Heart rate variability and exercise capacity of patients with repaired tetralogy of Fallot

Heart rate variability (HRV) has been used as a reliable method to detect cardiac autonomic nervous system activity. Peak oxygen uptake (VO₂ peak) has been a predictor of death for adults with repaired tetralogy of Fallot (TOF). This study investigated the correlation between HRV and exercise capacity in 30 patients with TOF after surgery for total correction. The median age of the patients was 14 years (range, 9–25 years), and the median follow-up period was 11.6 months (range, 5.3–20.2 months). Low- and high-frequency-domain HRV significantly correlated with VO₂ peak (r = 0.56, P = 0.001 and r = 0.44, P = 0.02, respectively). After the 1-year follow-up evaluation, VO₂ peak and HRV analysis did not differ from those at entry to the study. However, low- and high-frequency-domain HRV still correlated significantly with VO₂ peak (r = 0.43, P = 0.03 and r = 0.52, P = 0.007, respectively). Left ventricular early diastolic myocardial velocity was most closely correlated with the VO₂ peak (r = 0.51, P = 0.005). Impaired cardiovascular autonomic control and left ventricular diastolic dysfunction may be responsible for exercise intolerance in patients with repaired TOF. Long-term follow-up evaluation with exercise testing and 24-h Holter monitoring are warranted.     

Pulmonary Limitation to Exercise After Repair of D-Transposition of the Great Vessels: Atrial Baffle Versus Arterial Switch

This study evaluated resting pulmonary function and its impact on exercise capacity after atrial baffle (BAFFLE) and arterial switch (SWITCH) repair of D-transposition of the great vessels (DTGV). Previously decreased exercise capacity in DTGV patients has been primarily attributed to cardiovascular limitations, whereas pulmonary limitations have largely been overlooked. Resting flow volume loops were compared for BAFFLE (n = 34) and SWITCH (n = 32) patients. Peak exercise variables were compared for BAFFLE (n = 30) and SWITCH (n = 25). Lung disease (restrictive and/or obstructive) was present in 53% of DTGV patients (BAFFLE 62% and SWITCH 44%; p = 0.14). BAFFLE patients had a normal breathing reserve, whereas that of SWITCH patients was decreased (27.3 ± 28.3 vs. 13.0 ± 19.2; p = 0.04). BAFFLE patients attained a lower percent of predicted peak oxygen pulse (82.7 ± 20.5% vs. 94.7 ± 19.3%; p = 0.04) and peak oxygen consumption (VO_2peak) (26.6 ± 6.7 ml/kg/min vs. 37.3 ± 8.5 ml/kg/min; p < 0.01) than SWITCH patients. Patients after surgical repair for DTGV have an underappreciated occurrence of lung disease, even post-SWITCH. SWITCH patients have diminished breathing reserves, suggesting a pulmonary limitation to VO_2peak. BAFFLE patients have lower VO_2peaks, greater breathing reserves, and lower oxygen pulses than SWITCH patients, suggesting a cardiac limitation to peak aerobic capacity with probable secondary pulmonary limitations. Treating underlying lung disease in symptomatic patients after repair of DTGV may improve functional status.     

Myocardial Perfusion and Exercise Capacity 12?Years After Arterial Switch Surgery for D-Transposition of the Great Arteries

Peak exercise myocardial perfusion was evaluated in patients with D-transposition of the great arteries 12 years after the arterial switch operation (SWITCH) to evaluate coronary perfusion. Gas-exchange measurements were used to assess cardiac limiting factors to exercise capacity in SWITCH patients when compared to healthy gender-matched controls (CON). Peak myocardial perfusion was evaluated in 42 patients 12 years post-SWITCH, using technetium-99 m (Tetrofosmin). SWITCH exercise data was compared to 42 gender-matched controls (CON). One symptomatic and one asymptomatic SWITCH patient had abnormal exercise myocardial perfusion; both patients had variant coronary anatomy preoperatively. SWITCH patients had lower VO_2peak (p < 0.01), peak heart rates (p = 0.01), percentages of age-predicted peak heart rates (p < 0.01), and peak oxygen pulses indexed to body surface area (p < 0.01) than CON patients. Exercise testing with myocardial perfusion imaging helped to identify the rare SWITCH patient with coronary insufficiencies. This study demonstrates that exercise testing with myocardial perfusion scans can help identify patients at risk for myocardial events. This study also demonstrated that SWITCH patients have a mildly diminished VO_2peak when compared to CON patients.     

Exertional Oscillatory Ventilation During Cardiopulmonary Exercise Test in Fontan Patients with Total Cavopulmonary Connection

Exertional oscillatory ventilation (EOV) has been noted during cardiopulmonary exercise testing (CPX) in patients with heart failure. EOV is a predictor of poor prognosis in adult patients with heart failure. The objective of this study was to clarify the incidence and influence of EOV in Fontan patients. Symptom-limited CPX was performed in 36 Fontan patients at 12.3 ± 4.3 (6.5–24.4) years of age or 5.9 ± 2.0 (3.0–11.2) years after total cavopulmonary connection (TCPC). Mean age at the time of TCPC was 6.3 ± 3.3. All 36 TCPC patients were classified as New York Heart Association classification I or II. They also underwent cardiac catheterization subsequently. EOV was defined as cyclic fluctuations in minute ventilation at rest that persist during effort lasting ≥60% of the exercise duration, with an amplitude ≥15% of the average resting value. EOV was noted in 21 of 36 Fontan patients (58%) with good clinical status. Univariable analysis between Fontan patients with and those without EOV showed significant differences in age at TCPC (p < 0.05), age at CPX (p < 0.02), weight at CPX (p < 0.02), follow-up duration between TCPC and CPX (p < 0.04), ventricular morphology (p < 0.05), and metabolic equivalents (p < 0.05) and peak minute oxygen uptake (VO₂) per body weight (p < 0.05). Multivariable analysis showed that EOV was significantly related to peak VO₂ per kilogram. In conclusion, EOV was frequently noted during exercise in Fontan patients with good clinical status. EOV during exercise seems to be related to higher peak VO₂ per kilogram and younger age at TCPC, which is a contrary result to those for adult patients with chronic heart failure. EOV is a remarkable phenomenon during exercise to compensate for impaired cardiopulmonary function in Fontan patients.     

Comparison of Calculated with Measured Oxygen Consumption in Children Undergoing Cardiac Catheterization

Our objective was to compare calculated (LaFarge) with measured oxygen consumption (VO₂) using the AS/3 TM Compact Airway Module M-CAiOVX (Datex-Ohmeda, Helsinki, Finland; AS/3 TM) in children without cardiac shunts in a prospective, observational study. VO₂ was determined at the end of the routine diagnostic and/or interventional catheterization. VO₂ was calculated according to the formula of LaFarge and Miettinen for each child and compared with the measured VO₂. Data were compared using simple regression and Bland Altman analysis. Fifty-two children aged from 0.5 to 16 years (median, 6.9 years) and weighing 3.4 to 59.4 kg (median, 22.9 kg) were investigated. Calculated VO₂ values ranged from 59.0 to 230.8 ml/min, and measured VO₂ values from 62.7 to 282.2 ml/min. Comparison of calculated versus measured VO₂ values revealed a significant correlation (r = 0.90, p < 0.0001). Bias and precision were 8.9 and 48.3 ml/min, respectively (95% limits of agreement: −39.4 to 57.2 ml/min). Comparison of calculated VO₂ in children older than 3 years (n = 41), as restricted to the formula, with measured VO₂, revealed a slightly reduced correlation (r = 0.86, p < 0.0001). Bias and precision were 10.0 and 52.5 ml/min, respectively (95% limits of agreement: –42.4 to 62.5 ml/min). We conclude that calculation of VO₂ by the LaFarge formula does not provide reliable values compared to measured values. In clinical routine, measured rather than calculated VO₂ values should be used for the estimation of cardiac output and related variables.     

Responses of Plasma Norepinephrine and Heart Rate During Exercise in Patients After Fontan Operation and Patients with Residual Right Ventricular Outflow Tract Obstruction After Definitive Reconstruction

To determine the exercise responses of patients with congenital heart disease, 20 patients—5 who had undergone a right ventricular outflow tract reconstruction (group R; age, 15 ± 2 years), eight who had undergone a Fontan operation (group F; age, 13 ± 2 years), and seven who had a history of Kawasaki disease (group C; age, 15 ± 1 years)—performed a treadmill exercise test. Patients of group R had a significant residual right ventricular outflow obstruction. Oxygen uptake (VO₂), heart rate (HR), and plasma norepinephrine (NE) concentrations were measured at rest, during warm-up, at ventilatory threshold (VT), and at peak exercise. Exercise capacity was determined as a percentage of the predicted normal peak VO₂ (%pVO₂). The %pVO₂ for groups R and F was 65 ± 10 and 56 ± 11, respectively. Peak HR for groups R and F was 171 ± 4 and 155 ± 5, which were lower than the HR for group C (p < 0.001). Although NE concentrations at rest, during warm-up, and at VT were significantly greater in groups R and F (p < 0.05), there were no significant differences in the NE concentrations at peak exercise. Peak HR correlated with %pVO₂ (p < 0.001). The ratio of the increase in HR to NE from rest to VT was significantly lower in groups R and F than in group C (p < 0.001) and correlated with %pVO₂ (r= 0.80; p < 0.001). These data suggest that sympathetic nervous activity in groups R and F is increased at rest and during mild to moderate exercises, and reduced sinus node sensitivity to NE may be partly responsible for the abnormal HR response during exercise of patients with uncorrected congenital heart disease.     

Peak Circulatory Power as an Indicator of Clinical Status in Children After Fontan Procedure

Peak circulatory power (CircP), a product of peak exercise oxygen uptake (VO₂) and peak mean or systolic arterial blood pressure, has proved to be a strong predictor of poor outcome in adults with congenital heart disease. This study sought to compare CircP with other cardiopulmonary exercise (CPX) test variables and to assess whether CircP is superior in categorizing patients into well-functioning vs. poorly functioning at-risk groups in the pediatric population after a Fontan procedure. The CPX test reports of 50 patients were retrospectively reviewed after the Fontan procedure. The patients were divided into two groups. The well-functioning group included patients in New York Heart Association (NYHA) classes 1 and 2 (n = 36). The poorly functioning at-risk group included patients in NYHA classes 3 and 4 and those with significant indicators or outcomes of a poor prognosis (n = 14). The patients in the well-functioning group had significantly higher CircP values based on mean blood pressure (MBP) (P < 0.001), higher CircP values based on systolic blood pressure (SBP) (P < 0.001), and higher peak VO₂ (P = 0.004) than those in the poorly functioning at-risk group. At a cutoff value less than 2100.4 mmHg/mlO₂/kg/min, CircP MBP had a sensitivity of 85% in categorizing children to the poorly functioning at-risk group. CircP correlated well with the clinical status of our patients. CircP and peak VO₂ did not differ significantly in ability to identify poorly functioning patients. Further prospective analysis is needed to assess whether CircP can serve as a prognostic marker for the pediatric population after Fontan procedure.     

Impact of Exercise Training in Aerobic Capacity and Pulmonary Function in Children and Adolescents After Congenital Heart Disease Surgery: A Systematic Review with Meta-analysis

The aim of the study was to examine the effects of exercise training on aerobic capacity and pulmonary function in children and adolescents after congenital heart disease surgery. We searched MEDLINE, Cochrane Controlled Trials Register, EMBASE, (from the earliest date available to January 2015) for controlled trials that evaluated the effects of exercise training on aerobic capacity and pulmonary function (forced expiratory volume in 1 s and forced vital capacity) in children and adolescents after congenital heart disease surgery. Weighted mean differences and 95 % confidence intervals (CIs) were calculated,, and heterogeneity was assessed using the I ² test. Eight trials (n = 292) met the study criteria. The results suggested that exercise training compared with control had a positive impact on peak VO₂. Exercise training resulted in improvement in peak VO₂ weighted mean difference (3.68 mL kg^?1 min^?1, 95 % CI 1.58–5.78). The improvement in forced expiratory volume in 1 s and forced vital capacity after exercise training was not significant. Exercise training may improve peak VO₂ in children and adolescents after congenital heart disease surgery and should be considered for inclusion in cardiac rehabilitation. Further larger randomized controlled trials are urgently needed to investigate different types of exercise and its effects on the quality of life.     

Heart rate and oxygen uptake response to exercise in children with low peak exercise heart rate

Normal children achieve the same increase of oxygen uptake (VO₂) in response to exercise even though resting and submaximal exercise heart rates vary greatly as a function of age, body size and physical conditioning. To determine whether the VO₂ response to exercise is altered when heart rate is significantly reduced by heart disease, we compared 78 children who achieved a peak exercise heart rate of 150 beats/min to 201 controls of similar body size and normal peak exercise heart rates of 180 beats/min. All performed incremental (16.4 Watts/min) maximal cycle exercise. Separate analysis of males and females included heart rate, power (kg-m/min, Watts/kg), VO₂ (ml/min, ml/min per kg), O₂ pulse (VO₂/heart beat), V_E (l/min) and R (VCO₂/VO₂) at rest and during the 1st, 4th and last minute of exercise. Patients with low peak exercise heart rates had also lower resting submaximal exercise heart rates than controls. VO₂ at comparable exercise levels did not differ from controls and consequently O₂ pulse was greater in the patients than controls at rest and at all levels of exercise. A consistent gender difference was only found in controls where males achieved a higher VO₂ and lower heart rates at comparable levels of exercise. The data show a normal exercise VO₂ despite significantly lower heart rates. These findings cannot be explained by an increased arteriovenous difference alone and suggest that the patients retained the ability to effectively modulate stroke volume.     

Barriers to medication adherence in sickle cell disease: A comprehensive theory-based evaluation using the COM-B model

Background

Sickle cell disease (SCD) affects more than 100,000 Americans, with complications such as pain episodes and acute chest syndrome. Despite the efficacy of hydroxyurea in reducing these complications, adherence remains low. Study objectives were to examine barriers to hydroxyurea adherence, and to evaluate the relationship between barriers and their impact on adherence.

Methods

In this cross-sectional study, patients with SCD and their caregivers were enrolled if they were taking hydroxyurea. Study measures included demographics, self-report of adherence using visual analog scale (VAS), and the Disease Management and Barriers Interview (DMI)-SCD. The DMI-SCD was mapped to the Capability, Opportunity, Motivation, and Behavior (COM-B) model.

Results

Forty-eight caregivers (females 83%, median age 38 [34–43]) and 19 patients (male 53%, median age 15 [13.5–18]) participated. Using VAS, many patients (63%) reported low hydroxyurea adherence, while most caregivers (75%) reported high adherence. Caregivers endorsed barriers across multiple COM-B components, with physical opportunity (e.g., cost) and reflective motivation (e.g., SCD perceptions) being the most identified categories (48% and 42%), respectively. Patients’ most identified barriers included psychological capability (e.g., forgetfulness) and reflective motivation (84% and 68%), respectively. Patients’ and caregivers’ VAS scores negatively correlated with the number of barriers (r_s = –.53, p = .01; r_s = –.28, p = .05) and COM-B categories (r_s = –.51, p = .02; r_s = –.35, p = .01), respectively, suggesting lower adherence with more endorsed barriers.

Conclusions

Fewer barriers to hydroxyurea adherence were associated with higher adherence. Understanding barriers to adherence is essential to develop tailored interventions aimed at improving adherence.     

Cardiorespiratory Exercise Tolerance in Asymptomatic Children with Ebstein's Anomaly

The aim of the study was to evaluate cardiorespiratory exercise tolerance in asymptomatic children with Ebstein's anomaly. Eleven children with a mean age of 9.6 years were prospectively studied by spirometry, cardiopulmonary exercise testing (bicycle ergometer n= 8, treadmill test n= 3), and contrast echocardiography. A right-to-left atrial shunt was detected by contrast echocardiography in 7 children (group 1), whereas no shunt was found in 4 (group 2). VO₂ max was decreased [84.5 (SD = 16.8)] and was strongly correlated to oxygen saturation in group 1 (p < 0.0001). Oxygen saturation at peak uptake was significantly decreased compared to baseline [97.4 (SD = 2.0) vs 90% (SD = 9.5%), p= 0.02] and was significantly lower in group 1 than in group 2 [85.7 (2.2) vs 98.2% (SD = 1.2%), p= 0.03]. Oxygen desaturation was related to a right-to-left atrial shunt (p= 0.01). Decreased VO₂ max was also correlated to the small size of the left ventricle (p= 0.05). We concluded that decreased exercise tolerance in children with asymptomatic Ebstein's anomaly is related to a right-to-left atrial shunt and to a small left ventricle. In case of poor exercise tolerance, a contrast echocardiography should be performed to detect an atrial septal defect.     

Effects of preterm birth and fetal growth retardation on cardiovascular risk factors in young adulthood

Background

The association between low birth weight (LBW) and increased risk of obesity, hypertension and cardiovascular disease later in life is well documented in epidemiological studies. However, clinical follow-up studies of LBW populations have only partly supported this.

Aims

Evaluate associations between LBW and body fat, blood pressure (BP), lung and endothelial function, and maximal oxygen uptake (VO_2max) in 18 year old young adults.

Subjects

Thirty-seven subjects born prematurely with birth weight < 1501 g (VLBW group), 47 born at term with low weight (< 10th centile) for gestational age (SGA group) and 63 controls with normal birth weight participated in the study.

Outcome measures

Anthropometric measurements, BP, endothelial function, lung function and VO_2max were recorded.

Results

Both LBW groups were shorter, lighter, had smaller head circumference and higher subscapular-to-triceps skinfold-ratio than controls. Systolic and mean arterial BP was higher in the VLBW compared with the control group, whereas there were no differences between the groups in endothelial function. The VLBW group had reduced dynamic lung volumes lower carbon monoxide transfer factor and lower VO_2max compared with controls. In particular young adults born VLBW who were also growth retarded in utero had higher indices of central body fat, higher BP and lower VO_2max.

Conclusion

We found that very preterm birth, but not growth retardation at term, was associated with higher BP and a less favourable fat distribution. In particular, the young adults born VLBW who were also growth retarded in utero had less favourable outcomes.     

Exercise capacity in apparently healthy survivors of cancer

Aims

To evaluate cardiopulmonary exercise tolerance in a large cohort of apparently healthy paediatric cancer survivors in order to determine their participation in sporting activities.

Methods

A total of 84 young (<21 years) asymptomatic childhood cancer survivors, who had been exposed to anthracyclines (mean dose 212 mg/m²) and/or chest irradiation (median dose 2000 cGy), with normal left ventricular systolic function at rest (fractional shortening >29%), and 79 healthy controls were studied. Exercise testing was performed on a treadmill ergometer. Gas exchange analysis and derived variables were measured on a breath‐by‐breath basis. Pulmonary functional evaluation was performed before exercise. Echocardiographic evaluation at rest was performed within one month before the exercise test.

Results

There were no differences in exercise responses between patients and controls. In boys <13 years, mean VO₂ max was slightly but significantly lower than in controls. This finding was thought to be a result of decreased physical fitness as all the other exercise parameters were similar to those in the controls.

Conclusions

Results show that apparently healthy survivors of paediatric cancer can take part in dynamic sporting activities if they exhibit a normal response to cardiopulmonary exercise testing, while those that exhibit a reduced VO₂ max should be re‐evaluated after an aerobic training programme, and should undergo tailored dynamic physical activity if the VO₂ max does not normalise.     

Exercise capacity following pediatric heart transplantation: A systematic review

Pediatric HTs account for 13% of all HTs with >60% of recipients surviving at least 10 years post‐HT. The purpose of this systematic review is to synthesize the literature on exercise capacity of pediatric HT recipients to improve understanding of the mechanisms that may explain the decreased exercise capacity. Six databases were searched for studies that compared the exercise capacity of HT recipients ≤21 years old with a control group or normative data. Sixteen studies were included. Pediatric HT recipients, as compared to controls or normative data, exhibit significantly higher resting HR, and at peak exercise exhibit significantly decreased HR, VO₂, power, work, minute ventilation, and exercise duration. Peak VO₂ appears to improve within the first 2.5 years post‐HT; peak work remains constant; and there is inconclusive evidence that peak HR, HR recovery, and HR reserve improve with time since HT. These results are discussed in the context of the mechanisms that may explain the impaired exercise capacity of pediatric HT recipients, including chronotropic incompetence, graft dysfunction, side effects of immunosuppression therapy, and deconditioning. In addition, the limited literature on rehabilitation after pediatric HT is summarized.     

Sputum TWEAK expression correlates with severity and degree of control in non‐eosinophilic childhood asthma

Background

Tumor necrosis factor‐like weak inducer of apoptosis (TWEAK) is known to play a role in the pathogenesis of various inflammatory diseases. However, no study has been performed on childhood asthma.

Methods

Ninety‐five children with asthma and 78 controls aged 5‐18 years were included. Sputum induction, pulmonary function test (PFT), and methacholine challenge test were performed. The subjects were divided into the eosinophilic airway (EA) and non‐EA (NEA) groups based on sputum analysis and into the high and low TWEAK groups according to the TWEAK cutoff level (263.0 pg/mL). TWEAK in induced sputum supernatant was measured through enzyme‐linked immunosorbent assay.

Results

Children with asthma had higher TWEAK levels than healthy controls (493.0 [157.1‐904.3] vs 118.2 (67.5‐345.5) pg/mL, P < .001). Sputum TWEAK levels were significantly correlated with PFT parameters reflecting airway obstruction. This association was particularly prominent in subjects with NEA inflammation. Significant differences in FEF_25‐75 (maximum mid‐expiratory flow, % predicted; P = .017), AX (reactance area; P < .001), R5‐R20 (difference between resistance at 5 and 20 Hz; P = .025), and X5 (reactance at 5 Hz, % predicted; P < .001) were noted between the high and low TWEAK groups within the NEA group. Sputum TWEAK level also showed significant positive correlations with asthma severity (r = .358, P = .001) and control status (r = .470, P < .001), distinctively in subjects with NEA inflammation.

Conclusions

Airway TWEAK may play a role in small airway inflammation especially in children with non‐eosinophilic asthma.     

Serial Cardiopulmonary Exercise Testing in Patients with Previous Fontan Surgery

Patients with previous Fontan surgery have reduced peak oxygen consumption (Vo ₂), and data regarding progression of exercise intolerance is limited. The purpose of this study was to assess the evolution of exercise tolerance in patients with previous Fontan surgery. We performed a retrospective cohort study of patients with previous Fontan surgery who underwent cardiopulmonary exercise testing between November 2002 and January 2009. Patients were required to have completed at least two tests, with adequate levels of effort, ≥6 months apart. We identified 78 patients (55% male) who had undergone a total of 215 cardiopulmonary exercise tests. Age at initial study was 19.7 ± 10.2 years; time interval since previous Fontan surgery 13.3 ± 5.7 years; and time interval between the initial and the most recent exercise test was 3.0 ± 1.4 years. Morphologic left ventricle was present in 58 (74.4%) patients. At baseline, peak Vo ₂ averaged 24.7 ± 7.0 ml/kg/min (63.7% ± 15.8% predicted). At most recent study, peak Vo ₂ averaged 23.2 ± 7.2 ml/kg/min, (60.4% ± 13.9% predicted). Percent predicted peak Vo ₂ declined slowly, with a mean rate of decline of 1.25 ± 0.36 percentage points/y (p < 0.001). Most of the decline occurred in patients < 18 years of age (mean rate of decline 1.78 ± 0.46 percentage points/y; p = 0.0004). Thereafter, the rate of decline was less marked (mean rate of decline 0.54 ± 0.57 percentage points/y; p = not significant). Ventricular morphology, type of Fontan procedure, and cardiac medications were not predictive of progressive exercise intolerance. In conclusion, although the exercise function of previous Fontan patients tends to decline during late adolescence, it appears to stabilize during early adulthood.     

Exercise Capacity in Pediatric Heart Transplant Candidates: Is There Any Role for the 14 ml/kg/min Guideline?

A peak oxygen consumption (VO₂) of <14 ml/kg/min has been identified as a predictor of l-year mortality in adults with congestive heart failure (CHF) and is used as a criterion for listing for cardiac transplantation (OHT). The role of VO₂ measurement in children awaiting OHT has not been thoroughly evaluated. We sought to assess the degree of exercise impairment and the clinical applicability of the 14 ml/kg/min rule in children awaiting OHT. Cardiopulmonary exercise test (CPT) and cardiac catheterization data in all patients listed for OHT during the period of 1995–2003 were reviewed. Fourteen patients with a mean age of 15.5 ± 2.9 years underwent CPT with no serious adverse events at an interval of 6.6 ± 5.1 months prior to OHT. The etiology of CHF was multifactorial. Patients had impaired aerobic capacity with a mean peak VO₂ of 20.4 ± 6.8 ml/kg/min. Eleven of 14 patients (79%) had a peak VO₂ higher than the adult cutoff value of 14 ml/kg/min. Pediatric ambulatory patients with CHF can safely undergo CPT. Because of age-related differences in oxygen consumption and varied etiologies of CHF a peak VO₂ of <14 ml/kg/min is not a useful criterion for listing for OHT in this population.