Ramp Test Research Articles

#1806 Cycling is safe – effect of intradialytic cycle ergometry on cerebral oxygenation and cognitive function – a pilot study

Abstract Background and Aims Patients on chronic hemodialysis benefit from intradialytic exercise with improvements in endurance, muscle strength and health-related quality of life. It is not known whether the increased oxygen demand during intradialytic exercise negatively affects cerebral oxygenation and cerebral function. The aim of the study was to assess the risk of cerebral undersupply by measuring cerebral oxygenation, perfusion and cognitive function during and after intradialytic ergometer training. Method Twelve patience on maintenance hemodialysis (HD) trice weekly were included in the study. In an initial ramp test, using bed cycle ergometer, we first determined the maximum physical strength (Pmax) at the level of exhaustion (HD A). Then, one hour after start of a second HD (HD B), patients performed 40%, 50% and 60% of Pmax for 6 min. Pulmonary function tests, blood volume (BVM), cardiac output (by electrical cardiometry), regional cerebral oxygen saturation (rSO2) (by near-infrared spectroscopy) and cerebral blood flow (CBF, by Doppler sonography) were measured. The relative changes in rSO2, CBF and hematocrit were used to calculate cerebral oxygen supply (DO2). Cognitive tests (Stroop, Trail Making and Mini Addenbrookes Cognitive Examination Test) were performed before and after HD sessions with and, as controls, without ergometry (HD-C). Results Median age was 68 (42-85) years, 9/12 were male, complete data set was obtained in 10 patients. During step test exercise (HD B), at the highest exercise level (according to Borg (1-10) 6.75 ± 2.9), rSO2 increased (+6 ± 9%, p=0.034) without a significant change in CBF. In the meantime, relative blood volume decreased during ergometry (-5.8 ± 2.73%; p=0.002), causing a temporary increase of hematocrit. Despite a small decrease in CBF in 3 patients, the mean change of rSO2, CBF and hematocrit always had a positive trend in all patients, as a surrogate of stable cerebral oxygen supply (Table 1). In comparative cognitive tests (B vs. C), we observed no significant changes in cognitive functions. Conclusion In this pilot study, intradialytic bed-cycle ergometry during the first hour of HD for <20 min at 40-60% of patients’ individual maximum intensity had no negative effects on cerebral oxygenation and function. Specific studies testing the safety intradialytic exercise with different conditions, such as increasing intensity or duration, are needed.

INSCYD physiological performance software is valid to determine the maximal lactate steady state in male and female cyclists.

The maximal lactate steady state (MLSS) is defined as the highest workload that can be maintained without blood lactate accumulation over time. The power output at MLSS (PMLSS) is regularly implemented to define training zones, quantify training progress, or predict race performance. The gold standard methodology for MLSS determination requires two to five trials of constant-load exercise, which limits the practical application in training. The INSCYD software can calculate the PMLSS (PMLSSINSCYD) based on physiological data that can be obtained during a ∼1 h laboratory visit. However, to the best of our knowledge, the validity of the most recent software version has not yet been investigated. This study aimed to assess the validity of the software's calculations on PMLSS in cycling. The data for this study were retrieved from two published scientific sources. Thirty-one cyclists (19 males, 12 females) performed a 15 s sprint to estimate the VLamax, a ramp test for the assessment, and two to five constant-load tests to determine the PMLSS. The INSCYD software was used to calculate the PMLSS based on the , VLamax, sex, body mass, and body composition. The PMLSSINSCYD was higher than the PMLSS in the entire sample (mean difference: 4.6 W, p < 0.05, 95% CI 0.8-8.3 W) and in men (mean difference: 6.6 W, p < 0.05, 95% CI 1.3-11.8 W), but not in women (mean difference: 0.8 W, n.s., 95% CI -3.7 to 5.3 W), which was within the typical error of the PMLSS estimations (∼3%). In 12 subjects (nine males, three females), the PMLSSINSCYD differed by 3.1-7.3% compared to the MLSS. The Pearson correlations between the measured PMLSS and the calculated PMLSS (PMLSSINSCYD) were very strong in men (r = 0.974, p < 0.001, 95% CI 0.933-0.99), women (r = 0.984, p < 0.001, 95% CI 0.931-0.996), and for the entire sample (r = 0.992, p < 0.001, 95% CI 0.982-0.996). In conclusion, the PMLSS can be accurately calculated using the INSCYD software, but it still requires advanced testing equipment to collect valid and VLamax data.

Abstract GS02-10: Effects of a structured and individualized exercise program on fatigue and health-related quality of life in patients with metastatic breast cancer: the multinational randomized controlled PREFERABLE-EFFECT study

Abstract INTRODUCTION: Patients with metastatic breast cancer (mBC) often experience cancer- and treatment-related side effects that can impair daily life activities and health-related quality of life (HRQoL). Interventions are needed that improve HRQoL by alleviating fatigue and other side effects during palliative BC cancer treatment. Recent evidence-based international guidelines (ASCO, ACSM) recommend exercise for patients with BC during adjuvant treatment for reducing side effects. However, evidence of the effectiveness of exercise in patients with mBC is scarce. The PREFERABLE-EFFECT study (NCT04120298) was designed to assess the effects of a 9-month supervised exercise program in patients with mBC on fatigue, HRQoL, and other cancer- and treatment-related side effects. METHODS: PREFERABLE-EFFECT is a multinational, randomized controlled trial including patients with mBC from five European countries (Germany, Poland, Spain, Sweden, The Netherlands) and Australia. Participants were randomly assigned to usual care or an individualized, structured exercise program consisting of aerobic, resistance, and balance training. The first six months included twice weekly supervised exercise sessions of one hour. In the last three months, one supervised session was replaced by an unsupervised session, supplemented by an exercise App. All participants received general exercise advice (physical activity ≥ 30 min/day) and an activity tracker. Our primary outcomes, physical fatigue (subscale of the EORTC QLQ-FA12) and HRQoL (summary score of the EORTC QLQ-C30), were assessed at baseline, 3, 6, and 9 months. Among other physical fitness outcomes, maximal short exercise capacity was assessed with the Steep Ramp Test. The intervention effects (intention-to-treat) were determined by comparing the change from baseline to 3, 6 (i.e., primary endpoint) and 9 months between groups using separate mixed models for repeated measures, adjusted for baseline values of the outcome variable and stratification factors (mBC line of treatment (1st/2nd vs. 3rd or higher) and study center). A significant improvement of either or both primary outcomes (applying the Bonferroni-Holm method) was considered as successful. RESULTS: Between 2019-2022, we included 357 patients with mBC, with 178 patients randomized to the exercise intervention and 179 to usual care. Patients were, on average, 55.4 years of age (SD=11.1), most patients received 1st or 2nd line of treatment at study enrollment (74.8%) and had bone metastases (73.9%). At 6 months (primary endpoint), participation in the exercise intervention resulted in statistically significant positive effects on both primary outcomes, compared to usual care: physical fatigue was lower (mean difference: -5.3, 95% CI -10.0; -0.6, p=0.027, effect size (ES)=0.22) and HRQoL was better (+4.8, 95% CI 2.2; 7.4, p=0.0003, ES=0.33). Beneficial effects were also found at 3 months (physical fatigue: -3.4, -7.8; 1.0, ES=0.14 and QoL: 3.9, 1.5; 6.3, ES=0.27) and 9 months (physical fatigue: -5.6, -10.9; -0.4, ES=0.24 and QoL: +4.3, 1.4; 7.3, ES=0.31). Further, at the primary endpoint, we found positive exercise effects on physical fitness (+24.3 Watts, 15.5; 33.1, ES=0.42) and numerous QLQ-C30 scales, including social functioning (+5.5, 0.2; 10.8, ES=0.20), pain (-7.1, -12.1; -1.9, ES=0.28) and dyspnea (-7.6, -12.2; -3.0, ES=0.28). Two SAEs occurred (one wrist fracture and one sacral stress fracture), neither related to bone metastases. CONCLUSION: This large multinational study demonstrated significant beneficial effects of a supervised exercise intervention offered during palliative treatment on mBC patients’ fatigue, HRQoL, and other clinically relevant outcomes. Based on these findings, we recommend supervised resistance and aerobic exercise as part of supportive care regimens during palliative treatment of mBC. Citation Format: Anne May, Anouk Hiensch, Johanna Depenbusch, Martina Schmidt, Evelyn Monninkhof, Mireia Pelaez, Dorothea Clauss, Philipp Zimmer, Jon Belloso, Mark Trevaskis, Helene Rundqvist, Joachim Wiskemann, Jana Muller, Carlo Fremd, Renske Altena, Joanna Kufel-Grabowska, Rhode Bijlsma, Lobke van Leeuwen-Snoeks, Daan ten Bokkel-Huinink, Gabe Sonke, Bruce Mann, Prudence Francis, Gary Richardson, Isabel Álvarez, Wolfram Malter, Elsken Van der Wall, Neil Aaronson, Elżbieta Senkus, Ander Urriticoechea, Eva Zopf, Wilhelm Bloch, Martijn Stuiver, Yvonne Wengström, Karen Steindorf. Effects of a structured and individualized exercise program on fatigue and health-related quality of life in patients with metastatic breast cancer: the multinational randomized controlled PREFERABLE-EFFECT study [abstract]. In: Proceedings of the 2023 San Antonio Breast Cancer Symposium; 2023 Dec 5-9; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2024;84(9 Suppl):Abstract nr GS02-10.

STRUCTURED EXERCISE IMPROVES FATIGUE AND HEALTH-RELATED QUALITY OF LIFE IN METASTATIC BREAST CANCER PATIENTS: THE MULTINATIONAL RANDOMIZED CONTROLLED PREFERABLE-EFFECT STUDY

INTRODUCTION &amp; AIMS Exercise has been proven safe and effective for patients with breast cancer in the curative setting, however evidence in patients with metastatic breast cancer (mBC) is scarce. The aim of the PREFERABLE - EFFECT study (NCT04120298) was to evaluate the effects of a structured exercise program on fatigue, health-related quality of life (HRQoL), and other cancer- and treatment-related side effects in patients with mBC. METHODS The randomized controlled trial included patients with mBC from five European countries (Germany, Spain, Netherlands, Poland, Sweden) and Australia. Participants were randomly assigned to usual care (UC) or a 9-month supervised and individualized exercise program (EX) involving twice weekly aerobic, resistance, and balance exercises. The primary outcomes, physical fatigue (EORTC QLQ-FA12 subscale) and HRQoL (EORTC QLQ-C30 summary score) were assessed at baseline, 3, 6, and 9 months. Among other physical fitness outcomes, maximal short exercise capacity was assessed with the Steep Ramp Test. Changes from baseline to 3, 6 (primary endpoint) and 9 months were compared between groups using adjusted mixed models for repeated measures. RESULTS A total of 357 patients were randomized (EX=178, UC=179). On average, participants were 55.4 years of age (SD=11.1) and 73.9% had bone metastases. EX resulted in a significant reduction in physical fatigue (-5.3 [-10.0; -0.6], p=.027, ES=0.22) and improvement in HRQoL (+4.8 [2.2; 7.4], p=.0003, ES=0.33) compared to UC at 6 months (primary endpoint), as well as at 3 and 9 months. EX also improved physical fitness (+24.3 Watts, [15.5; 33.1], ES=0.42, at 6 months) and numerous relevant QLQ-C30 scales, including social functioning, pain, and dyspnoea. CONCLUSION This large multinational study demonstrates that supervised exercise improves fatigue, HRQoL, and other clinically relevant outcomes in patients with mBC. Based on these findings, supervised exercise should be recommended to patients with mBC.

Comparison of four in vitro test methods to assess nucleus pulposus replacement device expulsion risk.

Nucleus replacement devices (NRDs) are not routinely used in clinic, predominantly due to the risk of device expulsion. Rigorous in vitro testing may enable failure mechanisms to be identified prior to clinical trials; however, current testing standards do not specify a particular expulsion test. Multiple methods have therefore been developed, complicating comparisons between NRD designs. Thus, this study assessed the effectiveness of four previously reported expulsion testing protocols; hula-hoop (Protocol 1), adapted hula-hoop (Protocol 2), eccentric cycling (Protocol 3), and ramp to failure (Protocol 4), applied to two NRDs, one preformed and one in situ curing. Nucleus material was removed from 40 bovine tail intervertebral disks. A NRD was inserted posteriorly into each cavity and the disks were subjected to one of four expulsion protocols. NRD response was dependent on both the NRD design and the loading protocol. Protocol 1 resulted in higher migration and earlier failure rates compared to Protocol 2 in both NRDs. The preformed NRD was more likely to migrate when protocols incorporated rotation. The NRDs had equal migration (60%) and expulsion (60%) rates when using unilateral bending and ramp testing. Combining the results of multiple tests revealed complimentary information regarding the NRD response. Adapted hula-hoop (Protocol 2) and ramp to failure (Protocol 4), combined with fluoroscopic analysis, revealed complimentary insights regarding migration and failure risk. Therefore, when adopting the surgical approach and animal model used in this study, it is recommended that NRD performance be assessed using both a cyclic and ramp loading protocol.

Targeted effect of ischemic preconditioning on the gas exchange threshold in healthy males and females

Ischemic preconditioning (IPC) appears to improve exercise performance although there is uncertainty about the intensity dependence of this effect. The present study sought to clarify effects of IPC on physiological responses at and below peak oxygen uptake, including the gas exchange threshold (GET). Ten male and female participants completed five cycling ramp tests (10 W/min) to failure, with the final two tests preceded by either IPC (4 × 5 min 220 mmHg bilateral leg occlusions) or SHAM (20 mmHg), in a randomised crossover design. The rates of O2 uptake (V˙\\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{upgreek} \\setlength{\\oddsidemargin}{-69pt} \\begin{document}$$\\dot{V}$$\\end{document}O2), carbon dioxide output (V˙\\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{upgreek} \\setlength{\\oddsidemargin}{-69pt} \\begin{document}$$\\dot{V}$$\\end{document}CO2), and expired ventilation (V˙\\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{upgreek} \\setlength{\\oddsidemargin}{-69pt} \\begin{document}$$\\dot{V}$$\\end{document}E) were measured at rest and throughout exercise. Exercise data were fitted using several functions to identify GET, two ventilatory thresholds and peak V˙\\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{upgreek} \\setlength{\\oddsidemargin}{-69pt} \\begin{document}$$\\dot{V}$$\\end{document}O2. IPC increased V˙\\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{upgreek} \\setlength{\\oddsidemargin}{-69pt} \\begin{document}$$\\dot{V}$$\\end{document}O2 at GET by ~ 9% (IPC: 1.89 ± 0.51 L/min, SHAM: 1.73 ± 0.56 L/min; p = 0.055) and power output at GET by ~ 11% (IPC: 133 ± 36 W, SHAM: 120 ± 39 W; p = 0.022). In addition, peak power output increased by 2.4% following IPC (IPC: 217 ± 50 W, SHAM: 212 ± 51 W; p = 0.052), but there was no significant effect of IPC on peak V˙\\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{upgreek} \\setlength{\\oddsidemargin}{-69pt} \\begin{document}$$\\dot{V}$$\\end{document}O2 (IPC: 2.87 ± 0.68 L/min, SHAM: 2.84 ± 0.73 L/min; p = 0.60) or the ventilatory thresholds. The present results suggest that IPC improves GET and peak power output but not peak V˙\\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{upgreek} \\setlength{\\oddsidemargin}{-69pt} \\begin{document}$$\\dot{V}$$\\end{document}O2 during a maximal graded test.

Outcomes of left ventricular assist device implantations at Karolinska University Hospital: A retrospective study

ObjectiveTo descriptively present data and outcomes of Left ventricular assist device (LVAD) implantations at Karolinska University hospital. MethodsData were collected from consecutive patients (n=44) who were implanted with HeartMate 3 (HM3) at Karolinska University Hospital between 2017 and 2022. The study presents baseline characteristics, clinical course during the inpatient hospital care after implantation, adverse events, and clinical outcomes. ResultsMedian intensive care unit stay and hospital stay after HM3 implantation was 8 (interquartile range [IQR] 6; 15) and 28 days (IQR 22; 36), respectively. In total, 73% underwent ramp test at some point after the implantation. Death from all causes within 30 days post-implantation was 5%. A total of 21 patients (48%) underwent right heart catheterization, at a median of 0.5 years (IQR 0.3;0.7) after implantation, and all exhibited optimally unloaded left ventricles. During the study period, 34% of the patients were transplanted, 5% were explanted, and 16% died with LVAD. In total, 11% and 5% suffered from early and late right ventricle failure, respectively. Acute renal failure affected 46% and 18% had drive-line infection. Spontaneous cerebral haemorrhage and cerebral infarction affected 5% and 7% of the study population, respectively. Gastrointestinal bleeding affected 16%. The median LVAD-duration was 10 months (IQR 5;22). The one-year survival rate with LVAD was 85%, and the two-year survival rate was 80%. ConclusionsThe results of this low volume single-center retrospective study on LVAD implantations align with the results of other studies and international registries.

(842) - Ramp Tests in LVAD Patients: Let’s Have a Look to Your Numbers or the Position of Your Pump?

(842) - Ramp Tests in LVAD Patients: Let’s Have a Look to Your Numbers or the Position of Your Pump?

(216) - HeartMate 3 LVAD Outflow Graft Velocity Profile as Simplified Marker for Left Ventricular Unloading in Echocardiographic Speed Ramp Tests

(216) - HeartMate 3 LVAD Outflow Graft Velocity Profile as Simplified Marker for Left Ventricular Unloading in Echocardiographic Speed Ramp Tests

(186) - Phenotyping of Left Ventricular Volume Unloading During Echocardiographic Speed Ramp Tests and Non-Invasive Heartmate 3 Snoopy Monitoring

(186) - Phenotyping of Left Ventricular Volume Unloading During Echocardiographic Speed Ramp Tests and Non-Invasive Heartmate 3 Snoopy Monitoring

Multimodal prehabilitation in elective oncological colorectal surgery enhances postoperative functional recovery: A secondary analysis of the PREHAB randomized clinical trial

IntroductionColorectal cancer (CRC) ranks as the second leading cause of cancer-related deaths. The PREHAB trial revealed that prehabilitation in colorectal surgery leads to a reduction of severe complications and enhanced functional capacity. Nevertheless, risk selection for prehabilitation and the potential benefits for patients without postoperative complications remains unclear. This study aims to assess postoperative functional capacity, also in patients without postoperative complications. Materials & methodsThis study was a secondary analysis of the PREHAB trial. Functional capacity tests, including cardiopulmonary exercise testing (CPET), steep ramp test (SRT), 6-min walking test (6MWT), stair climb test (SCT), 30” sit-to-stand test (STS), timed-up-and-go test (TUG), and muscle strength assessments, were conducted at baseline (T0) and 4 weeks postoperatively (T3). The primary outcome was the relative change in functional capacity from baseline to postoperative (ΔT0-T3) per group (i.e., prehabilitation vs control). Secondary, identical analysis were performed for patients without postoperative complications in each group. ResultsIntention-to-treat analysis included 251 patients. For postoperative functional capacity, prehabilitation patients showed improvements in VO2peak (p = 0.024), VO2AT (p = 0.017), SRT (p = 0.001), 6MWT (p = 0.049), SCT (p = 0.012), and STS (p = 0.001) compared to the control group. Regarding muscle strength, prehabilitation patients showed improvements in estimated 1RM lateral pull down (p = 0.016), 1RM chest press (p = 0.001), 1RM leg press (p = 0.001) and HGS (p = 0.005) compared to controls. Additionally, prehabilitation patients more often reached baseline levels at T3 in VO2AT (p = 0.037), SRT (p = 0.008), 6MWT (p = 0.013), STS (p = 0.012), estimated 1RM lateral pull down (p = 0.002), 1RM chest press (p = 0.001) and 1RM leg press (p = 0.001) compared to controls. Moreover, even patients without postoperative complications in the prehabilitation group showed better postoperative functional capacity and more often reached baseline levels at T3, compared to controls. ConclusionMultimodal prehabilitation in CRC surgery is associated with improved postoperative functional capacity, even in patients without postoperative complications.

Five-Week, Low-Intensity Blood Flow Restriction Rowing Improves V̇ o2 max in Elite Rowers.

Held, S, Rappelt, L, Rein, R, Deutsch, J-P, Wiedenmann, T, and Donath, L. Five-week, low-intensity, blood flow restriction rowing improves V̇ o2 max in elite rowers. J Strength Cond Res 38(6): e299-e303, 2024-This controlled intervention study examined the effects of low-intensity rowing with blood flow restriction (BFR) on maximal oxygen uptake (V̇ o2 max), peak power output during ramp testing (PPO), and 2000-m time trial performance (P2k). Eleven, highly elite, male rowers (22.1 ± 1.6 years; 92.6 ± 3.8 kg; 1.93 ± 0.04 m; 7.9. ± 2.2 years rowing experience; 20.4 ± 2.0 h·w -1 training volume; 11.9 ± 1.1 session per week) trained 5 weeks without BFR (Base) followed by a 5-week BFR intervention period. BFR of the lower limb was applied through customized elastic wraps. BFR took place 3 times a week (accumulated net pBFR: 60 min·wk -1 ; occlusion per session: 2 times 10 min·session -1 ) and was used exclusively at low intensities (<2 mmol·L -1 ). V̇ o2 max, PPO, and P2k were examined before, between, and after both intervention periods. Bayesian's credible intervals revealed relevantly increased V̇ o2 max +0.30 L·min -1 (95% credible interval: +0.00 to +0.61 L·min -1 ) adaptations through BFR. By contrast, PPO +14 W (-6 to +34 W) and P2k -5 W (-14 to +3 W) were not noticeably affected by the BFR intervention. This study revealed that 15 sessions of BFR application with a cumulative total BFR load of 5 h over a 5-week macrocycle increased V̇ o2 max remarkably. Thus, pBFR might serve as a promising tool to improve aerobic capacity in highly trained elite rowers.

High-intensity interval training improves respiratory and cardiovascular adjustments before and after initiation of exercise.

Purpose: High-intensity interval training (HIIT) may induce training-specific physiological adaptations such as improved respiratory and cardiovascular adjustments before and after the onset of high-intensity exercise, leading to improved exercise performance during high-intensity exercise. The present study investigated the effects of HIIT on time-dependent cardiorespiratory adjustment during maximal exercise and before and after initiation of high-intensity exercise, as well as on maximal exercise performance. Methods: 21 healthy male college students were randomly assigned to HIIT group (n = 11) or control group (n = 10). HIIT group performed training on a cycle ergometer once a week for 8 weeks. The training consisted of three bouts of exercise at 95% maximal work rate (WRmax) until exhaustion. Before and after the HIIT program, dynamic cardiorespiratory function was investigated by ramp and step exercise tests, and HIIT-induced cardiac morphological changes were assessed using echocardiography. Results: HIIT significantly improved not only maximal oxygen uptake and minute ventilation, but also maximal heart rate (HR), systolic blood pressure (SBP), and time to exhaustion in both exercise tests (p < 0.05). Time-dependent increases in minute ventilation (VE) and HR before and at the start of exercise were significantly enhanced after HIIT. During high-intensity exercise, there was a strong correlation between percent change (from before to after HIIT program) in time to exhaustion and percent change in HRmax (r = 0.932, p < 0.001). Furthermore, HIIT-induced cardiac morphological changes such as ventricular wall hypertrophy was observed (p < 0.001). Conclusion: We have demonstrated that HIIT at 95% WRmax induces training-specific adaptations such as improved cardiorespiratory adjustments, not only during maximal exercise but also before and after the onset of high-intensity exercise, improvement of exercise performance mainly associated with circulatory systems.

Multimodal prehabilitation in elective oncological colorectal surgery enhances preoperative physical fitness: a single center prospective real-world data analysis.

Surgery can lead to curation in colorectal cancer (CRC) but is associated with significant morbidity. Prehabilitation plays an important role in increasing preoperative physical fitness to reduce morbidity risk; however, data from real-world practice is scarce. This study aimed to evaluate the change in preoperative physical fitness and to evaluate which patients benefit most from prehabilitation. In this single-arm prospective cohort study, consecutive patients undergoing elective colorectal oncological surgery were offered a 3- to 4-week multimodal prehabilitation program (supervised physical exercise training, dietary consultation, protein and vitamin supplementation, smoking cessation, and psychological support). The primary outcome was the change in preoperative aerobic fitness (steep ramp test (SRT)). Secondary outcomes were the change in functional walking capacity (6-minute walk test (6MWT)), and muscle strength (one-repetition maximum (1RM) for various muscle groups). To evaluate who benefit most from prehabilitation, participants were divided in quartiles (Q1, Q2, Q3, and Q4) based on baseline performance. In total, 101 patients participated (51.4% male, aged 69.7 ± 12.7 years). The preoperative change in SRT was +28.3 W, +0.36 W/kg, +16.7% (P<0.001). Patients in all quartiles improved at the group level; however, the relative improvement decreased from Q1-Q2, Q2-Q3, and Q3-Q4 (P=0.049). Change in 6MWT was +37.5 m, +7.7% (P<0.001) and 1RM improved with 5.6-33.2 kg, 16.1-32.5% for the various muscle groups (P<0.001). Prehabilitation in elective oncological colorectal surgery is associated with enhanced preoperative physical fitness regardless of baseline performance. Improvements were relatively larger in less fit patients.

Hemodynamic Optimization by Invasive Ramp Test in Patients Supported With HeartMate 3 Left Ventricular Assist Device.

In patients supported by the HeartMate 3 left ventricular assist device (HM3 LVAD), pump speed adjustments may improve hemodynamics. We investigated the hemodynamic implications of speed adjustments in HM3 recipients undergoing hemodynamic ramp tests. Clinically stable HM3 recipients who underwent routine invasive hemodynamic ramp tests between 2015 and 2022 at our center were included. Filling pressure optimization, defined as central venous pressure (CVP) <12 mm Hg and pulmonary capillary wedge pressure (PCWP) <18 mm Hg, was assessed at baseline and final pump speeds. Patients with optimized pressures were compared to nonoptimized patients. Overall 60 HM3 recipients with a median age of 62 years (56, 71) and time from LVAD implantation of 187 days (124, 476) were included. Optimized filling pressures were found in 35 patients (58%) at baseline speed. Speed was adjusted in 84% of the nonoptimized patients. Consequently, 39 patients (65%) had optimized pressures at final speed. There were no significant differences in hemodynamic findings between baseline and final speeds ( p > 0.05 for all). Six and 12 month readmission-free rates were higher in optimized compared with nonoptimized patients ( p = 0.03 for both), predominantly due to lower cardiac readmission-free rates ( p = 0.052). In stable outpatients supported with HM3 who underwent routine ramp tests, optimized hemodynamics were achieved in only 2 of 3 of the patients. Patients with optimized pressures had lower all-cause readmission rates, primarily driven by fewer cardiac-related hospitalizations.

Time-course Changes of Field- and Laboratory-based Performance Indicators in Junior Cyclists Through a Season.

This study aimed to assess the seasonal evolution of field-based and laboratory-based performance indicators in cyclists. Thirteen Junior male road cyclists (age 17.4±0.5 years) were followed up during a season, which was divided in three phases: early season (involving mainly training sessions), mid-season (including the first competitions), and late season (including the major competitions of the season). During each phase, field-based power output data were registered for the assessment of maximum mean power values, and laboratory-based endurance (ramp test and simulated 8-minute time trial), muscle strength/power (squat, lunge, hip thrust) and body composition indicators (dual-energy X-ray absorptiometry) were also assessed. A progressive (p<0.01) increase in maximum mean power values (e.g., 3.8±0.3 and 4.5±0.4 watts/kg in early and late season, respectively, for 60-minute efforts) and on 8-minute time trial performance (i.e., 5.3±0.3 and 5.6±0.4 watts/kg, respectively) was observed through the season. Yet, more "traditional" endurance indicators (i.e., ventilatory threshold, respiratory compensation point, or maximum oxygen uptake) seemed to show a ceiling effect beyond the mid-season. In addition, neither peak power output, body composition, nor muscle strength indicators followed a similar pattern to the aforementioned field-based indicators. In summary, in Junior cyclists field-based indicators seem more sensitive to monitor endurance cyclists' changes in actual fitness and performance capacity than more "traditional" laboratory-based markers in Junior cyclists.

P722 The steep ramp test is a valid practical test to assess cardiorespiratory fitness in patients with inflammatory bowel disease

Abstract Background Comprehensive disease management of inflammatory bowel disease (IBD) requires a holistic approach that extends beyond achieving endoscopic healing. Monitoring health-related physical fitness (HRPF) parameters (i.e. body composition, cardiorespiratory fitness, muscular strength, muscular endurance, and flexibility) may lead to a more proactive approach to managing IBD, as IBD may affect HRPF due to e.g. chronic inflammation, malnutrition, corticosteroid use, and reduced physical activity. Yet, knowledge regarding HRPF in patients with IBD is limited. Assessment of cardiorespiratory fitness (CRF), a key component of HRPF in other chronic diseases, could offer valuable insights into physical capacity and overall health. However, the gold standard, measuring oxygen uptake at peak exercise (VO2peak) achieved during cardiopulmonary exercise testing (CPET) is impractical for widespread implementation in clinical practice. The steep ramp test (SRT), a short-term maximal exercise test on a cycle ergometer, might serve as a less demanding assessment method to facilitate routine assessment of CRF in clinical practice and deliver more practical endpoints for intervention studies. This study aimed to examine the criterion validity of the SRT as compared with CPET in evaluating CRF in patients with IBD. Methods From August 2022 to October 2023, adult patients with IBD in remission or with mild-to-moderate clinical disease activity were consecutively enrolled. Each participant performed a SRT and a CPET within 14 days to examine CRF. The main outcome measures were the achieved work rate at peak exercise (WRpeak) for the SRT (SRT-WRpeak) and VO2peak as well as WRpeak for CPET (CPET-VO2peak and CPET-WRpeak). Validity of the SRT was evaluated with Pearson’s correlation coefficients between SRT-WRpeak and CPET-VO2peak and SRT-WRpeak and CPET-WRpeak. Results A total of 50 participants, with a mean age of 42.9 years and 56% diagnosed with CD, were included (Table 1). One participant was excluded from the analysis due to the inability to achieve a maximal effort during CPET. Mean (±SD) WRpeak attained at the SRT was 4.32 (±1.06) W·kg-1, and mean (±SD) VO2peak and WRpeak achieved during CPET were 33.47 (±9.85) mL·kg-1·min-1 and 2.90 (±0.95) W·kg-1, respectively. Figure 1 illustrates robust linear relationships with very strong correlations between SRT-WRpeak and CPET- VO2peak (r=0.945, p&amp;lt;0.001) and SRT-WRpeak and CPET-WRpeak (r=0.960, p&amp;lt;0.001). Conclusion Results of this study suggest that the SRT is a valid alternative test for examining CRF in patients with IBD, indicating its potential application in both clinical practice and intervention studies. Further research should explore the criterion validity of practical tests for other components of HRPF.

A verification phase adds little value to the determination of maximum oxygen uptake in well-trained adults.

The objective was to investigate if performing a sub-peak or supra-peak verification phase following a ramp test provides additional value for determining 'true' maximum oxygen uptake ( O2). 17 and 14 well-trained males and females, respectively, performed two ramp tests each followed by a verification phase. While the ramp tests were identical, the verification phase differed in power output, wherein the power output was either 95% or 105% of the peak power output from the ramp test. The recovery phase before the verification phase lasted until capillary blood lactate concentration was ≤ 4mmol·L-1. If a O2 plateau occurred during ramp test, the following verification phase was considered to provide no added value. If no O2 plateau occurred and the highest O2 ( O2peak) during verification phase was < 97%, between 97 and 103%, or > 103% of O2peak achieved during the ramp test, no value, potential value, and certain value were attributed to the verification phase, respectively. Mean (standard deviation) O2peak during both ramp tests was 64.5 (6.0) mL·kg-1·min-1 for males and 54.8 (6.2) mL·kg-1·min-1 for females. For the 95% verification phase, 20 tests showed either a O2 plateau during ramp test or a verification O2peak < 97%, indicating no value, 11 showed potential value, and 0 certain value. For the 105% verification phase, the values were 26, 5, and 0 tests, respectively. In well-trained adults, a sub-peak verification phase might add little value in determining 'true' maximum O2, while a supra-peak verification phase adds no value.

Impact of Interventricular Interaction on Ventricular Function: Insights From Right Ventricular Pressure-Volume Analysis

BackgroundInterventricular interactions may be responsible for the decline in ventricular performance observed in various disease states that primarily affect the contralateral ventricle. ObjectivesThis study sought to quantify the impact of such interactions on right ventricular (RV) size and function using clinically stable individuals with left ventricular assist devices (LVADs) as a model for assessing RV hemodynamics while LV loading conditions were acutely manipulated by changing device speed during hemodynamic optimization studies (ie, ramp tests). MethodsThe investigators recorded RV pressure-volume loops with a conductance catheter at various speeds during ramp tests in 20 clinically stable HeartMate3 recipients. ResultsWith faster LVAD speeds and greater LV unloading, indexed RV end-diastolic volume increased (72.28 ± 15.07 mL at low speed vs 75.95 ± 16.90 at high speed; P = 0.04) whereas indexed end-systolic volumes remained neutral. This resulted in larger RV stroke volumes and shallower end-diastolic pressure-volume relationships. Concurrently, RV end-systolic pressure decreased (31.58 ± 9.75 mL at low speed vs 29.58 ± 9.41 mL at high speed; P = 0.02), but contractility, as measured by end-systolic elastance, did not change significantly. The reduction in RV end-systolic pressure was associated with a reduction in effective arterial elastance from 0.65 ± 0.43 mm Hg/mL at low speed to 0.54 ± 0.33 mm Hg/mL at high speed (P = 0.02). ConclusionsInterventricular interactions resulted in improved RV compliance, diminished afterload, and did not reduce RV contractility. These data challenge the prevailing view that interventricular interactions compromise RV function, which has important implications for the understanding of RV-LV interactions in various disease states, including post-LVAD RV dysfunction.

A Low-Cost Test Platform for Performance Analysis of Phasor Measurement Units

In this paper, a customizable low-cost voltage waveform generator based on a real-time desktop PC and embedded data acquisition card synchronized with Coordinated Universal Time (UTC) is presented. A software approach to phase-locked loop synchronization with an external Global Positioning System (GPS) pulse signal is utilized to achieve a time uncertainty of ±1μs. This avoids expensive hardware modules for synchronization and timing purposes, which are commonly presented in literature. Besides the application for controlling the test platform, our own phasor data concentrator (PDC) application is running concurrently on the host PC. The latter is used for collecting and comparing the syncrophasor data from the test platform against the syncrophasor data measured by phasor measurement units (PMUs) under the test. The paper describes all procedures for generating reference test signals. Numerous case studies were performed, and experimental results for steady-state compliance as well as frequency ramp and phase modulation tests for dynamic compliance are presented in detail. All tests confirm that customizable test platform meets the requirements of IEEE/IEC standards. Compared to other calibrators, the cost as well as the specifications and point-by-point concept of data processing makes the described test platform suitable for performance analysis of PMU algorithms implemented on various development boards.