Assessment of biomarkers and clinical parameters as predictors of survival in patients with chagasic heart failure

BACKGROUND

Chagas disease, endemic in Latin America and spreading globally due to emigration, has a significant health burden, particularly in relation to chagasic heart failure (HF). Chagasic cardiomyopathy (CCM) is characterized by chronic inflammatory myocardial disease. This study aimed to identify inflammatory parameters and biomarkers that could aid in the management of patients with chagasic HF.

METHODS AND FINDINGS

A cohort study was conducted at a tertiary cardiology single-center over a mean follow-up period of 2.4 years. The study included patients with HF secondary to CCM enrolled between October 2013 and July 2017. Various clinical parameters, echocardiography findings, parasitemia status, brain natriuretic peptide (BNP) and troponin T (TnT) levels, and inflammatory biomarkers (IL-6, IL-10, IL-12p70, IL-17A, adiponectin, and IFN-γ) were assessed. The study encompassed a cohort of 103 patients, with a median age of 53 years and 70% being male. The left ventricular ejection fraction (LVEF) was 28%, with 40% of patients classified as NYHA II functional class. The median BNP level was 291 pg/ml. The observed mortality rate during the study period was 38.8%. Predictors of lower survival were identified as elevated levels of BNP, TnT, reduced LVEF, and increased adiponectin (thresholds: BNP > 309 pg/ml, TnT > 27.5 ng/ml, LVEF < 25.5%, adiponectin > 38 μg/mL). Notably, there was no evidence indicating a relationship between parasitemia and the inflammatory parameters with lower survival in these patients, including INF-γ, IL-6, IL-10, IL12-(p70), and IL17a.

CONCLUSION

Despite the presence of a chronic inflammatory process, the evaluated inflammatory biomarkers in this cohort were not predictive of survival in patients with chagasic HF with reduced ejection fraction (HFrEF). However, reduced LVEF, elevated BNP, adiponectin levels, and troponin T were identified as predictors of lower survival in these patients.

Effects of β-blocker therapy on exercise oscillatory ventilation in reduced ejection fraction heart failure patients: A case series study

BACKGROUND

Exercise oscillatory ventilation (EOV) is an abnormal breathing pattern that occurs in ~20% of patients with heart failure (HF) and is associated with poor prognosis and exercise intolerance. β-blockers (βb) are prescribed for most HF patients; however, their effect on EOV remains unclear. We evaluated the effect of βb on EOV in HF patients with reduced ejection fraction (HFrEF).

METHODS

Fifteen patients diagnosed with HF, ejection fraction < 45%, aged from 18 to 65 years, were included before starting βb therapy. Patients underwent clinical evaluation, cardiopulmonary exercise testing, echocardiography, laboratory exams (norepinephrine levels, B type natriuretic peptide) at baseline and after βb therapy optimized for six months. Presence of exercise oscillatory breathing was determined by two experienced observers who were blinded to the moment of the test (pre or post).

RESULTS

Fifteen patients (1 female), aged 49.5 ± 2.5 years, with HFrEF, NYHA I-III enrolled in the study. The etiologies of the HFrEF were idiopathic (n = 8) and hypertensive (n = 7). LVEF increased after βb therapy from 25.9 ± 2.5% to 33 ± 2.6%, P = 0.02; peak VO₂ did not significantly change (21.8 ± 1.7 vs 24.7 ± 1.9, P = 0.4); VE/VCO₂ slope changed from 32.1 ± 10.6-27.5 ± 9.1, P = 0.03. Before βb initiation, nine patients (60%) had EOV, but only two (13%) did after optimized therapy. McNemar test was used to evaluate the significance of the association between the two moments (P = 0.02).

CONCLUSION

In patients with HF, medical therapy with βb can reverse EOV. This may explain why these patients experience symptom improvement after βb therapy.

Acute high-intensity interval exercise versus moderate-intensity continuous exercise in heated water-based on hemodynamic, cardiac autonomic, and vascular responses in older individuals with hypertension

OBJECTIVES

This crossover study design aimed to assess hemodynamic, cardiac autonomic, and vascular responses to high-intensity interval (HIIE) vs moderate-intensity continuous exercise (MICE) in older individuals with hypertension.

METHODS

Twenty (67 ± 7 y) older individuals with hypertension were randomly assigned to perform HIIE, MICE, or control (CON) sessions in the heated swimming pool (30-32°C). Blood pressure (BP), arterial stiffness, endothelial reactivity, and heart rate variability (HRV) were measured pre, post, and 45 min (recovery) after each intervention followed by 24-h ambulatory BP and HRV.

RESULTS

One single aerobic exercise session was not effective to provoke post-exercise hypotension and vascular improvements. HIIE was superior to MICE and CON to increasing parasympathetic modulation at post and recovery. Exercise sessions showed to disturb the autonomic system at nighttime compared to CON.

CONCLUSIONS

These results may have important implications in water-based therapy and the elderly with hypertension.

Exercise Training in Heart Failure With Reduced Ejection Fraction and Permanent Atrial Fibrillation: A Randomized Clinical Trial

BACKGROUND

Heart failure (HF) associated with atrial fibrillation (AF) increases patients' physical inactivity, worsening their clinical condition and mortality. Exercise training is safe and has clear benefits in HF. However, little is known about the effects of exercise training on heart failure patients with reduced ejection fraction and permanent atrial fibrillation (HFAF).

OBJECTIVE

To test the hypothesis that exercise training improves functional capacity, cardiac function, and quality of life in patients with HFAF.

METHODS

This randomized clinical trial was conducted at the Heart Institute. Patients with HFAF, LVEF ≤40% and resting HR ≤80 bpm were included in the study. Cardiopulmonary testing, echocardiography, autonomic, and quality of life assessment were performed before and after the 12-week protocol period.

RESULTS

Twenty-six patients, 58±1 years, were randomized to exercise training (HFAF-trained, n=13) or no training (HFAF-untrained, n=13). At baseline, no differences between groups were found. Exercise improved VO₂ peak, slope VE/VCO₂, and quality of life. HFAF-trained significantly decreased resting HR (from 73±2 to 69±2 bpm, P=.02) and recovery HR (from 148±11 to 128±9 bpm, P=.001). Concomitantly, LVEF increased (from 31±1 to 36±0.9 %, P=.01), LA decreased (from 52±1.2 to 47±1mm, P=.03), and LV-ESV and LV-EDV deceased (from 69±2 to 64±1.8 mL/m², and 99±2.1 to 91±2, P<.05, respectively). No changes were observed in the untrained group.

CONCLUSION

Exercise training can improve exercise capacity, quality of life, and cardiac function in patients with heart failure with reduced ejection fraction and permanent atrial fibrillation.

Analysis of Cardiovascular Hemodynamic and Autonomic Variables in Individuals with Systemic Arterial Hypertension, Type 2 Diabetes Mellitus, and Parkinson's Disease: A Comparative Study

BACKGROUND

Systemic arterial hypertension (SAH), type 2 diabetes mellitus (T2DM), and Parkinson's disease (PD) are highly prevalent chronic diseases that can significantly impact the cardiovascular system.

AIM

The aim of this study was to compare hemodynamic and autonomic variables at rest in individuals with SAH, T2DM, or PD.

METHODS

Fifty sedentary or insufficiently active individuals (22 men) with SAH (age = 66 ± 5.0 yr), T2DM (age = 52 ± 10 yr) or PD (age = 68 ± 8.0 yr) had their resting blood pressure (BP), arterial stiffness, endothelial function, and heart rate variability (HRV) assessed and compared.

RESULTS

Systolic and diastolic BP were higher in SAH (130 ± 10 / 80 ± 10 mmHg) than T2DM (110 ± 14 / 75 ± 11 mmHg) and PD, and (123 ± 20 / 70 ± 11 mmHg) respectively. T2DM individuals showed lower arterial stiffness (8.4 ± 1.1 m/s), when compared to SAH (10.3 ± 2.3 m/s) and PD (10.6 ± 3.0 m/s). T2DM had greater resting tachycardia showed by the mean RR (759 ± 79 ms), than SAH (962 ± 169 ms) and PD (976 ± 134 ms), which was accompanied by higher sympathetic modulation (low frequency [LF]: 62 ± 19 nu) and lower parasympathetic modulation (high frequency [HF]: 32 ± 16 nu) when compared to SAH (LF: 40 ± 16 nu; HF: 61 ± 33 nu). No differences among groups were found on non-linear HRV markers and endothelial reactivity indexes.

CONCLUSIONS

Individuals with T2DM showed impaired levels of cardiac autonomic markers when compared to individuals with SAH and PD, despite of having lower levels of BP and arterial stiffness.

Effects of the exercise training on skeletal muscle oxygen consumption in heart failure patients with reduced ejection fraction

AIMS

Skeletal muscle dysfunction is a systemic consequence of heart failure (HF) that correlates with functional capacity. However, the impairment within the skeletal muscle is not well established. We investigated the effect of exercise training on peripheral muscular performance and oxygenation in HF patients.

METHODS AND RESULTS

HF patients with ejection fraction ≤40% were randomized 2:1 to exercise training or control for 12 weeks. Muscle tissue oxygen was measured noninvasively by near-infrared spectroscopy (NIRS) during rest and a symptom-limited cardiopulmonary exercise test (CPET) before and after intervention. Measurements included skeletal muscle oxygenated hemoglobin concentration, deoxygenated hemoglobin concentration, total hemoglobin concentration, VO₂ peak, VE/VCO₂ slope, and heart rate. Muscle sympathetic nerve activity by microneurography, and muscle blood flow by plethysmography were also assessed at rest pre and post 12 weeks. Twenty-four participants (47.5 ± 7.4 years, 58% men, 75% no ischemic) were allocated to exercise training (ET, n = 16) or control (CG, n = 8). At baseline, no differences between groups were found. Exercise improved VO₂ peak, slope VE/VCO₂, and heart rate. After the intervention, significant improvements at rest were seen in the ET group in muscle sympathetic nerve activity and muscle blood flow. Concomitantly, a significant decreased in Oxy-Hb (from 29.4 ± 20.4 to 15.7 ± 9.0 μmol, p = 0.01), Deoxi-Hb (from 16.3 ± 8.2 to 12.2 ± 6.0 μmol, p = 0.003) and HbT (from 45.7 ± 27.6 to 27.7 ± 13.4 μmol, p = 0.008) was detected at peak exercise after training. No changes were observed in the control group.

CONCLUSION

Exercise training improves skeletal muscle function and functional capacity in HF patients with reduced ejection fraction. This improvement was associated with increased oxygenation of the peripheral muscles, increased muscle blood flow, and decreased sympathetic nerve activity.

Residual Impact of Concurrent, Resistance, and High-Intensity Interval Training on Fasting Measures of Glucose Metabolism in Women With Insulin Resistance

We sought to assess the residual effects (post 72-h training cessation) on fasting plasma glucose (FPG) and fasting insulin (FI) after 12-weeks of high-intensity interval training (HIIT), resistance training (RT), or concurrent training (CT) in women with insulin resistance (IR). We also aimed to determine the training-induced, post-training residual impact of CT. A total of adult 45 women (age 38.5±9.2years) were included in the final analysis and were assigned to a control (CG; n=13, BMI 28.3±3.6kg/m2), HIIT [n=14, BMI 28.6±3.6kg/m2, three sessions/wk., 80-100% of the maximum heart rate (HRmax)], RT [n=8, BMI 29.4±5.5kg/m2, two sessions/wk., 8-10 points of the modified Borg, corresponding to 20 to 50% range of one maximum repetition test (1RM)], or CT group (n=10, BMI 29.1±3.0kg/m2, three sessions/wk., 80-100% of HRmax, and 8-10 Borg, or 20 to 50% range of 1RM, to each HIIT and RT compounds), with the latter including both HIIT and RT regimens. Training interventions lasted 12-weeks. The main outcomes were FPG and FI measured at pre- and 24-h and 72-h post-training (FPG24h, FI24h, and FPG72h, FI72h, respectively). Secondary endpoints were body composition/anthropometry and the adiposity markers waist circumference (WC) and tricípital skinfold (TSF). The residual effects 72-h post-training [delta (∆)] were significantly poorer (all p<0.01) in the CT group (∆FPG72h+6.6mg/dl, η 2: 0.76) than in the HIIT (∆FPG72h+1.2mg/dl, η 2: 0.07) and RT (∆FPG72h+1.0mg/dl, η 2: 0.05) groups. These findings reveal that HIIT reduces FPG and RT reduces FI 24-h post-training; both exercise interventions alone have remarkably better residual effects on FPG and FI (post-72h) than CT in women with insulin resistance.

Contemporary review of exercise in heart transplant recipients

Heart transplantation (HTx) is a therapeutic option for a selected group of patients with end-stage heart failure. Although secondary prevention including exercise therapy is recommended in the management of patients following HTx, little information is available on their metabolic and physiological consequences in HTx. Therefore, we aimed to conduct a contemporary review the effectiveness of exercise therapy on functional capacity, cardiovascular health and health-related quality of life for adult HTx patients. We searched the database MEDLINE for articles published between January 2015 and October 2020 and were able to include 6 studies involving 202 patients. Larger improvements in exercise capacity were seen after high-intensity interval training and in patients with evidence of cardiac reinnervation. Clinically relevant reductions were observed for daytime and 24 h ambulatory blood pressure after exercise training and following a single bout of aerobic exercise. Finally, limited data suggest that quality of life is higher in HTx patients following high-intensity training. In summary, the available evidence shows the potential for exercise as a vital treatment in patients following HTx. Yet, the scant data calls for more well-designed and adequately powered studies to support its effectiveness and to unravel optimal exercise characteristics, which would allow for more effective and person-tailored exercise prescription.

Atrial fibrillation in heart failure with reduced ejection fraction: a case report of exercise training

BACKGROUND

Heart failure (HF) and atrial fibrillation (AF) are often concomitant and act in a vicious cycle. Atrial fibrillation is associated with greater functional limitations and increased morbidity and mortality in patients with HF. Moreover, AF associated with HF increases patients' physical inactivity, worsening their clinical condition, and prognosis. Exercise training is safe and has clear benefits in HF. However, these benefits have not been demonstrated when AF is associated with HF.

CASE SUMMARY

We present the case of a 57-year-old man with permanent AF and HF with reduced ejection fraction, who underwent 12 weeks of exercise training that included cardiopulmonary exercise testing, neuromuscular sympathetic activity (NMSA), and muscle blood flow (MBF) before and after training.

DISCUSSION

Exercise training was shown to have a potential benefit in reducing the activity of the sympathetic nerve and increasing muscle blood flow, as well as increasing VO2peak and decreasing the VE/VCO2 slope in a patient with AF associated with HF with reduced ejection fraction. These results may indicate favourable clinical implications in this group of patients.

Hypotensive Effect of Heated Water-based Exercise in Older Individuals with Hypertension

Blood pressure (BP) and hemodynamic response to heated water-based (HEx) vs. land-based exercise (LEx) were assessed in 15 (6 men) older hypertensives (age 66.4±4.9 yr) under pharmacological treatment. Participants were randomly assigned to perform 30 min of moderate-intensity HEx (walking inside the pool), LEx (walking on a treadmill) and non-exercise control (CON) intervention. Resting BP, arterial stiffness, endothelial reactivity and heart rate variability (HRV) were measured before, immediately after, and 45 min after interventions. 24-h ambulatory BP monitoring was performed after interventions. Resting systolic (but not diastolic) BP reduced 9.9±3.1 mmHg (P<0.01) 45 min after HEx only. 24-h systolic and diastolic, daytime diastolic and nightime systolic BP were lower (P<0.05) after HEx than both LEx and CON. Daytime systolic BP was also lower (P<0.05) after HEx than CON. Nighttime diastolic was not different between interventions. HEx-induced ambulatory BP reduction ranged 4.5±1.3 mmHg (24-h diastolic BP) to 9.5±3.0 mmHg (nighttime systolic BP), and persisted for 18/11 h in systolic/diastolic BP, when compared with CON. No significant changes in arterial stiffness, endothelial reactivity and HRV were found during any intervention. These results suggest that HEx may have important implications for managing BP in older hypertensive under pharmacological treatment.

Prescribing high-intensity interval exercise by RPE in individuals with type 2 diabetes: metabolic and hemodynamic responses

We tested the hypothesis that rating of perceived exertion (RPE) is a tool as efficient as the heart rate (HR) response to the cardiopulmonary exercise test (CPX) for prescribing and self-regulating high-intensity interval exercise (HIIE), and that metabolic and hemodynamic response to HIIE is superior than to continuous moderate-intensity exercise (MICE) in individuals with type 2 diabetes mellitus (T2DM). Eleven participants (age = 52.3 ± 3 years) underwent HIIE prescribed and self-regulated by RPE (HIIE_RPE; 25 min), HIIE prescribed and regulated by an individual's HR response to CPX (HIIE_HR; 25 min), MICE prescribed and self-regulated by RPE (30 min) and control (30 min of seated resting) intervention in random order. HR, blood pressure (BP), capillary glucose, endothelial reactivity, and carotid-femoral pulse wave velocity were assessed before, immediately after, and 45 min after each intervention. Exercise HR, speed, and distance were measured during exercise sessions. Twenty-four-hour ambulatory BP was measured after each intervention. Exercise HR, speed, and distance were similar between HIIE_RPE and HIIE_HR. BP response was not different among HIIE_RPE, HIIE_HR, and MICE. Capillary glycaemia reduction was greater (P < 0.05) after HIIE_RPE (48.6 ± 9.6 mg/dL) and HIIE_HR (47.2 ± 9.5 mg/dL) than MICE (29.5 ± 11.5 mg/dL). Reduction (P < 0.05) in 24-h (6.7 ± 2.2 mm Hg) and tendency toward reduction (P = 0.06) in daytime systolic (7.0 ± 2.5 mm Hg) ambulatory BP were found only after HIIE_RPE. These results suggest that HIIE is superior to MICE for reducing glycaemia and ambulatory BP, and that the 6-20 RPE scale is a useful tool for prescribing and self-regulating HIIE in individuals with T2DM.

Safety profile and efficacy of ivabradine in heart failure due to Chagas heart disease: a post hoc analysis of the SHIFT trial

AIMS

The SHIFT trial showed that ivabradine reduced heart rate (HR) and the risk of cardiovascular outcomes. Concerns remain over the efficacy and safety of ivabradine on heart failure (HF) due to Chagas disease (ChD). We therefore conducted a post hoc analysis of the SHIFT trial to investigate the effect of ivabradine in these patients.

METHODS AND RESULTS

SHIFT was a randomized, double-blind, placebo-controlled trial in symptomatic systolic stable HF, HR ≥ 70 b.p.m., and in sinus rhythm. The ChD HF subgroup included 38 patients, 20 on ivabradine, and 18 on placebo. The ChD HF subgroup showed high prevalence of bundle branch right block and, compared with the overall SHIFT population, lower systolic blood pressure; higher use of diuretics, cardiac glycosides, and antialdosterone agents; and lower use of angiotensin-converting enzyme inhibitor/angiotensin II receptor blocker or target daily dose of beta-blocker. ChD HF presented a poor prognosis (all-cause mortality at 2 years was ~60%). The mean twice-daily dose of ivabradine was 6.26 ± 1.15 mg and placebo 6.43 ± 1.55 mg. Ivabradine reduced HR from 77.9 ± 3.8 to 62.3 ± 10.1 b.p.m. (P = 0.005) and improved functional class (P = 0.02). A trend towards reduction in all-cause death was observed in ivabradine arm vs. placebo (P = 0.07). Ivabradine was not associated with serious bradycardia, atrioventricular block, hypotension, or syncope.

CONCLUSIONS

ChD HF is an advanced form of HF with poor prognosis. Ivabradine was effective in reducing HR in these patients and improving functional class. Although our results are based on a very limited sample and should be interpreted with caution, they suggest that ivabradine may have a favourable benefit-risk profile in ChD HF patients.

High-Intensity Interval Training in Heart Transplant Recipients: A Systematic Review with Meta-Analysis

Heart transplantation (HTx) is considered an efficient and gold-standard procedure for patients with end-stage heart failure. After surgery, patients have lower aerobic power (VO2max) and compensatory hemodynamic responses. The aim of the present study was to assess through a systematic review with meta-analysis whether high-intensity interval training (HIIT) can provide benefits for those parameters. This is a systematic review with meta-analysis, which searched the databases and data portals PubMed, Web of Science, Scopus, Science Direct and Wiley until December 2016 (pairs). The following terms and descriptors were used: "heart recipient" OR "heart transplant recipient" OR "heart transplant" OR "cardiac transplant" OR "heart graft". Descriptors via DeCS and Mesh were: "heart transplantation'' OR "cardiac transplantation". The words used in combination (AND) were: "exercise training" OR "interval training" OR "high intensity interval training" OR "high intensity training" OR "anaerobic training" OR "intermittent training" OR "sprint training". The initial search identified 1064 studies. Then, only those studies assessing the influence of HIIT on the post-HTx period were added, resulting in three studies analyzed. The significance level adopted was 0.05. Heart transplant recipients showed significant improvement in VO2peak, heart rate and peak blood pressure in 8 to 12 weeks of intervention.

Functional Class in Children with Idiopathic Dilated Cardiomyopathy. A pilot Study

BACKGROUND

Idiopathic dilated cardiomyopathy (IDCM), most common cardiac cause of pediatric deaths, mortality descriptor: a low left ventricular ejection fraction (LVEF) and low functional capacity (FC). FC is never self reported by children.

OBJECTIVE

The aims of this study were (i) To evaluate whether functional classifications according to the children, parents and medical staff were associated. (iv) To evaluate whether there was correlation between VO2 max and Weber's classification.

METHOD

Prepubertal children with IDCM and HF (by previous IDCM and preserved LVEF) were selected, evaluated and compared. All children were assessed by testing, CPET and functional class classification.

RESULTS

Chi-square test showed association between a CFm and CFp (1, n = 31) = 20.6; p = 0.002. There was no significant association between CFp and CFc (1, n = 31) = 6.7; p = 0.4. CFm and CFc were not associated as well (1, n = 31) = 1.7; p = 0.8. Weber's classification was associated to CFm (1, n = 19) = 11.8; p = 0.003, to CFp (1, n = 19) = 20.4; p = 0.0001and CFc (1, n = 19) = 6.4; p = 0.04).

CONCLUSION

Drawing were helpful for children's self NYHA classification, which were associated to Weber's stratification.

Prescribing and Regulating Exercise with RPE after Heart Transplant: A Pilot Study

PURPOSE

The objective of this study is to analyze the use of the 6-20 RPE scale for prescribing and self-regulating heated water-based exercise (HEx) and land-based exercise (LEx) in heart transplant recipients.

METHODS

Fifteen (five females) clinically stable heart transplant recipients (time since surgery = 4.0 ± 2.5 yr) age 46.7 ± 11.8 yr underwent a symptom-limited maximal graded exercise test on a treadmill to determine their HR at anaerobic threshold (HRAT), respiratory compensation point (HRRCP), and maximal effort (HRmax). After a week, patients were randomized to perform 30 min of both HEx (walking inside the pool) and LEx (treadmill walking) sessions at a pace between 11 and 13 on the 6-20 RPE scale and had their HR measured every 4 min. The interval between sessions was 48-72 h.

RESULTS

No significant differences between sessions were found in the average HR during HEx and LEx. Patients showed a delay in HR increase during both interventions, with the stabilization beginning after 8 min of exercise. Exercise HR was maintained between the HRAT and HRRCP (in the aerobic exercise training zone) for the most part of both HEx (72% of HR measurements) and LEx (66% of HR measurements). Only a few HR measurements stayed below HRAT (HEx = 9%, LEx = 13%) or above HRRCP (HEx = 19%, LEx = 21%) during both exercise sessions.

CONCLUSION

Exercise HR was maintained in the aerobic exercise training zone (between HRAT and HRRCP) for the most part of both sessions, suggesting that the 6-20 RPE scale may be an efficient tool for prescribing and self-regulating HEx and LEx in heart transplant recipients.

Reverse auction: a potential strategy for reduction of pharmacological therapy cost

Background

Polypharmacy is a significant economic burden.

Objective

We tested whether using reverse auction (RA) as compared with commercial pharmacy (CP) to purchase medicine results in lower pharmaceutical costs for heart failure (HF) and heart transplantation (HT) outpatients.

Methods

We compared the costs via RA versus CP in 808 HF and 147 HT patients followed from 2009 through 2011, and evaluated the influence of clinical and demographic variables on cost.

Results

The monthly cost per patient for HF drugs acquired via RA was $10.15 (IQ 3.51-40.22) versus $161.76 (IQ 86.05‑340.15) via CP; for HT, those costs were $393.08 (IQ 124.74-774.76) and $1,207.70 (IQ 604.48-2,499.97), respectively.

Conclusion

RA may reduce the cost of prescription drugs for HF and HT, potentially making HF treatment more accessible. Clinical characteristics can influence the cost and benefits of RA. RA may be a new health policy strategy to reduce costs of prescribed medications for HF and HT patients, reducing the economic burden of treatment.

Determinants of peak VO2 in heart transplant recipients

Objective

To establish the determinants of the peak VO₂ in heart transplant recipients.

Methods

Patient's assessment was performed in two consecutive days. In the first day, patients performed the heart rate variability assessment followed by a cardiopulmonary exercise test. In the second day, patients performed a resting echocardiography. Heart transplant recipients were eligible if they were in a stable condition and without any evidence of tissue rejection diagnosed by endomyocardial biopsy. Patients with pacemaker, noncardiovascular functional limitations such as osteoarthritis and chronic obstructive pulmonary disease were excluded from this study.

Results

Sixty patients (68% male, 48 years and 64 months following heart transplantation) were assessed. Multivariate analysis selected the following variables: receptor's gender (P =0.001), receptor age (P =0.049), receptor Body Mass Index (P =0.005), heart rate reserve (P <0.0001), left atrium diameter (P =0.016). Multivariate analysis showed r=0.77 and r2=0.6 with P <0.001. Equation: peakVO₂ =32.851 - 3.708 (receptor gender) - 0.067 (receptor age) - 0.318 (receptor BMI) + 0.145 (heart rate reserve) - 0.111 (left atrium diameter).

Conclusion

The determinants of the peak VO₂ in heart transplant recipients were: receptor sex, age, Body Mass Index, heart rate reserve and left atrium diameter. Heart rate reserve was the unique variable positively associated with peak VO₂ . This data suggest the importance of the sympathetic reinnervation in peak VO₂ in heart transplant recipients.

Exercise training improves ambulatory blood pressure but not arterial stiffness in heart transplant recipients

BACKGROUND

Hypertension is the most prevalent comorbidity after heart transplantation (HT). Exercise training (ET) is widely recommended as a key non-pharmacologic intervention for the prevention and management of hypertension, but its effects on ambulatory blood pressure (ABP) and some mechanisms involved in the pathophysiology of hypertension have not been studied in this population. The primary purpose of this study was to investigate the effects of ET on ABP and arterial stiffness of HT recipients.

METHODS

40 HT patients, randomized to ET (n = 31) or a control group (n = 9) underwent a maximal graded exercise test, 24-hour ABP monitoring, and carotid-femoral pulse wave velocity (PWV) assessment before the intervention and at a 12-week follow-up assessment. The ET program was performed thrice-weekly and consisted primarily of endurance exercise (40 minutes) at ~70% of maximum oxygen uptake (Vo2MAX).

RESULTS

The ET group had reduced 24-hour (4.0 ± 1.4 mm Hg, p < 0.01) and daytime (4.8 ± 1.6 mm Hg, p < 0.01) systolic ABP, and 24-hour (7.0 ± 1.4 mm Hg, p < 0.001) daytime (7.5 ± 1.6 mm Hg, p < 0.001) and nighttime (5.9 ± 1.5 mm Hg, p < 0.001) diastolic ABP after the intervention. The ET group also had improved Vo2MAX (9.7% ± 2.6%, p < 0.001) after the intervention. However, PWV did not change after ET. No variable was changed in the control group after the intervention.

CONCLUSIONS

The 12-week ET program was effective for reducing ABP but not PWV in heart transplant recipients. This result suggests that endurance ET may be a tool to counteract hypertension in this high-risk population.

Physical activity: practice this idea

Sedentary habits or insufficient activities to promote health benefits can influence the occurrence of chronic diseases. The cardiovascular risk factors arise, at least partially, from the individual-environment interaction during life, and worsen with aging and lack of physical exercise. Health promotion and prevention are among the greatest challenges of public health policies. However, physical activity turns out to be rarely recommended and, thus have a very poor adhesion. In spite of consensus about the benefits of physical activity in both primary and secondary prevention, only 32% of adults and 66% of children and adolescents, according to Healthy People 2010 guideline, practice leisure-time physical activity. Thus, the regular practice of physical activity and healthy habits require changes in basic concepts in government and social policies. The higher involvement of public and private sectors related to health and education, the more expressive would be the reduction in socioeconomic costs and the improvement in quality of life.

Age affects exercise-induced improvements in heart rate response to exercise

The aim of the present study was to analyze the effects of age on cardiorespiratory fitness (CRF), muscle strength and heart rate (HR) response to exercise adaptation in women in response to a long-term twice-weekly combined aerobic and resistance exercise program. 85 sedentary women, divided into young (YG; n=22, 30.3 ± 6.2 years), early middle-aged (EMG; n=28, 44.1 ± 2.5 years), late middle-aged (LMG; n=20, 56.7 ± 3.5 years) and older (OG; n=15, 71.4 ± 6.9 years) groups, had their CRF, muscle strength (1-repetition maximum test) and HR response to exercise (graded exercise test) measured before and after 12 months of combined exercise training. Exercise training improved CRF and muscle strength in all age groups (P<0.05), and no significant differences were observed between groups. Exercise training also improved resting HR and recovery HR in YG and EMG (P<0.05), but not in LMG and OG. Maximal HR did not change in any group. Combined aerobic and resistance training at a frequency of 2 days/week improves CRF and muscle strength throughout the lifespan. However, exercise-induced improvements in the HR recovery response to exercise may be impaired in late middle-aged and older women.

MicroRNAs: a new paradigm in the treatment and diagnosis of heart failure?

MicroRNAs (miRNAs) are a group of newly discovered small RNAs, non-coding, which represent one of the most exciting areas of modern medical science as they modulate a huge and complex regulatory network of gene expression. Lines of evidence have recently suggested that miRNAs play a key role in the pathogenesis of heart failure. Some miRNAs highly expressed in the heart, such as miR-1, miR-133 and miR-208, are strongly associated with the development of cardiac hypertrophy, while the exact role of miR-21 in the cardiovascular system remains controversial. Serum levels of circulating miRNAs such as miR-423-5p are being evaluated as potential biomarkers in the diagnosis and prognosis of heart failure. On the other hand, the manipulation of levels of miRNAs using techniques such as mimicking the miRNAs (miRmimics) and antagonistic miRNAs (antagomiRs) is making increasingly evident the enormous potential of miRNAs as promising therapeutic strategies in heart failure.

Physical exercise and microRNAs: new frontiers in heart failure

Although the impact of exercise on survival of patients with heart failure has been recently questioned, exercise training improves quality of life, functional capacity, inflammation, endothelial and autonomic function. In recent years, interest has increased regarding a group of small non-protein coding RNAs called microRNAs. Studies have shown that the expression of these molecules changes in several pathological conditions, such as myocardial infarction, myocardial ischemia and heart failure, and when clinical improvement occurs, they seem to normalize. With the potential for practical applicability, markers that may be useful in diagnostic and prognostic assessment of heart failure have been identified, such as miR-423-5p. In addition, results of experimental studies have indicated that there are potential therapeutic effects of microRNAs. MicroRNAs are involved in the regulation of gene expression during fetal development and in adult individuals, increasing or decreasing in the heart in response to physiological stress, injury or hemodynamic overload. Thus, the study of the behavior of these molecules in physical exercise has brought important information about the effects of this therapeutic modality and represents a new era in the understanding of heart failure. This review aims to integrate the evidence on microRNAs in heart failure with greater relevance in the study of physical exercise.

MicroRNAs: new players in heart failure

MicroRNAs (miRNAs) are a class of non-coding small RNAs representing one of the most exciting areas of modern medical science. miRNAs modulate a large and complex regulatory network of gene expression of the majority of the protein-coding genes. Currently, evidences suggest that miRNAs play a crucial role in the pathogenesis of heart failure. Some miRNAs as miR-1, miR-133 and miR-208a are highly expressed in the heart and strongly associated with the development of cardiac hypertrophy. Recent data indicate that these miRNAs as well as miR-206 change their expression quickly in response to physical activity. The differential regulation of miRNAs in response to exercise suggests a potential value of circulating miRNAs (c-miRNAs) as biomarkers of physiological mediators of the cardiovascular adaptation induced by exercise. Likewise, serum levels of c-miRNAs such as miR-423-5p have been evaluated as potential biomarkers in the diagnosis and prognosis of heart failure. On the other hand, the manipulation of miRNAs levels using techniques such as 'miR mimics' and 'antagomiRs' is becoming evident the enormous potential of miRNAs as promising therapeutic strategies in heart failure.

Left cardiac sympathetic denervation for treatment of symptomatic systolic heart failure patients: a pilot study

AIMS

To evaluate the feasibility, safety, and potential beneficial effects of left cardiac sympathetic denervation (LCSD) in systolic heart failure (HF) patients.

METHODS AND RESULTS

In this prospective, randomized pilot study, inclusion criteria were New York Heart Association (NYHA) functional class II or III, left ventricular ejection fraction (LVEF) ≤40%, sinus rhythm, and resting heart rate >65 b.p.m., despite optimal medical therapy (MT). Fifteen patients were randomly assigned either to MT alone or MT plus LCSD. The primary endpoint was safety, measured by mortality in the first month of follow-up and morbidity according to pre-specified criteria. Secondary endpoints were exercise capacity, quality of life, LVEF, muscle sympathetic nerve activity (MSNA), brain natriuretic peptide (BNP) levels and 24 h Holter mean heart rate before and after 6 months. We studied clinical effects in long-term follow-up. Ten patients underwent LCSD. There were no adverse events attributable to surgery. In the LCSD group, LVEF improved from 25 ± 6.6 to 33 ± 5.2 (P = 0.03); 6 min walking distance improved from 167 ± 35 to 198 ± 47 m (P = 0.02). Minnesota Living with Heart Failure Questionnaire (MLWHFQ) score physical dimension changed from 21 ± 5 to 15 ± 7 (P = 0.06). The remaining analysed variables were unchanged. During 848 ± 549 days of follow-up, in the MT group, three patients either died or underwent cardiac transplantation (CT), while in the LCSD group six were alive without CT.

CONCLUSIONS

LCSD was feasible and seemed to be safe in systolic HF patients. Its beneficial effects warrant the development of a larger randomized trial. Trail registration: NCT01224899.

Physical training in Becker muscular dystrophy associated with heart failure

Becker muscular dystrophy (BMD) integrates dystrophy occurring due to genetic mutations that express the dystrophin protein in chromosome X. The onset of neuromuscular symptoms usually precedes the impairment of cardiac function, and may conversely happen by heart failure (HF). Physical training is well established in HF, however, when combined with BMD, it is controversial and without any scientific basis. This study presents the case of a patient with BMD associated with HF in cardiac transplant waiting list undergoing a physical training program.

Endothelial function in pre-pubertal children at risk of developing cardiomyopathy: a new frontier

Although it is known that obesity, diabetes, and Kawasaki's disease play important roles in systemic inflammation and in the development of both endothelial dysfunction and cardiomyopathy, there is a lack of data regarding the endothelial function of pre-pubertal children suffering from cardiomyopathy. In this study, we performed a systematic review of the literature on pre-pubertal children at risk of developing cardiomyopathy to assess the endothelial function of pre-pubertal children at risk of developing cardiomyopathy. We searched the published literature indexed in PubMed, Bireme and SciELO using the keywords 'endothelial', 'children', 'pediatric' and 'infant' and then compiled a systematic review. The end points were age, the pubertal stage, sex differences, the method used for the endothelial evaluation and the endothelial values themselves. No studies on children with cardiomyopathy were found. Only 11 papers were selected for our complete analysis, where these included reports on the flow-mediated percentage dilatation, the values of which were 9.80±1.80, 5.90±1.29, 4.50±0.70, and 7.10±1.27 for healthy, obese, diabetic and pre-pubertal children with Kawasaki's disease, respectively. There was no significant difference in the dilatation, independent of the endothelium, either among the groups or between the genders for both of the measurements in children; similar results have been found in adolescents and adults. The endothelial function in cardiomyopathic children remains unclear because of the lack of data; nevertheless, the known dysfunctions in children with obesity, type 1 diabetes and Kawasaki's disease may influence the severity of the cardiovascular symptoms, the prognosis, and the mortality rate. The results of this study encourage future research into the consequences of endothelial dysfunction in pre-pubertal children.

Effects of the recombinant form of the natural human B-type natriuretic peptide and levosimendan on pulmonary hyperventilation and chemosensivity in heart failure

BACKGROUND

The origin of dyspnea in chronic heart failure (HF) is multifactorial, and excessive ventilation is thought to play a role in inducing this symptom. Chemosensivity is augmented in HF, correlates with increased pulmonary ventilation (VE), and is an adverse prognostic marker. Despite increased blood levels of natriuretic peptides in clinical conditions associated with dyspnea, their effect on pulmonary VE and chemoreceptor activity remains unexplored.

METHODS

We tested in a prospective, placebo-controlled, three-way cross-over, double-blind randomized study the effects of the recombinant form of the natural human B-type natriuretic peptide (R-BNP) in comparison with placebo and levosimendan on chemoreflex sensitivity at rest, as well as their effects on pulmonary VE, systemic blood pressure, heart rate and sympathetic serum activity both at rest and during exercise.

RESULTS

Eleven stable chronic HF patients were randomized to sessions of 6-min treadmill-walking tests during placebo, or levosimendan or R-BNP intravenous infusion in the following conditions: room air, hypoxia, and hypercapnia. R-BNP administration determined higher pulmonary ventilatory response at rest and during exercise (P < 0.001) consequent to a boost of respiratory rate (P < 0.001) under room air and hypoxia conditions. Norepinephrine blood levels increased from rest to exercise in all conditions without differences among placebo, levosimendan, and R-BNP effects. BNP blood levels remained unchanged.

CONCLUSIONS

The novelty of the present findings is that R-BNP infusion in HF patients can boost pulmonary ventilatory response at rest and during exercise.

Ergoreflex activity in heart failure

A large body of evidence has suggested the existence of a reflex network that becomes hyperactive secondary to musculoskeletal alterations that occur in heart failure (HF) syndrome. Together with sympathoinhibitory cardiovascular reflexes, suppressed in the presence of the syndrome, heart failure can contribute to physical exercise intolerance. The hyperactivation of signals originated from receptors located in skeletal muscles (mechanoreceptors - metaboreceptors) is a recently proposed hypothesis to explain the origin of fatigue and dyspnea symptoms in HF. In HF, other alterations in the reflex control system, which are not mutually exclusive, contribute to dyspnea. The inappropriate stimulation of the arterial baroreceptors, with the consequent lack of inhibition of the muscle metaboreflex and carotid chemoreflex unloading and the increase in the renal vasoconstriction with angiotensin II release can also be considered. Although the functional alterations of the reflexes were used independently to illustrate the sympathetic excitation observed in HF, the interaction between these reflexes under normal and pathological conditions, especially its contribution to the sympathoexcitatory state found in HF, has not been broadly investigated. Therefore, questions about a possible association between the muscle receptors (mechano and metaboreceptors) in the genesis of the ergoreflex exacerbation, observed in HF, remain. Thus, the objective of this review was to integrate the knowledge on the mechano and metaboreflex (ergoreflex) in HF syndrome, as well as to clarify the influence of HF drug therapy on the ergoreflex.

Behavior of central and peripheral chemoreflexes in heart failure

The heart failure (HF) syndrome can be defined as the final pathway of any type of heart disease. The sympatho-inhibitory cardiovascular reflexes, such as the arterial baroreceptor reflex, are significantly decreased in HF. Patients with HF present higher ventilation for a certain workload when compared with normal individuals. This fact generates low ventilatory efficiency and is related to higher ventilation associated with the carbon dioxide production, which is a predictor of bad prognosis, in addition to being a limiting factor for the practice of exercises. There is evidence that the autonomic imbalance contributes to the pathogenesis and the progression of heart failure. The chemoreflexes are the main mechanisms of control and regulation of the ventilatory responses to the changes in concentrations of arterial oxygen and carbon dioxide. The chemoreflex activation causes an increase in the sympathetic activity, heart rate, arterial pressure and minute volume. However, the increase in the minute volume and the arterial pressure, due to negative feedback, cause inhibition of the sympathetic response at the chemoreflex activation. In spite of the functional alterations of the reflexes, their behavior in normal and pathological conditions, especially their contribution to the sympathoexcitatory state observed in HF has not been broadly studied. Therefore, this review aims at integrating the knowledge on central and peripheral chemoreflexes in HF syndrome, as well as clarifying the influence of the heart failure drug therapy on the chemoreflexes.

Hemodynamic response in one session of strength exercise with and without electrostimulation in heart failure patients: A randomized controlled trial

BACKGROUND

Studies have investigated the influence of neuromuscular electrostimulation on the exercise/muscle capacity of patients with heart failure (HF), but the hemodynamic overload has never been investigated. The aim of our study was to evaluate the heart rate (HR), systolic and diastolic blood pressures in one session of strength exercises with and without neuromuscular electrostimulation (quadriceps) in HF patients and in healthy subjects.

METHODS

Ten (50% male) HF patients and healthy subjects performed three sets of eight repetitions with and without neuromuscular electrostimulation randomly, with one week between sessions. Throughout, electromyography was performed to guarantee the electrostimulation was effective. The hemodynamic variables were measured at rest, again immediately after the end of each set of exercises, and during the recovery period.

RESULTS

Systolic and diastolic blood pressures did not change during each set of exercises among either the HF patients or the controls. Without electrostimulation: among the controls, the HR corresponding to the first (85 ± 13 bpm, p = 0.002), second (84 ± 10 bpm, p < 0.001), third (89 ± 17, p < 0.001) sets and recuperation (83 ± 16 bpm, p = 0.012) were different compared to the resting HR (77 bpm). Moreover, the recuperation was different to the third set (0.018). Among HF patients, the HR corresponding to the first (84 ± 9 bpm, p = 0.041) and third (84 ± 10 bpm, p = 0.036) sets were different compared to the resting HR (80 ± 7 bpm), but this increase of 4 bpm is clinically irrelevant to HF. With electrostimulation: among the controls, the HR corresponding to the third set (84 ± 9 bpm) was different compared to the resting HR (80 ± 7 bmp, p = 0.016). Among HF patients, there were no statistical differences between the sets. The procedure was well tolerated and no subjects reported muscle pain after 24 hours.

CONCLUSIONS

One session of strength exercises with and without neuromuscular electrostimulation does not promote a hemodynamic overload in HF patients.

Validation of the Portuguese version of the Minnesota Living with Heart Failure Questionnaire

BACKGROUND

The Minnesota Living with Heart Failure Questionnaire (MLHFQ) is an important measurement instrument for assessing the quality of life of heart failure patients. Despite being largely used within our context, the questionnaire had not yet been translated and validated into the Portuguese language.

OBJECTIVE

Of this study was to translate and validate the Portuguese version of the MLHFQ for use in heart failure patients.

METHODS

Forty patients with heart failure (30 men, LVEF 30+/-6%, 55% ischemic etiology, classified as NYHA I to III), clinically stable and on optimized drug therapy underwent maximal cardiopulmonary stress testing to assess their physical capacity. Right after the test, the MLHFQ duly translated into Portuguese was administered by the same investigator. The NYHA functional classification was provided by the medical team.

RESULTS

The Portuguese version of the MLHFQ had the same structure and metrics of the original version. There was no difficulty in the administration of the questionnaire or in the patient's understanding of the questions. The Portuguese version of the MLHFQ was consistent with peak VO2, duration of the cardiopulmonary test, and NYHA functional classification. There was no difference in the score mean for the questionnaire between the group of patients with ischemic etiology and the group with non-ischemic etiology.

CONCLUSION

The Portuguese version of the MLHFQ proposed in this study proved to be valid for heart failure patients, and constitutes a new and important instrument for assessing quality of life.

Exercise chemosensitivity in heart failure: ventilatory, chronotropic and neurohormonal responses

BACKGROUND

Heart failure (HF) is associated with resting increased peripheral and central chemosensitivity which may correlate with an increased ventilatory response to exercise. However, its sensitivity in HF during exercise was never really reported.

OBJECTIVE

We tested if stimulation of central and peripheral chemoreceptors in HF patients could modulate ventilatory, chronotropic, and neurohormonal response during submaximal exercise.

METHODS

We investigated central and peripheral chemosensitivity in 15 HF and 7 control (C) comparing response through three 6 minute walking tests conducted in a treadmill with : room air, hypoxia, and hypercapnia (in a randomic order).

RESULTS

RR at room air C and HF was 17±2 and 22±2 (p<.0001); at hypoxia 17±1 and 23±2 (p<.02); at CO25% was 20±2 and 22±5 (p<.02). Tidal volume (TV) at room air was 1.25±0.17 and 1.08±0.19 (p<.01); at hypoxia 1.65±0.34 and 1.2±0.2 (p<.0001); at CO25% 1.55±0.46 and 1.29±0.39 (p<.0001). At rest the increment in HF was higher for VE (C 33±40%, HF 62±94%, p<.01), HR(C 7±10%, HF 10±10%, p<0.05) at rest. During hypoxia exercise increment in HF was higher for RR (C 1±4, HF 11±6,p<.05), HR (C 12±2, HF 14±3, p<.05), VE/VO₂ (C -4±18%, HF 24±21%, p<.01), HR/VO₂ (C -26±11%, HF 11±5%, p<.01), VE/WD (C 36±10%, 46±14, p<.05%) and HR/WD (C 18±8%, HF 29±11, p<.01). During HF hypoxia exercise NO reduced, and IL-6, aldosterone levels increased. Neurohormonal levels unchanged in C.

CONCLUSION

Exercise peripheral and central chemosensitivity are increased in HF and may modulate respiratory pattern, cardiac chronotropic, and neurohormonal activity during exercise.

The carvedilol's beta-blockade in heart failure and exercise training's sympathetic blockade in healthy athletes during the rest and peak effort

In recent years, beta-blocker therapy has become a primary pharmacologic intervention in patients with heart failure by blocking the sympathetic activity. To compare the exercise training's sympathetic blockade in healthy subjects (athletes) and the carvedilol's sympathetic blockade in sedentary heart failure patients by the evaluation of the heart rate dynamic during an exercise test. A total of 26 optimized and 49 nonoptimized heart failure patients in a stable condition (for, at least, 3 months), 15 healthy athletes and 17 sedentary healthy subjects were recruited to perform a cardiopulmonary exercise test. The heart rate dynamic (rest, reserve, peak and the peak heart rate in relation to the maximum predicted for age) was analyzed and compared between the four groups. The heart rate reserve was the same between optimized (48 +/- 15) and nonoptimized (49 +/- 18) heart failure patients (P < 0.0001). The athletes (188 +/- 9) showed a larger heart rate reserve compared to sedentary healthy subjects (92 +/- 10, P < 0.0001). Athletes and healthy sedentary reached the maximum age-predicted heart ratefor their age, but none of the heart failure patients did. The carvedilol's sympathetic blockade occurred during the rest and during the peak effort in the same proportion, but the exercise training's sympathetic blockade in healthy subjects occurred mainly in the rest.