Peak VO2 Research Articles

Influence of cardiac rehabilitation on blood pressure in patients with coronary artery disease

Abstract Funding Acknowledgements Type of funding sources: None. Introduction One of the main goals of cardiac rehabilitation is the optimalisation of the cardiovascular risk to prevent the progression of heart disease. Arterial hypertension is one of the most important risk factors that however remains often undertreated. Purpose We analysed the patient data from our cardiac rehabilitation center over the last 3 years to assess the evolution in exercise capacity and blood pressure before and after the rehabilitation program. Methods Patients diagnosed with coronary artery disease (acute coronary syndrome, elective percutaneous coronary intervention or coronary artery bypass graft) between October 2019 and September 2022 were retrospectively included if they followed at least 50% of the total training sessions. Mean blood pressure at the beginning and end of the cardiac revalidation was derived from the mean values of the first 5 sessions and of the last 5 sessions. A change in 5 mmHg was investigated. Results The study enrolled 378 patients, of which 17 % female, with a mean age of 65.3 ± 9.68 years. Every patient followed an average of 42 training sessions (over < 6 months) and 149 patients (41%) had a systolic blood pressure drop of at least 5 mmHg. This decrease was more prevalent in men (133 of 149 (89%) in this group vs. 171 of 218 (78%) in the group with no difference in blood pressure (p <0,05)). These 149 patients had higher systolic blood pressure at the beginning of the sessions (mean systolic blood pressure of 132 ± 9,64 mmHg, p <0,05) and a significant difference in the number of patients who stopped smoking (86 of 129 (58%) vs. 98 of 218 (45%) (p< 0.05)) and were more likely to have no acute coronary syndrome (i.e. more elective procedures) (107 of 149 (72%) vs. 133 of 218 (61%) (p <0,05)). There was no difference in the antihypertensive treatment between the 2 groups at the beginning of the cardiac rehabilitation. The evolution in exercise capacity between the beginning and the end of the rehabilitation sessions showed in both groups together an increase in exercise capacity of 3ml/min/kg in peak VO2 (=18% improvement in peak VO2). In the group with a decrease of 5 mmHg in blood pressure, the exercise capacity improved on average with 1,6 METS (32%) vs. 1,1 METS (19%) in the group with no change in blood pressure. In other words, a positive trend could be observed for a drop in the systolic blood pressure with at least 5 mmHg in relation with an improvement in exercise capacity (p=0,06). The mean systolic blood pressure for all patients at the end of the cardiac rehabilitation was 124 ± 8.36 mmHg. Conclusion Following cardiac rehabilitation in patients with coronary artery disease, a decrease in blood pressure was seen in 41% of the participants. This decrease was mainly seen in males that stopped smoking and had no acute coronary disease. A trend towards a significant relation between improved exercise capacity (in METS) and improved blood pressure was observed.

Chronotropic incompetence and exercise capacity after cardiac surgery with left atrium incision

Abstract Funding Acknowledgements Type of funding sources: None. Introduction Chronotropic incompetence (CI) is sometimes observed during exercise training of cardiac rehabilitation in patients who underwent cardiac surgery, however, little is known which factors affect to the incidence of CI and exercise capacity of those patients. Purpose Because the possibility exists that cardiac sympathetic nerves might be impaired by surgical procedure, moreover CI is sometimes observed in patients after mitral valve surgery, we hypothesized that the incidence of CI was higher in patients with left atrium incision (LAI) during surgical operation as compared with those without LAI. And if so, which factor determines the exercise capacity of patients after cardiac surgery with LAI. We thus aimed this study to elucidate the hypothesis with cardiopulmonary exercise testing (CPX). Methods We performed CPX in total 153 patients who had undergone elective cardiac operation (45 patients with LAI, age 60.5±11.0; 108 patients without LAI, age 62.0±11.7). We analyzed chronotropic response index (CRI), peak oxygen uptake (peak VO2/W), anaerobic threshold (AT), and peak oxygen pulse (peak VO2/HR) with CPX, echocardiography, and blood hemoglobin concentration (Hb). Results The value of CRI was significantly reduced in the patients with LAI as compared with those without LAI (with LAI 0.24±0.22 vs. without LAI; 0.44±0.18, p<0.001). Exercise capacity such as peak oxygen uptake (peak VO2), anaerobic threshold showed no significant difference between two groups. In patients with LAI, peak VO2 showed significant correlations between peak oxygen pulse (peak VO2/HR; r=0.36, p<0.05), Hb (r=0.40, p<0.01) and left atrium dimension (LAD) measured by echocardiography (r=-0.54, p<0.001). Conclusions The present study demonstrated that higher incidence of CI was shown in patients with LAI as compared with those without LAI. Moreover peak VO2 of patients with LAI showed significant correlations with peak VO2/HR, Hb and LAD. These results suggest that 1) left atrium incision impairs cardiac sympathetic nerves and causes CI, 2) peak VO2/HR and Hb which is essential element of oxygen pulse are important factors for exercise capacity in patients after LAI with CI. Left atrium enlargement may indicates pre-operative damages of left atrium, 3) LAD which may indicate left atrium function, also is an important factor of exercise capacity in those patients.

Cardiac Rehabilitation - tackling ventricular remodeling and improving functional capacity

Abstract Funding Acknowledgements Type of funding sources: None. Introduction Exercise-based cardiac rehabilitation (CR) is part of the management of patients with established cardiovascular disease. Echocardiography and CPET are used to evaluate cardiac function and cardiorespiratory fitness improvement after such interventions. Purpose To analyze the cardiovascular impact of an exercise based CR program on ventricular remodeling and functional capacity. Methods Prospective cohort study which included consecutive pts who were participating in a centre-based CR program lasting 8-12 weeks from 2019 to 2021. The CR program included initial evaluation by cardiologist and rehabilitation specialist with collection of clinical characteristics, three times weekly supervised exercise sessions, appointment with rehabilitation nurse, nutritionist and psycologist and educational sessions. Lab tests, echocardiogram and CPET were done before and after completion of the program. Results We analysed 349 patients (82% male, mean age 60 ±11,4 years) most of which referred by ischemic heart disease (83%) followed by valvular heart disease (7%). After program completion there was a significant improvement in echo ejection fraction (48,4 ± 12,8% vs 52,07 ± 12,8% Z=-5,036 p<0.001), although other parameters didn’t show the same trend namely left atrial volume and TAPSE. Regarding CPET data, there was a significant improvement in test duration (496,6 ± 158 seconds vs 542,9 ± 147 seconds, p<0.001), in workload (66,2 ± 41,6W vs 123,6 ± 48W, p<0.001), peak VO2 (15,8 ± 4,72mL/(kg.min) vs 16,75 ± 5,17mL/(kg.min) p=0.004) and O2 pulse (11,1 ± 2,8 vs 11,8 ± 2,9; p<0.001). Similar improvements were also seen when analysing pts with reduced ejection fraction regarding ejection fraction, duration of test and workload (p<0.005) but not on peak VO2 (14,4 +- 4,3mL/(kg.min) vs 15,2 +- 4,7mL/(kg.min), p=0.11) or pulse O2. Conclusions Exercise based cardiac rehabilitation has a very favorable impact in terms of cardiorespiratory fitness evaluated by several CPET parameters and such impact is also present in high risk individuals with reduced ejection fraction. Advocating for increasing referral of these patients is key to better improve cardiorespiratory capacity.

Feasibility and effect of 3/7 strength training method in cardiac rehabilitation: preliminary results

Abstract Funding Acknowledgements Type of funding sources: Foundation. Main funding source(s): Erasmus Hospital. Background Cardiovascular rehabilitation (CR) is a type 1A intervention for cardiovascular disease. Among the various exercise modalities, resistance training (RT) is recommended for improving cardiorespiratory fitness (volume of oxygen consumption [VO2] peak). However, different modalities of RT coexist and which modalities should be preferred is still a matter of discussion. A RT method, called 3/7, allowed in healthy young subject greater strength gains with a shorter training time. However, the feasibility, the safety and its effects have never been studied in CR. Purpose The aim was to assess the feasibility, safety and efficiency of the 3/7 method in CR to improve VO2 peak. Methods In this single center randomized clinical trial, participants underwent 12 weeks of supervised training. Intervention: Group 3/7 consisting of 5 incremental sets of 3 to 7 repetitions with 15 s of inter-set intervals of RT on leg press; leg extension, leg curl, triceps press machines. Group 3X9 (usual care) of 3 sets of 9 repetitions with 1 min of inter set intervals on the same machine and at the same intensity (70% of 1RM). Patients completed 3 sessions per week; endurance training is the same in both groups. The primary outcome was a change in VO2 peak during the cardiopulmonary exercise test from baseline to 12 weeks. Secondary outcomes were isokinetic leg strength at 60°/sec and feasibility. Results Between 2019 and 2022 101 patients (92 male) were enrolled and randomized to 3/7 (n=49) or 3x9 RT (n=52). The mean age was 62y±8 (range 34 – 85). A total of 65 participants completed testing at 12 weeks for the primary outcome, including 32 in the 3/7 group and 33 in the 3X9 group. There were similar improvements from baseline between groups, VO2 peak by 19% in 3/7 group with 17% in the 3X9 group (mean [SD] oxygen uptake: 3/7, 3.6 [4.1] mL/kg/min; 3X9, 3.3 [4.5] mL/kg/min; P = .4). 3/7 improved quadriceps strength by 12% compared with 11% in the 3X9 group (mean [SD] isokinetic leg strength: 3/7, 23 [21] N/m; 3X9, 10 [22] N/m; P = .01). We had more dropouts in the usual care group compared to the 3/7 group (19 vs 17). 3/7 group had high feasibility scores and low rates of withdrawal due to serious adverse events (1). Most dropouts were due to other conditions (Lost of follow-up [n=11], COVID-19 [n=6], other medical problems [n=6], returns to work [n=5], withdrew [n=4]). Conclusion(s) In this randomized clinical trial, a 12-week RT of the 3/7 method coupled with endurance training improved VO2 peak to the same level than the usual care in cardiac rehabilitation, but more leg strength was observed. The 3/7 method may reduce the number of dropouts compared to usual RT program because the time training is reduced for the same volume of work. Implications: These findings support inclusion of 3/7 method in cardiac rehabilitation programs as an adjunct or alternative modality to usual care.

Impact of wearable devices with feedbacks for increasing daily walking activity and physical capacities in cardiovascular patients: a meta-analysis of randomized controlled trials

Abstract Funding Acknowledgements Type of funding sources: None. Background Despite the known benefits of physical activity, patients with cardiovascular disease do not practice enough nor maintain a regular physical activity for their health [1-4] . Walking is one of the easiest ways to stay physically active and can be implemented easily in everyday life [5]. Wearable physical activity monitoring devices have the potential to help increase physical activity through self-monitoring and feedback. Purpose To review randomized controlled trials using wearable physical activity monitoring device as an intervention to increase daily walking activity and improve physical capacities in cardiovascular diseases (CVD) patients. Methods Design: Systematic review and meta-analysis of randomized controlled trials (RCTs). Data Sources: PubMed, Embase, Web of Science. Eligibility criteria: Randomized controlled studies including patients over 18 years of age with CVD comparing an intervention group using a wearable physical activity monitoring device with feedback to usual care or to a control group receiving no feedback on their physical activity and reporting a change in the daily number of steps and/or a change in the distance covered in the 6-minute walking test (6MWT) or a change in peak oxygen uptake (VO2 peak). Outcomes: Primary outcome was daily number of steps, secondary ouctomes were distance covered in the 6-minute walking test (6MWT) and/or peak oxygen uptake (VO2 peak). Results Sixteen RCTs were included. The intervention of wearing a physical activity monitoring device with feedback significantly improved daily number of steps compared with controls (standardized mean difference ((SMD) 0.85; 95% CI [0.42; 1.27], p < 0.01). The effect was greater when the duration of the intervention was less than 3 months (SMD 1.0; 95% CI [0.18; 1.82], p < 0.01) than when the duration of the intervention was 3 months or longer (SMD 0.71; 95% CI [0.27; 1.16], p < 0.01) but no significant interaction was found between subgroups (p = 0.55). Six MWT distance and VO2 peak showed only small effects (SMD 0.34 (95% CI [-0.11; 0.80], p = 0.02) and SMD 0.53 (95% CI [0.03; 1.03], p = 0.07), respectively).

Exercise hemodynamics and metabolisms in (very) sportive patients after orthotopic heart transplantation

Abstract Funding Acknowledgements Type of funding sources: None. Purpose After orthotopic heart transplantation (HTX), patients benefit with improved survival and quality of life, but exercise physiology becomes complicated and exercise capacity usually remains limited at 60-70% of predicted values. However, there are also patients who return to demanding or competitive sports even after HTX. For these patients, optimal exercise hemodynamics and metabolisms are crucial. It was the aim of this study to investigate this question more closely in (very) sportive patients after HTX. Methods 6 patients after orthotopic HTX (1 female, 54±16 yrs old, BMI 23.6±2.8, 11±7 yrs post-transplant) from different sports disciplines (Cycling [2x], Triathlon, Hockey, Table-Tennis, Scuba Diving) could be included (Table 1). We performed cardiopulmonary exercise test (CPET) on a bicycle ergometer using a ramp protocol (15 watts/minute) and consecutive inertgas rebreathing (IGR) on different exercise steps (rest, light, moderate, heavy) of each 4-5 minutes. The hemodynamic measurements and blood gas analysis were conducted at the last minute of each IGR step. The study was approved by the local ethics committee. Results For CPET: one patient reached extraordinary exercise capacity with a peak load of 345 watts (182% of pred.) and a peak VO2 of 58.9 ml/kg/min (163% of pred.). Corresponding values at first ventilatory threshold (VT1) were 280 watts and 44.1 ml/kg/min. The results of the other patients showed a more homogenic profile: Mean peak load was 172±44 watts (104±14% of pred.) and peak VO2 was mean 25.6±4.5 ml/kg/min (91±14% of pred.). Values at VT1 were 108±27 watts and 18.0±2.5 ml/kg/min. Selected IGR results for all patients are displayed in Table 2. The hemodynamic measurements revealed a steadily increase in cardiac output (CO), cardiac index (CI), arteriovenous oxygen difference (avDO2), heart rate and systolic blood pressure from rest to the different exercise steps. However, an increase in stroke volume (SV) beyond light to moderate exercise often remained limited (peak SV 101±14 ml/beat). Also, peak CO (13.9±1.8 l/min) remained slightly below predicted values (89% of pred.). Conclusion Hemodynamic measurements revealed satisfying exercise adaptions and adequate prerequisites for intensive physical activities in selected patients even after HTX. However, compared to healthy athletes, SV was clearly limited to normal values (<120 ml/beat). The deficit in CO occurs with moderate to heavy exercise levels could be partially compensated by increased avDO2 due to excellent peripheral function. Therefore, regular exercise training is crucial for this target group.

Predictors of the efficacy of AV-optimised His bundle pacing in patients with a prolonged PR interval: a stratified analysis of the HOPE-HF clinical trial

Abstract Funding Acknowledgements Type of funding sources: Foundation. Main funding source(s): British Heart Foundation. Background HOPE-HF was a randomised, placebo-controlled, cross-over trial of AV-optimised His bundle pacing in patients with heart failure (LVEF ≤40%), a PR interval (≥200ms) and without left bundle branch block.1,2. In this analysis we studied the impact of baseline PR interval and acute blood pressure change at the optimal AV-delay on the placebo-controlled effect of His bundle pacing on the trial endpoints of peak VO2 (primary) and patient symptoms (using the Minnesota Living with Heart Failure Questionnaire). Methods and Results 167 patients were successfully implanted and randomised to 6 month blocks of pacing and placebo. We performed a non-invasive, high-precision protocol to calculate the optimal AV delay and associated acute blood-pressure response at randomisation. To test the impact of the baseline PR interval and acute BP response on the placebo-controlled effect of AV-optimised His bundle pacing on endpoints we compared Bayesian ordinal regression models and the relative explained variance (REV) of variables in the model. There was weak evidence that His-bundle pacing improved peak VO2 across all patients (OR 1.31, 95% CrI 0.86 to 2.01, Pr(OR > 1)=89%). The baseline PR interval had little impact on this benefit (REV 0%), and the blood pressure response was more likely (88% vs 12%) to be predictive. However, there was strong evidence that overall AV-optimised His-bundle pacing improved patient symptoms as compared to placebo (OR 1.58, 95% CrI 1.04 to 2.40, Pr(OR>1)=98%). Again, the baseline PR interval had little impact on this benefit (REV 0%) and the blood pressure response was much more likely (97% vs 3%) to be predictive. Higher acute BP increments led to greater placebo-controlled improvements in MLWHF at 6-months. Conclusion An individual’s acute BP response with AV-optimised His-pacing is a powerful predictor of their placebo-controlled improvement in symptoms (MLWHF) at 6-months. This can form the basis of patient selection for future studies and clinical practice.

Left atrial mechanics and functional capacity in HFpEF patients with paroxysmal atrial fibrillation

Abstract Funding Acknowledgements Type of funding sources: None. Background Exercise capacity and ventilatory efficiency are often impaired in heart failure patients with preserved ejection fraction (HFpEF). Since left atrial (LA) pressure, particularly during exercise plays a major role in the exercise intolerance observed in these patients, we aimed to characterize the contribution of resting LA mechanical properties, assessed by two-dimensional speckle tracking echocardiography upon exercise capacity. Objective To evaluate relationship between LA mechanics, measured by LA strain (LAS) and parameters of exercise capacity, assessed by cardiopulmonary exercise testing (CPET) in HFpEF patients with dyspnea and paroxysmal atrial fibrillation (AF). Methods The study included 23 consecutive patients (63 ± 8 years, 83 % males) with dyspnea (NYHA≥II), paroxysmal AF and preserved LV ejection fraction (≥50%), referred for elective pulmonary vein ablation. The probability of HFpEF was estimated using H2FPEF score. During sinus rhythm, all patients underwent speckle tracking echocardiography and cardiopulmonary exercise testing by treadmill. Peak oxygen uptake (VO2max) served as measure of functional capacity and ventilation/carbon dioxide output (VE/VCO2) slope as surrogate of ventilation/perfusion mismatch. Results Out of all the echocardiographic indices, only LA contractile strain and strain rate showed significant correlation with peak VO2 (both p < 0.05). All three strain components of LA phasic function, i.e. reservoir, conduit and contractile LAS, had significant relationship with VE/VCO2 slope (all p<0.050). Patients with LA strain rate above the median had significantly higher VE/VCO2 slope (p=0.025) and lower peak VO2 (p=0.010). In contrast, no correlations were observed between exercise parameters and LA volumes or LA emptying fraction or any other echocardiographic indices. Conclusions In HFpEF patients, VO2 max and VE/VCO2 slope are closely related to LA contractile strain, suggesting that abnormalities in LA mechanics may contribute to the blunted exercise capacity observed. Therefore, these markers can be used as an echocardiographic surrogate of functional capacity in HFpEF patients with paroxysmal AF.

Effect of resistance training on HbA1c and other cardiovascular risk factors in patients with type 2 diabetes: a systematic review and meta-analysis of randomized controlled trials

Abstract Funding Acknowledgements Type of funding sources: None. Introduction Obesity, hypertension, hyperlipidemia, and other cardiovascular risk factors are commonly clustered in patients with diabetes type II (T2DM). As a result, patients with T2DM are at increased cardiovascular (CV) risk. Exercise therapy is recommended in the prevention and management of patients with T2DM. In the last decade, dynamic resistance training has attracted more interest as an exercise therapy in the management of patients with diabetes. Though, the primary outcome in these intervention trials has mostly been glycated hemoglobin (HbA1c). Given the high prevalence of other CV risk factors in patients with T2DM, knowledge on the impact of dynamic resistance training on the overall CV risk profile of these patients is important. Purpose To perform a systematic review with meta-analysis to investigate the effects of resistance training on HbA1c and other traditional cardiovascular risk factors in patients with T2DM. Methods and analyses A systematic search was conducted in the electronic databases MEDLINE, Embase, SPORTdiscus and PEDro from the earliest date available until the first of September 2021 to identify peer reviewed randomized controlled trials investigating the effect of resistance training on HbA1C in adults with T2DM. Primary outcome was HbA1C. Secondary outcomes included traditional CV risk factors (i.e. blood pressure, blood lipids, body composition) and physical fitness (muscle strength, exercise capacity). Effect sizes were calculated using random effect models. Data are reported as weighted mean and 95% confidence limits. Results Fourteen trials could be included in the meta-analysis. Resistance training was found to significantly reduce HbA1c [-0.35 % (95% CL -0.61 to -0.11)], systolic blood pressure [-4.6 mmHg (95%CL -8.7 to -0.39)], diastolic blood pressure -2.25 (95%CL -4.45 to -0.048)) and body fat (-0 0.038). Muscle strength was significantly improved in the three studies reporting this outcome. Other cardiovascular risk factors including fasting plasma glucose, high-density-lipoprotein, low-density-lipoprotein, triglycerides and peak oxygen uptake capacity (VO2 peak) remained unchanged after resistance training in patients with T2DM. Conclusion The available data suggests that resistance training can exert favorable effects on HbA1C but also on blood pressure, body composition and muscle strength of patients with type 2 diabetes. Further research is needed to determine the impact of different resistance training characteristics such as volume, frequency and type of training on the overall CV risk profile of patients with type 2 diabetes.

Gender disparities in Cardiac Rehabilitation - Are we concealing apples from Eve?

Abstract Funding Acknowledgements Type of funding sources: None. Introduction Cardiovascular disease is a leading cause of death in both men and women and cardiac rehabilitation (CR) is recommended as part of secondary prevention for these patients. Despite this, there are still important asymmetries when it comes to enrolment of women in CR programs. Purpose To determine differences between referral and outcomes of cardiac rehabilitation programs among women. Methods Prospective cohort study which included consecutive pts who were participating in a centre-based CR program lasting 8 weeks from 2019 to 2021. We analyzed prevalence of risk factors, lab echocardiographic and CPET data in women who were enrolled in the program. Statistical analysis was performed with Mann-Whitney and Wilcoxon tests Results: From a total of 349 patients, 60 women completed a CR program – 17,8% of pts – representing a far smaller percentage when accounting to acute coronary syndrome events in our center in those 2 years (31% women). Mean age of female participants was 60 ± 11,8 years; 74% had hypertension, 64% dyslipidemia, 19% diabetes and only 40% had never smoked. There were no significant differences when compared to male, except for thyroid disease which was more frequent among women (p<0.01). Regarding lab data we noticed an improvement of LDL-c, total cholesterol, HDL-c, although only NTproBNP showed a statistically significant reduction (p=0.001). There was also an improvement of LVEF, once again without statistical significance (in contrast to the male population). After completion of the program, there was an improvement regarding CPET duration and workload (p<0.001 and p=0.019). Interestingly there was no difference in terms of peak VO2/kg, a data that goes in line with some reports of less impact of exercise based CR in this parameter in women. Moreover, there were no differences between genders in terms of outcome, namely admissions or cardiovascular death. Conclusion Women still have a lower rate of enrolment in CR programs, despite results showing a similar benefit to men. CR effectiveness by CPET should include other parameters besides VO2 peak. Strategies should be developed to improve women participation in CR.

Cardiac rehabilitation in older populations - never too late to rehabilitate

Abstract Funding Acknowledgements Type of funding sources: None. Introduction Age is one of the most determinant cardiovascular risk factors and the prevalence of cardiovascular disease is higher after 70 years old. Referral to cardiac rehabilitation programs for elder individuals is often overlooked since such patients are deemed as frail, high risk and may show lack of competence when attending these programs. Purpose To assess differences in clinical characteristics and outcomes between pts >70 years old with younger ones. Methods Prospective cohort study which included consecutive pts who were participating in a centre-based CR program lasting 8-12 weeks from 2019 to 2021. We analysed prevalence of risk factors, lab echocardiographic and CPET data in women who were enrolled in the program. Statistical analysis was performed with Chi-square and Wilcoxon tests. Results From a pool of 349 patients, only 74 (21%) were 70 or more years old. In this group most of pts were male (90,5%), mean age of 75,2 +- 4,34 year-old. 90% pts had arterial hypertension (n=67), 76% had dyslipidemia, 34% were diabetic and 57,5% were smokers or past smokers. Most patients were in NYHA II (64,2%) and the remainder in NYHA I (29,9%) and III (6%). Mean ejection fraction was 52 +- 14%. NTproBNP in first evaluation 1335 pg/mL, LDL-c 80,4mg/dL and HDL 46,8%. Both groups (<70 and >70years) were relatively homogeneous, except for differences in sex (male sex mor prevalent (p=0.019) and hypertension (p=0.006). Interestingly there were no significant differences in both groups regarding hospital admissions, rate of reinfarction and cardiovascular death. In both groups we noted a significant improvement in echo and CPET, reaching statistical significance in ejection fraction variation (p=0.01), duration of CPET (p=0.048) workload peak; however, in contrast to younger patients, VO2 peak improvement was non significative. Conclusions Although there is a higher prevalence in cardiovascular disease among older people, CR referral is far lower. As we can see, such interventions are safe and effective also in older pts and thus we should identify factors going against their inclusion in CR programs and prioritize risk stratification.

Left Ventricle Size Correlates with Peak Exercise Capacity in Pediatric Cancer Survivors Exposed to Anthracycline Chemotherapy

Cancer survivors exposed to anthracycline chemotherapy are at risk for developing cardiomyopathy, which may have delayed clinical manifestation. In a retrospective cross-sectional study, we evaluated the utility of cardiopulmonary exercise testing (CPET) for detecting early cardiac disease in 35 pediatric cancer survivors by examining the associations between peak exercise capacity (measured via percent predicted peak VO2) and resting left ventricular (LV) function on echocardiography and cardiac magnetic resonance imaging (cMRI). We additionally assessed the relationships between LV size on resting echocardiography or cMRI and percent predicted peak VO2 since LV growth arrest can occur in anthracycline-exposed patients prior to changes in LV systolic function. We found reduced exercise capacity in this cohort, with low percent predicted peak VO2 (62%, IQR: 53–75%). While most patients in our pediatric cohort had normal LV systolic function, we observed associations between percent predicted peak VO2 and echocardiographic and cMRI measures of LV size. These findings indicate that CPET may be more sensitive in manifesting early anthracycline-induced cardiomyopathy than echocardiography in pediatric cancer survivors. Our study also highlights the importance of assessing LV size in addition to function in pediatric cancer survivors exposed to anthracyclines.

Oxygen utilisation in patients on prolonged parenteral nutrition; a case-controlled study

Parenteral nutrition (PN) deficient in mitochondrial substrates and thiamine may lead to acidosis. This, combined with fatigue seen in patients with intestinal failure (IF), may suggest suboptimal oxidative metabolism. We therefore studied oxygen utilisation in otherwise apparently well-nourished individuals with intestinal failure receiving long term PN. This was a retrospective analysis conducted in a tertiary IF institution, from 2010 to 2019, comparing treadmill/bicycle cardiopulmonary exercise test (CPET) derived variables including peak oxygen consumption (VO2 peak), anaerobic threshold (AT) and ventilatory efficiency (minute ventilation (VE)/CO2 output (VCO2) of patients with IF (cases) to those without (controls), matched in a 1:2 ratio for age (±3 years), gender, use of beta-blockers and physiology parameters of p-POSSUM score (±5). All subjects were free of sepsis and metastatic malignancy. Mann-Whitney or Student's t-test for continuous and Fisher's exact or chi-squared test for categorical variables were used as appropriate. Data shown represent mean or median values. Participants (31 cases, 62 controls) were comparable in age (65.4 vs. 65.3, p=0.98); p-POSSUM parameters (18.0 vs. 17.0, p=0.45); gender (p=1.00); smoking status (p=0.52); use of beta-blockers (p=1.00) and ≤10mg/day of oral steroids (p=0.34). Participants had been on PN for 11.0 (6.0-24.0) months and were adequately nourished (requirements 27.6kcal/kg/day, replacement 23.5kcal/kg/day). No differences were found between VO2 peak (15.2 vs. 14.6ml/kg/min, p=0.96), AT (10.4 vs. 11.0ml/kg/min, p=0.44) and VE/VCO2 (33.0 vs. 33.0, p=0.96) of the examined groups. Patients with intestinal failure receiving PN who are apparently well-nourished also appear to have normal oxygen utilisation, suggesting alternative causes for fatigue. More studies will be required to determine whether CPET could reliably be used to assess perioperative risk in this group of patients.

Feasibility, Usability, and Safety of ParaGym, an Intelligent Mobile Exercise App for Individuals With Paraplegia: Protocol for a Pilot Block-Randomized Controlled Trial

Exercise is crucial for individuals with paraplegia to reduce the risk of secondary diseases and improve independence and quality of life. However, numerous barriers such as inadequate accessibility restrict their participation in exercise programs. Digital exercise apps can help overcome these barriers. Personalization is considered a crucial feature of mobile exercise apps, as people with paraplegia have individual requirements regarding exercise programs depending on their level of impairment. Despite the increasing popularity of mobile exercise apps, there are none available that target the individual needs of this cohort. The ParaGym mobile exercise app prototype was designed to automatically tailor exercise sessions to the individual needs of users with paraplegia. This study aims to evaluate the feasibility, usability, safety, and preliminary effectiveness of the ParaGym mobile exercise app prototype. This pilot block-randomized controlled feasibility trial will include 45 adult participants with paraplegia. Eligible participants will be block randomized to either the intervention or waitlist control group. The intervention group will perform a 6-week exercise program using the ParaGym mobile exercise app, comprising three 35-minute exercise sessions per week. The waitlist control group will continue their usual care and receive access to the app after study completion. Participants will record all exercise sessions conducted with the app as well as additional exercise sessions conducted during the study period using exercise diaries. The primary outcomes include feasibility, usability, and safety. Feasibility will be assessed through semistructured interviews, study adherence, and retention rates. Usability will be measured using the System Usability Scale. Safety will be determined by the occurrence of adverse events. Secondary outcomes include the effects of the intervention on peak exercise capacity (VO2 peak); handgrip strength; independence, which will be measured using the Spinal Cord Independence Measure III (SCIM III); and health-related quality of life, which will be measured using the Short Form-36 Health Survey (SF-36). Recruitment commenced in November 2022. Overall, 12 participants were enrolled at the time of submission. Data collection commenced in January 2023, with completion expected in April 2023. To the best of our knowledge, this is the first study to assess the feasibility, usability, and safety of an intelligent mobile exercise app for individuals with paraplegia. Thereafter, the app should be adapted according to the findings of this trial. Future trials with an updated version of the app should aim for a larger sample size, longer intervention duration, and more diverse target group. In the long term, a fully marketable version of the ParaGym app should be implemented. This would increase the access to personalized, independent, and evidence-based exercise training for this cohort and, in the future, other people who use wheelchairs. German Clinical Trials Register DRKS00030370; https://drks.de/search/de/trial/DRKS00030370. DERR1-10.2196/45652.

Effects of Sacubitril/Valsartan on Exercise Capacity in Patients with Heart Failure with Reduced Ejection Fraction and the Role of Percentage of Delayed Enhancement Measured by Cardiac Magnetic Resonance in Predicting Therapeutic Response: A Multicentre Study.

Background: This study aims to evaluate the cardiopulmonary effects of sacubitril/valsartan therapy in patients with heart failure with reduced ejection fraction (HFrEF), investigating a possible correlation with the degree of myocardial fibrosis, as assessed by cardiac magnetic resonance. Methods: A total of 134 outpatients with HFrEF were enrolled. Results: After a mean follow-up of 13.3 ± 6.6 months, an improvement in ejection fraction and a reduction in E/A ratio, inferior vena cava size and N-terminal pro-B-type natriuretic peptide levels were observed. At follow-up, we observed an increase in VO2 peak of 16% (p<0.0001) and in O2 pulse of 13% (p=0.0002) as well as an improvement in ventilatory response associated with a 7% reduction in the VE/VCO2 slope (p=0.0001). An 8% increase in the ΔVO2/Δ work ratio and an 18% increase in exercise tolerance were also observed. Multivariate logistic regression analysis showed that the main predictors of events during follow-up were VE/VCO2 slope >34 (OR 3.98; 95% CI [1.59-10.54]; p=0.0028); ventilatory oscillatory pattern (OR 4.65; 95% CI [1.55-16.13]; p=0.0052); and haemoglobin level (OR 0.35; 95% CI [0.21-0.55]; p<0.0001). In patients who had cardiac magnetic resonance, when delayed enhancement >4.6% was detected, a lower response after sacubitril/valsartan therapy was observed as expressed by improvement in ΔVO2 peak, O2 pulse, LVEF and N-terminal pro-B-type natriuretic peptide. No significant differences were observed in ΔVO2/Δ work and VE/VCO2 slope. Conclusion:Sacubitril/valsartan improves cardiopulmonary functional capacity in HFrEF patients. The presence of myocardial fibrosis on cardiac magnetic resonance is a predictor of response to therapy.

Former SARS-CoV-2 Infection Was Related to Decreased VO2 Peak and Exercise Hypertension in Athletes.

The impact of former COVID-19 infection on the performance of athletes is not fully understood. We aimed to identify differences in athletes with and without former COVID-19 infections. Competitive athletes who presented for preparticipation screening between April 2020 and October 2021 were included in this study, stratified for former COVID-19 infection, and compared. Overall, 1200 athletes (mean age 21.9 ± 11.6 years; 34.3% females) were included in this study from April 2020 to October 2021. Among these, 158 (13.1%) athletes previously had COVID-19 infection. Athletes with COVID-19 infection were older (23.4 ± 7.1 vs. 21.7 ± 12.1 years, p < 0.001) and more often of male sex (87.7% vs. 64.0%, p < 0.001). While systolic/diastolic blood pressure at rest was comparable between both groups, maximum systolic (190.0 [170.0/210.0] vs. 180.0 [160.0/205.0] mmHg, p = 0.007) and diastolic blood pressure (70.0 [65.0/75.0] vs. 70.0 [60.0/75.0] mmHg, p = 0.012) during the exercise test and frequency of exercise hypertension (54.2% vs. 37.8%, p < 0.001) were higher in athletes with COVID-19 infection. While former COVID-19 infection was not independently associated with higher blood pressure at rest and maximum blood pressure during exercise, former COVID-19 infection was related to exercise hypertension (OR 2.13 [95%CI 1.39-3.28], p < 0.001). VO2 peak was lower in athletes with compared to those without COVID-19 infection (43.4 [38.3/48.0] vs. 45.3 [39.1/50.6] mL/min/kg, p = 0.010). SARS-CoV-2 infection affected VO2 peak negatively (OR 0.94 [95%CI 0.91-0.97], p < 0.0019). In conclusion, former COVID-19 infection in athletes was accompanied by a higher frequency of exercise hypertension and reduced VO2 peak.

P310 CARDIOPULMONARY EXERCISE TEST IN THE EVALUATION OF A PATIENT WITH HFREF: THE IMPORTANCE IN THE ANALYSIS OF GAS KINETICS

Abstract Introduction exertional dyspnea is a symptom present in several diseases, identifying the origin is of fundamental diagnostic and therapeutic importance. Cardiorespiratory exercise testing (CPET) is a valuable tool not only to assess functional capacity but also for diagnostic and prognostic purposes. Clinical case 55–year–old patient with a history of episode of acute pulmonary edema. Echocardiogram showed FE 35% with diffuse left ventricular (LV) hypokinesis and mild–to–moderate mitral insufficiency (MI). Diagnostic coronarography showed lesion–free coronary tree. An interrupted CPET at 140W showed peak O2 consumption of 23.6 mL/kg/min that excluded indication for cardiac transplantation. An echocardiogram from us confirmed dilated cardiomyopathy (CMPD) with FE=32%, diffuse VS hypokinesia and mild–to–moderate functional MI. CPET was repeated, maximal for respiratory quotient (1.42) interrupted due to muscle exhaustion, indicative of moderate reduction in functional capacity with peak VO2 at 64% of predicted, preserved anaerobic threshold at 51% of VO2 max and reduced VO2/W and Pulse Oxygen Ratio (VO2/HR) values from cardiogenic limitation. Also evident drop in VO2/HR during the final stages of the test and associated change in slope of the VO2/Work relationship a sign of decline in stroke volume and cardiogenic efficiency. Absent signs of ventilatory limitation, pulmonary vascular (Ve/VCO2=20.8 in normal range), or exercise desaturation. In the final phase of the test increase in VCO2 and Ve/VCO2 and Ve/VO2 equivalents. In order to find the explanation to the data collected by CPET, exercise echocardiogram was performed, which revealed the development of severe mitral valvular insufficiency and subsequent pulmonary hypertension justifying the behavior of the parameters collected by CPET. Discussion The oxygen pulse represents a metabolic surrogate for stroke volume. Normally during the active phases of exertion there is a progressive increase followed by a plateau. The evident flattening of the VO2/Work curve during the final phases of exercise and the concomitant decrease in oxygen pulse denote inadequate cardiac performance relative to the increased energy demands during exercise. Conclusions CPET proves to be a valuable clinical tool to guide the diagnostic–therapeutic pathway, particularly in the presence of complex heart disease (CMPD or IM).

Home-based exercise in patients on maintenance dialysis: a systematic review and meta-analysis of randomized clinical trials.

The impact of home-based exercise on physical performance and quality of life (QoL) in patients on maintenance dialysis has not yet been fully established. We searched four large electronic databases to identify randomized controlled trials (RCTs) reporting the impact of home-based exercise interventions vs. usual care or intradialytic exercise interventions, on physical performance and QoL in patients on dialysis. The meta-analysis was performed using fixed effects modeling. We included 12 unique RCTs involving 791 patients of various ages on maintenance dialysis. Home-based exercise interventions were associated with an improvement of walking speed at the 6 Minutes Walking Test [6MWT; nine RCTs; pooled weighted mean differences (WMD): 33.7 m, 95% confidence interval (CI) 22.8-44.5; P<0.001; I2=0%) and in aerobic capacity as assessed by the peak oxygen consumption (VO2 peak; 3 RCTs; pooled WMD: 2.04ml/kg/min, 95% CI 0.25-3.83; P=0.03; I2=0%). They were also associated with improved QoL, as assessed by the Short Form (36) Health (SF-36) score. Stratifying the RCTs by control groups, no significant difference was found between home-based exercise and intradialytic exercise interventions. Funnel plots did not reveal any significant publication bias. Our systematic review and meta-analysis showed that home-based exercise interventions for 3-6 months were associated with significant improvements in physical performance in patients on maintenance dialysis. However, further RCTs with a longer follow-up should be conducted to assess the safety, adherence, feasibility, and effects on QoL of home-based exercise programs in dialysis patients.

P68 DILATED CARDIOMYOPATHY AND MICRODELETION SYNDROME: A CASE REPORT

Abstract A 45–year–old man was admitted to our Coronary Care Unit because of acute pulmonary edema and atrial flutter with high ventricular response. The patient was an active smoker, obese and reported a previous alcohol abuse. Blood tests showed increased NT–proBNP values. Transthoracic echocardiography showed a severely enlarged and dysfunctional left ventricle (LVEF 15%). Acute phase treatment required noninvasive ventilation, amine support, and electrical cardioversion with progressive improvement of patient’s clinical condition. At coronary angiography no significant coronary stenosis was found. (fig.2). Cardiac magnetic resonance showed no area of fibrosis or inflammation(fig.3). Furthermore, a new diagnosis of diabetes mellitus type 2 and mild cognitive impairment was also made during hospitalization. Upon clinical stabilization, therapy with bisoprolol, sacubitril/valsartan, spironolactone, furosemide, and direct anticoagulant was introduced and titrated with progressive improvement until normalization during follow–up of systolic function indices, ventricular volumes, and nt–proBNP values until normalization at approximately 6 months after discharge. Cardiopulmonary exercise test was performed and found good cardiopulmonary performance and absence of cardiogenic limitation to exercise (VO2 peak 22.9 ml/min/kg corresponding to 93% of predicted and VO/HR 18 ml/beat, VE/VCO2 slope equal to 24). Genetic test showed a missense mutation in heterozygosity of LMNA gene (1634 G&amp;gt;A, p. Arg545His) currently coded as likely pathogenic and heterozygous deletion of 534 kb at the level of the short arm (p) of chromosome 16 at band p11.2. Dilated cardiomyopathies associated with mutations in the LMNA gene, coding for Lamina A/C (a component of the cellular basal lamina), tend to have an inauspicious prognosis as they are related to arrhythmic and extracardiac manifestations (myopathies, lipodystrophies, and neuropathies). 16p11 microdeletion syndrome is characterized by obesity and cognitive impairment, frequently associated with congenital heart disease, less often with dilated and hypertrophic cardiomyopathy pictures. The rapid introduction and titration to the maximum tolerated dose of heart failure therapy had an extremely positive effect in our patient who had an overlapping of genetically determined dilated cardiomyopathy and 16p11 microdeletion syndrome.

Interval walking training in type 2 diabetes: A pilot study to evaluate the applicability as exercise therapy.

There are few established easy-to-perform exercise protocols with evidence-based effects for individuals with type 2 diabetes (T2D). A unique exercise regimen, interval walking training (IWT), has been reported to be beneficial for improving metabolic function, physical fitness and muscle strength in adults of overall health. This pilot study aims to demonstrate descriptive statistics of IWT adherence and changes in various data before and after the intervention of IWT in adults with T2D, perform statistical hypothesis testing, and calculate effect sizes. We performed a single-arm interventional pilot study with IWT for 20 weeks. We enrolled 51 participants with T2D aged 20-80 years with glycohemoglobin (HbA1c) levels of 6.5-10.0% (48-86 mmol/mol) and a body mass index of 20-34 kg/m2, respectively. The target was 60 min/week of fast walking for 20 weeks. The participants visited the hospital and were examined at 4-week intervals during this period. Between the start of IWT and after 20 weeks, we measured and evaluated changes in glucose and lipid metabolism data, body composition, physical fitness, muscle strength, dietary calorie intake, and daily exercise calories. All included participants completed IWT, with 39% of them reaching the target length of fast walking over 1,200 minutes in 20 weeks. In the primary outcome, HbA1c levels, and in the secondary, lipid metabolism and body composition, no significant changes were observed except for high-density lipoprotein cholesterol (HDL-C) (from 1.4 mmol/L to 1.5 mmol/L, p = 0.0093, t-test). However, in the target achievement group, a significant increase in VO2 peak by 10% (from 1,682 mL/min to 1,827 mL/min, p = 0.037, t-test) was observed. Effect sizes were Cohen's d = 0.25 of HDL-C, -0.55 of triglyceride, and 0.24 of VO2 peak in the target achievement group, which were considered to be of small to medium clinical significance. These results could be solely attributed to IWT since there were no significant differences in dietary intake and daily life energy consumption before and after the study. IWT could be highly versatile and was suggested to have a positive effect on lipid metabolism and physical fitness. In future randomized controlled trial (RCT) studies, the detailed effects of IWT, focusing on these parameters, will be examined. Trial registration: This trial was registered with the Japanese University Hospital Medical Information Network Clinical Trials Registry (UMIN-CTR: Usefulness on interval walking training in patients with type 2 diabetes. 000037303).