Cardiopulmonary Exercise Testing Research Articles

Ten questions about cardiopulmonary exercise testing: all that the cardiologist dares or dares not to ask

In patients with cardiovascular, pulmonary, muscular and neurological diseases, cardiopulmonary exercise testing (CPET) is a valuable tool providing clinically-relevant diagnostic and prognostic information by evaluation of exercise response. CPET requires to be performed in dedicated centers able to correctly carry out the examination and to carefully evaluate the results. CPET analyzes functional capacity revealing both symptomatic and asymptomatic intolerance to exercise. One of the most important advantages for clinicians derived by the use of CPET, beyond standard exercise electrocardiography testing, is the capability not only to grade the severity of the disease, but also to distinguish between different causes of dyspnea and exercise impairment. Indications for CPET use in clinical practice are increasing in the last decades, evolving beyond the routine use as a training tool in athletes. In fact, CPET represents an important step in the management of patients with heart failure or pulmonary hypertension, as suggested by international guidelines. CPET role in helping for the selection of patients candidate to heart transplantation is also well known. Beyond its clinical usefulness, scientific interest in CPET is constantly expanding, mainly due to the safety of the exam and to the huge size of the pathophysiological information that it offers. The aim of this paper is to simply explain everyday applications and potential further purposes of CPET in clinical practice. Our review is intended both for physicians approaching CPET for the first time and for clinicians with an interest in expanding their knowledge in this field.

Aerobic exercise training combined with local strength exercise restores muscle blood flow and maximal aerobic capacity in long-term Hodgkin lymphoma survivors.

It is unclear whether muscle blood flow (MBF) is altered in long-term Hodgkin lymphoma (HL) survivors. We tested the hypothesis that 1) MBF response during mental stress (MS) is impaired in long-term HL survivors and 2) aerobic exercise training combined with local strength exercise (ET) restores MBF responses during MS in these survivors. Eighteen 5-year HL survivors and 10 aged-paired healthy subjects (HC) were studied. Twenty HL survivors were randomly divided into two groups: exercise-trained (HLT, n = 10) and untrained (HLUT, n = 10). Maximal aerobic capacity was evaluated by a cardiopulmonary exercise test and forearm blood flow (FBF) by venous occlusion plethysmography. MS was elicited by Stroop color and word test. ET was conducted for 4 mo, 3/wk for 60 min each session. The aerobic exercise intensity corresponded to anaerobic threshold up to 10% below the respiratory compensation point. The strength exercises consisted of two to three sets of chest press, pulley and squat exercises, 12-15 repetitions each exercise at 30-50% of the maximal voluntary contraction. Baseline was similar in HL survivors and HC, except peak oxygen consumption (peak V̇o2, P = 0.013) and FBF (P = 0.006) that were lower in the HL survivors. FBF responses during MS were lower in HL survivors (P < 0.001). ET increased peak V̇o2 (11.59 ± 3.07%, P = 0.002) and FBF at rest (33.74 ± 5.13%, P < 0.001) and during MS (24 ± 5.31%, P = 0.001). Further analysis showed correlation between the changes in peak V̇o2 and the changes in FBF during MS (r = 0.711, P = 0.001). In conclusion, long-term HL survivors have impaired MBF responses during MS. ET restores MBF responses during MS.NEW & NOTEWORTHY Long-term Hodgkin lymphoma (HL) survivors have impaired muscle blood flow responses during mental stress and decreased maximal aerobic capacity. Supervised aerobic exercise training combined with local strength exercises restores muscle blood flow responses during mental stress and maximal aerobic capacity in these survivors. These findings provide evidence of safety and effectiveness of exercise training in HL survivors. Moreover, they highlight the importance of exercise training in the treatment of this set of patients.

Chronotropic Incompetence among People with HIV Improves with Exercise Training in the Exercise for Healthy Aging Study.

People with HIV (PWH) have lower exercise capacity compared to peers without HIV, which may be explained by chronotropic incompetence (CI), the inability to increase heart rate during exercise. The Exercise for Healthy Aging Study included adults ages 50-75 with and without HIV. Participants completed 12 weeks of moderate intensity exercise, before randomization to moderate or high intensity for 12 additional weeks. We compared adjusted heart rate reserve (AHRR; CI <80%) on cardiopulmonary exercise testing by HIV serostatus and change from baseline to 12 and 24 weeks using mixed effects models. Among 32 PWH and 37 controls (median age 56, 7% female, mean BMI 28 kg/m2), 28% of PWH compared to 11% of controls had CI at baseline (p = 0.067). AHRR was lower among PWH (91 vs 101%; difference 10%, 95% CI 1.9-18.9; p = 0.02). At week 12, AHRR normalized among PWH (+8%, 95% CI 4-11; p < 0.001) and was sustained at week 24 (+5, 95%CI 1-9; p = 0.008) compared to no change among controls (95%CI -4 to 4; p = 0.95; pinteraction = 0.004). After 24 weeks of exercise, only 15% PWH and 10% of controls had CI (p = 0.70). Chronotropic incompetence contributes to reduced exercise capacity among PWH and improves with exercise training.

Persisting exercise ventilatory inefficiency in subjects recovering from COVID-19. Longitudinal data analysis 34 months post-discharge

BackgroundSARS-CoV-2 infection has raised concerns about long-term health repercussions. Exercise ventilatory inefficiency (EVin) has emerged as a notable long-term sequela, potentially impacting respiratory and cardiovascular health. This study aims to assess the long-term presence of EVin after 34 months and its association with cardiorespiratory health in post-COVID patients.MethodsIn a longitudinal study on 32 selected post-COVID subjects, we performed two cardiopulmonary exercise tests (CPETs) at 6 months (T0) and 34 months (T1) after hospital discharge. The study sought to explore the long-term persistence of EVin and its correlation with respiratory and cardiovascular responses during exercise. Measurements included also V̇O2peak, end-tidal pressure of CO2 (PETCO2) levels, oxygen uptake efficiency slope (OUES) and other cardiorespiratory parameters, with statistical significance set at p < 0.05. The presence of EVin at both T0 and T1 defines a persisting EVin (pEVin).ResultsOut of the cohort, five subjects (16%) have pEVin at 34 months. Subjects with pEVin, compared to those with ventilatory efficiency (Evef) have lower values of PETCO2 throughout exercise, showing hyperventilation. Evef subjects demonstrated selective improvements in DLCO and oxygen pulse, suggesting a recovery in cardiorespiratory function over time. In contrast, those with pEvin did not exhibit these improvements. Notably, significant correlations were found between hyperventilation (measured by PETCO2), oxygen pulse and OUES, indicating the potential prognostic value of OUES and Evin in post-COVID follow-ups.ConclusionsThe study highlights the clinical importance of long-term follow-up for post-COVID patients, as a significant group exhibit persistent EVin, which correlates with altered and potentially unfavorable cardiovascular responses to exercise. These findings advocate for the continued investigation into the long-term health impacts of COVID-19, especially regarding persistent ventilatory inefficiencies and their implications on patient health outcomes.

Physiological and Locomotor Profiling Enables to Differentiate Between Sprinters, 400-m Runners, and Middle-Distance Runners.

Thron, M, Woll, A, Doller, L, Quittmann, OJ, Härtel, S, Ruf, L, and Altmann, S. Physiological and locomotor profiling enables to differentiate between sprinters, 400-m runners, and middle-distance runners. J Strength Cond Res XX(X): 000-000, 2024-Different approaches exist for characterizing athletes, e.g., physiological and locomotor profiling. The aims of this study were to generate and compare physiological and locomotor profiles of male and female runners and to evaluate relationships between the different approaches. Thirty-four highly trained adolescent and young adult female and male athletes (n = 11 sprinters; n = 11,400-m runners; n = 12 middle-distance runners) performed two 100-m sprints on a running track to determine maximal sprinting speed (MSS) and maximal lactate accumulation rate (ċLamax). A cardiopulmonary exercise test was performed on a treadmill to determine maximal aerobic speed (MAS) and maximal oxygen uptake (V̇o2max). Anaerobic speed reserve (ASR) was calculated as the difference between MSS and MAS. Group comparisons were conducted with a 2-way ANOVA (discipline × sex; p < 0.05) and Bonferroni post hoc tests and Cohen's d as effect size. Parameters were correlated by Pearson's correlation coefficients. Maximal aerobic speed and V̇o2max were higher in 400-m and middle-distance runners compared with sprinters (p ≤ 0.02; -2.24 ≤ d ≤ -1.29). Maximal sprinting speed and ċLamax were higher in sprinters and 400-m runners compared with middle-distance runners (0.03 ≤ p ≤ 0.28; 0.73 ≤ d ≤ 1.23). Anaerobic speed reserve was highest in sprinters and lowest in middle-distance runners (p ≤ 0.03; 1.24 ≤ d ≤ 2.79). High correlations were found between ASR and MAS, MSS, and ċLamax (p < 0.01; -0.55 ≤ r ≤ 0.91) and between ċLamax and MSS (p < 0.01; r = 0.74). Our results indicate that athletes of different sprinting and running disciplines show differing physiological and locomotor profiles, and that the parameters of these approaches are related to each other. This can be of interest for assessing strengths and weaknesses (e.g., for talent identification) or training prescription in these disciplines.

#1555 The effects of different interdialytic intervals on cardiorespiratory fitness assessed with CPET in hemodialysis patients

Abstract Background and Aims Long interdialytic interval in thrice-weekly hemodialysis is associated with excess cardiovascular and all-cause mortality risk. Impaired cardiorespiratory fitness is a strong predictor of mortality in hemodialysis. This study investigated differences in cardiorespiratory fitness assessed with cardiopulmonary exercise testing (CPET) between the end of the 2-day and the 3-day interdialytic interval. Method A total of 28 hemodialysis patients, randomized in two different sequences of evaluation underwent CPET and spirometry examination at the end of the 2-day and the 3-day intervals. The primary outcome was the difference in oxygen uptake at peak exercise [VO2peak (ml/kg/min)] assessed with CPET. Volume status was assessed with interdialytic-weight-gain (IDWG), lung ultrasound, bioimpedance spectroscopy (BIS), and inferior vena cava measurements. A total of 14 age- and sex-matched controls were also evaluated. Results Hemodialysis patients at the end of both 2-day and 3-day intervals presented lower values in all major CPET parameters than controls. VO2peak (ml/kg/min) was significantly higher at the end of the 2-day than the 3-day interval (15.24 ± 4.18 vs 13.64 ± 2.76; p &amp;lt; 0.001); similar were the results for VO2peak (ml/min) (1188 ± 257 vs 1074 ± 224; p &amp;lt; 0.001) and VO2peak (%predicted) (58.9 ± 9.2 vs 52.3 ± 8.6; p &amp;lt; 0.001). Numerical but no statistically significant differences were detected in VO2-anaerobic-threshold(ml/kg/min) and VO2-anaerobic-threshold(ml/min) between the two time-points. Maximal work load (90.1 ± 23.2 vs 79.3 ± 25.1; p &amp;lt; 0.001), exercise duration, HR at peak exercise and oxygen pulse also showed lower values at the end of the 3-day interval. FEV1 levels were similar between the two evaluations. Generalized-linear-mixed-model analysis including IDWG as random covariate attenuated the observed differences in VO2peak (ml/kg/min). Changes in BIS-derived overhydration indexes were moderately correlated with changes of VO2peak (ml/kg/min). Conclusion The 3-day interval was associated with further impairment of VO2 at peak exercise. This effect was predominantly driven by excess fluid accumulation during the extra interdialytic day.

Serial cardiopulmonary exercise testing in young patients after one-and-half ventricle repair and Fontan procedure: a comparative study.

The Fontan procedure is the palliative surgical treatment for different congenital heart diseases (CHD) with a univentricular heart, but it has been associated with decreased exercise capacity, cardiovascular morbidity, and premature mortality. The one-and-half ventricle repair (1.5VR) was introduced as an alternative to the Fontan procedure, specifically for selected patients with borderline hypoplastic right ventricle (HRV), aiming for a more physiological circulation. Despite these efforts, the benefit of 1.5VR over Fontan circulation comparison on clinical and functional outcomes remains unclear. The aim of this study was to investigate and compare young patients with HRV after 1.5VR with those with functional single right or left ventricles (FSRV or FSLV) after Fontan palliation over a 10-year follow-up period. In this retrospective observational study, serial cardiopulmonary exercise tests (CPETs) performed in patients with 1.5VR and Fontan circulation between September 2002 and March 2024 have been analyzed. Only patients with at least 10 years of follow-up were considered. A total of 41 patients were included (age at baseline 8.6±2.6 years): 21 with FSLV, 12 with FSRV, and 10 with 1.5VR. No differences in cardiorespiratory fitness and efficiency were shown at the first CPET assessment among the three groups. At 10-year follow-up, 1.5VR had higher cardiorespiratory fitness and efficiency compared to FSLV and FSRV patients. These findings suggest that the 1.5VR may provide superior long-term functional outcomes than the Fontan procedure in patients with borderline HRV. Further studies are needed to evaluate the impact on hard clinical endpoints.

Relationship among muscle strength, muscle endurance, and skeletal muscle oxygenation dynamics during ramp incremental cycle exercise.

Peak oxygen uptake (VO2), evaluated as exercise tolerance, is a strong predictor of life prognosis regardless of health condition. Several previous studies have reported that peak VO2 is higher in those with a greater decrease in muscle oxygen saturation (SmO2) in the active muscles during incremental exercise. However, the skeletal muscle characteristics of individuals exhibiting a greater decrease in SmO2 during active muscle engagement in incremental exercise remain unclear. This study aimed to clarify the relationship among muscle strength, muscle endurance, and skeletal muscle oxygenation dynamics in active leg muscles during incremental exercise. Twenty-four healthy young men were included and categorized into the non-moderate-to-high muscular strength and endurance group (those with low leg muscle strength, endurance, or both; n = 11) and the moderate-to-high muscular strength and endurance group (those with both moderate-to-high leg muscle strength and endurance; n = 13). All participants underwent cardiopulmonary exercise testing combined with near-infrared spectroscopy to assess whole-body peak VO2 and the change in SmO2 at the lateral vastus lateralis from rest to each exercise stage as skeletal muscle oxygenation dynamics. A linear mixed-effects model, with the change in SmO2 from rest to each stage as the dependent variable, individual participants as random effects, and group and exercise load as fixed effects, revealed significant main effects for both group (P = 0.001) and exercise load (P < 0.001) as well as a significant interaction between the two factors (P < 0.001). Furthermore, multiple-comparison test results showed that the change in SmO2 from rest to 40%-100% peak VO2 was significantly higher in the moderate-to-high muscular strength and endurance group than in the non-moderate-to-high muscular strength and endurance group. Maintaining both muscle strength and endurance at moderate or higher levels contributes to high skeletal muscle oxygenation dynamics (i.e., greater decrease in SmO2) during moderate- or high-intensity exercise.

Optimizing cardiopulmonary rehabilitation duration for long COVID patients: an exercise physiology monitoring approach.

The presence of prolonged symptoms after COVID infection worsens the workability and quality of life. 200 adults with long COVID syndrome were enrolled after medical, physical, and mental screening, and were divided into two groups based on their performance. The intervention group (n = 100) received supervised rehabilitation at Department of Pulmonology, Semmelweis University with the registration number 160/2021 between 01/APR/2021-31/DEC/2022, while an age-matched control group (n = 100) received a single check-up. To evaluate the long-term effects of the rehabilitation, the intervention group was involved in a 2- and 3-month follow-up, carrying out cardiopulmonary exercise test. Our study contributes understanding long COVID rehabilitation, emphasizing the potential benefits of structured cardiopulmonary rehabilitation in enhancing patient outcomes and well-being. Significant difference was found between intervention group and control group at baseline visit in pulmonary parameters, as forced vital capacity, forced expiratory volume, forced expiratory volume, transfer factor for carbon monoxide, transfer coefficient for carbon monoxide, and oxygen saturation (all p < 0.05). Our follow-up study proved that a 2-week long, patient-centered pulmonary rehabilitation program has a positive long-term effect on people with symptomatic long COVID syndrome. Our data showed significant improvement between two and three months in maximal oxygen consumption (p < 0.05). Multidisciplinary, individualized approach may be a key element of a successful cardiopulmonary rehabilitation in long COVID conditions, which improves workload, quality of life, respiratory function, and status of patients with long COVID syndrome.

Pulmonary responses following cardiac rehabilitation and the relationship with functional outcomes in children and young adults with heart disease

IntroductionPatients with congenital heart disease (CHD) often have pulmonary abnormalities and exercise intolerance following cardiac surgery. Cardiac rehabilitation (CR) improves exercise capacity in patients with CHD, but minimal study has been performed to see if resting and dynamic pulmonary performance improves following CR in those with prior cardiac surgery.MethodsThis was a retrospective cohort study of all patients who completed ≥12 weeks of CR from 2018 through 2022. Demographic, cardiopulmonary exercise test (CPET), spirometry, 6-minute walk, functional strength measures, and outcomes data were collected. Data are presented as median[IQR]. A Student's t-test was used for comparisons between groups and serial measurements were measured with a paired t-test. A p &amp;lt; 0.05 was considered significant.ResultsThere were a total of 37 patients [age 16.7 (14.2–20.1) years; 46% male] included. Patients with prior surgery (n = 26) were more likely to have abnormal spirometry data than those without heart disease (n = 11) (forced vital capacity [FVC] 76.7 [69.1–84.3]% vs. 96.4 [88.1–104.7]%, p = 0.002), but neither group experienced a significant change in spirometry. On CPET, peak oxygen consumption increased but there was no change in other pulmonary measures during exercise. Percent predicted FVC correlated with hand grip strength (r = 0.57, p = 0.0003) and percent predicted oxygen consumption (r = 0.43, p = 0.009). The number of prior sternotomies showed negative associations with both percent predicted FVC (r = −0.43, p = 0.04) and FEV1 (r = −0.47, p = 0.02).DiscussionYouth and young adults with a prior history of cardiac surgery have resting and dynamic pulmonary abnormalities that do not improve following CR. Multiple sternotomies are associated with worse pulmonary function.

Kinematics but not kinetics alterations to single-leg drop jump movements following a subject-tailored fatiguing protocol suggest an increased risk of ACL injury

IntroductionNeuromuscular fatigue causes a transient reduction of muscle force, and alters the mechanisms of motor control. Whether these alterations increase the risk of anterior cruciate ligament (ACL) injury is still debated. Here we compare the biomechanics of single-leg drop jumps before and after the execution of a fatiguing exercise, evaluating whether this exercise causes biomechanical alterations typically associated with an increased risk of ACL lesion. The intensity of the fatiguing protocol was tailored to the aerobic capacity of each participant, minimizing potential differential effects due to inter-individual variability in fitness.MethodsTwenty-four healthy male volunteers performed single leg drop jumps, before and after a single-set fatiguing session on a cycle ergometer until exhaustion (cadence: 65–70 revolutions per minute). For each participant, the intensity of the fatiguing exercise was set to 110% of the power achieved at their anaerobic threshold, previously identified by means of a cardiopulmonary exercise test. Joint angles and moments, as well as ground reaction forces (GRF) before and after the fatiguing exercise were compared for both the dominant and the non-dominant leg.ResultsFollowing the fatiguing exercise, the hip joint was more extended (landing: Δ=−2.17°, p = 0.005; propulsion: Δ=−1.83°, p = 0.032) and more abducted (landing: Δ=−0.72°, p = 0.01; propulsion: Δ=−1.12°, p = 0.009). Similarly, the knee joint was more extended at landing (non-dominant leg: Δ=−2.67°, p &amp;lt; 0.001; dominant: Δ=−1.4°, p = 0.023), and more abducted at propulsion (both legs: Δ=−0.99°, p &amp;lt; 0.001) and stabilization (both legs: Δ=−1.71°, p &amp;lt; 0.001) hence increasing knee valgus. Fatigue also caused a significant reduction of vertical GRF upon landing (Δ=−0.21 N/kg, p = 0.003), but not during propulsion. Fatigue did not affect joint moments significantly.ConclusionThe increased hip and knee extension, as well as the increased knee abduction we observed after the execution of the fatiguing exercise have been previously identified as risk factors for ACL injury. These results therefore suggest an increased risk of ACL injury after the execution of the participant-tailored fatiguing protocol proposed here. However, the reduced vertical GRF upon landing and the preservation of joint moments are intriguing, as they may suggest the adoption of protective strategies in the fatigued condition to be evaluated in future studied.

Cardiopulmonary exercise testing, computed tomography-derived body composition, systemic inflammation and survival after elective abdominal aortic aneurysm repair: A retrospective cohort study.

Cardio-pulmonary exercise testing (CPEX) is selectively used before intervention for abdominal aortic aneurysm (AAA). Sarcopenia, a chronic condition defined by reduced skeletal muscle function and volume, can be assessed radiologically by computed tomography (CT)-derived body composition analysis (CT-BC), and is associated with systemic inflammation. The aim was to describe the association between CT-BC, CPEX, inflammation and survival in patients undergoing elective intervention for AAA. Patients were recruited retrospectively from a single, secondary-care centre-operative database. Cases undergoing elective endovascular aneurysm repair (EVAR) and open surgical repair (OSR) between 31 March 2015 and 25 June 2020 were included. There were 176 patients (130 EVAR, 46 OSR) available for analysis in the final study; median (interquartile range [IQR]) follow-up was 60.5 [27] months, and all completed a minimum of 2 years follow-up. Preoperative CPEX tests were recorded. CT sarcopenia score [CT-SS, range 0 to 2, calculated based on normal/low SMI (0/1) and normal/low SMD (0/1)] assessed radiological sarcopenia. Preoperative modified Glasgow Prognostic score (mGPS) was used to assess systemic inflammation. Mean [95% confidence interval (CI) survival in the CT-SS 0 vs. CT-SS 1 vs. CT-SS 2 subgroups was 80.1 (73.6 to 86.6) months vs. 70.3 (63.5 to 77.1) months vs. 63.8 (53.4 to 74.2) months] (P = 0.01). CT-SS was not associated with CPEX results (P > 0.05). Elevated CT-SS [hazard ratio (HR) 1.83, 95% CI, 1.16 to 2.89, P < 0.01] was independently associated with increased hazard of long-term mortality; however, CPEX results were not (P > 0.05). CPEX test results were not consistently associated with body composition and did not have significant prognostic value in patients undergoing elective treatment for AAA.

TAKING A WALK ON THE HEART FAILURE SIDE: COMPARISON OF METABOLIC VARIABLES DURING WALKING AND MAXIMAL EXERTION

Abstract Background Although cardiopulmonary exercise testing (CPET) is the gold standard to assess exercise capacity, simpler tests (i.e. 6–minute walk test, 6MWT) are also commonly used. Aim of this study was to evaluate the relationship between cardiorespiratory parameters during CPET and 6MWT in a large, multicenter, heterogeneous population. Methods We included athletes, healthy subjects, and heart failure (HF) patients of different severity, including left ventricular assist device (LVAD) carriers, who underwent both CPET and 6MWT with oxygen consumption measurement. Results We enrolled 186 subjects (16 athletes, 40 healthy, 115 non–LVAD HF patients, and 15 LVAD carriers). CPET–peakV̇O2 was 41.0 [35.0–45.8], 26.2 [23.1–31.0], 12.8 [11.1–15.3], and 15.2 [13.6–15.6] ml/Kg/min in athletes, healthy, HF patients, and LVAD carriers, respectively (p&amp;lt;0.001). During 6MWT they used 63.5 [56.3–76.8], 72.0 [57.8– 81.0], 95.5 [80.3–109], and 95.0 [92.0–99.0] % of their peakV̇O2, respectively. None of the athletes, 1 healthy (2.5%), 30 HF patients (26.1%), and 1 LVAD carrier (6.7%), reached a 6MWT–V̇O2 higher than their CPET–peakV̇O2. Both 6MWT–V̇O2 and walked distance were significantly associated with CPET–peakV̇O2 in the whole population (R2=0.637 and R2=0.533, p=&amp;lt;0.001) but not in the sub–groups. This was confirmed after adjustment for groups. Conclusion The 6MWT can be a maximal effort especially in most severe HF patients and suggest that, in absence of prognostic studies related to 6MWT metabolic values, CPET should remain the first method of choice in the functional assessment of patients with HF as well as in sport medicine

LONG–TERM FUNCTIONAL LIMITATIONS ON CARDIOPULMONARY EXERCISE TESTING IN A COHORT OF PATIENTS WITH EMOTIONS–TRIGGERED TAKOTSUBO SYNDROME

Abstract Background In patients with prior Takotsubo syndrome (TTS), long lasting functional cardiac limitations were described as compared with normal subjects. Emotions–triggered Takotsubo syndrome (E–TTS) has more favorable outcomes than TTS preceded by a physical trigger or by no identifiable factors. The aim of the present study was to assess long–term cardiac functional limitations in a cohort of asymptomatic E–TTS patients. Methods We enrolled n=39 asymptomatic patients with a diagnosis of E–TTS. Cardiopulmonary exercise tests (CPET) were performed at 30 [12–40] months median follow–up from the acute event. A cohort of n=39 individuals matched for age, sex, body mass index and comorbidities served as control. Results Despite recovery of left ventricular ejection fraction, patients with prior E–TTS had lower peak VO2 and percentage of predicted peak VO2 (17.8 ± 3.6 vs 22.5 ± 6.5; P &amp;lt; 0.001 and 75.2 ± 14.1 % vs 100.6 ± 17.1%, P &amp;lt;0.001), VO2 at anaerobic threshold (AT) (11.1 [10.1–12.9] vs 14.4 [12.5–18.7]; P &amp;lt;0.001), peak O2 pulse (9.7 ± 2.5 vs 13.1 ± 3.5; P &amp;lt;0.001) and higher VE/VCO2 slope (30.4 ± 3.7 vs 27.2 ± 3.5; P &amp;lt;0.001) compared with matched controls. We found no statistically significant differences in heart rate reserve (HRR), respiratory equivalent ratio (RER), mean blood pressure and peak PetCO2 between patients and controls. Conclusions Despite their overall favorable outcome, asymptomatic patients with E–TTS were found to have long–term subclinical functional cardiac impairments. CPET proved to be a useful tool in the long–term evaluation of E–TTS patients after recovery of LVEF. Further studies are needed to fully clarify the origin of the detected CPET abnormalities as well as their prognostic relevance in patience with recovered E–TTS.

New Models for Prediction of Post-Operative Pulmonary Complications in Lung Resection Candidates

IntroductionIn recent years, ventilatory efficiency (VE/VCO2slope) and partial pressure of end-tidal carbon dioxide (PETCO2) emerged as independent predictors of post-operative pulmonary complications (PPC). Single parameters may give only partial information regarding peri-procedural hazards. Accordingly, our aim was to create prediction models with improved ability to stratify PPC risk in patients scheduled for elective lung resection surgery.MethodsThispost-hocanalysis was comprised of consecutive lung resection candidates from two prior prospective trials. All individuals completed pulmonary function tests and cardiopulmonary exercise testing (CPET). Logistic regression analyses were used for identification of risk factors for PPC that were entered into the final risk prediction models. Two risk models were developed; the first used rest PETCO2(for patients with no available CPET data), the second used VE/VCO2slope (for patients with available CPET data). ROC analysis with the De-Long test and area under the curve (AUC) were used for comparison of models.ResultsThe dataset from 423 patients was randomly split into the derivation (n=310) and validation (n=113) cohorts. Two final models were developed, both including sex, thoracotomy, „atypical“ resection and FEV1/FVC ratio as risk factors. In addition, the first model also included rest PETCO2, while the second model used VE/VCO2slope from CPET. AUCs of risk scores were 0.795 (95% CI: 0.739–0.851) and 0.793 (95% CI: 0.737–0.849); both p&lt;0.001. No differences in AUCs were found between the derivation and validation cohorts.ConclusionsWe created two multicomponental models for PPC risk prediction, both having excellent predictive properties.

Six-minute walk test in healthy British service personnel

IntroductionThe 6 min walk test (6MWT) is a widely used, safe and effective submaximal exercise test. The primary outcome is the distance walked, but additional physiological and patient-reported metrics can...

IMPROVING THE KNOWLEDGE, RISK STRATIFICATION AND OUTCOMES IN ADVANCED HEART FAILURE. THE ISMETT HEART FAILURE REGISTRY

Abstract Background Advanced heart failure (AdHF) accounts for approximately 10% of patients in HF clinics worldwide. Clinical management of patients with AdHF remains challenging and most of the available studies focus on chronic but not advanced HF. Registry studies may provide important insights into this specific population. Methods All consecutive patients referred to our centre for AdHF therapies candidacy (left ventricular assist device (LVAD), heart transplant (HTx)) are prospectively studied and enrolled in the registry. On the same day, all patients undergo a comprehensive clinical and instrumental examination, including electrocardiogram, echocardiography, extended laboratory tests and right heart catheterisation. Most patients also undergo a cardiopulmonary exercise test and, in the case of a non–ischaemic aetiology, cardiac magnetic resonance imaging and genetic testing, if not already performed. Echocardiography is also performed to assess advanced echocardiographic measures (biventricular and atrial strain, myocardial work, 3–D chambers assessment). Results Forty–five patients were enrolled from March 1, 2023 to December 22, 2023 (enrolment rate 4.5 patients/month). Mean age was 54 years and 2/3 were male. Median disease duration was 69 (28–165) months. Non–ischemic HF was the most common aetiology with a NYHA IV prevalence of 4% (all others were in NYHA III). 31% of patients had chronic kidney disease and overall liver function was preserved. 67% of patients were treated with sacubitril/valsartan, &amp;gt; 90% were taking beta–blockers (median dose 4.8 mg bisoprolol–equivalent dose) and 84% SGLT2 inhibitors. Both standard and advanced echocardiography showed features of advanced disease. Over a median follow–up of 4 (2 – 6) months 2 (4%) patients died, 5 (11%) underwent urgent HTx and 8 (18%) underwent LVAD implantation. For most variables, there was a trend showing that patients with events were sicker but, currently, the sample size limited the statistical power. Conclusions A systematic comprehensive evaluation of patients with AdHF evaluated for advanced HF therapies could help to reduce the knowledge gap for this high–risk HF population.

Comparison of Cardiorespiratory Fitness Prediction Equations and Generation of New Predictive Model for Patients with Obesity.

Cardiorespiratory fitness (CRF) is a critical marker of overall health and a key predictor of morbidity and mortality, but the existing prediction equations for CRF are primarily derived from general populations and may not be suitable for patients with obesity. Predicted CRF from different non-exercise prediction equations was compared with measured CRF of patients with obesity who underwent maximal cardiopulmonary exercise testing (CPET). Multiple linear regression was used to develop a population-specific non-exercise CRF prediction model for treadmill exercise including age, sex, weight, height and physical activity level as determinants. 660 patients underwent CPET during the study period. Within the entire cohort, R2 values had a range of 0.24-0.46. Predicted CRF was statistically different from measured CRF for 19 included equations. Only 50% of patients were correctly classified into the measured CRF categories according to predicted CRF. A multiple model for CRF prediction (ml/min) was generated (R2 = 0.78) and validated using two cross-validation methods. Most used equations provide inaccurate estimates of CRF in patients with obesity, particularly in cases of severe obesity and low CRF. Therefore, a new prediction equation was developed and validated specifically for patients with obesity, offering a more precise tool for clinical CPET interpretation and risk stratification in this population.

Effects of Obesity and Sex on Ventilatory Constraints during a Cardiopulmonary Exercise Test in Children.

Ventilatory constraints are common during exercise in children, but the effects of obesity and sex are unclear. The purpose of this study was to investigate the effects of obesity and sex on ventilatory constraints (i.e., expiratory flow limitation (EFL) and dynamic hyperinflation) during a maximal exercise test in children. Thirty-four 8-12-year-old children without obesity (18 females) and 54 with obesity (23 females) completed pulmonary function testing and maximal cardiopulmonary exercise tests. EFL was calculated as the overlap between tidal flow-volume loops during exercise and maximal expiratory flow-volume loops. Dynamic hyperinflation was calculated as the change in inspiratory capacity from rest to exercise. Maximal minute ventilation was not different between children with and without obesity. Average end-inspiratory lung volumes (EILV) and end-expiratory lung volumes (EELV) were significantly lower during exercise in children with obesity (EILV: 68.8 ± 0.7%TLC; EELV: 41.2 ± 0.5%TLC) compared with children without obesity (EILV: 73.7 ± 0.8%TLC; EELV: 44.8 ± 0.6%TLC; P < 0.001). Throughout exercise, children with obesity experienced more EFL and dynamic hyperinflation compared with those without obesity (P < 0.001). Also, males experienced more EFL and dynamic hyperinflation throughout exercise compared with females (P < 0.001). At maximal exercise, the prevalence of EFL was similar in males with and without obesity, however the prevalence of EFL in females was significantly different with 57% of females with obesity experiencing EFL compared with 17% of females without obesity (P < 0.05). At maximal exercise, 44% of children with obesity experienced dynamic hyperinflation compared with 12% of children without obesity (P = 0.002). Obesity in children increases the risk of developing mechanical ventilatory constraints such as dynamic hyperinflation and EFL. Sex differences were apparent with males experiencing more ventilatory constraints compared with females.

The association between body mass index, exercise capacity, and health-related quality of life in heart transplant recipients

IntroductionPre-transplant obesity and weight gain after heart transplantation are both associated with increased risk of poor clinical outcomes. We aimed to assess the association between overweight or obesity, exercise capacity, and health-related quality of life in heart transplant recipients.MethodsThis study is based on baseline data from the IronIC trial, in which we randomized 102 heart transplant recipients with iron deficiency to ferric derisomaltose or placebo. We performed cardio pulmonary exercise testing in all participants. To assess quality of life, we used the SF-36v2 questionnaire, using two sum scores: the physical component summary and the mental component summary. A minimal clinically important difference was defined as ≥2 and ≥3 for the physical and the mental component summary, respectively.Results24/102 heart transplant recipients (24%) had a body mass index (BMI) ≥30 kg/m2. Peak oxygen consumption was 17.3 ± 4.6 ml/kg/min in the obese group vs. 24.7 ± 6.4 ml/kg/min in the group with a BMI &amp;lt;30 for a between-group difference of 7.4 (95% confidence interval 4.7–10.2) ml/kg/min: p &amp;lt; 0.001. The physical component summary score was on average 5.2 points lower in the patients with a body mass index ≥30 than in the lower weight group (p = 0.04).ConclusionAlmost a quarter of our heart transplant recipients in long-term follow-up had a BMI ≥30 kg/m2. These patients had substantially lower exercise capacity and lower quality of life in the physical domain.