Cardiopulmonary Exercise Test in Leukemia Patients After Chemotherapy: A Feasibility Study

Impaired aerobic capacity in adolescents and young adults after treatment for cancer or non-malignant haematological disease

PURPOSE

Childhood cancer survivors are at increased risk for cardiovascular disease. Maximal oxygen uptake (VO_2max) is a major determinant of cardiovascular morbidity. The aim of this study was to compare aerobic capacity, measured by cardiopulmonary exercise test (CPET), of adolescents and young adults in remission with that of healthy controls and to identify the predictors of aerobic capacity in this population.

METHOD

This is a controlled cross-sectional study.

RESULTS

A total of 477 subjects (77 in remission and 400 controls), aged from 6 to 25 years, were included, with a mean delay between end of treatment and CPET of 2.9 ± 2.3 years in the remission group. In this group, the mean VO_2max was significantly lower than in controls (37.3 ± 7.6 vs. 43.3 ± 13.1 mL/kg/min, P < 0.01, respectively), without any clinical or echocardiographic evidence of heart failure. The VAT was significantly lower in the remission group (26.9 ± 6.0 mL/kg/min vs. 31.0 ± 9.9 mL/kg/min, P < 0.01, respectively). A lower VO_2max was associated with female sex, older age, higher BMI, radiotherapy, and hematopoietic stem cell transplantation.

CONCLUSION

Impaired aerobic capacity had a higher prevalence in adolescents and young adults in cancer remission. This impairment was primarily related to physical deconditioning and not to heart failure.

TRIAL REGISTRY

NCT04815447.

IMPACT

In childhood cancer survivors, aerobic capacity is five times more impaired than in healthy subjects. This impairment mostly reflects early onset of physical deconditioning. No evidence of heart failure was observed in this population.

Cardiopulmonary Exercise Test With Comorbidity Index Before Allogeneic Hematopoietic Stem Cell Transplantation

Purpose:

To evaluate the role of the cardiopulmonary exercise test (CPET) with comorbidity index as a predictor of overall survival (OS) and non-relapse mortality (NRM) in patients with hematological malignancies who undergo allogeneic hematopoietic stem cell transplantation (HSCT).

Methods:

We retrospectively analyzed consecutive adult patients with hematological malignancies who underwent HLA-matched donor-HSCT at Chungnam National University Hospital (Daejeon, South Korea) between January 2014 and December 2020. Maximal oxygen consumption (VO2max) was classified using the recommendations of the Mayo Clinic database.

Results:

Of 72 patients, 38 (52.8%) had VO2max values lower than the 25th percentile (VO2max ≤ 25th) of an age- and sex-matched normal population. Patients with VO2max ≤ 25th had no significant differences both OS and NRM (30 month OS 29.8% vs 41%, P = .328; and 30 month NRM 16% vs 3.3%, P = .222), compared with other patients. VO2max ≤ 25th was assigned a weight of 1 when added to the Hematopoietic Cell Transplantation-specific Comorbidity Index (HCT-CI) to form a composite comorbidity/CPET index (HCT-CI/CPET). Patients with HCT-CI/CPET scores of 0 to 1 demonstrated significantly better OS and NRM than did patients with HCT-CI/CPET scores ≥2 [median OS not reached vs 6 months, P < .001 and 30 month NRM 7.4% vs 33.3%, P = .006]. An HCT-CI/CPET score ≥2 was the only adverse risk factor for NRM on multivariate analysis [hazard ratio (HR) of NRM 10.36 (95% CI 1.486-2.25, P = .018)].

Conclusion:

The composite HCT-CI/CPET score can predict the survival and mortality of patients with hematological malignancies who undergo allogeneic HSCT.

Heart rate response and chronotropic incompetence during cardiopulmonary exercise testing in childhood acute lymphoblastic leukemia survivors

Cardiopulmonary exercise tests (CPET) focusing on analyses of heart rate (HR) responses and chronotropic incompetence (CI) could provide early information about treatment's negative cardiac effects. We examined childhood acute lymphoblastic leukemia (ALL) survivors' HR response during maximal CPET and identified survivors with CI. A total of 250 childhood ALL survivors underwent a CPET on ergocycle to assess their HR response. We used a multiparametric structure of three methods to assess survivors' CI, as follows: 1) age-predicted HR_max (APMHR): failure to achieve 85% of the APMHR at the peak of CPET; 2) HR reserve (HRR): failure to achieve 80% of the HRR at the peak of CPET; and 3) metabolic chronotropic relationship (MCR): failure to reach an MCR slope ratio >0.8 at each stage of the CPET. Among 250 childhood ALL survivors, 216 survivors performed a maximum CPET. We observed that 73 males and 74 females did not achieve their predicted HR_max. We found that 6 survivors did not achieve 85% of their APMHR (80.9 ± 3.9%) and had an MCR below 80% (53.9 ± 13.8%). In addition, 16 survivors did not achieve 80% of their HRR (71.0 ± 7.4%) and among them, 15 survivors had an MCR below 80% (61.0 ± 12.1%). Survivors with CI had a significantly lower cardiorespiratory fitness than those without CI. This study shows that survivors are at risk of developing altered HR responses and CI many years after the end of their cancer treatments. These findings highlight the importance of early detection of cardiac damage due to cancer treatments.

Impact of respiratory physical therapy on heart rate autonomic control in children with leukemia

INTRODUCTION

Considering that heart rate (HR) autonomic control is impaired in cancer and subsequent respiratory effort may overload the heart, we aimed to evaluate the effect of a respiratory physical therapy session on HR autonomic regulation in children with leukemia so as to confirm its safety.

METHODS

We selected children with leukemia (n = 10) and healthy children (n = 11), which were submitted to a session of respiratory physical therapy. We used Spiron Kids (NCS, Brazil), Children's Voldyne (HUDSON RCI, USA), and Shaker (NCS, Brazil) as respiratory devices. The respiratory exercise protocols were founded on three standardized protocols. HR variability (HRV) was analyzed before, in the first minute and 5 to 10 min after intervention.

RESULTS

We recognized no change between rest and recovery from intervention in HRV (rMSSD-square root mean square of the differences between adjacent normal R-R intervals)-Control: p = 0.8111, Leukemia: p = 0.1197, among groups: p = 0.6574; SD1-standard deviation from instantaneous beat-to-beat variability-Control: p = 0.8111, Leukemia: p = 0.131, among groups: p = 0.6556; 0V-with no variation (3 equal symbols, for example (2,2,2)-Control: p = 0.3679, Leukemia: p = 0.3553, among groups: p = 0.7421); 2UV-with two variations to the contrary (the three symbols form a peak or a valley, for instance (3,5,3)-Control: p = 0.3679, Leukemia: p = 0.2359, among groups: p = 0.4007). HF-high frequency component, range 0.15 to 0.4 Hz-decreased 0 to 1 min after intervention in the leukemia group (p = 0.0303) and no change was observed in the control group between rest versus recovery from intervention (p = 0.9761). No significant change was reported in HF between groups (p = 0.8700). Two leukemia subjects treated with vincristine presented different HRV responses to the intervention group.

CONCLUSION

A respiratory physical therapy session did not significantly change autonomic control of HR in children with leukemia. Yet, clinicians should be mindful of subjects undergoing treatment with vincristine.

Maximal cardiopulmonary exercise testing in childhood acute lymphoblastic leukemia survivors exposed to chemotherapy

PURPOSE

The purpose of this study was to demonstrate if childhood acute lymphoblastic leukemia (ALL) survivors exposed to chemotherapy (i.e., doxorubicin) are able to achieve a safe maximal cardiopulmonary exercise test (CPET).

METHODS

A total of 250 childhood ALL survivors were eligible to undergo a CPET on ergocycle. Analyses were performed in 216 survivors and stratified in regard to their prognostic risk groups: 99 survivors (55 males and 44 females) at standard risk and 117 survivors (56 males and 61 females) at high risk.

RESULTS

Results showed that 100% (n = 216) of survivors completed a maximal CPET confirmed by the achievement of two out of three of the following criteria: 197 survivors (91.2%) reached a peak RER value of ≥ 1.15, 197 survivors (91.2%) reached a RPE score > 7, and 210 survivors (97.2%) reached a maximal heart rate ≥ 85% of the predicted value. Linear regression analysis showed a significant association between the survivors' cumulative dose of doxorubicin and their VO₂ peak measured. Two non-fatal adverse events were observed and reported at the end of the maximal CPET, while non-fatal adverse events were reported in 5 survivors during the recovery period. None of these events resulted in a long-term complication.

CONCLUSION

Childhood ALL survivors with prior exposure to chemotherapy can achieve a safe maximal CPET. They were able of achieving a maximal exercise test without being limited by symptoms, potential overprotection, or musculoskeletal issues. Thus, it should be the norm to realize a CPET prior a physical activity program to propose an optimal prescription. This study provides important information regarding the maximal physiological parameters that childhood ALL survivors are able to reach and have important clinical implications in the exercise and oncology field for this population of survivors.

Developing and validating equations to predict V˙O2 peak from the 6MWT in Childhood ALL Survivors

INTRODUCTION

The 6-Minute Walking Test (6MWT) is a safe, standardized and well utilized method to assess the functional capacity. Recently, it was reported that the published prediction equations cannot accurately predict a valid maximal oxygen consumption (V̇O₂ peak) value in cancer survivors. Thus, the aim of this study was to establish and to validate a new equation based on the 6MWT to predict V̇O₂ peak in childhood acute lymphoblastic leukemia (ALL) survivors.

METHODS

A total of 200 childhood ALL survivors were enrolled in this study, among which 168 participants underwent a cardiopulmonary exercise test and a 6MWT to assess their functional capacity and their cardiorespiratory fitness. In addition, participants completed a physical activity questionnaire. Participants were randomly divided in two groups to establish the equations (n = 118 (70%)) and to validate it (n = 50 (30%)). Multiple linear regression analyses were used to determine a new prediction equation for V̇O₂ peak from 6MWT using clinical and specific variables related to the disease. The accuracy in between V̇O₂ peak measured and V̇O₂ peak predicted were assessed using the Bland and Altman method.

RESULTS

The new establish clinical V̇O₂ peak equation is: V̇O₂ peak (mL.kg^-1.min^-1) = (-0.283*age(years)) - (0.099*weight(kg)) + (0.071*6MWD(meters)) -(0.135*HR end(bpm)) + 22.789 with a mean bias of 2.67 mL.kg^-1.min^-1 (95% CI (-9.64 to 14.98)). The new establish disease-specific V̇O₂ peak equation is: V̇O₂ peak (mL.kg^-1.min^-1) = (-0.236*age(years)) - (0.094*weight(kg)) -(0.120*HR end(bpm)) + (0.067*6MWD(meters)) + (0.065*MVLPA(min/day)) - (0.204*DT(years)) + 25.145 with a mean bias of 2.51 mL.kg^-1.min^-1 (95% CI (-9.98 to 15.01)).

CONCLUSION

This is the first study that predicted V̇O₂ peak from a 6MWT using clinical and specific variables related to the disease of childhood ALL survivors. The availability of these newly established V̇O₂ peak equations makes them an accurate tool to provide a better follow-up and better adapted physical training for survivors. We invite researchers to use our assessment procedures for their further studies.IMPLICATIONS FOR REHABILITATIONIt is critical to understand the cardiorespiratory fitness of the childhood ALL survivorsThe maximal oxygen consumption (i.e., V̇O₂ peak) is recognized as the gold standard to measure the patient's cardiorespiratory fitness in the field of exercise physiologyThis study is novel and reports the validation of two new VO₂ peak equations, from 6MWT, by using clinical and disease-specific variables of childhood ALL survivorsThe availability of such validated equations can better facilitate the follow-up of survivors' cardiorespiratory fitness, by relevant health care professionals and exercise physiologists.