Variables Measured During Cardiopulmonary Exercise Testing as Predictors of Mortality in Chronic Systolic Heart Failure

Application of an echocardiographic index to characterize right ventricular-pulmonary arterial coupling in heart failure

Heart failure (HF), with its high morbidity and mortality, remains a global public health issue. Right ventricular (RV) dysfunction is a sign of deterioration in the natural history of HF, and a thorough evaluation of the relationship between RV contractility and its afterload through RV-pulmonary arterial (RV-PA) coupling can aid in accurately assessing overall RV function. The ratio of RV end-systolic elastance (Ees) to pulmonary arterial elastance (Ea) invasively measured by right heart catheterization served as the gold standard for evaluating RV-PA coupling. An echocardiographic index termed tricuspid annular plane systolic excursion/pulmonary artery systolic pressure (TAPSE/PASP) has been shown to correlate well with Ees/Ea. TAPSE/PASP is recognized as a non-invasive surrogate of RV-PA coupling and has been extensively studied in patients with HF. This review briefly describes the methods of assessing RV-PA coupling, mainly discussing echocardiography, summarizes the clinical utility of TAPSE/PASP in patients with different HF types, and provides an overview of the available literature.

Comprehensive Cardiac Rehabilitation Following Acute Myocardial Infarction Improves Clinical Outcomes Regardless of Exercise Capacity

BACKGROUND

Reduced exercise capacity is a prognostic indicator of adverse outcomes in patients with acute myocardial infarction (AMI). However, few studies have evaluated the effectiveness of comprehensive cardiac rehabilitation (CR) in this population. This study aimed to clarify the efficacy of comprehensive CR in patients with AMI and reduced exercise capacity.Methods and Results: This cohort study included 610 patients with AMI who underwent percutaneous coronary intervention. Major adverse cardiovascular events (MACE) were compared between patients who participated in comprehensive outpatient CR for 150 days (CR group; n=430) and those who did not (non-CR group; n=180). During the mean (±SD) follow-up period of 6.1±4.0 years, the CR group exhibited a lower incidence of MACE (log-rank P=0.002). Multivariable analysis revealed that Killip classification, diuretics at discharge, and participation in comprehensive CR were independently associated with MACE. The CR group was further divided into 2 groups, namely reduced exercise capacity (% predicted peak V̇O2<80%; n=241) and preserved exercise capacity (≥80%; n=147), based on the initial cardiopulmonary exercise test. Despite distinct exercise capacities, the incidence of MACE was comparable and physical parameters improved similarly after comprehensive CR in both groups.

CONCLUSIONS

Comprehensive CR in patients with AMI effectively reduced the incidence of MACE regardless of initial exercise capacity. Cardiologists should actively encourage patients with low exercise capacity to participate in comprehensive CR.

Effect of Left Ventricular Diastolic Dysfunction on the Cardiopulmonary Exercise Test in Patients With Cardiovascular Disease

Left ventricular diastolic dysfunction exists in patients with heart failure with reduced ejection fraction and causes activity restriction and a poor prognosis, but there have been few reports about exercise tolerance in patients with diastolic dysfunction, regardless of left ventricular ejection fraction (LVEF). In this study, 294 cardiovascular disease patients who performed a cardiopulmonary exercise test (CPX) with an adequate examination by echocardiography at Fukuoka University Hospital from 2011 to 2020 were investigated. Patients were divided into groups with grade I and grade II or III diastolic dysfunction according to diagnostic criteria, regardless of LVEF, by echocardiography. After adjusting for age, gender, body mass index, smoking, and LVEF by propensity score matching, we compared the results of CPX between the grade I and grade II/III groups. There were no significant differences in hemodynamic parameters, or in the respiratory exchange ratio, oxygen uptake per body weight, oxygen uptake per heart rate, or parameters of ventilatory volume. Ventilatory equivalents per oxygen uptake and per carbon dioxide output were significantly worse in the grade II/III group from the rest to peak periods during CPX. In conclusion, left ventricular diastolic dysfunction worsens ventilatory efficacy during CPX. This effect potentially contributes to a poor prognosis in left ventricular diastolic dysfunction.

Prognostic Value of Body Surface Area-Adjusted Oxygen Uptake Efficiency Slope in Heart Failure Patients

Background

COVID-19 has been associated with a higher risk of developing heart failure (HF). Among the parameters derived from cardiopulmonary exercise testing (CPET), oxygen uptake efficiency slope (OUES) has become one of the most important parameters for predicting the prognosis of HF patients. However, the clinical utilization of OUES is limited owing to its variation with patient height and weight. This study aimed to evaluate the prognostic value of body surface area-adjusted OUES (OUES/BSA) in adults with HF.

Methods

Thirty-six HF patients (mean age, 57 ± 12 years; 30 men) undergoing CPET between July 2019 and May 2020 who were followed up for 12 months were enrolled. The endpoints were major cardiovascular (CV) events, including hospitalization due to acute decompensated HF, left ventricular assist device implantation, heart transplantation, and cardiovascular-related death. We analyzed the correlations between clinical/CPET variables and major CV events.

Results

Among the analyzed CPET variables, OUES/BSA had better correlation with maximal oxygen uptake (VO2max) than other variables. In univariate Cox proportional analysis, OUES/BSA and peak VO2 were both significant independent prognostic factors. The cutoff value of OUES/BSA was 595 ml/min/m2 with an area under the curve of 0.929. The patients with OUES/BSA < 595 ml/min/m2 had a lower CV event-free survival rate at 12 months of follow-up compared with the other group (33.3% and 100%, respectively; log-rank test, p < 0.001).

Conclusions

BSA-adjusted OUES is an effective independent predictor for prognosis in HF patients and can be an alternative to peak VO2 for risk stratification in HF patients, regardless of exercise intensity. However, further large-scale studies are required to validate our findings.

Impact of Changes in Rectus Femoris Cross-Sectional Area Measured by Ultrasound on the Prognosis of Patients With Acute Heart Failure

BACKGROUND

Low muscle mass in patients with acute heart failure (AHF) is associated with poor prognosis; however, this is based on a single baseline measurement, with little information on changes in muscle mass during hospitalization and their clinical implications. This study investigated the relationship between changes in rectus femoris cross-sectional area (RFCSA) on ultrasound and the prognosis of patients with AHF.Methods and Results: This is a retrospective evaluation of 284 AHF patients (mean [±SD] age 79.1±11.9 years; 116 female). RFCSA assessments at admission (pre-RFCSA), ∆RFCSA (i.e., the percentage change in RFCSA from admission to 2 weeks), and composite prognosis (all-cause death and heart failure-related readmission) within 1 year were determined. Patients were divided into 4 groups according to their median pre-RFCSA and ∆RFCSA after sex stratification: Group A, higher pre-RFCSA/better ∆RFCSA; Group B, higher pre-RFCSA/worse ∆RFCSA; Group C, lower pre-RFCSA/better ∆RFCSA; Group D, lower pre-RFCSA/worse ∆RFCSA. In the Cox regression analysis, with Group A as the reference, the cumulative event rate of Group C (hazard ratio [HR] 3.39; 95% confidence interval [CI] 0.71-16.09; P=0.124) did not differ significantly; however, the cumulative event rates of Group B (HR 7.93; 95% CI 1.99-31.60; P=0.003) and Group D (HR 9.24; 95% CI 2.57-33.26; P<0.001) were significantly higher.

CONCLUSIONS

∆RFCSA during hospitalization is useful for risk assessment of prognosis in patients with AHF.

Development of deep-learning models for real-time anaerobic threshold and peak VO2 prediction during cardiopulmonary exercise testing

AIMS

Exercise intolerance is a clinical feature of patients with heart failure (HF). Cardiopulmonary exercise testing (CPET) is the first-line examination for assessing exercise capacity in patients with HF. However, the need for extensive experience in assessing anaerobic threshold (AT) and the potential risk associated with the excessive exercise load when measuring peak oxygen uptake (peak VO2) limit the utility of CPET. This study aimed to use deep-learning approaches to identify AT in real time during testing (defined as real-time AT) and to predict peak VO2 at real-time AT.

METHODS AND RESULTS

This study included the time-series data of CPET recorded at the Department of Cardiovascular Medicine, Kyushu University Hospital. Two deep neural network models were developed to: (i) estimate the AT probability using breath-by-breath data and (ii) predict peak VO2 using the data at the real-time AT. The eligible CPET contained 1472 records of 1053 participants aged 18-90 years and 20% were used for model evaluation. The developed model identified real-time AT with 0.82 for correlation coefficient (Corr) and 1.20 mL/kg/min for mean absolute error (MAE), and the corresponding AT time with 0.86 for Corr and 0.66 min for MAE. The peak VO2 prediction model achieved 0.87 for Corr and 2.25 mL/kg/min for MAE.

CONCLUSION

Deep-learning models for real-time CPET analysis can accurately identify AT and predict peak VO2. The developed models can be a competent assistant system to assess a patient's condition in real time, expanding CPET utility.

Multimodality magnetic resonance evaluating the effect of enhanced physical exercise on the growth rate, flow haemodynamics, aneurysm wall and ventricular-aortic coupling of patients with small abdominal aortic aneurysms (AAA MOVE trial): a study protocol for an open-label randomised controlled trial

INTRODUCTION

The best lifestyle for small abdominal aortic aneurysms (sAAA) is essential for its conservative management. Physical exercise can improve the cardiopulmonary function of the patients, but it remains unclear which specific type of exercise is most beneficial for individuals with sAAA. The current study was designed to investigate the effect of physician-guided enhanced physical exercise programme on the aorto-cardiac haemodynamic environment, aneurysm sac wall, cardiac function and growth rate of sAAA by multimodality MRI.

METHODS AND ANALYSIS

AAA MOVE study is a prospective, parallel, equivalence, randomised controlled trial. Eligible individuals will be recruited if they are diagnosed with sAAA (focal dilation of abdominal aorta with maximum diameter <5 cm), without contraindication for MRI scanning, or severe heart failure, or uncontrolled arrhythmia. Participants will be randomly allocated to intervention group (physician-guided enhanced physical exercise programme: mainly aerobic training) and control group (standard clinical care) separately in a 1:1 ratio. The primary outcome is 12-month growth rate of sAAA. The first set of secondary outcomes involve multimodality MRI parameters covering flow haemodynamics, aortic wall inflammation and cardiac function. The other secondary outcome (safety end point) is a composite of exercise-related injury, aneurysm rupture and aneurysm intervention. Follow-up will be conducted at 6 and 12 months after intervention.

ETHICS AND DISSEMINATION

This study was approved by the Ethics Committee on Biomedical Research of West China Hospital (approval number: 2023-783) on 16 June 2023. Main findings from the trial will be disseminated through presentations at conferences, peer-reviewed publications and directly pushed to smartphone of participants.

TRIAL REGISTRATION NUMBER

ChiCTR2300073334.

Prognostic Value of Hemodynamic Gain Index in Patients With Heart Failure With Reduced Ejection Fraction

BACKGROUND

Assessment of functional capacity in patients with heart failure with reduced ejection fraction (HFrEF) is essential for risk stratification, and it traditionally relied on cardiopulmonary exercise testing (CPET)-derived peak oxygen consumption (peak Vo2).

OBJECTIVES

This study sought to investigate the prognostic value of alternative nonmetabolic exercise testing parameters in a contemporary cohort with HFrEF.

METHODS

Medical records of 1,067 consecutive patients with chronic HFrEF who underwent CPET from December 2012 to September 2020 were reviewed for a primary outcome that was a composite of all-cause mortality, left ventricular assist device implantation, and/or heart transplantation. Multivariable Cox regression and log-rank testing were used to determine prognostic values of various exercise testing variables.

RESULTS

The primary outcome was identified in 331 of 954 patients (34.7%) of the HFrEF cohort (median follow-up time, 946 days). After adjustment for demographics, cardiac parameters, and comorbidities, higher hemodynamic gain index (HGI) and peak rate-pressure product (RPP) were associated with greater event-free survival (adjusted HR per doubling: 0.76 and 0.36; 95% CI: 0.67-0.87 and 0.28-0.47; all P < 0.001, respectively). Moreover, HGI (area under the curve [AUC]: 0.69; 95% CI: 0.65-0.72) and peak RPP (AUC: 0.71; 95% CI: 0.68-0.74) were comparable to the standard peak Vo2 (AUC: 0.70; 95% CI: 0.66-0.73; P for comparison = 0.607 and 0.393, respectively) for primary outcome discrimination.

CONCLUSIONS

HGI and peak RPP show good correlation with peak Vo2 in terms of prognostication and outcome discrimination in patients with HFrEF and may serve as suitable alternatives to CPET-derived prognostic variables.

Cardiac resynchronization using fusion pacing during exercise

INTRODUCTION

Fusion pacing requires correct timing of left ventricular pacing to right ventricular activation, although it is unclear whether this is maintained when atrioventricular (AV) conduction changes during exercise. We used cardiopulmonary exercise testing (CPET) to compare cardiac resynchronization therapy (CRT) using fusion pacing or fixed AV delays (AVD).

METHODS

Patients 6 months post-CRT implant with PR intervals < 250 ms performed two CPET tests, using either the SyncAV™ algorithm or fixed AVD of 120 ms in a double-blinded, randomized, crossover study. All other programming was optimized to produce the narrowest QRS duration (QRSd) possible.

RESULTS

Twenty patients (11 male, age 71 [65-77] years) were recruited. Fixed AVD and fusion programming resulted in similar narrowing of QRSd from intrinsic rhythm at rest (p = .85). Overall, there was no difference in peak oxygen consumption (V̇O2 PEAK , p = .19), oxygen consumption at anaerobic threshold (VT1, p = .42), or in the time to reach either V̇O2 PEAK (p = .81) or VT1 (p = .39). The BORG rating of perceived exertion was similar between groups. CPET performance was also analyzed comparing whichever programming gave the narrowest QRSd at rest (119 [96-136] vs. 134 [119-142] ms, p < .01). QRSd during exercise (p = .03), peak O2 pulse (mL/beat, a surrogate of stroke volume, p = .03), and cardiac efficiency (watts/mL/kg/min, p = .04) were significantly improved.

CONCLUSION

Fusion pacing is maintained during exercise without impairing exercise capacity compared with fixed AVD. However, using whichever algorithm gives the narrowest QRSd at rest is associated with a narrower QRSd during exercise, higher peak stroke volume, and improved cardiac efficiency.

Practical guidelines for exercise prescription in patients with chronic heart failure

Chronic heart failure (HF) is a major cause of morbidity, mortality, disability, and health care costs. A hallmark feature of HF is severe exercise intolerance, which is multifactorial and stems from central and peripheral pathophysiological mechanisms. Exercise training is internationally recognized as a Class 1 recommendation for patients with HF, regardless of whether ejection fraction is reduced or preserved. Optimal exercise prescription has been shown to enhance exercise capacity, improve quality of life, and reduce hospitalizations and mortality in patients with HF. This article will review the rationale and current recommendations for aerobic training, resistance training, and inspiratory muscle training in patients with HF. Furthermore, the review provides practical guidelines for optimizing exercise prescription according to the principles of frequency, intensity, time (duration), type, volume, and progression. Finally, the review addresses common clinical considerations and strategies when prescribing exercise in patients with HF, including considerations for medications, implantable devices, exercise-induced ischemia, and/or frailty.

Incremental Role of New York Heart Association Class and Cardiopulmonary Exercise Test Indices for Prognostication in Heart Failure: A Cohort Study

BACKGROUND

Central Illustration : Incremental Role of New York Heart Association Class and Cardiopulmonary Exercise Test Indices for Prognostication in Heart Failure: A Cohort Study LVEF: left ventricular ejection fraction; HR: hazard ratio; CI: confidence interval; NYHA: New York Heart Association; VO 2: oxygen consumption.

BACKGROUND

The accuracy of the New York Heart Association (NYHA) classification to assess prognosis may be limited compared with objective cardiopulmonary exercise test (CPET) parameters in heart failure (HF).

OBJECTIVE

To investigate the prognostic value of the NYHA classification in addition to Weber class.

METHODS

Adult outpatients with HF undergoing CPET in a Brazilian tertiary care center were included. The physician-assigned NYHA class and the CPET-derived Weber class were stratified into "favorable" (NYHA I or II; Weber A or B) or "adverse" (NYHA III or IV; Weber C or D). Patients with one favorable class and one adverse class were defined as "discordant." The primary endpoint was time to all-cause mortality. A 2-sided p value < 0.05 was considered statistically significant.

RESULTS

A total of 834 patients were included. Median age was 57 years; 42% (351) were female, and median left ventricular ejection fraction was 32%. Among patients with concordant NYHA and Weber classes, those with adverse NYHA and Weber classes had significantly higher all-cause mortality compared to those with favorable classes (hazard ratio [HR]: 5.65; 95% confidence interval [CI]: 3.38 to 9.42). Among patients with discordant classes, there was no significant difference in all-cause mortality (HR: 1.38; 95% CI: 0.82 to 2.34). In the multivariable model, increments in NYHA class (HR: 1.55 per class increase; 95% CI: 1.26 to 1.92) and reductions in peak VO 2 (HR: 1.47 per 3 ml/kg/min decrease; 95% CI: 1.28 to 1.70) significantly predicted mortality.

CONCLUSIONS

Physician-assigned NYHA class and objective CPET measures provide complementary prognostic information for patients with HF.

Incidental Cardiovascular Abnormalities in the Abdominal Aortic Aneurysm (AAA) Surveillance Population During the AAA Get Fit Trial: A Case Series and Review of the Literature

Background The prevalence of cardiovascular disease and incidence of major adverse cardiovascular events (MACEs) is very high among the abdominal aortic aneurysm (AAA) surveillance population. Formal assessments of and interventions to reduce cardiovascular risk are not a routine part of the surveillance programme at present. However, its potential importance is highlighted by incidental findings during the AAA Get Fit Trial, a randomised controlled trial which included baseline cardiopulmonary exercise testing (CPET). We speculate that CPET can act as an opportunistic screening programme to identify cardiovascular disease in AAA surveillance patients. Methods The AAA Get Fit Trial was a prospective, randomised controlled trial at a tertiary vascular centre, Manchester University NHS Foundation Trust, conducted between November 2017 and August 2019. Patients underwent CPET at baseline, 8, 16, 24 and 36 weeks as well as clinical history and examination and blood tests. We report on incidental cardiovascular abnormalities diagnosed during the trial. Results Of the 59 participants in the trial, four (6.8%) were identified to have abnormal findings suggestive of unstable cardiovascular disease. On subsequent further investigation, two patients were diagnosed and treated for severe coronary artery disease after abnormal ECG findings were noted during CPET. One patient was diagnosed with unstable angina after obtaining a detailed history on baseline assessment which was treated medically before going on to have a successful elective AAA repair. Conclusions There is a high incidence of MACEs among this high-risk population both pre and perioperatively. Identifying and treating cardiovascular disease among the AAA surveillance population must be a focus of the future AAA screening programme.

Relationship of maximum walking speed with peak oxygen uptake and anaerobic threshold in male patients with heart failure

This retrospective observational study aimed to examine the relationships of maximum walking speed (MWS) with peak oxygen uptake (peak VO2) and anaerobic threshold (AT) obtained by cardiopulmonary exercise testing (CPX) in patients with heart failure. The study participants were 104 consecutive men aged ≥ 20 years who had been hospitalized or had undergone outpatient care at our hospital for heart failure between February 2019 and January 2023. MWS was measured in a 5-m section with a 1-m run-up before and after the course. Multivariable analysis was used to examine the association between MWS and peak VO2 and AT by CPX. The Pearson correlation coefficient showed that MWS was positively correlated with percent-predicted peak VO2 and percent-predicted AT (r = 0.463, p < 0.001; and r = 0.485, p < 0.001, respectively). In the multiple linear regression analysis employing percent-predicted peak VO2 and percent-predicted AT as the objective variables, only MWS demonstrated a significant positive correlation (standardized β: 0.471, p < 0.001 and 0.362, p < 0.001, respectively). Multiple logistic regression analyses, using an 80% cutoff in percent-predicted peak VO2 and AT, revealed that only MWS was identified as a significant factor in both cases (odds ratio [OR]: 1.239, 95% confidence interval [CI]: 1.071-1.432, p = 0.004 and OR: 1.469, 95% CI: 1.194-1.807, p < 0.001, respectively). MWS was correlated with peak VO2 and AT in male patients with heart failure. The MWS measurement as a screening test for exercise tolerance may provide a simple means of estimating peak VO2 and AT in heart failure patients.

Exercise Physiology and Cardiopulmonary Exercise Testing

Aerobic, or endurance, exercise is an energy requiring process supported primarily by energy from oxidative adenosine triphosphate synthesis. The consumption of oxygen and production of carbon dioxide in muscle cells are dynamically linked to oxygen uptake (V̇O2) and carbon dioxide output (V̇CO2) at the lung by integrated functions of cardiovascular, pulmonary, hematologic, and neurohumoral systems. Maximum oxygen uptake (V̇O2max) is the standard expression of aerobic capacity and a predictor of outcomes in diverse populations. While commonly limited in young fit individuals by the capacity to deliver oxygen to exercising muscle, (V̇O2max) may become limited by impairment within any of the multiple systems supporting cellular or atmospheric gas exchange. In the range of available power outputs, endurance exercise can be partitioned into different intensity domains representing distinct metabolic profiles and tolerances for sustained activity. Estimates of both V̇O2max and the lactate threshold, which marks the upper limit of moderate-intensity exercise, can be determined from measures of gas exchange from respired breath during whole-body exercise. Cardiopulmonary exercise testing (CPET) includes measurement of V̇O2 and V̇CO2 along with heart rate and other variables reflecting cardiac and pulmonary responses to exercise. Clinical CPET is conducted for persons with known medical conditions to quantify impairment, contribute to prognostic assessments, and help discriminate among proximal causes of symptoms or limitations for an individual. CPET is also conducted in persons without known disease as part of the diagnostic evaluation of unexplained symptoms. Although CPET quantifies a limited sample of the complex functions and interactions underlying exercise performance, both its specific and global findings are uniquely valuable. Some specific findings can aid in individualized diagnosis and treatment decisions. At the same time, CPET provides a holistic summary of an individual's exercise function, including effects not only of the primary diagnosis, but also of secondary and coexisting conditions.

Cardiopulmonary Exercise Testing in Patients with Heart Failure: Impact of Gender in Predictive Value for Heart Transplantation Listing

BACKGROUND

Exercise testing is key in the risk stratification of patients with heart failure (HF). There are scarce data on its prognostic power in women. Our aim was to assess the predictive value of the heart transplantation (HTx) thresholds in HF in women and in men.

METHODS

Prospective evaluation of HF patients who underwent cardiopulmonary exercise testing (CPET) from 2009 to 2018 for the composite endpoint of cardiovascular mortality and urgent HTx.

RESULTS

A total of 458 patients underwent CPET, with a composite endpoint frequency of 10.5% in females vs. 16.0% in males in 36-month follow-up. Peak VO2 (pVO2), VE/VCO2 slope and percent of predicted pVO2 were independent discriminators of the composite endpoint, particularly in women. The International Society for Heart Lung Transplantation recommended values of pVO2 ≤ 12 mL/kg/min or ≤14 if the patient is intolerant to β-blockers, VE/VCO2 slope > 35, and percent of predicted pVO2 ≤ 50% showed a higher diagnostic effectiveness in women. Specific pVO2, VE/VCO2 slope and percent of predicted pVO2 cut-offs in each sex group presented a higher prognostic power than the recommended thresholds.

CONCLUSION

Individualized sex-specific thresholds may improve patient selection for HTx. More evidence is needed to address sex differences in HF risk stratification.

Symptom-limited exercise capacity is associated with long-term survival

The prognostic value of exercise capacity has been demonstrated in subjects with established cardiovascular diseases. We aim to evaluate the independence of exercise capacity measured by treadmill exercise test (TET) in predicting long-term outcomes among various comorbidities. This study was conducted from January 2003 to December 2012 in a tertiary medical center in Taiwan. Subjects referred for symptom-limited TET were recruited. Peak achieved metabolic equivalents (METs) were determined by treadmill grade and speed at peak exercise. The main outcomes were cardiovascular and all-cause mortality by linking to the National Death Registry. A total of 18,954 participants (57.8 ± 12.8 years, 62% men) achieved a mean peak METs of 9.2. Subjects in the lowest tertile of peak METs were older, had poorer renal function, lower hemoglobin, and more comorbidities. During a median follow-up of 4.3 years, there were 642 mortalities and 132 cardiovascular deaths. Peak METs significantly predicted cardiovascular death and all-cause mortality in the multivariable Cox regression models [hazard ratio (95% confidence intervals): 0.788 (0.660-0.940) and 0.835 (0.772-0.903), respectively]. The prognostic influence of peak METs consistently appeared in the subgroups, regardless of age, gender, body weight, comorbidities, use of beta-blockers, or the presence of exercise-induced ischemia. The fitness was more predictive of long-term outcomes in young or those with ischemic changes during TET (P for interaction: 0.035 and 0.018, respectively). The benefit of fitness was nonlinearly associated with long-term survival. The prognostic impacts of exercise capacity were universally observed in subjects with or without various comorbidities.

Exertional Cardiac and Pulmonary Vascular Hemodynamics in Patients With Heart Failure With Reduced Ejection Fraction

BACKGROUND

Exertional dyspnea is a cardinal manifestation of heart failure with reduced ejection fraction (HFrEF), but quantitative data regarding exertional hemodynamics are lacking.

OBJECTIVES

We sought to characterize exertional cardiopulmonary hemodynamics in patients with HFrEF.

METHODS

We studied 35 patients with HFrEF (59 ± 12 years old, 30 males) who completed invasive cardiopulmonary exercise testing. Data were collected at rest, at submaximal exercise and at peak effort on upright cycle ergometry. Cardiovascular and pulmonary vascular hemodynamics were recorded. Fick cardiac output (Qc) was determined. Hemodynamic predictors of peak oxygen uptake (VO2) were identified.

RESULTS

Left ventricular ejection fraction and cardiac index were 23% ± 8% and 2.9 ± 1.1 L/min/m2, respectively. Peak VO2 was 11.8 ± 3.3 mL/kg/min, and the ventilatory efficiency slope was 53 ± 13. Right atrial pressure increased from rest to peak exercise (4 ± 5 vs 7 ± 6 mmHg,). Mean pulmonary arterial pressure increased from rest to peak exercise (27 ± 13 vs 38 ± 14 mmHg). Pulmonary artery pulsatility index increased from rest to peak exercise, while pulmonary arterial capacitance and pulmonary vascular resistance declined.

CONCLUSIONS

Patients with HFrEF suffer from marked increases in filling pressures during exercise. These findings provide new insight into cardiopulmonary abnormalities contributing to impairments in exercise capacity in this population.

CLINICAL TRIAL REGISTRATION

clinicaltrials.gov identifier: NCT03078972.

Prognostic Role of Metabolic Exercise Testing in Heart Failure

Heart failure is a clinical syndrome with significant heterogeneity in presentation and severity. Serial risk-stratification and prognostication can guide management decisions, particularly in advanced heart failure, when progression toward advanced therapies or end-of-life care is warranted. Each currently utilized prognostic marker carries its own set of challenges in acquisition, reproducibility, accuracy, and significance. Left ventricular ejection fraction is foundational for heart failure syndrome classification after clinical diagnosis and remains the primary parameter for inclusion in most clinical trials; however, it does not consistently correlate with symptoms and functional capacity, which are also independently prognostic in this patient population. Utilizing the left ventricular ejection fraction as the sole basis of prognostication provides an incomplete characterization of this condition and is prone to misguide medical decision-making when used in isolation. In this review article, we survey and exposit the important role of metabolic exercise testing across the heart failure spectrum, as a complementary diagnostic and prognostic modality. Metabolic exercise testing, also known as cardiopulmonary exercise testing, provides a comprehensive evaluation of the multisystem (i.e., neurological, respiratory, circulatory, and musculoskeletal) response to exercise performance. These differential responses can help identify the predominant contributors to exercise intolerance and exercise symptoms. Additionally, the aerobic exercise capacity (i.e., oxygen consumption during exercise) is directly correlated with overall life expectancy and prognosis in many disease states. Specifically in heart failure patients, metabolic exercise testing provides an accurate, objective, and reproducible assessment of the overall circulatory sufficiency and circulatory reserve during physical stress, being able to isolate the concurrent chronotropic and stroke volume responses for a reliable depiction of the circulatory flow rate in real time.

How Does the Method Used to Measure the VE/VCO2 Slope Affect Its Value? A Cross-Sectional and Retrospective Cohort Study

Cardiopulmonary exercise testing (CPET) was limited to peak oxygen consumption analysis (VO₂peak), and now the ventilation/carbon dioxide production (VE/VCO₂) slope is recognized as having independent prognostic value. Unlike VO₂peak, the VE/VCO₂ slope does not require maximal effort, making it more feasible. There is no consensus on how to measure the VE/VCO₂ slope; therefore, we assessed whether different methods affect its value. This is a retrospective study assessing sociodemographic data, left ventricular ejection fraction, CPET parameters, and indications of patients referred for CPET. The VE/VCO₂ slope was measured to the first ventilatory threshold (VT1-slope), secondary threshold (VT2-slope), and included all test data (full-slope). Of the 697 CPETs analyzed, 308 reached VT2. All VE/VCO₂ slopes increased with age, regardless of test indications. In patients not reaching VT2, the VT1-slope was 32 vs. 36 (p < 0.001) for the full-slope; in those surpassing VT2, the VT1-slope was 29 vs. 33 (p < 0.001) for the VT2-slope and 37 (all p < 0.001) for the full-slope. The mean difference between the submaximal and full-slopes was ±4 units, sufficient to reclassify patients from low to high risk for heart failure or pulmonary hypertension. We conclude that the method used for determining the VE/VCO₂ slope greatly influences the result, the significant variations limiting its prognostic value. The calculation method must be standardized to improve its prognostic value.

Heart failure classification based on resting ejection fraction does not display a unique exercise response pattern

BACKGROUND

Heart failure with preserved (HFpEF), mildly reduced (HFmrEF) and reduced (HFrEF) ejection fraction (EF) remains a controversial categorization. Whether these three categories reflect a distinct pattern of exercise limitation in cardiopulmonary exercise testing (CPET) needs to be investigated. We aimed to analyze whether CPET variables differ between all heart failure categories (HF).

METHODS

We analyzed CPET variables of stable HFpEF (n = 123), HFmrEF (n = 31), and HFrEF (n = 153; 74 patients with and 79 patients without left ventricular assist device, LVAD) patients. The association between HF and peak oxygen consumption (VO_2peak) was used as a primary outcome, while the association between HF, oxygen uptake efficiency slope (OUES), and increase of O₂ pulse (ΔO₂ pulse) were analyzed as secondary outcomes.

RESULTS

VO_2peak displayed a consistent decline across all HF categories (19.8 ml ± 6.2/kg/min vs. 17.5 ± 7.9 ml/kg/min vs. 13.7 ± 4.0 ml/kg/min, p < 0.001). OUES only showed differences between HFpEF and HFrEF (1.8 ± 0.6 vs. 1.4 ± 0.5, p < 0.001) as well as HFmrEF and HFrEF (1.9 ± 0.9 vs. 1.4 ± 0.5, p = 0.004). ΔO₂ pulse differed between HFpEF and HFrEF (7.7 ± 3.5 ml/beat/kg*100 vs. 5.5 ± 3.0 ml/beat/kg*100, p < 0.001) as well as HFpEF and HFmrEF (7.7 ± 3.5 ml/beat/kg*100 vs. 6.3 ± 4.1 ml/beat/kg*100, p = 0.049). Outcome variables did not differ between HFrEF with and without LVAD support (VO_2peak: p = 0.364, OUES: p = 0.129, ΔO₂ pulse: p = 0.564).

CONCLUSIONS

HF did not display a distinct CPET profile. Thus, EF-based categorization does not entirely reflect exercise limitations. CPET variables could contribute to better characterize HF phenotypes.

Age- and sex-stratified normal values for circulatory and ventilatory power during ramp exercise derived from a healthy Japanese population

Circulatory power (CP) and ventilatory power (VP), obtained by cardiopulmonary exercise testing (CPX), have been suggested to be excellent prognostic markers for heart failure. However, the normal values of these parameters in healthy Japanese populations remain unknown; thus, we aimed to investigate these values in such a population. A total of 391 healthy Japanese participants, 20-78 years of age, underwent CPX with a cycle ergometer with ramp protocols. Systolic blood pressure (SBP), heart rate, oxygen uptake ([Formula: see text]O₂) at peak exercise, and the slope of minute ventilation ([Formula: see text]E) versus carbon dioxide ([Formula: see text]CO₂) ([Formula: see text]E vs. [Formula: see text]CO₂ slope) were measured. CP was calculated by multiplying the peak [Formula: see text]O₂ and SBP values, and VP was calculated by dividing the peak SBP value by the [Formula: see text]E versus [Formula: see text]CO₂ slope. For males and females, the average CP values were 6119 ± 1280 (mean ± standard deviation) and 4775 ± 914 mmHg·mL/min/kg, respectively (p < 0.001). The average VP values for males and females were 8.0 ± 1.3 and 6.9 ± 1.3 mmHg (p < 0.001). CP decreased with age in both sexes. VP increased with age in females, with no significant change in males. We calculated the normal values for CP and VP in a healthy Japanese population. The results can contribute to the evaluation of patients' CPX results as a reference.

Effect of Traditional Chinese Exercises on Patients with Chronic Heart Failure (TCE-HF): A Systematic Review and Meta-Analysis

Exercise-based cardiac rehabilitation is safe and effective for chronic heart failure (CHF) patients. The present study aimed to investigate the effects of traditional Chinese exercise (TCE) on patients with CHF and the impact of exercise types and duration. Evaluation of randomized controlled trials (RCTs) of TCE in patients with CHF published since 1997 from PubMed, Embase, Web of Science, the Cochrane Library, Chongqing VIP, Wanfang Databases, and the China National Knowledge was performed. A total of 41 RCTs, including 3209 patients with CHF, were included. It showed that TCE significantly increased 6-min walk distance (6MWD) [mean difference (MD) = 72.82 m, p < 0.001] and left ventricular ejection fraction (MD = 5.09%, p < 0.001), whereas reduced B-type natriuretic peptide (BNP) (MD = −56.80 pg/mL, p < 0.001), N-terminal pro-BNP (MD = −174.94 pg/mL, p < 0.05), and Minnesota Living with Heart Failure Questionnaire scores (MD = −11.31, p < 0.001). However, no significant difference was found in the effects of TCE on peak oxygen consumption. The increase in TCE weekly duration and program duration significantly improved 6MWD (MD = 71.91 m, p < 0.001; MD = 74.11 m, p < 0.001). The combination of TCE and conventional aerobic exercise significantly improved 6MWD (MD = 19.86 m, p < 0.005). TCE improves exercise capacity, cardiac function, and quality of life in patients with CHF, which might be an optimal and available pattern of exercise-based cardiac rehabilitation.

[Cardiopulmonary exercise testing for exercise prescription in cardiac rehabilitation]

Aerobic endurance training is a core component of exercise training (ET) during cardiac rehabilitation (CR). Improvements of cardiopulmonary performance and symptom-free exercise capacity that can be achieved by ET during CR are essential for patient's prognosis and quality of life. Before initiating exercise training in CR, a detailed risk stratification including incremental exercise testing is required in order to ensure safe and effective exercise training conditions. Cardiopulmonary exercise testing (CPX) with measurement of respiratory gases is considered the gold standard of cardiopulmonary performance diagnostics. The oxygen uptake measured at the highest exercise intensity achieved (peakVO₂) has strong prognostic implications in primary and secondary prevention of cardiovascular diseases, respectively. The use of CPX with measurement of peakVO₂ and determination of ventilatory thresholds (VT) enables a reliable determination of the individual cardiopulmonary performance (peakVO₂) and also the aerobic exercise capacity. In addition, CPX is a valuable tool to detect increments in exercise capacity that were achieved by ET during CR. The measurement of peakVO₂ and the determination of ventilatory thresholds are basic parameters for an individually tailored exercise prescription. In addition, the targeted control of aerobic endurance training on the basis of CPX parameters increases the effectiveness and safety of the exercise program during CR. In this article, recommendations for an individual exercise prescription, based on the results of CPX, are given for patients with coronary heart disease (CHD), heart failure, as well as for patients with CHD and concomitant type 2 diabetes mellitus.

Sex differences in heart failure patients assessed by combined echocardiographic and cardiopulmonary exercise testing

Background

We aimed to test the differences in peak VO₂ between males and females in patients diagnosed with heart failure (HF), using combined stress echocardiography (SE) and cardiopulmonary exercise testing (CPET).

Methods

Patients who underwent CPET and SE for evaluation of dyspnea or exertional intolerance at our institution, between January 2013 and December 2017, were included and retrospectively assessed. Patients were divided into three groups: HF with preserved ejection fraction (HFpEF), HF with mildly reduced or reduced ejection fraction (HFmrEF/HFrEF), and patients without HF (control). These groups were further stratified by sex.

Results

One hundred seventy-eight patients underwent CPET-SE testing, of which 40% were females. Females diagnosed with HFpEF showed attenuated increases in end diastolic volume index (P = 0.040 for sex × time interaction), significantly elevated E/e' (P < 0.001), significantly decreased left ventricle (LV) end diastolic volume:E/e ratio (P = 0.040 for sex × time interaction), and lesser increases in A-VO₂ difference (P = 0.003 for sex × time interaction), comparing to males with HFpEF. Females diagnosed with HFmrEF/HFrEF showed diminished increases in end diastolic volume index (P = 0.050 for sex × time interaction), mostly after anaerobic threshold was met, comparing to males with HFmrEF/HFrEF. This resulted in reduced increases in peak stroke volume index (P = 0.010 for sex × time interaction) and cardiac output (P = 0.050 for sex × time interaction).

Conclusions

Combined CPET-SE testing allows for individualized non-invasive evaluation of exercise physiology stratified by sex. Female patients with HF have lower exercise capacity compared to men with HF. For females diagnosed with HFpEF, this was due to poorer LV compliance and attenuated peripheral oxygen extraction, while for females diagnosed with HFmrEF/HFrEF, this was due to attenuated increase in peak stroke volume and cardiac output. As past studies have shown differences in clinical outcomes between females and males, this study provides an essential understanding of the differences in exercise physiology in HF patients, which may improve patient selection for targeted therapeutics.

Cardiopulmonary exercise testing for heart failure: pathophysiology and predictive markers

Despite the numerous recent advancements in therapy, heart failure (HF) remains a principle cause of both morbidity and mortality. HF with preserved ejection fraction (HFpEF), a condition that shares the prevalence and adverse outcomes of HF with reduced ejection fraction, remains poorly recognised in its initial manifestations. Cardiopulmonary exercise testing (CPET), defined as a progressive work exercise test that includes non-invasive continuous measurement of cardiovascular and respiratory parameters, provides a reliable mode to evaluate for early features and for the assessment of prognostic features of both forms of HF. While CPET measurements are standard of care for advanced HF and transplant programmes, they merit a broader clinical application in the early diagnosis and assessment of patients with HFpEF. In this review, we provide an overview of the pathophysiology of exercise intolerance in HF and discuss key findings in CPETs used to evaluate both severity of impairment and the prognostic implications.

Rapid cardiovascular aging following allogeneic hematopoietic cell transplantation for hematological malignancy

Introduction

Allogeneic hematopoietic cell transplantation (allo-HCT) offers a potential cure for high-risk hematological malignancy; however, long-term survivors experience increased cardiovascular morbidity and mortality. It is unclear how allo-HCT impacts cardiovascular function in the short-term. Thus, this 3-month prospective study sought to evaluate the short-term cardiovascular impact of allo-HCT in hematological cancer patients, compared to an age-matched non-cancer control group.

Methods

Before and ~3-months following allo-HCT, 17 hematological cancer patients (45 ± 18 years) underwent cardiopulmonary exercise testing to quantify peak oxygen uptake (VO₂peak)-a measure of integrative cardiovascular function. Then, to determine the degree to which changes in VO₂peak are mediated by cardiac vs. non-cardiac factors, participants underwent exercise cardiac MRI (cardiac reserve), resting echocardiography (left-ventricular ejection fraction [LVEF], global longitudinal strain [GLS]), dual-energy x-ray absorptiometry (lean [LM] and fat mass [FM]), blood pressure (BP) assessment, hemoglobin sampling, and arteriovenous oxygen difference (a-vO₂diff) estimation via the Fick equation. Twelve controls (43 ± 13 years) underwent identical testing at equivalent baseline and 3-month time intervals.

Results

Significant group-by-time interactions were observed for absolute VO₂peak (p = 0.006), bodyweight-indexed VO₂peak (p = 0.015), LM (p = 0.001) and cardiac reserve (p = 0.019), which were driven by 26, 24, 6, and 26% reductions in the allo-HCT group (all p ≤ 0.001), respectively, as no significant changes were observed in the age-matched control group. No significant group-by-time interactions were observed for LVEF, GLS, FM, hemoglobin, BP or a-vO₂diff, though a-vO₂diff declined 12% in allo-HCT (p = 0.028).

Conclusion

In summary, allo-HCT severely impairs VO₂peak, reflecting central and peripheral dysfunction. These results indicate allo-HCT rapidly accelerates cardiovascular aging and reinforces the need for early preventive cardiovascular intervention in this high-risk group.

Peak Work Rate Increases With Lower Extremity-Focused Exercise Training in Adolescents With Fontan Circulation

Background Skeletal muscle deficits are associated with worse exercise performance in the Fontan circulation and may be improved by exercise training. We aimed to assess the change in leg lean mass (a marker of skeletal muscle), exercise performance, and functional health status after a lower extremity-focused exercise intervention in adolescents with Fontan circulation. Methods and Results Densitometry for measurement of leg lean mass, cardiopulmonary exercise test, exercise cardiac magnetic resonance, peripheral vascular testing, physical activity questionnaire, and quality of life assessment were performed at baseline and after a 24-week, hybrid center- and home-based training program. Leg lean mass Z-scores were generated, and exercise parameters were expressed as percentage expected based on reference data. The effect of training was assessed by paired t-tests and simple linear regression. Twenty participants (15.6±1.7 years, 50% male) demonstrated low baseline leg lean mass Z-scores with no significant improvement with training (-1.38±1.02 pre versus -1.31±1.06 post, P=0.33). Maximum and percent predicted work increased from 121.9±29.8 (0.66±0.12) to 131.3±35.1 (0.70±0.15) watts (P=0.02). Peak respiratory exchange ratio increased (1.19±0.02 versus 1.25±0.01, P=0.02) but percent predicted oxygen consumption was unchanged, suggesting higher anaerobic activity after training. Physical activity questionnaire score positively associated with peak work at baseline (ß=18.13 [95% CI, 0.83-35.44], R²=0.21; P=0.04) but physical activity questionnaire, quality of life scores, exercise cardiac magnetic resonance performance, and peripheral vascular function were unchanged with training. Conclusions Peak work rate and anaerobic activity increased with lower extremity-focused training in adolescents with Fontan circulation. Larger studies should test the impact of these changes on functional status and quality of life.

Association Between Upper Limb Strength Through 1-Repetition Maximum Test and V'O2peak in Heart Failure

Purpose: This study aimed to evaluate whether there is a correlation between the maximum strength of upper limb when performing a multijoint exercise and peak oxygen uptake (V'O_2peak) in Chronic Heart Failure (CHF) subjects. Method: This cross-sectional study involved CHF subjects with a left ventricular ejection fraction (LVEF) less than 50%, who underwent a cardiopulmonary exercise test (CPET) on a treadmill and 1-repetition maximum (1-RM) test for upper limb strength using a bench press exercise. Results: The sample consisted of 16 individuals aged 54 ± 12 years with a LVEF of 37 ± 7%. The V'O_2peak was 14.98 ± 5.4 ml·min^-1·kg^-1 and mean maximum load in the 1-RM test was 38 ± 16 kg. There was strong correlation of V'O_2peak with the load in the 1-RM test (r = 0.70; p = .037; r² = 0.48). Conclusion: There is a strong correlation between the load in 1-RM test for upper limb with V'O_2peak in CHF individuals. It is a safe, inexpensive and reproducible way to assess the muscle strength in this population.

Editor's Choice - The Abdominal Aortic Aneurysm Get Fit Trial: A Randomised Controlled Trial of Exercise to Improve Fitness in Patients with Abdominal Aortic Aneurysm

OBJECTIVE

Ruptured abdominal aortic aneurysm (AAA) carries a mortality rate of up to 80%. Elective repair prevents rupture, but peri-operative mortality remains at 2% - 3%. This mortality rate and long term survival rate are associated with impaired peak oxygen uptake (peak VO₂), oxygen uptake at anaerobic threshold (AT) and ventilatory equivalent for CO₂ (VECO₂) at AT on cardiopulmonary exercise testing (CPET). Improving fitness to optimise these variables could improve peri-operative and long term survival, but the required exercise training suitable for patients with AAA has yet to be established. This randomised controlled trial aimed to evaluate the effectiveness of 24 week, patient directed, community based exercise on CPET measured fitness in AAA surveillance patients.

METHODS

This was a prospective randomised controlled trial in a tertiary UK vascular centre conducted using CONSORT guidelines. Patients on AAA surveillance (n = 56) were randomly assigned to either (1) a 24 week community exercise programme (CEP) with choice of gym or home exercises, or (2) standard clinical care including advice on weight loss and exercise. The primary outcome was change in peak VO₂ at 24 weeks, with secondary outcomes including AT, VECO₂, cardiovascular biomarkers (lipid profile, pro-B-type natriuretic peptide, and high sensitivity C reactive protein, body mass index, and HRQoL. Follow up was at eight, 16, 24, and 36 weeks to evaluate duration of benefit. All analyses were performed on an intention to treat basis.

RESULTS

CEP patients (n = 28) achieved mean (95% confidence interval [CI]) improvements from baseline in peak VO₂ of 1.5 (95% CI 0.5 - 2.5), 2.1 (95% CI 1.1 - 3.2), 2.3 (95% CI 1.2 - 3.3), and 2.2 (95% CI 1.1, 3.3) mL/kg/min at 8, 16, 24, and 36 weeks, respectively. These changes in CEP patients were significantly greater than those seen in control patients at 16 (p = .002), 24 (p = .031), and 36 weeks (p < .001). There were also significant improvements in AT, triglyceride levels, and HRQoL in CEP patients.

CONCLUSION

This CEP significantly improved those CPET parameters associated with impaired peri-operative and long term survival in patients following AAA repair. These improvements were maintained at 12 weeks following the end of the programme.

The association of exercise test variables with long-term mortality in patients with chronic Chagas disease

Background

The identification of variables obtained in the exercise test (ET) associated with increased risk of death is clinically relevant and would provide additional information for the management of Chagas disease (CD). The objective of the present study was to evaluate the association of ET variables with mortality in patients with chronic CD.

Methods

This retrospective longitudinal observational study included 232 patients (median age 46.0 years; 50% women) with CD that were followed at the Evandro Chagas National Institute of Infectious Diseases (Rio de Janeiro, Brazil) and performed an ET between 1989 and 2000. The outcome of interest was all-cause mortality.

Results

There were 103 deaths (44.4%) during a median follow-up of 21.5 years (IQR 25–75% 8.0–27.8), resulting in 24.5 per 1,000 patients/year incidence rate. The ET variables associated with mortality after adjustments for potential confounders were increased maximal (HR 1.02; 95% CI 1.00–1.03 per mmHg) and change (HR 1.03; 95% CI 1.01–1.06 per mmHg) of diastolic blood pressure (DBP) during ET, ventricular tachycardia at rest (HR 3.95; 95% CI 1.14–13.74), during exercise (HR 2.73; 95% CI 1.44–5.20), and recovery (HR 2.60; 95% CI 1.14–5.91), and premature ventricular complexes during recovery (HR 2.06; 1.33–3.21).

Conclusion

Our findings suggest that ET provides important prognostic value for mortality risk assessment in patients with CD, with hemodynamic (increased DBP during exercise) and electrocardiographic (presence of ventricular arrhythmias) variables independently associated with an increased mortality risk in patients with CD. The identification of individuals at higher mortality risk can facilitate the development of intervention strategies (e.g., close follow-up) that may potentially have an impact on the longevity of patients with CD.

Development and appropriateness of a scoring method for International Classification of Functioning, Disabilities, and Health assessment in older patients with heart failure: a Delphi survey of expert panel in Japan

OBJECTIVE

The number of older patients with heart failure (HF) is increasing in Japan and has become a social problem. There is an urgent need to develop a comprehensive assessment methodology based on the common language of healthcare; the International Classification of Functioning, Disability and Health (ICF). The purpose of this study was to develop and confirm the appropriateness of a scoring methodology for 43 ICF categories in older people with HF.

DESIGN

Cross-sectional survey. We applied the RAND/University of California at Los Angeles (UCLA) Appropriateness Method with a modified Delphi method.

SETTING AND PARTICIPANTS

We included a panel of 26 multidisciplinary experts on HF care consisting of home physicians, cardiovascular physicians, care managers, nurses, physical therapists, a pharmacist, occupational therapist, nutritionist and a social worker.

MEASURES

We conducted a literature review of ICF linking rules and developed a questionnaire on scoring methods linked to ICF categories in older people with HF. In the Delphi rounds, we sent the expert panel a questionnaire consisting of three questions for each of the 43 ICF categories. The expert panel responded to the questionnaire items on a 1 (very inappropriate) - 9 (very appropriate) Likert scale and repeated rounds until a consensus of 'Appropriate' and 'Agreement' was reached on all items.

RESULTS

A total of 21 panel members responded to all the Delphi rounds. In the first Delphi round, six question items in four ICF categories did not reach a consensus of 'Agreement', but the result of our modifications based on panel members' suggestions reached to a consensus of 'Appropriate' and 'Agreement' on all questions in the second Delphi round.

CONCLUSION

The ICF-based scoring method for older people with HF developed in this study was found to be appropriate. Future work is needed to clarify whether comprehensive assessment and information sharing based on ICF contributes to preventing readmissions.

Resistance Training in Patients With Coronary Artery Disease, Heart Failure, and Valvular Heart Disease: A REVIEW WITH SPECIAL EMPHASIS ON OLD AGE, FRAILTY, AND PHYSICAL LIMITATIONS

PURPOSE

Current guidelines recommend individually adapted resistance training (RT) as a part of the exercise regime in patients with cardiovascular diseases. The aim of this review was to provide insights into current knowledge and understanding of how useful, feasible, safe, and effective RT is in patients with coronary artery disease (CAD), heart failure (HF), and valvular heart disease (VHD), with particular emphasis on the role of RT in elderly and/or frail patients.

REVIEW METHODS

A review based on an intensive literature search: systematic reviews and meta-analyses published in 2010 or later; recent studies not integrated into meta-analyses or systematic reviews; additional manual searches.

SUMMARY

The results highlight the evaluation of effects and safety of RT in patients with CAD and HF with reduced ejection fraction (HFrEF) in numerous meta-analyses. In contrast, few studies have focused on RT in patients with HF with preserved ejection fraction (HFpEF) or VHD. Furthermore, few studies have addressed the feasibility and impact of RT in elderly cardiac patients, and data on the efficacy and safety of RT in frail elderly patients are limited. The review results underscore the high prevalence of age-related sarcopenia, disease-related skeletal muscle deconditioning, physical limitations, and frailty in older patients with cardiovascular diseases (CVD). They underline the need for individually tailored exercise concepts, including RT, aimed at improving functional status, mobility, physical performance and muscle strength in older patients. Furthermore, the importance of the use of assessment tools to diagnose frailty, mobility/functional capacity, and physical performance in the elderly admitted to cardiac rehabilitation is emphasized.

Heart Failure in Cardiac Rehabilitation: A REVIEW AND PRACTICAL CONSIDERATIONS

PURPOSE

Exercise cardiac rehabilitation (CR) represents an evidence-based therapy for patients with heart failure with reduced ejection fraction (HFrEF) and this article provides a concise review of the relevant exercise testing and CR literature, including aspects unique to their care.

CLINICAL CONSIDERATIONS

A hallmark feature of HFrEF is exercise intolerance (eg, early-onset fatigue). Drug therapies for HFrEF target neurohormonal pathways to blunt negative remodeling of the cardiac architecture and restore favorable loading conditions. Guideline drug therapy includes β-adrenergic blocking agents; blockade of the renin-angiotensin system; aldosterone antagonism; sodium-glucose cotransport inhibition; and diuretics, as needed.

EXERCISE TESTING AND TRAINING

Various assessments are used to quantify exercise capacity in patients with HFrEF, including peak oxygen uptake measured during an exercise test and 6-min walk distance. The mechanisms responsible for the exercise intolerance include abnormalities in ( a ) central transport (chronotropic response, stroke volume) and ( b ) the diffusion/utilization of oxygen in skeletal muscles. Cardiac rehabilitation improves exercise capacity, intermediate physiologic measures (eg, endothelial function and sympathetic nervous system activity), health-related quality of life (HRQoL), and likely clinical outcomes. The prescription of exercise in patients with HFrEF is generally similar to that for other patients with cardiovascular disease; however, patients having undergone an advanced surgical therapy do present with features that require attention.

SUMMARY

Few patients with HFrEF enroll in CR and as such, many miss the derived benefits, including improved exercise capacity, a likely reduction in risk for subsequent clinical events (eg, rehospitalization), improved HRQoL, and adoption of disease management strategies.

Could SGLT2 Inhibitors Improve Exercise Intolerance in Chronic Heart Failure?

Despite the constant improvement of therapeutical options, heart failure (HF) remains associated with high mortality and morbidity. While new developments in guideline-recommended therapies can prolong survival and postpone HF hospitalizations, impaired exercise capacity remains one of the most debilitating symptoms of HF. Exercise intolerance in HF is multifactorial in origin, as the underlying cardiovascular pathology and reactive changes in skeletal muscle composition and metabolism both contribute. Recently, sodium-related glucose transporter 2 (SGLT2) inhibitors were found to improve cardiovascular outcomes significantly. Whilst much effort has been devoted to untangling the mechanisms responsible for these cardiovascular benefits of SGLT2 inhibitors, little is known about the effect of SGLT2 inhibitors on exercise performance in HF. This review provides an overview of the pathophysiological mechanisms that are responsible for exercise intolerance in HF, elaborates on the potential SGLT2-inhibitor-mediated effects on these phenomena, and provides an up-to-date overview of existing studies on the effect of SGLT2 inhibitors on clinical outcome parameters that are relevant to the assessment of exercise capacity. Finally, current gaps in the evidence and potential future perspectives on the effects of SGLT2 inhibitors on exercise intolerance in chronic HF are discussed.

Cardiopulmonary exercise responses in patients with non-ischemic heart failure and a mildly reduced ejection fraction

Background: The cardiopulmonary response to exercise in patients with heart failure exhibiting a mildly reduced ejection fraction (41% ≤ EF ≤ 49%) remains unclear. Materials & methods: A total of 193 consecutive patients with heart failure (excluding those with coronary artery disease) who underwent cardiopulmonary exercise (CPX) tests were examined. CPX variables were compared among patients with reduced, mildly reduced, and preserved EF. Results: The CPX test responses of patients with mildly reduced EF were similar to those of patients with reduced or preserved EF; however, increases in systolic blood pressure during exercise differed significantly (32 ± 26, 50 ± 24, and 41 ± 31 mmHg, respectively; p = 0.016). Grip strength and an increase in systolic blood pressure during exercise were independently associated with peak oxygen uptake in patients with mildly reduced EF (β = 0.41, 0.35, respectively; p < 0.05). Conclusion: Measurements of grip strength and blood pressure during exercise are useful predictors of prognoses in patients with non-ischemic and mildly reduced EF.

Adult patients with allied disorders of Hirschsprung’s disease in emergency department: An 11-year retrospective study

BACKGROUND

In the past years, only a few studies with a limited number of adult patients analyzed clinical features of allied disorders of Hirschsprung’s disease (ADHD), most of which were individual case reports or lacked detailed clinical information. Although many studies have reported patients presenting to the emergency department (ED) with recurrent abdominal symptoms for a number of disorders, there are few data involving ADHD. However, owing to a lack of awareness of the disease, misdiagnoses and mistreatments are common. Severe complications such as perforation, bleeding, malabsorption, and even death in ADHD had been reported by many studies.

AIM

To assist ED clinicians in having a more comprehensive understanding of this disease and making an early suspected diagnosis of ADHD more effectively.

METHODS

We enrolled 53 patients who visited the ED and were eventually diagnosed with ADHD over the past 11 years in our hospital. Their basic information, clinical manifestations, and imaging findings were analyzed. Blood indices were compared between the ADHD and irritable bowel syndrome (IBS) groups.

RESULTS

Adult patients with ADHD had a mean age of 48.8 ± 14.3 years, and 77.4% had been treated before admission. The transverse colon was the most common dilated part (73.6%), and constipation (67.9%) was the most common symptom. ADHD patients can present with uncommon symptoms and false-negative imaging findings. Logistic regression analysis indicated that body mass index (BMI) [odds ratio (OR) = 0.786, P = 0.013], cholinesterase (per 1000 units; OR = 0.693, P = 0.008), and blood chlorine (OR = 0.816, P = 0.022) were determined to be independent related factors between the ADHD and IBS groups. The area under the receiver operating characteristics curve of these three indices combined was 0.812 (P < 0.001).

CONCLUSION

Emergency physicians should be vigilant regarding patients with chronic constipation, abdominal pain, or abdominal distension, and consider the possibility of ADHD despite its rarity. Abdominal computed tomography examination is recommended as a useful tool in the suspected diagnosis of ADHD. BMI, cholinesterase, and blood chlorine have good discriminative abilities between ADHD and IBS. The nutritional status of adult patients with ADHD is worthy of further attention. Surgical treatment for adult patients with ADHD is important and inevitable.

Increases in Hepatokine Selenoprotein P Levels Are Associated With Hepatic Hypoperfusion and Predict Adverse Prognosis in Patients With Heart Failure

Background

Although multiorgan networks are involved in the pathophysiology of heart failure (HF), interactions of the heart and the liver have not been fully understood. Hepatokines, which are synthesized and secreted from the liver, have regulatory functions in peripheral tissues. Here, we aimed to clarify the clinical impact of the hepatokine selenoprotein P in patients with HF.

Methods and Results

This is a prospective observational study that enrolled 296 participants consisting of 253 hospitalized patients with HF and 43 control subjects. First, we investigated selenoprotein P levels and found that its levels were significantly higher in patients with HF than in the controls. Next, patients with HF were categorized into 4 groups according to the presence of liver congestion using shear wave elastography and liver hypoperfusion by peak systolic velocity of the celiac artery, which were both assessed by abdominal ultrasonography. Selenoprotein P levels were significantly elevated in patients with HF with liver hypoperfusion compared with those without but were not different between the patients with and without liver congestion. Selenoprotein P levels were negatively correlated with peak systolic velocity of the celiac artery, whereas no correlations were observed between selenoprotein P levels and shear wave elastography of the liver. Kaplan‐Meier analysis demonstrated that patients with HF with higher selenoprotein P levels were significantly associated with increased adverse cardiac outcomes including cardiac deaths and worsening HF.

Conclusions

Liver‐derived selenoprotein P correlates with hepatic hypoperfusion and may be a novel target involved in cardiohepatic interactions as well as a useful biomarker for predicting prognosis in patients with HF.

Frailty Status Modifies the Efficacy of Exercise Training Among Patients With Chronic Heart Failure and Reduced Ejection Fraction: An Analysis From the HF-ACTION Trial

BACKGROUND

Supervised aerobic exercise training (ET) is recommended for stable outpatients with heart failure (HF) with reduced ejection fraction (HFrEF). Frailty, a syndrome characterized by increased vulnerability and decreased physiologic reserve, is common in patients with HFrEF and associated with a higher risk of adverse outcomes. The effect modification of baseline frailty on the efficacy of aerobic ET in HFrEF is not known.

METHODS

Stable outpatients with HFrEF randomized to aerobic ET versus usual care in the HF-ACTION (Heart Failure: A Controlled Trial Investigating Outcomes of Exercise Training) trial were included. Baseline frailty was estimated using the Rockwood frailty index (FI), a deficit accumulation-based model of frailty assessment; participants with FI scores >0.21 were identified as frail. Multivariable Cox proportional hazard models with multiplicative interaction terms (frailty treatment arm) were constructed to evaluate whether frailty modified the treatment effect of aerobic ET on the primary composite end point (all-cause hospitalization and mortality), secondary end points (composite of cardiovascular death or cardiovascular hospitalization, and cardiovascular death or HF hospitalization), and Kansas City Cardiomyopathy Questionnaire score. Separate models were constructed for continuous (FI) and categorical (frail versus not frail) measures of frailty.

RESULTS

Among 2130 study participants (age, 59±13 years; 28% women), 1266 (59%) were characterized as frail (FI>0.21). Baseline frailty burden significantly modified the treatment effect of aerobic ET (P interaction: FI × treatment arm=0.02; frail status [frail versus nonfrail] × treatment arm=0.04) with a lower risk of primary end point in frail (hazard ratio [HR], 0.83 [95% CI, 0.72-0.95]) but not nonfrail (HR, 1.04 [95% CI, 0.87-1.25]) participants. The favorable effect of aerobic ET among frail participants was driven by a significant reduction in the risk of all-cause hospitalization (HR, 0.84 [95% CI, 0.72-0.99]). The treatment effect of aerobic ET on all-cause mortality and other secondary endpoints was not different between frail and nonfrail patients (P interaction>0.1 for each). Aerobic ET was associated with a nominally greater improvement in Kansas City Cardiomyopathy Questionnaire scores at 3 months among frail versus nonfrail participants without a significant treatment interaction by frailty status (P interaction>0.2).

CONCLUSION

Among patients with chronic stable HFrEF, baseline frailty modified the treatment effect of aerobic ET with a greater reduction in the risk of all-cause hospitalization but not mortality.

2022 AHA/ACC/HFSA Guideline for the Management of Heart Failure: A Report of the American College of Cardiology/American Heart Association Joint Committee on Clinical Practice Guidelines

AIM

The "2022 AHA/ACC/HFSA Guideline for the Management of Heart Failure" replaces the "2013 ACCF/AHA Guideline for the Management of Heart Failure" and the "2017 ACC/AHA/HFSA Focused Update of the 2013 ACCF/AHA Guideline for the Management of Heart Failure." The 2022 guideline is intended to provide patient-centric recommendations for clinicians to prevent, diagnose, and manage patients with heart failure.

METHODS

A comprehensive literature search was conducted from May 2020 to December 2020, encompassing studies, reviews, and other evidence conducted on human subjects that were published in English from MEDLINE (PubMed), EMBASE, the Cochrane Collaboration, the Agency for Healthcare Research and Quality, and other relevant databases. Additional relevant clinical trials and research studies, published through September 2021, were also considered. This guideline was harmonized with other American Heart Association/American College of Cardiology guidelines published through December 2021. Structure: Heart failure remains a leading cause of morbidity and mortality globally. The 2022 heart failure guideline provides recommendations based on contemporary evidence for the treatment of these patients. The recommendations present an evidence-based approach to managing patients with heart failure, with the intent to improve quality of care and align with patients' interests. Many recommendations from the earlier heart failure guidelines have been updated with new evidence, and new recommendations have been created when supported by published data. Value statements are provided for certain treatments with high-quality published economic analyses.

2022 AHA/ACC/HFSA Guideline for the Management of Heart Failure

AIM

The "2022 AHA/ACC/HFSA Guideline for the Management of Heart Failure" replaces the "2013 ACCF/AHA Guideline for the Management of Heart Failure" and the "2017 ACC/AHA/HFSA Focused Update of the 2013 ACCF/AHA Guideline for the Management of Heart Failure." The 2022 guideline is intended to provide patient-centric recommendations for clinicians to prevent, diagnose, and manage patients with heart failure.

METHODS

A comprehensive literature search was conducted from May 2020 to December 2020, encompassing studies, reviews, and other evidence conducted on human subjects that were published in English from MEDLINE (PubMed), EMBASE, the Cochrane Collaboration, the Agency for Healthcare Research and Quality, and other relevant databases. Additional relevant clinical trials and research studies, published through September 2021, were also considered. This guideline was harmonized with other American Heart Association/American College of Cardiology guidelines published through December 2021.

STRUCTURE

Heart failure remains a leading cause of morbidity and mortality globally. The 2022 heart failure guideline provides recommendations based on contemporary evidence for the treatment of these patients. The recommendations present an evidence-based approach to managing patients with heart failure, with the intent to improve quality of care and align with patients' interests. Many recommendations from the earlier heart failure guidelines have been updated with new evidence, and new recommendations have been created when supported by published data. Value statements are provided for certain treatments with high-quality published economic analyses.

Peak oxygen uptake is a strong prognostic predictor for pulmonary hypertension due to left heart disease

Background

Pulmonary hypertension in left heart disease (PH-LHD), which includes combined post- and precapillary PH (Cpc-PH) and isolated postcapillary PH (Ipc-PH), differs significantly in prognosis. We aimed to assess whether cardiopulmonary exercise testing (CPET) predicts the long-term survival of patients with PH-LHD.

Methods

A single-center observational cohort enrolled 89 patients with PH-LHD who had undergone right heart catherization and CPET (mean pulmonary arterial pressure > 20 mm Hg and pulmonary artery wedge pressure ≥ 15 mm Hg) between 2013 and 2021. A receiver operating characteristic curve was plotted to determine the cutoff value of all-cause death. Survival was estimated using the Kaplan–Meier method and analyzed using the log-rank test. The Cox proportional hazards model was performed to determine the association between CPET and all-cause death.

Results

Seventeen patients died within a mean of 2.2 ± 1.3 years. Compared with survivors, nonsurvivors displayed a significantly worse 6-min walk distance, workload, exercise time and peak oxygen consumption (VO₂)/kg with a trend of a lower oxygen uptake efficiency slope (OUES) adjusted by Bonferroni’s correction. Multivariate Cox regression revealed that the peak VO₂/kg was significantly associated with all-cause death after adjusting for Cpc-PH/Ipc-PH. Compared with Cpc-PH patients with a peak VO₂/kg ≥ 10.7 ml kg⁻¹ min⁻¹, Ipc-PH patients with a peak VO₂/kg < 10.7 ml kg⁻¹ min⁻¹ had a worse survival (P < 0.001).

Conclusions

The peak VO₂/kg is independently associated with all-cause death in patients with PH-LHD. The peak VO₂/kg can also be analyzed together with Cpc-PH/Ipc-PH to better indicate the prognosis of patients with PH-LHD.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12872-022-02574-0.

Exercise Prescription Enhances Maximal Oxygen Uptake and Anaerobic Threshold in Young Single Ventricle Patients with Fontan Circulation

A modified Fontan procedure is performed to palliate single ventricle malformations. This hemodynamic arrangement sets systemic venous pressure unphysiologically high which predisposes the patient to severe long-term complications. As a means of self-care, exercise may ease transpulmonary flow. We investigated the effects of 6-month exercise prescription on pediatric Fontan patients. Eighteen stable Fontan patients (14 ± 2.6 years, 160.4 ± 11.3 cm, and 51.4 ± 14.4 kg) were recruited. Baseline fitness was assessed by physical activity questionnaire, body composition, cardiorespiratory performance, and muscle fitness tests. Exercise prescription was individually tailored for a 6-month training period at home. At entrance to the study, Fontan patients had lower than normal maximal oxygen uptake (VO_2max) of 28. ± 5.9 ml/kg/min (61 ± 11% of normal). VO_2max significantly correlated with weekly amount of habitual exercise and muscle mass of the lower limbs (p < 0.001 for both). After 6 months of training, the patients had improved their anaerobic threshold of 18 ± 3.5 vs 20 ± 4.8 ml/kg/min, p = 0.007, and workload tolerance of 119 ± 39 vs 132.4 ± 44 W, p = 0.001. At EUROFIT tests, the patient muscle fitness was below age-matched reference, but correlations existed between VO_2max and lower limb muscle tests. Our patients with Fontan hemodynamics were able to positively respond to an exercise program by enhancing submaximal performance which should be beneficial for getting through daily activities. Future studies should correlate whether hemodynamic findings at Fontan completion influence physical activity and exercise reserves, and whether these predict predisposition to chronic complications.

Cardiopulmonary function during exercise in heart failure with reduced ejection fraction following baroreflex activation therapy

PURPOSE

Baroreflex activation therapy has favorable effects in heart failure patients. We report the results of a single-center study of baroreflex activation therapy in heart failure with reduced ejection fraction including cardiopulmonary exercise testing for the first time to show the effect on exercise capacity.

METHODS

A total of 17 patients were treated with baroreflex activation therapy. Eligibility criteria were the New York Heart Association class ⩾III and ejection fraction ⩽35% on guideline-directed medical and device therapy. The New York Heart Association class, quality of life, and 6-min hall walk distance were assessed in all patients. Twelve patients underwent cardiopulmonary exercise testing before and 8.9 ± 6.4 months after initiation of baroreflex activation therapy.

RESULTS

The New York Heart Association class and 6-min hall walk distance improved after baroreflex activation therapy, while quality of life remained stable. Weight-adapted peak oxygen uptake increased significantly from 10.1 (8.2-12.9) ml/min/kg to 12.1 (10.4-14.6) ml/min/kg (p = 0.041). Maximal heart rate was stable. Maximal oxygen pulse increased from 9.7 (5.5-11.3) to 9.9 (7.1-12.1) ml/heartbeat (p = 0.047) in 10 patients with low maximal oxygen pulse at baseline (<16.5 ml/heartbeat). There was no significant change in maximal oxygen pulse in the whole cohort. Ventilatory efficiency remained stable.

CONCLUSION

Weight-adapted peak oxygen uptake improved after baroreflex activation therapy, pointing to an enhanced exercise capacity. Ventilatory efficiency and heart rate did not change, while oxygen pulse increased in patients with low oxygen pulse at baseline, indicating an improvement in circulatory efficiency, that is, a beneficial effect on stroke volume and peripheral oxygen extraction.

Right ventricular function and its coupling to pulmonary circulation predicts exercise tolerance in systolic heart failure

Aims

Right ventricular (RV) dysfunction, pulmonary hypertension, and exercise intolerance have prognostic values, but their interrelation is not fully understood. We investigated how RV function alone and its coupling with pulmonary circulation (RV‐PA) predict cardio‐respiratory fitness in patients with heart failure and reduced ejection fraction (HFrEF).

Methods and results

The Evaluation of Resynchronization Therapy for Heart Failure (EARTH) study included 205 HFrEF patients with narrow (n = 85) and prolonged (n = 120) QRS duration undergoing implantable cardioverter defibrillator implantation. All patients underwent a comprehensive evaluation with exercise tolerance tests and echocardiography. We investigated the correlations at baseline between RV parameters {size, function [tricuspid annular plane systolic excursion (TAPSE), RV fractional area change (RV‐FAC), and RV myocardial performance index (RV‐MPI)], pulmonary artery systolic pressure (PASP), and tricuspid regurgitation}; left ventricular ejection fraction (LVEF), left ventricular end‐diastolic volume index (LVEDVi), and left atrial volume index (LAVi); and cardiopulmonary exercise test (CPET) [peak VO₂, minute ventilation/carbon dioxide production (VE/VCO₂), 6 min walk distance (6MWD), and submaximal exercise duration (SED)]. We also studied the relationship between RV‐PA coupling (TAPSE/PASP ratio) and echocardiographic parameters in patients with both data available. Univariate and multivariate linear regression models were used. Patients enrolled in EARTH (overall population) were mostly male (73.2%), mean age 61.0 ± 9.8 years, New York Heart Association class II–III (87.8%), mean LVEF of 26.6 ± 7.7%, and reduced peak VO₂ (15.1 ± 4.6 mL/kg/min). Of these, 100 had both TAPSE and PASP available (TAPSE/PASP population): they exhibited higher BNP, wider QRS duration, larger LVEDVi, with more having tricuspid regurgitation compared with the 105 patients for whom these values were not available (all P < 0.05). RV‐FAC (β = 7.5), LAVi (β = −0.1), and sex (female, β = −1.9) predicted peak VO₂ in the overall population (all P = 0.01). When available, TAPSE/PASP ratio was the only echocardiographic parameter associated with peak VO₂ (β = 6.8; P < 0.01), a threshold ≤0.45 predicting a peak VO₂ ≤ 14 mL/kg/min (0.39 for VO₂ ≤ 12). RV‐MPI was the only echocardiographic parameter associated with ventilatory inefficiency (VE/VCO₂) and 6MWD (β = 21.9 and β = −69.3, respectively, both P ≤ 0.01) in the overall population. In presence of TAPSE/PASP, it became an important predictor for those two CPET (β = −18.0 and β = 72.4, respectively, both P < 0.01), together with RV‐MPI (β = 18.5, P < 0.01) for VE/VCO₂. Tricuspid regurgitation predicted SED (β = −3.2, P = 0.03).

Conclusions

Right ventricular function assessed by echocardiography (RV‐MPI and RV‐FAC) is closely associated with exercise tolerance in patients with HFrEF. When the TAPSE/PASP ratio is available, this marker of RV‐PA coupling becomes the stronger echocardiographic predictor of exercise capacity in this population, highlighting its potential role as a screening tool to identify patients with reduced exercise capacity and potentially triage them to formal peak VO₂ and/or evaluation for advanced HF therapies.

Usefulness of ventilatory inefficiency in predicting prognosis across the heart failure spectrum

Aims

The minute ventilation–carbon dioxide production relationship (VE/VCO₂ slope) is widely used for prognostication in heart failure (HF) with reduced left ventricular ejection fraction (LVEF). This study explored the prognostic value of VE/VCO₂ slope across the spectrum of HF defined by ranges of LVEF.

Methods and results

In this single‐centre retrospective observational study of 1347 patients with HF referred for cardiopulmonary exercise testing, patients with HF were categorized into HF with reduced (HFrEF, LVEF < 40%, n = 598), mid‐range (HFmrEF, 40% ≤ LVEF < 50%, n = 164), and preserved (HFpEF, LVEF ≥ 50%, n = 585) LVEF. Four ventilatory efficiency categories (VC) were defined: VC‐I, VE/VCO₂ slope ≤ 29; VC‐II, 29 < VE/VCO₂ slope < 36; VC‐III, 36 ≤ VE/VCO₂ slope < 45; and VC‐IV, VE/VCO₂ slope ≥ 45. The associations of these VE/VCO₂ slope categories with a composite outcome of all‐cause mortality or HF hospitalization were evaluated for each category of LVEF. Over a median follow‐up of 2.0 (interquartile range: 1.9, 2.0) years, 201 patients experienced the composite outcome. Compared with patients in VC‐I, those in VC‐II, III, and IV demonstrated three‐fold, five‐fold, and eight‐fold increased risk for the composite outcome. This incremental risk was observed across HFrEF, HFmrEF, and HFpEF cohorts.

Conclusions

Higher VE/VCO₂ slope is associated with incremental risk of 2 year all‐cause mortality and HF hospitalization across the spectrum of HF defined by LVEF. A multilevel categorical approach to the interpretation of VE/VCO₂ slope may offer more refined risk stratification than the current binary approach employed in clinical practice.