0.05). In conclusion, HF patients demonstrate a less favourable SR pattern during cycle exercise than control subjects, characterized by an attenuated mean and anterograde SR and by increased OSI

Effects of High-Intensity Interval Training versus Continuous Training on Physical Fitness, Cardiovascular Function and Quality of Life in Heart Failure Patients

Introduction Physical fitness is an important prognostic factor in heart failure (HF). To improve fitness, different types of exercise have been explored, with recent focus on high-intensity interval training (HIT). We comprehensively compared effects of HIT versus continuous training (CT) in HF patients NYHA II-III on physical fitness, cardiovascular function and structure, and quality of life, and hypothesize that HIT leads to superior improvements compared to CT. Methods Twenty HF patients (male:female 19:1, 64±8 yrs, ejection fraction 38±6%) were allocated to 12-weeks of HIT (10*1-minute at 90% maximal workload—alternated by 2.5 minutes at 30% maximal workload) or CT (30 minutes at 60–75% of maximal workload). Before and after intervention, we examined physical fitness (incremental cycling test), cardiac function and structure (echocardiography), vascular function and structure (ultrasound) and quality of life (SF-36, Minnesota living with HF questionnaire (MLHFQ)). Results Training improved maximal workload, peak oxygen uptake (VO2peak) related to the predicted VO2peak, oxygen uptake at the anaerobic threshold, and maximal oxygen pulse (all P<0.05), whilst no differences were present between HIT and CT (N.S.). We found no major changes in resting cardiovascular function and structure. SF-36 physical function score improved after training (P<0.05), whilst SF-36 total score and MLHFQ did not change after training (N.S.). Conclusion Training induced significant improvements in parameters of physical fitness, although no evidence for superiority of HIT over CT was demonstrated. No major effect of training was found on cardiovascular structure and function or quality of life in HF patients NYHA II-III

Effects of General Physical Activity Promoting Interventions on Functional Outcomes in Patients Hospitalized over 48 Hours: A Systematic Review and Meta-Analysis of Randomized Controlled Trials

Low physical activity of patients is a global problem and associated with loss of strength and independent mobility. This study analyzes the effect of general physical activity promoting interventions on functional and hospital outcomes in patients hospitalized over 48 h. Five electronic databases were searched for randomized controlled trials. For outcomes reported in two studies or more, a meta-analysis was performed to test between-group differences (intervention versus control) using a random-effects model. The Grading of Recommendations Assessment, Development, and Evaluation (GRADE) approach was used to rate the certainty of evidence for each outcome. Out of 23,302 identified studies, we included four studies (in total n = 368 participants). We found with moderate certainty of evidence 0 reported falls in the intervention (n = 126) versus five reported falls in the control (n = 122), a non-statistically significant difference between intervention and control groups (p = 0.06). In addition, we found with (very) low certainty of evidence no statistically significant differences between groups on activities of daily living (ADL-activity) and time spent standing and walking. Overall, we found no conclusive evidence on the effect of general physical activity promoting interventions on functional outcomes. More research is needed to understand and improve the effect of general physical activity promoting interventions for patients during the hospital stay

Newport Transect 02, Image 10

This still image was captured from a video transect in Newport, Oregon. Researchers are able to use this image to quantify relative abundance and diversity of benthic (i.e. bottom-dwelling) organisms.https://digitalcommons.linfield.edu/biol_transects_photos/1019/thumbnail.jp

Interval exercise, but not endurance exercise, prevents endothelial ischemia-reperfusion injury in healthy subjects

Endothelial ischemia-reperfusion (I/R) injury importantly contributes to the poor prognosis during ischemic (myocardial) events. Preconditioning, i.e., repeated exposure to short periods of ischemia, effectively reduces endothelial I/R injury. In the present study, we examined the hypothesis that exercise has preconditioning effects on endothelial I/R injury. Therefore, we studied whether an acute bout of endurance or interval exercise is able to protect against endothelial I/R injury. In 17 healthy young subjects, we examined changes in brachial artery endothelial function using flow-mediated dilation (FMD) before and after a bout of high-intensity interval exercise, moderate-intensity endurance exercise, or a control intervention. Subsequently, I/R injury was induced by inflation of a blood pressure cuff around the upper arm to 220 mmHg for 20 min and 20 min of reperfusion followed by another FMD measurement. Near-infrared spectrometry was used to examine local tissue oxygenation during exercise. No differences in brachial artery FMD were found at baseline for the three conditions. I/R induced a significant decline in FMD (7.1 ± 2.3 to 4.3 ± 2.3, P < 0.001). When preceded by the interval exercise bout, no change in FMD was present after I/R (7.7 ± 3.1 to 7.2 ± 3.1, P = 0.56), whereas the decrease in FMD after I/R could not be prevented by the endurance exercise bout (7.8 ± 3.1 to 3.8 ± 1.7, P < 0.001). In conclusion, a single bout of lower limb interval exercise, but not moderate-intensity endurance exercise, effectively prevents brachial artery endothelial I/R injury. This indicates the presence of a remote preconditioning effect of exercise, which is selectively present after short-term interval but not continuous exercise in healthy young subjects

Aging attenuates the protective effect of ischemic preconditioning against endothelial ischemia-reperfusion injury in humans

Item does not contain fulltextReperfusion is mandatory after ischemia but also triggers ischemia-reperfusion (I/R) injury. Ischemic preconditioning (IPC) can limit endothelial I/R injury. Nonetheless, translation of IPC to the clinical arena is often disappointing. Since application of IPC typically relates to older patients, efficacy of IPC may be attenuated with aging. Our objective was to examine the impact of advanced age on the ability of IPC to protect against endothelial dysfunction due to I/R injury. We included 15 healthy young (20-25 yr) and 15 older (68-77 yr) men. We examined brachial artery endothelial function using flow-mediated dilation (FMD) before and after arm I/R (induced by inflation of an upper-arm blood pressure cuff for 20 min and 15 min of reperfusion). In a randomized order, I/R was preceded by IPC or a control intervention consisting of three cycles of 5 min upper-arm cuff inflation to 220 or 20 mmHg, respectively. As a result, in young men, FMD decreased significantly after I/R (6.4 +/- 2.7 to 4.4 +/- 2.5%). This decrease was not present when I/R was preceded by IPC (5.9 +/- 2.3 to 5.6 +/- 2.5%). IPC-induced protection appeared to be significantly reduced in the elderly patients (P = 0.04). Although FMD decreased after I/R in older men (3.5 +/- 1.7 to 2.5 +/- 1.0%), IPC could not prevent this (3.7 +/- 2.1 to 2.2 +/- 1.1%). In conclusion, this study is the first to observe in humans in vivo that older age is associated with an abolished effect of IPC to protect against endothelial dysfunction after I/R in the brachial artery. This provides a possible explanation for the problematic translation of strategies that reduce I/R injury from preclinical work to the clinical arena

Results of the SF-36 and Minnesota living with HF questionnaire (MLHFQ).

<p>Data is presented as mean±SD. P-values refers to 2-way repeated measures ANOVA between the 2 training groups. Results of the SF-36 were scored on a 0–100 scale, in which a high score represents a better quality of life. Results of the MLHFQ were scored on a 0–105 scale, in which a low score indicates few HF-related complaints.</p><p>^† Data was available for 7 subjects in the HIT-group.</p><p>^‡ Data was available for 8 subjects in the CT-group.</p><p>Results of the SF-36 and Minnesota living with HF questionnaire (MLHFQ).</p

Flow-chart of the inclusion of subjects.

<p>Flow-chart of the inclusion of subjects.</p

Brachial (BA) and superficial femoral artery (SFA) endothelium-dependent vasodilation through flow-mediated dilation (FMD), peak diameter and endothelium-independent dilation (GTN), and common carotid artery (CCA) intima-media thickness (IMT).

<p>Data is presented as mean±SD. P-values refer to 2-way repeated measures ANOVA between the 2 training groups.</p><p>^# For statistical reasons, data was analyzed with three separate tests to determine <i>time</i>, <i>group</i> and <i>time*group</i> P-values. Due to technical problems, BA GTN/FMD-GTN ratio/peak blood flow was available for 9 subjects in the HIT-group and SFA FMD was available for 8 subjects in the HIT-group. CCA IMT and IMT-to-lumen ratio were available for 8 subjects in each group. SR_AUC; shear rate area-under-the-curve. CADC; conduit artery dilating capacity.</p><p>Brachial (BA) and superficial femoral artery (SFA) endothelium-dependent vasodilation through flow-mediated dilation (FMD), peak diameter and endothelium-independent dilation (GTN), and common carotid artery (CCA) intima-media thickness (IMT).</p