ECSS Paris 2023: OP-MH44
INTRODUCTION: Physical activity training programs during cardiac rehabilitation reportedly reduce morbidity and hospitalization in heart failure (HF) patients. While acute oxygen supplementation has been shown to improve muscle oxygenation and enhance exercise duration and intensity, its effects during a prolonged training program remain unclear. This study aims to investigate (1) the effects of oxygen-supplemented during training on maximal and submaximal performance, 6-minute walk test (6MWT), and quality of life in HF patients; (2) the impact of oxygen supplementation during acute exercise on lactate concentration and performance. METHODS: Twenty-four HF patients (ejection fraction <50%, with no resting desaturation) were randomly assigned to an oxygen supplementation (O₂) group or a placebo control group. The O₂ group received supplemental oxygen during all exercise sessions throughout the two-month training program. The control group trained under room air conditions. All participants completed baseline and post-program assessments, including measurements of maximal and submaximal aerobic capacity, 6-minute walk test (6MWT) distance, disease severity (New York Heart Association- NYHA classification), and quality of life (Kansas City Cardiomyopathy Questionnaire, KCCQ). Participants also performed an acute submaximal effort test at 80% of their maximum heart rate, with and without supplemental oxygen. Lactate concentration, heart rate, and rate of perceived exertion were recorded every three minutes throughout the test. RESULTS: The O₂ group showed significant improvements in maximal (p=0.007) and submaximal (p=0.003) aerobic tests, 6MWT (p<0.001), and KCCQ score (p=0.011) compared to controls. NYHA classification improved in 90% of the O₂ group versus 16% in controls. Oxygen supplementation during the acute submaximal test extended exercise duration (p<0.001) and led to a slower rise in lactate and heart rate (p<0.001) compared to exercise without oxygen supplementation. CONCLUSION: Supplemental oxygen during training in HF patients undergoing cardiac rehabilitation improved aerobic performance and quality of life. It also prolonged exercise duration and moderated physiological responses during single submaximal exercise. Oxygen supplementation should be considered in rehabilitation programs, even for patients without resting desaturation.
Read CV Einat KodeshECSS Paris 2023: OP-MH44
INTRODUCTION: Arm ergometer (AE) exercise training have shown to improve functional capacity of patients with peripheral artery disease (PAD) [1], bypassing the main barrier to exercise in these patients: the pain during walking exercise. The only study that investigated the mechanism underlying this adaptation observed that chronically training with AE improved muscle oxygen saturation (StO₂) in the leg muscles during walking [2]. However, the how AE exercise acutely affects StO₂ in the leg muscles remain unknown. Thus, the aim of this study was to analyze the acute responses of AE exercise on StO₂ in the leg affected by PAD. The secondary objectives were to analyze oxy-, deoxy-, and total hemoglobin responses, describe the intensity of leg pain symptoms during exercise in AE, and examine the relationship between StO₂ during AE and PAD severity. METHODS: Fourteen patients (57% men, 66 ± 6 years, 27.4 ± 4.6 kg/m2) with PAD and symptoms of intermittent claudication were recruited. PAD severity was assessed using the ankle-brachial index. The exercise session consisted of 15 sets of 2 minutes of AE exercise with an intensity between 13-15 on the Borgs perceived exertion scale. The Near-Infrared Spectroscopy sensor was placed on the calf muscle of the leg most affected by the disease. Prior to exercise, a physiological calibration was performed using arterial occlusion to establish a functional zero for tissue oxygenation. StO₂, oxy-, deoxy-, and total hemoglobin. These variables were continuously recorded throughout the entire session. At the end of each set, leg pain and perception exertion were recorded. RESULTS: During AE there was an increase in leg StO₂ throughout the sets (Rest: 57.9 ± 3.6 vs. Peak: 66.8 ± 6.1 %, p<0.001) with a mean rise of 9.0 ± 4.1 %. On average, the participants reached peak StO₂ in the 9.9 ± 4.1 set. Additionally, there was an increase in oxyhemoglobin (Rest: 10.7 ± 10.2 vs. Peak: 26.6 ± 13.7 µM, p<0.001) with average increases of 15.9 ± 7.9 µM, and total hemoglobin (Rest: 0.2 ± 5.1 vs. Peak: 14.9 ± 12.4 µM, p<0.001) with average increases of 14.6 ± 11.2 µM; and a decrease in deoxyhemoglobin (Rest: 0.1 ± 2.2 vs. Trough: -4.8 ± 6.7 µM, p=0.017) with average decreases of -4.9 ± 6.7 µM. Perceived exertion remained at an average of 13.5 ± 0.9, and two patients reported pain in the leg during AE. There were no associations between StO₂ responses and PAD severity (p>0.160). CONCLUSION: A single session of AE increased StO₂, oxy-, and total hemoglobin while decreasing deoxyhemoglobin, and these responses occurs independently of PAD severity. Finally, two out of 14 patients reported leg pain during the AE. This study was supported by the São Paulo Research Foundation (FAPESP) under grant number 2022/14412-8. [1] Walker RD et. al. Influence of upper- and lower-limb exercise training (...). J Vasc Surg. 2000. [2] Tew G et. al. Limb-specific and cross-transfer effects of arm-crank exercise (...). Clin Sci (Lond). 2009.
Read CV Marilia CorreiaECSS Paris 2023: OP-MH44
INTRODUCTION: Cardiorespiratory fitness (CRF) is an important modifiable risk factor for atherosclerotic cardiovascular disease (ASCVD). It remains unknown, however, if the associations of CRF with ASCVD risk differ by genetic risk. We examined prospective relationships of CRF with incident ASCVD across genetic susceptibility strata. METHODS: This prospective study included 69,447 UK Biobank participants (mean age 58 years; 54% female) without prevalent ASCVD and who completed a sub-maximal cycle test. Maximal oxygen consumption (mlO2/min/kg) was estimated using a validated bike ergometry procedure, standardised within sex and age strata, and categorised to create low (20th percentile), intermediate (20-80th percentiles) and high (80th percentile) fitness groups. Genetic susceptibility to ischaemic heart disease was quantified with weighted polygenic risk scores, and was used to assign participants to low, intermediate, and high genetic risk groups. Cox regression models were used to estimate the hazard of developing ASCVD and its major sub-components. In line with international definitions, ASCVD included all documented cases of ischaemic heart disease (IHD: comprising myocardial infarction, angina, coronary revascularisation procedures), ischaemic stroke, and peripheral arterial disease. We investigated IHD and major ischaemic events (myocardial infarction and ischaemic stroke) as nested secondary outcomes. RESULTS: During a median follow-up of 12 years, there were 5,448 incident ASCVD, 4,177 IHD, and 2,299 major ischaemic events. Each 1-standard deviation difference in sex- and age-standardised CRF (equivalent to 5.6 mLO2/kg/min) was associated with an 8% (hazard ratio [95% confidence interval]: 0.92 [0.89-0.95]) lower hazard of ASCVD, independently of demographic, lifestyle and health-related factors, and genetic risk. There was weak evidence of multiplicative interaction (p=0.06) between CRF and genetic risk, suggesting that the associations might be slightly stronger in the low genetic risk group (0.87 [0.80-0.94]) compared with intermediate (0.94 [0.90-0.98] and high genetic risk groups (0.91 [0.86-0.97]). There was no evidence of additive interaction (p=0.78). The 10-year absolute risk differences between low and high CRF groups were 1.2% and 1.6% within high and low genetic risk categories, respectively. Similar patterns of associations were found for incident IHD and major ischaemic events. CONCLUSION: Across all strata of genetic risk for cardiovascular disease, higher CRF is strongly associated with lower risk of ASCVD and its major sub-components. Adults should be encouraged to increase or maintain CRF levels, irrespective of genetic susceptibility.
Read CV Youngwon KimECSS Paris 2023: OP-MH44