Stavroula Spetsioti

Cardiovascular effects of high-intensity interval aerobic training combined with strength exercise in patients with chronic heart failure. A randomized phase III clinical trial

BACKGROUND The aim of this work was to evaluate the effect of high-intensity interval exercise (i.e., 30s at 100% of max workload, followed by 30s at rest, 45 min 3 days/week working-out schedule for 12 weeks) on left ventricular function and aortic elastic properties among chronic heart failure (CHF) patients. METHODS This study is a phase III clinical trial. Of the 100 consecutive CHF patients (NYHA classes II-IV, ejection fraction<50%) that were randomly allocated, 72 completed the study (exercise training group, n=33, 63 ± 9 years, 88% men, and control group, n=39, 56 ± 11 years, 82% men). All patients underwent cardiopulmonary stress test, non-invasive high-fidelity tonometry of the radial artery, pulse wave velocity measurement using a SphygmoCor device and echocardiography before and after the completion of the training program. RESULTS Both groups reported similar medical characteristics and physical activity status. General mixed effects models revealed that the intervention group reduced pulse wave velocity by 9% (p=0.05); Emv/Vp by 14% (p=0.06); E to A ratio by 24% (p=0.004), E to Emv ratio by 8% (p=0.05), MLHFQ score by 66% (p=0.003) and the depression score by 19% (p=0.5); increased augmentation index by 29%; VTI by 4% (p=0.05), 6-minute-walk distance up to 13% (p=0.05), peak oxygen uptake by 28% (p=0.001) and peak power by 25% (p=0.005). There were no significant changes in the control group. CONCLUSION Interval high-intensity aerobic training, combined with strength exercise, seems to benefit aortic dilatation capacity and augmented systolic pressure in parallel with improvement in left ventricular diastolic function and quality of life.

Effects of interval-load versus constant-load training on the BODE index in COPD patients

The BODE index is frequently used to assess functional capacity in patients with COPD. The aim of this study was to investigate the effectiveness of interval-load training (ILT) to improve the BODE index in comparison to the commonly implemented constant-load training (CLT). Forty-two patients with COPD [FEV(1): (mean+/-SEM) 42+/-3% predicted] were randomly allocated to either ILT (n=21) or CLT (n=21). The training program consisted of cycling exercise 3 days/week for 10 weeks. Patients assigned to ILT exercised at a mean intensity of 126+/-4% of baseline peak work rate (Wpeak) with 30-s work periods alternated with 30-s rest periods for 45 min per day, whereas patients allocated to CLT exercised at a mean intensity of 76+/-5% of baseline Wpeak for 30 min per day. The BODE index and its components: body mass index, FEV(1), MMRC dyspnea score and the 6-min walk test (6-MWT) as well as cycling Wpeak were assessed before and after both exercise training regimes. Both ILT and CLT significantly (p<0.001) decreased the BODE index (from 4.8+/-0.5 to 4.0+/-0.5 units and from 4.4+/-0.5 to 3.8+/-0.5 units, respectively). In addition, both ILT and CLT significantly decreased the MMRC dyspnea score by 0.4+/-0.1 units and increased the 6-MWT (by 52+/-16 and 44+/-12 m, respectively) as well as cycling Wpeak (by 14+/-2 and 10+/-2W, respectively). The magnitude of these changes was not significantly different between ILT and CLT. Consequently, ILT is equally effective to CLT in terms of improving the BODE index in patients with COPD and as such it may constitute an alternative rehabilitative modality in COPD.

Home-based maintenance tele-rehabilitation reduces the risk for acute exacerbations of COPD, hospitalisations and emergency department visits

Pulmonary rehabilitation (PR) remains grossly underutilised by suitable patients worldwide. We investigated whether home-based maintenance tele-rehabilitation will be as effective as hospital-based maintenance rehabilitation and superior to usual care in reducing the risk for acute chronic obstructive pulmonary disease (COPD) exacerbations, hospitalisations and emergency department (ED) visits. Following completion of an initial 2-month PR programme this prospective, randomised controlled trial (between December 2013 and July 2015) compared 12 months of home-based maintenance tele-rehabilitation (n=47) with 12 months of hospital-based, outpatient, maintenance rehabilitation (n=50) and also to 12 months of usual care treatment (n=50) without initial PR. In a multivariate analysis during the 12-month follow-up, both home-based tele-rehabilitation and hospital-based PR remained independent predictors of a lower risk for 1) acute COPD exacerbation (incidence rate ratio (IRR) 0.517, 95% CI 0.389–0.687, and IRR 0.635, 95% CI 0.473–0.853), respectively, and 2) hospitalisations for acute COPD exacerbation (IRR 0.189, 95% CI 0.100–0.358, and IRR 0.375, 95% CI 0.207–0.681), respectively. However, only home-based maintenance tele-rehabilitation and not hospital-based, outpatient, maintenance PR was an independent predictor of ED visits (IRR 0.116, 95% CI 0.072–0.185). Home-based maintenance tele-rehabilitation is equally effective as hospital-based, outpatient, maintenance PR in reducing the risk for acute COPD exacerbation and hospitalisations. In addition, it encounters a lower risk for ED visits, thereby constituting a potentially effective alternative strategy to hospital-based, outpatient, maintenance PR. Home tele-rehabilitation reduces risk of COPD exacerbation; is effective alternative to in-hospital rehabilitation http://ow.ly/T17g30ap9cY

Quadriceps muscle blood flow and oxygen availability during repetitive bouts of isometric exercise in simulated sailing

Abstract In this study, we wished to determine whether the observed reduction in quadriceps muscle oxygen availability, reported during repetitive bouts of isometric exercise in simulated sailing efforts (i.e. hiking), is because of restricted muscle blood flow. Six national-squad Laser sailors initially performed three successive 3-min hiking bouts followed by three successive 3-min cycling tests sustained at constant intensities reproducing the cardiac output recorded during each of the three hiking bouts. The blood flow index (BFI) was determined from assessment of the vastus lateralis using near-infrared spectroscopy in association with the light-absorbing tracer indocyanine green dye, while cardiac output was determined from impedance cardiography. At equivalent cardiac outputs (ranging from 10.3±0.5 to 14.8±0.86 L · min−1), the increase from baseline in vastus lateralis BFI across the three hiking bouts (from 1.1±0.2 to 3.1±0.6 nM · s−1) was lower (P = 0.036) than that seen during the three cycling bouts (from 1.1±0.2 to 7.2±1.4 nM · s−1) (Cohens d: 3.80 nM · s−1), whereas the increase from baseline in deoxygenated haemoglobin (by ∼17.0±2.9 μM) (an index of tissue oxygen extraction) was greater (P = 0.006) during hiking than cycling (by ∼5.3±2.7 μM) (Cohens d: 4.17 μM). The results suggest that reduced vastus lateralis muscle oxygen availability during hiking arises from restricted muscle blood flow in the isometrically acting quadriceps muscles.

Hemodynamic effects of high intensity interval training in COPD patients exhibiting exercise-induced dynamic hyperinflation.

Dynamic hyperinflation (DH) has a significant adverse effect on cardiovascular function during exercise in COPD patients. COPD patients with (n = 25) and without (n = 11) exercise-induced DH undertook an incremental (IET) and a constant-load exercise test (CLET) sustained at 75% peak work (WRpeak) prior to and following an interval cycling exercise training regime (set at 100% WRpeak with 30-s work/30-s rest intervals) lasting for 12 weeks. Cardiac output (Q) was assessed by cardio-bio-impedance (PhysioFlow, enduro, PF-O7) to determine Q mean response time (QMRT) at onset (QMRT(ON)) and offset (QMRT(OFF)) of CLET. Post-rehabilitation only those patients exhibiting exercise-induced DH demonstrated significant reductions in QMRT(ON) (from 82.2 ± 4.3 to 61.7 ± 4.2 s) and QMRT(OFF) (from 80.5 ± 3.8 to 57.2 ± 4.9 s ). These post-rehabilitation adaptations were associated with improvements in inspiratory capacity, thereby suggesting that mitigation of the degree of exercise-induced DH improves central hemodynamic responses in COPD patients.

Interval training induces clinically meaningful effects in daily activity levels in COPD

Mounting evidence suggests that daily activity levels (DAL) in patients with chronic obstructive pulmonary disease (COPD) are markedly low compared with healthy age-matched individuals and are associated with poorer health status and prognosis [1]. COPD severity negatively impacts on DAL since patients with low DAL experience greater ventilatory, central haemodynamic and peripheral muscle oxygenation constraints during activities of daily living when compared with more physically active counterparts [2, 3]. Although exercise training as part of pulmonary rehabilitation has shown to mitigate the aforementioned physiological constraints [4], there is no evidence of clinically meaningful improvements in DAL following pulmonary rehabilitation [5] as manifested by a mean increase of at least 1000 steps·day−1 [6]. This has been attributed to methodological shortfalls, such as lack of adequately controlled studies, small sample size, short duration of pulmonary rehabilitation programmes, application of activity monitors non-validated for COPD patients [5] and insufficient exercise intensities to induce true physiological training effects. Interval exercise training has been shown to allow application of intense loads to peripheral muscles that induce substantial physiological effects manifested by mitigation of respiratory and central haemodynamic limitations and partial restoration of peripheral muscle dysfunction in patients with diverse COPD severity [7, 8]. In this context, it is reasoned that application of this training modality would allow transfer of the aforementioned physiological benefits into clinically meaningful improvements in DAL [2, 3]. Accordingly, the purpose of this randomised controlled study was to investigate the effect of a 12-week high-intensity interval exercise training programme in DAL in addition to usual care in patients with COPD. 12 weeks of interval training induces clinically meaningful effects in amount and intensity of daily activities in COPD http://ow.ly/rZXI3002awp