Exercise Tolerance Test Research Articles

Post-concussion exercise tolerance testing using the Bruce Protocol in adolescents

Post-concussion exercise tolerance testing using the Bruce Protocol in adolescents

The Responsiveness of Exercise Tests in COPD: A Randomized Controlled Trial

BackgroundChronic obstructive pulmonary disease (COPD) is characterised by reduced exercise tolerance and improving physical performance is an important therapeutic goal. A variety of exercise tests are commonly used to assess exercise tolerance, including laboratory and field-based tests. The responsiveness of these tests to common COPD interventions is yet to be compared, but may inform test selection in clinical and research settings. Research QuestionWhat exercise test possesses the greatest sensitivity to change pre- to post-intervention in patients with COPD? Study Design and Methods154 patients with symptomatic COPD were recruited and randomised (2:1:1) to six weeks of long-acting muscarinic antagonist (LAMA), pulmonary rehabilitation (PR), or usual care (UC). Pre- and post-intervention, participants performed a ramp-incremental and constant work rate cycle ergometer exercise test (ICET and CWRCT), incremental and endurance shuttle walk test (ISWT and ESWT), six-minute walk test (6MWT), and a four metre gait speed test (4MGS). Results103 participants (67 ± 8 y; 75 [73%] males; FEV1: 50.6 ± 16.8 % predicted) completed the study. Significant improvements in the ICET, CWRCT, ISWT, ESWT, and 6MWT were observed following PR (p<0.05), with the greatest improvements seen in the constant work rate protocols (% change: CWRCT: 42%; ESWT: 41%). InterpretationThe ESWT and CWRCT appeared to be the most responsive exercise test protocols to LAMA and PR. The magnitude of change was much greater after a programme of rehabilitation compared to bronchodilator therapy.

Comparison of autonomic nervous system dysfunction, arterial stiffness, and heart rate recovery according to spinal cord injury level.

To investigate the differences in autonomic nervous system (ANS) dysfunction, arterial stiffness, and the degree of delay in post-exercise heart rate recovery (HRR) according to the level of spinal cord injury (SCI), and propose preventive measures against cardiovascular diseases after SCI. This retrospective study included 51 patients with SCI. Based on the neurological level of injury (NLI), patients were divided into two groups: Group A (NLI at and above T6) and Group B (NLI below T6). To assess ANS dysfunction, the head-up tilt test and 24-hour ambulatory blood pressure monitoring were conducted. Arterial stiffness was measured using the pulse wave velocity test. The exercise tolerance test was conducted to measure post-exercise HRR. Group A had significantly higher values in the head-up tilt test and 24-hour ambulatory blood pressure monitoring. In the pulse wave velocity test, both sides (left and right) had significantly higher values in Group B. One minute after the exercise tolerance test, Group A had significantly slower HRR (18.8 ± 11.1 beats/minute) than Group B. Understanding the impact of ANS dysfunction and arterial stiffness on HRR in SCI according to NLI may provide insights for clinical management and preventative strategies for cardiovascular diseases.

Outcomes of Chronic Thromboembolic Pulmonary Hypertension After Balloon Pulmonary Angioplasty and Pulmonary Endarterectomy

BackgroundThe contemporary outcome of balloon pulmonary angioplasty (BPA) and pulmonary endarterectomy (PEA) in patients with chronic thromboembolic pulmonary hypertension (CTEPH) are unclear. ObjectivesThis study aimed to clarify the characteristics and outcomes of CTEPH patients treated with BPA and PEA in Japan. MethodsAmong 1,270 participants enrolled between 2018 and 2023 in the CTEPH AC (Chronic Thromboembolic Pulmonary Hypertension Anticoagulant) registry, a Japanese nationwide CTEPH registry, 369 treatment-naive patients (BPA strategy: n = 313; PEA strategy: n = 56) and 690 on-treatment patients (BPA strategy: n = 561; PEA strategy: n = 129) were classified according to the presence of prior reperfusion therapy. Morbidity and mortality events (all-cause death, rescue mechanical reperfusion therapy, and/or initiation of parenteral pulmonary vasodilators), pulmonary hemodynamics, exercise tolerance, and relevant laboratory test results were evaluated. ResultsThe BPA strategy was chosen in older patients than the PEA strategy (mean age, BPA vs PEA: 66.5 ± 12.6 years vs 62.5 ± 11.8 years; P = 0.028). Median follow-up period was 615 (Q1-Q3: 311-997) days in treatment-naive patients and 1,136 (Q1-Q3: 684-1,300) days in on-treatment patients. BPA strategy had as acceptable morbidity and mortality as PEA strategy (5-year morbidity and mortality event rate, BPA vs PEA: 10.2% [95% CI: 5.2%-19.5%] vs 16.1% [95% CI: 4.3%-50.6%] in treatment-naive patients; 9.7% [95% CI: 6.7%-13.8%] vs 6.9% [95% CI: 2.7%-17.3%] in on-treatment patients), with greater improvement of renal function; glomerular filtration rate in propensity score-matched population (difference between change: 4.9 [95% CI: 0.5-9.3] mL/min/1.73 m2; P = 0.030). ConclusionsBPA strategy was more frequently chosen in older patients compared with PEA strategy and showed acceptable outcomes for efficacy with greater advantage for improvement in renal function. (Multicenter registry of chronic thromboembolic pulmonary hypertension in Japan; UMIN000033784)

Effectiveness and mechanism of Huoxin pill on heart failure after percutaneous coronary intervention: Study protocol for a double-blind, randomised, placebo-controlled parallel trial

BackgroundCoronary heart disease (CHD) is the most common cardiovascular disease facing human beings. Cardiac remodelling is an important pathological factor for the progression of heart failure (HF) after CHD. At present, Chinese medicine is widely used in the treatment of HF, but there are still some drugs lack of evidence-based and mechanism evidence. Multi-omics techniques can deep explore candidate pathogenic factors and construct gene regulatory networks.This trial is intended to evaluate the effect on Huoxin pill (HXP) in the treatment of HF after programmable communication interface (PCI). Meantime, multi-omics analysis technique will be used to target the fundamental pathological links of cardiac remodelling, so as to study the mechanism of HXP in the treatment of HF after PCI. MethodsThis study is a randomized, double-blind, placebo-controlled trial. Sixty patients with HF undergoing PCI are recruited from the First Affiliated Hospital of Henan University of CM. All selected patients will be randomly attributed to receive conventional treatment + HXP or placebo. The packaging, dosage and smell of placebo and heart activating pill were identical. The primary outcome is NYHA cardiac function grade, while the secondary outcomes included Lee's HF score, exercise tolerance test, and quality of life evaluation. Additional indicators include cardiac ultrasound, electrocardiogram, 24-h dynamic electrocardiogram, myocardial injury indicators, and energy metabolism indicators. DiscussionThis study may provide a new treatment option for patients with HF after PCI and provide evidence for the treatment of CHD and HF with HXP. Trial registration2023-10-08 registered in China Clinical Trial Registry, registration number ChiCTR2300076402.

Brachycephalic obstructive airway syndrome: a respiratory review

This article reviews the pathogenesis, diagnosis and therapeutic options for the respiratory aspects of brachycephalic obstructive airway syndrome. Brachycephalic obstructive airway syndrome is a condition estimated to affect around 50% of the brachycephalic dog population, which, over recent decades, has seen a meteoric rise in popularity and ownership. Several primary and secondary respiratory abnormalities that can compromise the respiratory capacity of these patients should be considered. Diagnosis primarily takes the form of clinical examination and the use of an exercise tolerance test, with other diagnostics acting as a useful adjunct in fully detailing the abnormalities present. Treatments are mainly focussed on increasing the amount of space within the upper respiratory tract through removal of various primary and secondary anatomical abnormalities; however, the optimal methods are yet to be identified. While understanding of these breeds' respiratory issues has increased among owners and the veterinary profession, there are still many challenges and unknowns in the management of these patients. It is important veterinary professionals take an active approach to these patients and are able to effectively communicate which are affected in order to maximise the welfare of this cohort and uphold their ethical responsibilities to them.

Doxorubicin treatment reduces expression of cardiac iron transporters

Doxorubicin (DOX) is an effective anticancer therapy. Unfortunately, the toxicity of DOX is not limited to cancerous cells, with the heart particularly prone to DOX-induced damage. While the mechanisms of DOX cardiotoxicity remain unclear, accumulation of iron within the heart may exacerbate the detrimental effects of DOX. Thus, understanding the effects of DOX on iron transport and storage protein expression would provide further insight on the mechanisms of disrupted iron handling and may lead to potential therapeutic targets for cardioprotection. Our goal was to investigate changes in gene expression of iron transporters in a preclinical model of DOX-induced cardiotoxicity. Female Sprague Dawley rats (2-3 month-old) were randomly divided to receive DOX or saline consistent with standard clinical treatment (i.e., intravenous infusion once every 3 weeks for 4 total cycles and a cumulative dose of ~160 mg/m2). One week following the fourth cycle measures of cardiac function, assessed by echocardiography, and cardiorespiratory capacity, determined by a graded exercise tolerance test, were completed. Cardiac tissue was also collected and cardiac mitochondria were isolated for measurement of reactive oxygen species production. At endpoint, DOX treatment resulted in a lower heart weight to tibia length ratio, reduced cardiorespiratory capacity, impaired ventricular fractional shortening and greater cardiac mitochondrial hydrogen peroxide emission. We found significant reductions in expression of transmembrane/cytoplasmic iron transporters (transferrin receptor 1 and divalent metal transporter 1) and the inner mitochondrial membrane transporter mitoferrin-2 with DOX treatment compared to saline. Expression of genes encoding for ferroportin-1, mitoferrin-1, ABCB8 and ferrochelatase were also downregulated in the DOX-treated group compared to saline, but these did not reach statistical significance. These findings are the first to describe changes in gene expression of proteins involved in iron homeostasis in a clinically relevant model of DOX-induced cardiotoxicity. Further studies are needed to investigate interventional approaches that improve cardiac iron handling to determine if they provide cardioprotection during DOX treatment. This research was funded by the National Institute of Health (NIH), R01 HL144858. This is the full abstract presented at the American Physiology Summit 2024 meeting and is only available in HTML format. There are no additional versions or additional content available for this abstract. Physiology was not involved in the peer review process.

Pilot study to evaluate the safety and effectiveness of etidronate treatment for arterial calcification due to deficiency of CD73 (ACDC).

Arterial calcification due to deficiency of CD73 (ACDC; OMIM 211800) is a rare genetic disease resulting in calcium deposits in arteries and small joints causing claudication, resting pain, severe joint pain, and deformities. Currently, there are no standard treatments for ACDC. Our previous work identified etidronate as a potential targeted ACDC treatment, using in vitro and in vivo disease models with patient-derived cells. In this study, we test the safety and effectiveness of etidronate in attenuating the progression of lower-extremity arterial calcification and vascular blood flow based on the computed tomography (CT) calcium score and ankle-brachial index (ABI). Seven adult patients with a confirmed genetic diagnosis of ACDC were enrolled in an open-label, nonrandomized, single-arm pilot study for etidronate treatment. They took etidronate daily for 14 days every 3 months and were examined at the NIH Clinical Center bi-annually for 3 years. They received a baseline evaluation as well as yearly follow up after treatment. Study visits included imaging studies, exercise tolerance tests with ABIs, clinical blood and urine testing, and full dental exams. Etidronate treatment appeared to have slowed the progression of further vascular calcification in lower extremities as measured by CT but did not have an effect in reversing vascular and/or periarticular joint calcifications in our small ACDC cohort. Etidronate was found to be safe and well tolerated by our patients and, despite the small sample size, appeared to show an effect in slowing the progression of calcification in our ACDC patient cohort.(ClinicalTrials.gov Identifier NCT01585402).

Menstruation-Related Angina—The Wee Hours

AbstractLiterature reveals two kinds of menstruation-related anginas—cardiac syndrome X (CSX) and catamenial angina. CSX generally occurs in perimenopausal or postmenopausal women; catamenial angina affects females from puberty to menopause with existing/preexisting or predisposed to coronary artery disease. CSX involves recurring anginal-type retrosternal chest pains during exercise or rest with no significant findings on angiogram. Catamenial angina is menstruation-associated recurrent nonexertional left-sided chest pain alongside diaphoresis, hot flushes, and persistent lethargy. Pathophysiology of both anginas revolve around decreased levels of estrogen. Estrogen is known to act via genomic and nongenomic pathways on cardiomyocytes, endothelial cells, and smooth muscle cells to exert its cardioprotective effect. These cardioprotective effects could be lost during the postovulation phase and at the end of menstruation as well as during perimenopause or menopause owing to the decreased levels of estrogen. Evaluation should begin with a history and physical examination and focus on noninvasive tests such as exercise tolerance test, electrocardiogram, and echocardiogram. Reducing symptoms that cause discomfort and improving quality of life should be the main goal in management. Nitrates along with β blockers and analgesics for pain are the main pharmacologic modalities. Exercise training, smoking cessation, weight loss, and dietary changes are nonpharmacological modalities. Proper awareness and effective communication with patients or caregivers can lead to early diagnosis and treatment initiation.

An Investigation of Contrast-Induced Acute Kidney Injury in Patients Undergoing Percutaneous Coronary Intervention: A Cross-Sectional Study From Pakistan.

Background and objective Contrast-induced acute kidney injury (CIAKI) is a complicationobserved among individuals undergoing primary percutaneous coronary intervention (PCI) and is associated with high morbidity and mortality rates. It is characterized by an elevation in serum creatinine (SCr) levels >0.5 mg/dl or a 50% relative increase in SCrfrom the baseline value following exposure to contrast within a 48- to 72-hour timeframe, in the absence of any alternative causes foracute kidney injury (AKI). This study aimed to assess the incidence of CIAKI in patients following PCI. Methods This prospective study was conducted from July to December 2022, after obtaining ethical approval from the institutional ethics committee (reference no: 147/LRH/MTI). A total of 159 consecutive patients who met the selection criteria were enrolled. A detailed patient and family history was obtained, and a thorough physical examination was conducted. Baseline tests, including SCr, were performed, with SCr repeated 72 hours post-PCI. All investigations were performed in the affiliated hospital's main laboratory and conducted by the same biochemist. Results The study included 159 patients presenting with myocardial infarction, angina pectoris, or ischemic features on EKG, exercise tolerance test (ETT), or echocardiogram and underwent PCI. The patients had a mean age of 51 ± 9 years, baseline SCr of 0.77 ± 0.41 mg/dl, SCr 72 hours post-procedure of 0.83 ± 0.41 mg/dl, and an average contrast volume of 128.6 ± 63 ml; 87 (55%) patients were male, and 72 (45%) were female. CIAKI was observed in 15 (9.4%) patients. Hypertensionand diabetes mellitus were the most prevalent comorbidities. Male gender, diabetes mellitus, and hypertension had a clinically significant association with the development of CIAKI (p<0.05). ST-elevation myocardial infarction (STEMI) was the predominant clinical presentation in 81 (50.9%) cases. Conclusions This study examines the frequency, risk factors, and associations of CIAKI following PCI at a tertiary care hospital in a low-middle-income country. We believe our findings provide future directions for identifying and minimizing the risk of CIAKI in this patient population.

Assessing Functional Capacity in Directly and Remotely Monitored Home-Based Settings in Individuals With Chronic Respiratory Diseases: Protocol for a Multinational Validation Study.

Pulmonary rehabilitation is widely recommended to improve functional status and as secondary and tertiary prevention in individuals with chronic pulmonary diseases. Unfortunately, access to timely and appropriate rehabilitation remains limited. To help close this inaccessibility gap, telerehabilitation has been proposed. However, exercise testing is necessary for effective and safe exercise prescription. Current gold-standard tests, such as maximal cardiopulmonary exercise testing (CPET) and the 6-minute walk test (6MWT), are poorly adapted to home-based or telerehabilitation settings. This was an obstacle to the continuity of services during the COVID-19 pandemic. It is essential to validate tests adapted to these new realities, such as the 6-minute stepper test (6MST). This test, strongly inspired by 6MWT, consists of taking as many steps as possible on a "stepper" for 6 minutes. This study aims to evaluate the metrological qualities of 6MST by (1) establishing concurrent validity and agreement between the 6MST and CPET, as well as with the 6MWT; (2) determining test-retest reliability in a home-based setting with direct and remote (videoconferencing) monitoring; and (3) documenting adverse events and participant perspectives when performing the 6MST in home-based settings. Three centers (Centre de recherche de l'Institut universitaire de cardiologie et de pneumologie de Québec in Québec, Groupement des Hôpitaux de l'Institut Catholique de Lille in France, and FormAction Santé in France) will be involved in this multinational project, which is divided into 2 studies. For study 1 (objective 1), 30 participants (Québec, n=15; France, n=15) will be recruited. Two laboratory visits will be performed to assess anthropometric data, pulmonary function, and the 3 exercise tolerance tests (CPET, 6MWT, and 6MST). Concurrent validity (paired sample t tests and Pearson correlations) and agreement (Bland-Altman plots with 95% agreement limits) will be evaluated. For study 2 (objectives 2 and 3), 52 participants (Québec, n=26; France, n=26) will be recruited. Following a familiarization trial (trial 1), the 6MST will be conducted on 2 separate occasions (trials 2 and 3), once under direct supervision and once under remote supervision, in a randomized order. Paired sample t test, Bland-Altman plots, and intraclass correlations will be used to compare trials 2 and 3. A semistructured interview will be conducted after the third trial to collect participants' perspectives. Ethical approval was received for this project (October 12, 2023, in Québec and September 25, 2023, in France) and the first participant was recruited in February 2024. This study innovates by validating a new clinical test necessary for the development and implementation of new models of rehabilitation adapted to home and telerehabilitation contexts. This study also aligns with the United Nations Sustainable Development Goals by contributing to augmenting health care service delivery (goal 3) and reducing health care access inequalities (goal 11). ClinicalTrials.gov NCT06447831; https://clinicaltrials.gov/study/NCT06447831. DERR1-10.2196/57404.

Evaluation of patients with chronic obstructive pulmonary disease by maximal inspiratory pressure and diaphragmatic excursion with ultrasound sonography

BackgroundDecreased respiratory muscle strength and muscle mass is key in diagnosing respiratory sarcopenia. However, the role of reduced diaphragm activity, expressed as the maximal level of diaphragmatic excursion (DEmax), in diagnosing respiratory sarcopenia in patients with chronic obstructive pulmonary disease (COPD) remains unclear. This study aimed to characterize patients with COPD and low DEmax and maximal inspiratory pressure (MIP), a measure of inspiratory muscle strength, and assess the role of DEmax in respiratory sarcopenia. MethodsPatients with COPD underwent spirometry, exercise tolerance (VO2peak) test, and MIP measurement. DEmax and sternocleidomastoid thickness at the maximal inspiratory level (TscmMIL) were assessed using ultrasound sonography. ResultsOverall, 58 patients with COPD (median age, 76 years; median %FEV1, 51.3 %) were included, 28 of whom showed a %MIP of ≥80 %, defined as having preserved MIP. Based on the %MIP of 80 % and median value of DEmax (48.0 mm) as thresholds, the patients were stratified into four groups: both-high (n = 18), %MIP-alone low (n = 11), DEmax-alone low (n = 10), and both-low (n = 19) groups. The both-low group exhibited the lowest %FEV1, Δinspiratory capacity, VO2peak, and TscmMIL, and these values were significantly lower than those of the both-high group. Except for %FEV1, these values were significantly lower in the both-low group than in the %MIP-alone low group despite adjusting DEmax level for body mass index. ConclusionMeasuring DEmax along with MIP can characterize patients with COPD, reduced exercise capacity, and decreased accessory respiratory muscle mass and can help diagnose respiratory sarcopenia.

Effects of exercise training after acute coronary syndromes in octogenarians - prospective 12-month evaluation.

Aim: To demonstrate the impact of individual exercise training on the course of the disease, exercise tolerance and quality of life (QoL) in patients over 75 years after acute coronary syndrome (ACS). Materials and methods: Study included octogenarians after ACS randomly assigned into two groups: a training group (ExT) subjected to individualized physical training and a control group (CG) with standard recommendations for activity. Patients underwent exercise tolerance test (ETT), 6-minute walk test (6-MWT), NHP and QoL questionnaires evaluation, lab tests, ECG, echocardiographic examination at the beginning and after 2, 6 and 12 months. Results: Study included 51 patients, mean age 80 years, 50% men, all patients completed the study. Initial physical capacity was comparable in both groups. After 2-month training the average ETT exercise time increased by 12.5% (p=0.0004), the load increased by 13% (p=0.0005) and the 6-MWT results improved by 8.3% (p=0.0114). Among CG these changes were not significant. But 6 and 12 months after training cessation 6-MWT results returned to the initial values (p=0.069, p=0.062 respecitvely). Average ETT exercise time and average load decreased significantly after 12 months (p=0.0009, p=0.0006). Level of pain was significantly lower at the end of the training in ExT group (p=0.007), but it returned to initial 12 months later (p=0.48). QoL deteriorated significantly in the ExT group 12 months after training cessation (p=0.04). Conclusions: Cardiac rehabilitation in octogenarians after ACS was safe and improved physical performance in a short period of time. Cessation of training resulted in a loss of achieved effects and deterioration of the QoL.

A Comparative Study of the Tolerance to Stress Response Under Spinal Anaesthesia in Diabetic Versus Non-Diabetic Patients

INTRODUCTION: Activation of sympathetic nervous system, increase of catabolic hormone release and pituitary gland suppression are responses to surgical stress. Neural blockade via epidural or spinal anesthesia, intravenous administration of high-dose of strong opioid analgesics, and infusion of anabolic hormones such as insulin are three main methods for balancing stress responses to surgery. However, there are conflicting reports about the extent of autonomic disturbances occurring after inducing spinal anesthesia in diabetic patients due to underlying autonomic neuropathy. METHODOLOGY: An observational cohort study was conducted in an operative room of a tertiary health care center involving 25 diabetic patients and 25 non-diabetic patients to evaluate the tolerance to stress. The diabetic patients undergone an exercise tolerance test to evaluate for postural hypotension which would indicate presence of autonomic neuropathy. Stress parameters such as heart rate, mean blood pressure, blood glucose level, and temperature were measured at regular intervals pre, peri- and post-operatively. RESULTS: Intraoperative heart rate, mean blood pressure, and blood glucose level were high in diabetic patients with autonomic neuropathy (p≤0.05). Temperature was higher in diabetic patients with autonomic neuropathy initially (p≤0.05) and had a higher fall peri-and post-operatively (T=15 minutes, T=20 minutes, and T=after surgery). A significant differences in the parameters of stress response were observed in diabetic patients with autonomic neuropathy. CONCLUSION: By understanding the correlation between stress-response in diabetic patients with autonomic neuropathy peri-operatively will help the anesthetist to provide customized services to every patient

Influence of acute dietary nitrate supplementation timing on nitrate metabolism, central and peripheral blood pressure and exercise tolerance in young men

PurposeDietary nitrate (NO3−) supplementation can lower systolic blood pressure (SBP) and improve exercise performance. Salivary flow rate (SFR) and pH are key determinants of oral NO3− reduction and purported to peak in the afternoon. We tested the hypotheses that NO3−-rich beetroot juice (BR) would increase plasma [nitrite] ([NO2−]), lower SBP and improve exercise performance to a greater extent in the afternoon (AFT) compared to the morning (MORN) and evening (EVE).MethodTwelve males completed six experimental visits in a repeated-measures, crossover design. NO3−-depleted beetroot juice (PL) or BR (~ 13 mmol NO3−) were ingested in the MORN, AFT and EVE. SFR and pH, salivary and plasma [NO3−] and [NO2−], brachial SBP and central SBP were measured pre and post supplementation. A severe-intensity exercise tolerance test was completed to determine cycling time to exhaustion (TTE).ResultsThere were no between-condition differences in mean SFR or salivary pH. The elevation in plasma [NO2−] after BR ingestion was not different between BR-MORN, BR-AFT and BR-EVE. Brachial SBP was unchanged following BR supplementation in all conditions. Central SBP was reduced in BR-MORN (− 3 ± 4 mmHg), BR-AFT (− 4 ± 3 mmHg), and BR-EVE (− 2 ± 3 mmHg), with no differences between timepoints. TTE was not different between BR and PL at any timepoint.ConclusionAcute BR supplementation was ineffective at improving TTE and brachial SBP and similarly effective at increasing plasma [NO2−] and lowering central SBP across the day, which may have implications for informing NO3− supplementation strategies.

Effect of sodium-related glucose transporter 2 -Inhibitors on exercise capacity in heart failure patients with reduced ejection fraction, does etiology matter?

Abstract Introduction Recently sodium-related glucose transporter 2 (SGLT2) inhibitors were found to improve cardiovascular outcomes significantly, however their effects on exercise capacity are yet unclear. Aim To assess in patients with heart failure with reduced ejection fraction (HFrEF), if etiology may have a role in treatment response to SGLT2-I and exercise improvement. Methods We included patients with a recent diagnosis of HF with ejection fraction ≤ 40%, between June 2014 and September 2022. An exhaustive initial evaluation was performed with laboratory tests, echocardiography, and exercise tolerance test, performing a 6-minute-walking test (6MWT). Patients were reassessed after 6 months, prior treatment optimization. Finally, patients were divided according to the HF etiology into ischemic and non-ischemic, comparing the results between the patients who received SGLT2-i and those who did not. Results Among the 462 patients included (275 non-ischemic and 187 ischemic; mean age 64.1 ±14.0 vs 61.9 ± 19.8 years, women 27.5% vs 15.8%), 45 and 41 patients respectively, received treatment with SGLT2-i. In both groups, patients who received SGLT2-i, had a significant higher prevalence of hypertension, dyslipidemia, and diabetes mellitus (Non-ischemic: hypertension 68.9 % vs 50.9%, p = 0.02; dyslipidemia 42.2% vs 25.8%, p= 0.02; diabetes mellitus 55.6% vs 28.3 %, p &amp;lt;0.001; Ischemic: hypertension 68.3% vs 50.3%, p = 0.04, dyslipidemia 75.6% vs 47.9, p&amp;lt; 0.02, diabetes mellitus 78% vs 38.4% p&amp;lt;0.001) and were as well treated with ARNI on a higher percentage (Non-ischemic 35.6% vs 13.9% p&amp;lt; 0.001, Ischemic: 39% vs 17.8%, p = 0.004). In the non-ischemic group, patients treated with SGLT2-i had a higher mean age (68.2±12.2 vs 63.3±14.3; p = 0.03). No other differences were observed between the baseline characteristics and the treatment. Treatment with SGLT2-i improved performance in 6MWT (+32.5 m [95% CI 10.7-54.4]) only in non-ischemic group while no differences have been found in ischemic patients. Conclusions Treatment with SGLT2-inhibitors has been associated with an improvement in exercise ability at six months only in patients with HFrEF of non-ischemic etiology whereas in patients with ischemic etiology it has not shown improvement in functional capacity. Our study suggests that, in clinical setting, non-ischemic patients may have a greater benefit with SGLT2-inhibitors treatment in term of exercise capacity.

Abstract 13317: Current Smoking Impedes Recovery in Cardiac Rehabilitation

Purpose: Current smoking is a powerful predictor of future morbidity and mortality and those who smoke are more likely to have higher risk clinical profiles and less likely to engage in secondary prevention. Little is known about how those who smoke benefit from secondary prevention following a cardiac event, such as cardiac rehabilitation (CR). The purpose of this study was to compare improvements in fitness among those who smoke vs those who do not during CR. Methods: Data were gathered on 2208 individuals entering the University of Vermont CR program from 1/1996-12/2021. Self-reported smoking status was collected at CR entry (current vs. formerly vs. never smoking). Cardiorespiratory fitness (CRF)(peak oxygen capacity [VO2peak]) was assessed via exercise tolerance test at entry to and exit from CR. Change in Peak VO2 was compared by smoking status univariately and in a multivariate model controlling for other potential contributing variables like age, sex, entry VO2, number and severity of exercise-limiting comorbidities, BMI, and number of CR sessions attended. Results: On average patients improved by 3.26 in their CRF during the course of CR. In univariate analyses improvement by smoking status was 2.29, 3.06, and 3.55 (current, former, never smoker respectively). The final multivariate model included smoking status, CRF at intake, comorbidities, age, BMI, and interactions between smoking status and age, and BMI and age. Least square means from this model were improvements of 1.95, 3.10, and 3.53 (current, former, never smoker respectively). Conclusion: These data suggest that those who are currently smoking improve less in fitness during CR than those who formerly or never smoked and that controlling for covariates highlights that the biggest difference in the effect of smoking is truly between the current smokers and the former/never smokers. Further research should be conducted to see if successful smoking cessation can improve fitness related gains during CR.

A Single, Multimodal Exercise Tolerance Test Can Assess Combat Readiness in Army-ROTC Cadets: A Brief Report.

Using a formal instrument design process, we constructed the METT to mimic the demands of the ACFT and assessed its reliability, validity, and responsiveness. The METT demonstrates minimal measurement error (i.e., a 2% coefficient of variation), concurrent validity with the ACFT (R2 = 0.327, F = 10.67, p < 0.001), the ability to classify cadets who may be at-risk for failing the ACFT (X2 = 8.16, p = 0.017, sensitivity = 0.878, specificity = 0.667), and appropriate change following a training intervention (5.69 ± 8.9%). The METT has the potential to provide a means to monitor progress, identify areas for improvement, and guide informed decision-making regarding individualization of cadet combat training plans.

Abstract P3196: Voluntary Exercise Training Does Not Prevent High Phosphate Diet-induced Mitochondrial Dysfunction

Inorganic phosphate (Pi) is used extensively as a preservative and a flavor enhancer in processed foods consumed as part of a Western diet. Mice fed high-Pi diet (HP) for 12 weeks display decreased maximal exercise capacity but no change in cardiac function. Expression of fatty acid metabolism genes are decreased and expression of glucose metabolism genes are increased in skeletal muscle after HP diet. Consequently, mitochondrial function is significantly impaired in skeletal muscle from mice fed HP diet. In the current study we test the hypothesis that voluntary exercise training prevents the negative metabolic consequences of HP diet. We housed mice in voluntary wheel running cages and fed them a normal-Pi (NP) or HP diet. HP diet did not alter body weight or composition, and NP- and HP-fed mice voluntarily ran the same distance in wheel cages throughout the study. Using incline treadmill exercise tolerance tests we observed no differences in medium-intensity exercise capacity between NP- and HP-fed mice subjected to voluntary wheel running, contrary to findings in sedentary mice. Despite preserved exercise capacity, muscle mitochondrial function in mice fed HP diet was significantly decreased after 5 weeks, which continued to decline after 12 weeks of HP diet and voluntary exercise. To investigate mechanisms of HP-induced mitochondrial dysfunction we measured expression of key metabolic genes and found that fatty acid metabolism genes were significantly decreased in muscle from mice fed HP diet and subjected to voluntary exercise. These data suggest that voluntary exercise training does not prevent the negative metabolic consequences of consuming a high-phosphate diet. Thus, dietary Pi may represent a novel and modifiable target to reduce physical inactivity associated with the Western diet.

Aerobic exercise simultaneous with non-invasive ventilation reduces the length of stay in intensive care in patients with heart failure: a randomised clinical trial

Introduction Early cardiac rehabilitation using non-invasive ventilation (NIV) and aerobic exercise may reduce the length of hospital stay in patients with heart failure (HF), however, there is still no evidence of this effect on patients in the intensive care unit (ICU). Objectives to investigate the effects of aerobic exercise (AE) performed simultaneously with non-invasive ventilation (NIV) on the length of intensive care stay (LICUS) in patients diagnosed with decompensated heart failure (HF) admitted to the intensive care units (ICU). Methods Twenty-eight patients admitted to the intensive care unit (ICU) because of decompensation of HF were randomised into two groups: the intervention group (AE + NIV), and a control group. The intervention group’s treatment strategy involved simultaneous AE with NIV daily. The control group performed non-simultaneous AE and NIV daily during their ICU stay. The primary outcome was LICUS. The secondary outcomes were the length of hospital stay, peripheral and respiratory muscle strength, functional status, functional classification, and exercise tolerance. Results The mean LICUS was shorter in AE + NIV than in the control group (6.3 ± 4.7 days vs 8.3 ± 3.6 days, respectively; p = 0.015). Secondary outcomes were similar between groups, except for exercise hemodynamics, which was improved in AE + NIV, as showed by the decreased diastolic blood pressure immediately after the exercise tolerance test. Conclusion The use of AE simultaneous with NIV reduced the LICUS of patients admitted to the ICU because of decompensated HF. This innovative approach is a promising tool for accelerating ICU discharge during the in-hospital rehabilitation of patients with HF.