Effect of physical exercise training in patients with Chagas heart disease: study protocol for a randomized controlled trial (PEACH study)

Effect of an exercise-based cardiac rehabilitation program on quality of life of patients with chronic Chagas cardiomyopathy: results from the PEACH randomized clinical trial

To investigate the effect of an exercise-based cardiac rehabilitation program on the quality of life (QoL) of patients with chronic Chagas cardiomyopathy (CCC). PEACH study was a single-center, superiority randomized clinical trial of exercise training versus no exercise (control). The sample comprised Chagas disease patients with CCC, left ventricular ejection fraction < 45%, without or with HF symptoms (CCC stages B2 or C, respectively). QoL was assessed at baseline, after three months, and at the end of six months of follow-up using the SF-36 questionnaire. Patients randomized for the exercise group (n = 15) performed exercise training (aerobic, strength and stretching exercises) for 60 min, three times a week, during six months. Patients in the control group (n = 15) were not provided with a formal exercise prescription. Both groups received identical nutritional and pharmaceutical counseling during the study. Longitudinal analysis of the effects of exercise training on QoL, considering the interaction term (group × time) to estimate the rate of changes between groups in the outcomes (represented as beta coefficient), was performed using linear mixed models. Models were fitted adjusting for each respective baseline QoL value. There were significant improvements in physical functioning (β =  + 10.7; p = 0.02), role limitations due to physical problems (β =  + 25.0; p = 0.01), and social functioning (β =  + 19.2; p < 0.01) scales during the first three months in the exercise compared to the control group. No significant differences were observed between groups after six months. Exercise-based cardiac rehabilitation provided short-term improvements in the physical and mental aspects of QoL of patients with CCC.Trial registration: ClinicalTrials.gov Identifier: NCT02517632; August 7, 2015.

Exercise-based cardiac rehabilitation for adults with heart failure

BACKGROUND

People with heart failure experience substantial disease burden that includes low exercise tolerance, poor health-related quality of life (HRQoL), increased risk of mortality and hospital admission, and high healthcare costs. The previous 2018 Cochrane review reported that exercise-based cardiac rehabilitation (ExCR) compared to no exercise control shows improvement in HRQoL and hospital admission amongst people with heart failure, as well as possible reduction in mortality over the longer term, and that these reductions appear to be consistent across patient and programme characteristics. Limitations noted by the authors of this previous Cochrane review include the following: (1) most trials were undertaken in patients with heart failure with reduced (< 45%) ejection fraction (HFrEF), and women, older people, and those with heart failure with preserved (≥ 45%) ejection fraction (HFpEF) were under-represented; and (2) most trials were undertaken in a hospital or centre-based setting.

OBJECTIVES

To assess the effects of ExCR on mortality, hospital admission, and health-related quality of life of adults with heart failure.

SEARCH METHODS

We searched CENTRAL, MEDLINE, Embase, CINAHL, PsycINFO and Web of Science without language restriction on 13 December 2021. We also checked the bibliographies of included studies, identified relevant systematic reviews, and two clinical trials registers.

SELECTION CRITERIA

We included randomised controlled trials (RCTs) that compared ExCR interventions (either exercise only or exercise as part of a comprehensive cardiac rehabilitation) with a follow-up of six months or longer versus a no-exercise control (e.g. usual medical care). The study population comprised adults (≥ 18 years) with heart failure - either HFrEF or HFpEF.

DATA COLLECTION AND ANALYSIS

We used standard Cochrane methods. Our primary outcomes were all-cause mortality, mortality due to heart failure, all-cause hospital admissions, heart failure-related hospital admissions, and HRQoL. Secondary outcomes were costs and cost-effectiveness. We used GRADE to assess the certainty of the evidence.

MAIN RESULTS

We included 60 trials (8728 participants) with a median of six months' follow-up. For this latest update, we identified 16 new trials (2945 new participants), in addition to the previously identified 44 trials (5783 existing participants). Although the existing evidence base predominantly includes patients with HFrEF, with New York Heart Association (NYHA) classes II and III receiving centre-based ExCR programmes, a growing body of trials includes patients with HFpEF with ExCR undertaken in a home-based setting. All included trials employed a usual care comparator with a formal no-exercise intervention as well as a wide range of active comparators, such as education, psychological intervention, or medical management. The overall risk of bias in the included trials was low or unclear, and we mostly downgraded the certainty of evidence of outcomes upon GRADE assessment. There was no evidence of a difference in the short term (up to 12 months' follow-up) in the pooled risk of all-cause mortality when comparing ExCR versus usual care (risk ratio (RR) 0.93, 95% confidence interval (CI) 0.71 to 1.21; absolute effects 5.0% versus 5.8%; 34 trials, 36 comparisons, 3941 participants; low-certainty evidence). Only a few trials reported information on whether participants died due to heart failure. Participation in ExCR versus usual care likely reduced the risk of all-cause hospital admissions (RR 0.69, 95% CI 0.56 to 0.86; absolute effects 15.9% versus 23.8%; 23 trials, 24 comparisons, 2283 participants; moderate-certainty evidence) and heart failure-related hospital admissions (RR 0.82, 95% CI 0.49 to 1.35; absolute effects 5.6% versus 6.4%; 10 trials; 10 comparisons, 911 participants; moderate-certainty evidence) in the short term. Participation in ExCR likely improved short-term HRQoL as measured by the Minnesota Living with Heart Failure (MLWHF) questionnaire (lower scores indicate better HRQoL and a difference of 5 points or more indicates clinical importance; mean difference (MD) -7.39 points, 95% CI -10.30 to -4.77; 21 trials, 22 comparisons, 2699 participants; moderate-certainty evidence). When pooling HRQoL data measured by any questionnaire/scale, we found that ExCR may improve HRQoL in the short term, but the evidence is very uncertain (33 trials, 37 comparisons, 4769 participants; standardised mean difference (SMD) -0.52, 95% CI -0.70 to -0.34; very-low certainty evidence). ExCR effects appeared to be consistent across different models of ExCR delivery: centre- versus home-based, exercise dose, exercise only versus comprehensive programmes, and aerobic training alone versus aerobic plus resistance programmes.

AUTHORS' CONCLUSIONS

This updated Cochrane review provides additional randomised evidence (16 trials) to support the conclusions of the previous 2018 version of the review. Compared to no exercise control, whilst there was no evidence of a difference in all-cause mortality in people with heart failure, ExCR participation likely reduces the risk of all-cause hospital admissions and heart failure-related hospital admissions, and may result in important improvements in HRQoL. Importantly, this updated review provides additional evidence supporting the use of alternative modes of ExCR delivery, including home-based and digitally-supported programmes. Future ExCR trials need to focus on the recruitment of traditionally less represented heart failure patient groups including older patients, women, and those with HFpEF.

Assessment of health-related quality of life in patients with Chagas cardiomyopathy using Minnesota living with heart failure questionnaire: A validation study

OBJECTIVE

Chagas cardiomyopathy (ChC) is the most severe clinical form of Chagas disease and, in association with psychosocial factors, can compromise the health-related quality of life (HRQoL) of affected patients. To date, there is no specific instrument to assess the HRQoL of these patients, and the Minnesota Living with Heart Failure Questionnaire (MLwHFQ), specific for heart failure, is being used both in research and current clinical practice. Therefore, we aimed to verify the validity of the MLwHFQ in the assessment of HRQoL of patients with ChC.

METHODS

Fifty patients with ChC (50.6 ± 10.1 years, NYHA I-III) were evaluated. The MLwHFQ, Short-Form of Health Survey (SF-36), Beck Depression Inventory (BDI), and Human Activity Profile (HAP) were applied. All patients underwent echocardiography and Cardiopulmonary Exercise Testing (CPET).

RESULTS

The MLwHFQ score correlated with almost all SF-36 domains (with r-value ranging from -0.38 to -0.69), except pain (p = 0.118). The MLwHFQ score also correlated with the BDI score (r = 0.748; p < 0.001), HAP score (r = -0.558; p = 0.001), peak oxygen uptake (r = -0.352; p = 0.01), and left ventricular ejection fraction (r = -0.329; p = 0.021). There was no significant difference in the score found on the MLwHFQ among NYHA classes (p = 0.101), as well as between patients with systolic dysfunction (n = 30) and preserved cardiac function (n = 20) (p = 0.058). Similarly, there was no significant difference in the score found on the physical (p = 0.423) and mental (p = 0.858) components of SF-36 between patients with systolic dysfunction and preserved cardiac function (p = 0.271 and p = 0.609, respectively). There was also no difference in the mental component of SF-36 among NYHA classes (p = 0.673). However, the HRQoL using the physical component of SF-36 was worse in advanced NYHA classes (p = 0.014).

CONCLUSION

MLwHF correlated with most SF-36 HRQoL domains, depressive symptoms, physical activity, and systolic function and seems to be valid in assessing the HRQoL of ChC patients.

Clinical trials for Chagas disease: etiological and pathophysiological treatment

Chagas disease (CD) is caused by the flagellate protozoan Trypanosoma cruzi. It is endemic in Latin America. Nowadays around 6 million people are affected worldwide, and 75 million are still at risk. CD has two evolutive phases, acute and chronic. The acute phase is mostly asymptomatic, or presenting unspecific symptoms which makes it hard to diagnose. At the chronic phase, patients can stay in the indeterminate form or develop cardiac and/or digestive manifestations. The two trypanocide drugs available for the treatment of CD are benznidazole (BZ) and nifurtimox (NFX), introduced in the clinic more than five decades ago. WHO recommends treatment for patients at the acute phase, at risk of congenital infection, for immunosuppressed patients and children with chronic infection. A high cure rate is seen at the CD acute phase but better treatment schemes still need to be investigated for the chronic phase. There are some limitations within the use of the trypanocide drugs, with side effects occurring in about 40% of the patients, that can lead patients to interrupt treatment. In addition, patients with advanced heart problems should not be treated with BZ. This is a neglected disease, discovered 114 years ago that still has no drug effective for their chronic phase. Multiple social economic and cultural barriers influence CD research. The high cost of the development of new drugs, in addition to the low economical return, results in the lack of investment. More economic support is required from governments and pharmaceutical companies on the development of more research for CD treatment. Two approaches stand out: repositioning and combination of drugs, witch drastically decrease the cost of this process, when compared to the development of a new drug. Here we discuss the progress of the clinical trials for the etiological and pathophysiological treatment for CD. In summary, more studies are needed to propose a new drug for CD. Therefore, BZ is still the best option for CD. The trials in course should clarify more about new treatment regimens, but it is already possible to indicate that dosage and time of treatment need to be adjusted.

The association between variables of cardiopulmonary exercise test and quality of life in patients with chronic Chagas cardiomyopathy (Insights from the PEACH STUDY)

Studies investigating the association between functional capacity and quality of life (QoL) in individuals with chronic Chagas cardiomyopathy (CCC) usually do not include a gold-standard evaluation of functional capacity, limiting the validity and the interpretation of the results. The present study is a cross-section analysis aiming to evaluate the association between functional capacity (quantified by cardiopulmonary exercise test [CPET]) and QoL in individuals with CCC. QoL was assessed using the SF-36 questionnaire. Sociodemographic, anthropometric, clinical, cardiac function and maximal progressive CPET variables were obtained from PEACH study. Generalized linear models adjusted for age, sex, and left ventricular ejection fraction were performed to evaluate the association between CPET variables and QoL. After adjustments, VO2 peak and VO2 AT were both associated with physical functioning (β = +0.05 and β = +0.05, respectively) and physical component summary (β = +0.03 and β = +0.03, respectively). Double product was associated with physical functioning (β = +0.003), general health perceptions (β = +0.003), physical component summary (β = +0.002), and vitality (β = +0.004). HRR≤12bpm was associated with physical functioning (β = -0.32), role limitations due to physical problems (β = -0.87), bodily pain (β = -0.26), physical component summary (β = -0.21), vitality (β = -0.38), and mental health (β = -0.19). VE/VCO2 slope presented association with all mental scales of SF-36: vitality (β = -0.028), social functioning (β = -0.024), role limitations due to emotional problems (β = -0.06), mental health (β = -0.04), and mental component summary (β = -0.02). The associations between CPET variables and QoL demonstrate the importance of CPET inclusion for a more comprehensive evaluation of individuals with CCC. In this setting, intervention strategies aiming to improve functional capacity may also promote additional benefits on QoL and should be incorporated as a treatment strategy for patients with CCC.

Cost-effectiveness of an exercise-based cardiovascular rehabilitation program in patients with chronic Chagas cardiomyopathy in Brazil: An analysis from the PEACH study

OBJECTIVES

The present study aimed to perform a cost-effectiveness analysis of an exercise-based cardiovascular rehabilitation (CR) program in patients with chronic Chagas cardiomyopathy (CCC).

METHODS

Cost-effectiveness analysis alongside a randomised clinical trial evaluating the effects of a 6-month exercise-based CR program. The intervention group underwent 3 weekly exercise sessions. The variation of peak oxygen consumption (VO_2peak ) was used as a measurement of clinical outcome. Cost information from all healthcare expenses (examinations, healthcare visits, medication and hospitalisation) were obtained from the medical records in Brazilian reais (R$) and transformed into dollars using the purchasing power parity ($PPP). The longitudinal costs variation was evaluated through linear mixed models, represented by β coefficient, adjusted for the baseline values of the dependent variable. The cost-effectiveness evaluation was determined through an incremental cost-effectiveness ratio using the HEABS package (Stata 15.0).

RESULTS

The intervention group presented higher costs with healthcare visits (β = +3317.3; p < 0.001), hospitalisation (β = +2810.4; p = 0.02) and total cost (β = +6407.9; p < 0.001) after 3 months of follow-up. Costs related to healthcare visits (β = +2455.8; p < 0.001) and total cost (β = +4711.4; p < 0.001) remained higher in the intervention group after 6 months. The CR program showed an incremental cost-effectiveness ratio (ICER) of $PPP 1874.3 for each increase of 1.0 ml kg^-1  min^-1 of VO_2peak .

CONCLUSIONS

The CR program can be considered a cost-effective alternative and should be included as an intervention strategy in the care of patients with CCC.

Factors related to the discontinuation and mortality rates of a cardiac rehabilitation programme in patients with Chagas disease: a 6-year experience in a Brazilian tertiary centre

OBJECTIVES

To describe the clinical and sociodemographic characteristics of participants as well as discontinuation and mortality rates in a cardiac rehabilitation programme (CRP) tailored to Chagas disease (CD).

METHODS

Participants underwent functional capacity, anthropometry and cardiac function evaluations before beginning a CRP. Univariate and multivariate Cox proportional hazards models were performed to investigate the associations between clinical and sociodemographic characteristics at baseline with discontinuation rates and deaths.

RESULTS

Forty-two patients were enrolled in the CRP (61.9% men, mean age of 58.1 ± 11.8 years). During a median follow-up period of 10.8 months, 74% discontinued and 14% died while enrolled in CRP. 34% of the patients who discontinued CRP died during follow-up. White race (HR = 0.09; 95% CI 0.01-1.00), right ventricular systolic dysfunction (HR = 10.54; 95% CI 1.24-89.50) and oxygen pulse (HR = 0.69; 95% CI 0.48-0.99) were independently associated with death while enrolled in CRP. Married status (HR = 0.44; 95% CI 0.21-0.95) was independently associated with discontinuation rates from CRP. VO₂ peak (HR = 0.85; 95% CI 0.74-0.98) and CRP discontinuation due to CD-related reasons (HR = 8.33; 95% CI 1.91-36.27) were the variables independently associated with death after discontinuation of CRP.

CONCLUSION

In this population, sociodemographic aspects and severity of CD were important determinants of CRP discontinuation and mortality.

Exercise training improves microvascular function in patients with Chagas heart disease: Data from the PEACH study

BACKGROUND

Chagas heart disease (CHD) impairs the systemic microvascular function. We investigated the effects of exercise training on cutaneous microvascular function among patients with CHD.

METHODS

Patients from the PEACH study were randomly assigned to a supervised exercise training 3 times/week for 6 months (Trained; n = 10) or a control group (Untrained; n = 8). Both groups underwent evaluation of microvascular function before, and at 3- and 6-months of follow-up. Cutaneous vascular conductance (CVC) was assessed in the skin of the forearm using laser speckle contrast imaging coupled with iontophoresis of acetylcholine (ACh), sodium nitroprusside (SNP) and during post-occlusive reactive hyperemia (PORH).

RESULTS

At 3-months of follow-up, no difference was detected between groups in CVC responses to ACh (p = 0.50), SNP (p = 0.26) and HRPO (p = 0.65). However, at 6-months of follow-up, trained vs. untrained patients improved CVC induced by SNP-iontophoresis (0.19 ± 0.10 vs. 0.14 ± 0.15 APU.mmHg^-1; p = 0.05) and PORH (0.63 ± 0.15 vs. 0.48 ± 0.18 APU.mmHg^-1; p = 0.05). CVC response to ACh-iontophoresis was similar between groups (0.19 ± 0.11 vs. 0.22 ± 0.17 APU.mmHg^-1; p = 0.38).

CONCLUSION

Exercise training performed during 6 months improved the cutaneous microvascular function of CHD patients. Further studies evaluating the mechanism involved in this response are warranted.

Effect of Physical Exercise Training in Patients With Chagas Heart Disease (from the PEACH STUDY)

Chagas heart disease (HD) is a chronic fibrosing myocarditis with high mortality. The PEACH study aimed to evaluate if exercise training can improve the functional capacity of Chagas HD patients with left ventricular dysfunction and/or heart failure. The PEACH study was a single center, parallel-group, clinical trial that randomized 30 clinical stable Chagas HD patients with left ventricular ejection fraction <45% or heart failure symptoms to either supervised exercise training 3 times/week for 6 months or a control group. Both groups had the same monthly pharmaceutical and nutritional counseling and usual care. Primary end point was functional capacity assessed by peak exercise oxygen consumption (peak VO₂) obtained by cardiopulmonary exercise test. Secondary end points included other cardiopulmonary exercise test variables, cardiac function by echocardiography, body composition, muscle respiratory strength, and metabolic biomarkers. Peak VO₂ increased among patients in exercise group from 17.60 ± 4.65 mlO₂ kg^-1 min^-1 to 19.40 ± 5.51 mlO₂ kg^-1 min^-1 while decreased in controls from 15.40 ± 6.30 mlO₂ kg^-1 min^-1 to 12.96 ± 4.50 mlO₂ kg^-1 min^-1, resulting in significant difference in change in peak VO₂ between groups after 6 months (β = +4.6, p = 0.004). There were significant differences between groups in changes in anaerobic threshold (β = 3.7, p = 0.05), peak oxygen pulse (β = +2.7, p = 0.032) and maximum minute ventilation (β = +13.9, p < 0.0001) after 6 months of intervention. In conclusion, exercise training improved functional capacity of chronic Chagas HD patients with left ventricular dysfunction and/or heart failure.

Is endothelial microvascular function equally impaired among patients with chronic Chagas and ischemic cardiomyopathy?

BACKGROUND

Chronic Chagas cardiomyopathy (CCC) and cardiomyopathies due to other etiologies involve differences in pathophysiological pathways that are still unclear. Systemic microvascular abnormalities are associated with the pathogenesis of ischemic heart disease. However, systemic microvascular endothelial function in CCC remains to be elucidated. Thus, we compared the microvascular endothelial function of patients presenting with CCC to those with ischemic cardiomyopathy disease.

METHODS

Microvascular reactivity was assessed in 21 patients with cardiomyopathy secondary to Chagas disease, 21 patients with cardiomyopathy secondary to ischemic disease and 21 healthy controls. Microvascular blood flow was assessed in the skin of the forearm using laser speckle contrast imaging coupled with iontophoresis of acetylcholine (ACh).

RESULTS

Peak increase in forearm blood flow with ACh iontophoresis in relation to baseline was greater in healthy controls than in patients with heart disease (controls: 162.7 ± 58.4% vs. ischemic heart disease: 74.1 ± 48.3% and Chagas: 85.1 ± 68.1%; p < 0.0001). Patients with Chagas and ischemic cardiomyopathy presented similar ACh-induced changes from baseline in skin blood flow (p = 0.55).

CONCLUSION

Endothelial microvascular function was equally impaired among patients with CCC and ischemic cardiomyopathy.