Abnormal neurovascular control during central and peripheral chemoreceptors stimulation in heart failure patients with preserved ejection fraction.

PURPOSE: Central and peripheral chemoreceptors are hypersensitized in patients with heart failure with reduced ejection fraction. Whether this autonomic alteration occurs in patients with heart failure with preserved ejection fraction (HFpEF) remains little known. We test the hypothesis that the central and peripheral chemoreflex control of muscle sympathetic nerve activity (MSNA) is altered in HFpEF. METHODS: Patients aged 55-80 years with symptoms of heart failure, body mass index ≤ 35 kg/m2, left ventricular ejection fraction > 50%, left atrial volume index > 34 mL/m2, left ventricular early diastolic filling velocity and early diastolic tissue velocity of mitral annulus ratio (E/e' index) ≥ 13, and BNP levels > 35 pg/mL were included in the study (HFpEF, n = 9). Patients without heart failure with preserved ejection fraction (non-HFpEF, n = 9), aged-paired, were also included in the study. Peripheral chemoreceptors stimulation (10% O2 and 90% N2, with CO2 titrated) and central chemoreceptors stimulation (7% CO2 and 93% O2) were conducted for 3 min. MSNA was evaluated by microneurography technique, and forearm blood flow (FBF) by venous occlusion plethysmography. RESULTS: During hypoxia, MSNA responses were greater (p < 0.001) and FBF responses were lower in patients with HFpEF (p = 0.006). Likewise, MSNA responses during hypercapnia were higher (p < 0.001) and forearm vascular conductance (FVC) levels were lower (p = 0.030) in patients with HFpEF. CONCLUSIONS: Peripheral and central chemoreflex controls of MSNA are hypersensitized in patients with HFpEF, which seems to contribute to the increase in MSNA in these patients. In addition, peripheral and central chemoreceptors stimulation in patients with HFpEF causes muscle vasoconstriction.

Metrics of care and cardiovascular outcomes in patients with ST-elevation myocardial infarction treated with pharmacoinvasive strategy: a decade-long network in a populous city in Brazil.

BACKGROUND: Pharmacoinvasive strategy is an effective myocardial reperfusion therapy when primary percutaneous coronary intervention (p-PCI) cannot be performed in a timely manner. METHODS: Authors sought to evaluate metrics of care and cardiovascular outcomes in a decade-long registry of a pharmacoinvasive strategy network for the treatment of ST-elevation myocardial infarction (STEMI). Data from a local network including patients undergoing fibrinolysis in county hospitals and systematically transferred to the tertiary center were accessed from March 2010 to September 2020. Numerical variables were described as median and interquartile range. Area under the curve (AUC-ROC) was used to analyze the predictive value of TIMI and GRACE scores for in-hospital mortality. RESULTS: A total of 2,710 consecutive STEMI patients aged 59 [51-66] years, 815 women (30.1%) and 837 individuals with diabetes (30.9%) were analyzed. The time from symptom onset to first-medical-contact was 120 [60-210] minutes and the door-to-needle time was 70 [43-115] minutes. Rescue-PCI was required in 929 patients (34.3%), in whom the fibrinolytic-catheterization time was 7.2 [4.9-11.8] hours, compared to 15.7 [6.8-22,7] hours in those who had successful lytic reperfusion. All cause in-hospital mortality occurred in 151 (5.6%) patients, reinfarction in 47 (1.7%) and ischemic stroke in 33 (1.2%). Major bleeding occurred in 73 (2.7%) patients, including 19 (0.7%) cases of intracranial bleeding. C-statistic confirmed that both scores had high predictive values for in-hospital mortality, demonstrated by TIMI AUC-ROC of 0.80 [0,77-0.84] and GRACE AUC-ROC of 0.86 [0.83-0.89]. CONCLUSION: In a real world registry of a decade-long network for the treatment of ST-elevation myocardial infarction based on the pharmacoinvasive strategy, low rates of in-hospital mortality and cardiovascular outcomes were observed, despite prolonged time metrics for both fibrinolytic therapy and rescue-PCI. Register Clinicaltrials.gov NCT02090712 date of first registration 18/03/2014.

A common oral pathogen Porphyromonas gingivalis induces myocarditis in rats.

AIM: To evaluate whether Porphyromonas gingivalis (P. gingivalis) inoculation could induce cardiac remodelling in rats. MATERIALS AND METHODS: The study was conducted on 33 Wistar rats, which were distributed in the following experimental groups: not inoculated; inoculated with 1 × 108 CFU/ml of bacteria; inoculated with 3 × 108 CFU/ml of bacteria. The animals were inoculated at baseline and on the 15th day of follow-up. Blood collection was performed at baseline and 60 min after each inoculation. At 29 days, the animals were subjected to echocardiography and at 30 days to haemodynamic studies before sacrificing them. RESULTS: Impact of the bacteria was more evident in rats that received higher P. gingivalis concentration. Thus, 3 × 108 CFU/ml of bacteria increased the rectal temperature and water content in the lung as well as myocardial necrosis and fibrosis. P. gingivalis induced the intensification of DNA fragmentation and increased the levels of malondialdehyde, oxidized proteins, and macrophage expression in the myocardium. These findings were associated with lower LV isovolumetric relaxation time, +dP/dt, -dP/dt, and higher end-diastolic pressure. CONCLUSIONS: P. gingivalis bacteraemia is significantly associated with adverse cardiac remodelling and may play a biological role in the genesis of heart failure.

Neuromuscular electrical stimulation improves exercise tolerance in patients with advanced heart failure on continuous intravenous inotropic support use-randomized controlled trial.

OBJECTIVE: To evaluate the impact of a short-term neuromuscular electrical stimulation program on exercise tolerance in hospitalized patients with advanced heart failure who have suffered an acute decompensation and are under continuous intravenous inotropic support. DESIGN: A randomized controlled study. SUBJECTS: Initially, 195 patients hospitalized for decompensated heart failure were recruited, but 70 were randomized. INTERVENTION: Patients were randomized into two groups: control group subject to the usual care ( n = 35); neuromuscular electrical stimulation group ( n = 35) received daily training sessions to both lower extremities for around two weeks. MAIN MEASURES: The baseline 6-minute walk test to determine functional capacity was performed 24 hours after hospital admission, and intravenous inotropic support dose was daily checked in all patients. The outcomes were measured in two weeks or at the discharge if the patients were sent back home earlier than two weeks. RESULTS: After losses of follow-up, a total of 49 patients were included and considered for final analysis (control group, n = 25 and neuromuscular electrical stimulation group, n = 24). The neuromuscular electrical stimulation group presented with a higher 6-minute walk test distance compared to the control group after the study protocol (293 ± 34.78 m vs. 265.8 ± 48.53 m, P < 0.001, respectively). Neuromuscular electrical stimulation group also demonstrated a significantly higher dose reduction of dobutamine compared to control group after the study protocol (2.72 ± 1.72 µg/kg/min vs. 3.86 ± 1.61 µg/kg/min, P = 0.001, respectively). CONCLUSION: A short-term inpatient neuromuscular electrical stimulation rehabilitation protocol improved exercise tolerance and reduced intravenous inotropic support necessity in patients with advanced heart failure suffering a decompensation episode.

Exercise Ventilation in COPD: Influence of Systolic Heart Failure.

Systolic heart failure is a common and disabling co-morbidity of chronic obstructive pulmonary disease (COPD) which may increase exercise ventilation due to heightened neural drive and/or impaired pulmonary gas exchange efficiency. The influence of heart failure on exercise ventilation, however, remains poorly characterized in COPD. In a prospective study, 98 patients with moderate to very severe COPD [41 with coexisting heart failure; 'overlap' (left ventricular ejection fraction < 50%)] underwent an incremental cardiopulmonary exercise test (CPET). Compared to COPD, overlap had lower peak exercise capacity despite higher FEV1. Overlap showed lower operating lung volumes, greater ventilatory inefficiency and larger decrements in end-tidal CO2 (PETCO2) (P < 0.05). These results were consistent with those found in FEV1-matched patients. Larger areas under receiver operating characteristic curves to discriminate overlap from COPD were found for ventilation ([Formula: see text]E)-CO2 output [Formula: see text]CO2) intercept, [Formula: see text]E-[Formula: see text]CO2 slope, peak [Formula: see text]E/[Formula: see text]CO2 ratio and peak PETCO2. Multiple logistic regression analysis revealed that [Formula: see text]CO2 intercept ≤ 3.5 L/minute [odds ratios (95% CI) = 7.69 (2.61-22.65), P < 0.001] plus [Formula: see text]E-[Formula: see text]CO2 slope ≥ 34 [2.18 (0.73-6.50), P = 0.14] or peak [Formula: see text]E/[Formula: see text]CO2 ratio ≥ 37 [5.35 (1.96-14.59), P = 0.001] plus peak PETCO2 ≤ 31 mmHg [5.73 (1.42-23.15), P = 0.01] were indicative of overlapping. Heart failure increases the ventilatory response to metabolic demand in COPD. Variables reflecting excessive ventilation might prove useful to assist clinical interpretation of CPET responses in COPD patients presenting heart failure as co-morbidity.

Heart Failure Impairs Muscle Blood Flow and Endurance Exercise Tolerance in COPD.

Heart failure, a prevalent and disabling co-morbidity of COPD, may impair cardiac output and muscle blood flow thereby contributing to exercise intolerance. To investigate the role of impaired central and peripheral hemodynamics in limiting exercise tolerance in COPD-heart failure overlap, cycle ergometer exercise tests at 20% and 80% peak work rate were performed by overlap (FEV1 = 56.9 ± 15.9% predicted, ejection fraction = 32.5 ± 6.9%; N = 16), FEV1-matched COPD (N = 16), ejection fraction-matched heart failure patients (N = 15) and controls (N = 12). Differences (Δ) in cardiac output (impedance cardiography) and vastus lateralis blood flow (indocyanine green) and deoxygenation (near-infrared spectroscopy) between work rates were expressed relative to concurrent changes in muscle metabolic demands (ΔO2 uptake). Overlap patients had approximately 30% lower endurance exercise tolerance than COPD and heart failure (p < 0.05). ΔBlood flow was closely proportional to Δcardiac output in all groups (r = 0.89-0.98; p < 0.01). Overlap showed the largest impairments in Δcardiac output/ΔO2 uptake and Δblood flow/ΔO2 uptake (p < 0.05). Systemic arterial oxygenation, however, was preserved in overlap compared to COPD. Blunted limb perfusion was related to greater muscle deoxygenation and lactate concentration in overlap (r = 0.78 and r = 0.73, respectively; p < 0.05). ΔBlood flow/ΔO2 uptake was related to time to exercise intolerance only in overlap and heart failure (p < 0.01). In conclusion, COPD and heart failure add to decrease exercising cardiac output and skeletal muscle perfusion to a greater extent than that expected by heart failure alone. Treatment strategies that increase muscle O2 delivery and/or decrease O2 demand may be particularly helpful to improve exercise tolerance in COPD patients presenting heart failure as co-morbidity.

Exercise training prevents the deterioration in the arterial baroreflex control of sympathetic nerve activity in chronic heart failure patients.

Arterial baroreflex control of muscle sympathetic nerve activity (ABRMSNA) is impaired in chronic systolic heart failure (CHF). The purpose of the study was to test the hypothesis that exercise training would improve the gain and reduce the time delay of ABRMSNA in CHF patients. Twenty-six CHF patients, New York Heart Association Functional Class II-III, EF ≤ 40%, peak V̇o2 ≤ 20 ml·kg(-1)·min(-1) were divided into two groups: untrained (UT, n = 13, 57 ± 3 years) and exercise trained (ET, n = 13, 49 ± 3 years). Muscle sympathetic nerve activity (MSNA) was directly recorded by microneurography technique. Arterial pressure was measured on a beat-to-beat basis. Time series of MSNA and systolic arterial pressure were analyzed by autoregressive spectral analysis. The gain and time delay of ABRMSNA was obtained by bivariate autoregressive analysis. Exercise training was performed on a cycle ergometer at moderate intensity, three 60-min sessions per week for 16 wk. Baseline MSNA, gain and time delay of ABRMSNA, and low frequency of MSNA (LFMSNA) to high-frequency ratio (HFMSNA) (LFMSNA/HFMSNA) were similar between groups. ET significantly decreased MSNA. MSNA was unchanged in the UT patients. The gain and time delay of ABRMSNA were unchanged in the ET patients. In contrast, the gain of ABRMSNA was significantly reduced [3.5 ± 0.7 vs. 1.8 ± 0.2, arbitrary units (au)/mmHg, P = 0.04] and the time delay of ABRMSNA was significantly increased (4.6 ± 0.8 vs. 7.9 ± 1.0 s, P = 0.05) in the UT patients. LFMSNA-to-HFMSNA ratio tended to be lower in the ET patients (P < 0.08). Exercise training prevents the deterioration of ABRMSNA in CHF patients.

Molecular basis for the improvement in muscle metaboreflex and mechanoreflex control in exercise-trained humans with chronic heart failure.

Previous studies have demonstrated that muscle mechanoreflex and metaboreflex controls are altered in heart failure (HF), which seems to be due to changes in cyclooxygenase (COX) pathway and changes in receptors on afferent neurons, including transient receptor potential vanilloid type-1 (TRPV1) and cannabinoid receptor type-1 (CB1). The purpose of the present study was to test the hypotheses: 1) exercise training (ET) alters the muscle metaboreflex and mechanoreflex control of muscle sympathetic nerve activity (MSNA) in HF patients. 2) The alteration in metaboreflex control is accompanied by increased expression of TRPV1 and CB1 receptors in skeletal muscle. 3) The alteration in mechanoreflex control is accompanied by COX-2 pathway in skeletal muscle. Thirty-four consecutive HF patients with ejection fractions <40% were randomized to untrained (n = 17; 54 ± 2 yr) or exercise-trained (n = 17; 56 ± 2 yr) groups. MSNA was recorded by microneurography. Mechanoreceptors were activated by passive exercise and metaboreceptors by postexercise circulatory arrest (PECA). COX-2 pathway, TRPV1, and CB1 receptors were measured in muscle biopsies. Following ET, resting MSNA was decreased compared with untrained group. During PECA (metaboreflex), MSNA responses were increased, which was accompanied by the expression of TRPV1 and CB1 receptors. During passive exercise (mechanoreflex), MSNA responses were decreased, which was accompanied by decreased expression of COX-2, prostaglandin-E2 receptor-4, and thromboxane-A2 receptor and by decreased in muscle inflammation, as indicated by increased miRNA-146 levels and the stable NF-κB/IκB-α ratio. In conclusion, ET alters muscle metaboreflex and mechanoreflex control of MSNA in HF patients. This alteration with ET is accompanied by alteration in TRPV1 and CB1 expression and COX-2 pathway and inflammation in skeletal muscle.

Sildenafil improves microvascular O2 delivery-to-utilization matching and accelerates exercise O2 uptake kinetics in chronic heart failure.

Nitric oxide (NO) can temporally and spatially match microvascular oxygen (O(2)) delivery (Qo(2mv)) to O(2) uptake (Vo(2)) in the skeletal muscle, a crucial adjustment-to-exercise tolerance that is impaired in chronic heart failure (CHF). To investigate the effects of NO bioavailability induced by sildenafil intake on muscle Qo(2mv)-to-O(2) utilization matching and Vo(2) kinetics, 10 males with CHF (ejection fraction = 27 ± 6%) undertook constant work-rate exercise (70-80% peak). Breath-by-breath Vo(2), fractional O(2)extraction in the vastus lateralis {∼deoxygenated hemoglobin + myoglobin ([deoxy-Hb + Mb]) by near-infrared spectroscopy}, and cardiac output (CO) were evaluated after sildenafil (50 mg) or placebo. Sildenafil increased exercise tolerance compared with placebo by ∼20%, an effect that was related to faster on- and off-exercise Vo(2) kinetics (P < 0.05). Active treatment, however, failed to accelerate CO dynamics (P > 0.05). On-exercise [deoxy-Hb + Mb] kinetics were slowed by sildenafil (∼25%), and a subsequent response "overshoot" (n = 8) was significantly lessened or even abolished. In contrast, [deoxy-Hb + Mb] recovery was faster with sildenafil (∼15%). Improvements in muscle oxygenation with sildenafil were related to faster on-exercise Vo(2) kinetics, blunted oscillations in ventilation (n = 9), and greater exercise capacity (P < 0.05). Sildenafil intake enhanced intramuscular Qo(2mv)-to-Vo(2) matching with beneficial effects on Vo(2) kinetics and exercise tolerance in CHF. The lack of effect on CO suggests that improvement in blood flow to and within skeletal muscles underlies these effects.

Effects of home-based exercise training for patients with chronic heart failure and sleep apnoea: a randomized comparison of two different programmes.

OBJECTIVE: To evaluate the effects of home-based exercise for patients with chronic heart failure and sleep apnoea and to compare two different training programmes. DESIGN: A randomized, prospective controlled trial. SETTING: Department of Cardiology, University Hospital, Brazil. SUBJECTS: Fifty chronic heart failure patients with sleep apnoea were randomized in three groups: Group 1 (aerobic training, n = 18), Group 2 (aerobic with strength training, n = 18), and Group 3 (untrained, n = 14). INTERVENTIONS: The training programme for Groups 1 and 2 began with three supervised exercise sessions, after they underwent three months of home-based exercise. Patients were followed by weekly telephone call and were reviewed monthly. Group 3 had the status of physical activity evaluated weekly by interview to make sure they remained untrained. MAIN OUTCOME MEASURES: At baseline and after three months: cardiopulmonary exercise testing, isokinetic strength and endurance, Minnesota living with heart failure questionnaire and polysomnography. Adherence was evaluated weekly. RESULTS: Of the 50 patients enrolled in the study, 45 completed the programme. Clinical events: Group 1 (one death), Group 2 (one myocardial infarction), Group 3 (one death and two strokes). None were training related. Training groups showed improvement in all outcomes evaluated and the adherence was an important factor (Group 1 = 98.5% and Group 2 = 100.2%, P = 0.743). Untrained Group 3 demonstrated significant decrease or no change on measurements after three months without training. CONCLUSION: Home-based exercise training is an important therapeutic strategy in chronic heart failure patients with sleep apnoea, and strength training resulted in a higher increase in muscle strength and endurance.

Pharmaco-invasive Strategy in Myocardial Infarction: Descriptive Analysis, Presentation of Ischemic Symptoms and Mortality Predictors. / Estratégia Fármaco-Invasiva no Infarto do Miocárdio: Análise Descritiva, Apresentação de Sintomas Isquêmicos e Preditores de Mortalidade.

BACKGROUND: ST-segment elevation myocardial infarction (STEMI) is defined by symptoms accompanied by typical electrocardiogram changes. However, the characterization of ischemic symptoms is unclear, especially in subgroups such as women and the elderly. OBJECTIVES: To analyze the typification of ischemic symptoms, temporal metrics and observe the occurrence of in-hospital outcomes, in the analysis of predictive scores, in patients with STEMI, in a drug-invasive strategy. METHODS: Study involving 2,290 patients. Types of predefined clinical presentations: typical pain, atypical pain, dyspnea, syncope. We measured the time between the onset of symptoms and demand for care and the interval between arrival at the medical unit and thrombolysis. Odds-ratios (OR; CI-95%) were estimated in a regression model. ROC curves were constructed for mortality predictors. The adopted significance level (alpha) was 5%. RESULTS: Women had a high prevalence of atypical symptoms; longer time between the onset of symptoms and seeking care; delay between arrival at the emergency room and fibrinolysis. Hospital mortality was 5.6%. Risk prediction by Killip-Kimball classification: AUC: [0.77 (0.73-0.81)] in class ≥II. Subgroups studied [OR (CI-95%)]: women [2.06 (1.42-2.99); p=0.01]; chronic renal failure [3.39 (2.13-5.42); p<0.001]; elderly [2.09 (1.37-3.19) p<0.001]; diabetics [1.55 (1.04-2.29); p=0.02]; obese 1.56 [(1.01-2.40); p=0.04]: previous stroke [2.01 (1.02-3.96); p=0.04] correlated with higher mortality rates. CONCLUSION: Despite higher mortality rates in some subgroups, significant disparity persists in women, with delays in symptom recognition and prompt thrombolysis. We highlight the applicability of the Killip-Kimball score in prediction, regardless of the clinical presentation.

FUNDAMENTO: O infarto do miocárdio com elevação do segmento-ST (IAMCSST) é definido por sintomas acompanhados por alterações típicas do eletrocardiograma. Entretanto, a caracterização dos sintomas isquêmicos não é clara, principalmente em subgrupos, como mulheres e idosos. OBJETIVOS: Analisar a tipificação dos sintomas isquêmicos, métricas temporais e observar a ocorrência de desfechos intra-hospitalares, em análise dos escores preditivos, em pacientes com IAMCSST, em estratégia fármaco-invasiva. MÉTODOS: Estudo envolvendo 2.290 pacientes. Tipos de apresentações clínicas pré-definidas: dor típica, dor atípica, dispnéia, sincope. Medimos o tempo entre o início dos sintomas à demanda pelo atendimento e o intervalo entre a chegada à unidade-médica e trombólise. Odds-ratios (OR; IC-95%) foram estimadas em modelo de regressão. Curvas ROCs foram construídas para preditores de mortalidade. Nível de significância adotado (alfa) foi de 5%. RESULTADOS: Mulheres apresentaram alta prevalência de sintomas atípicos; maior tempo entre o início dos sintomas e a procura por atendimento; atraso entre a chegada ao pronto-socorro e a fibrinólise. A mortalidade hospitalar foi de 5,6%. Predição de risco pela classificação Killip-Kimball: AUC: [0,77 (0,73-0,81)] em classe ≥II. Subgrupos estudados [OR (IC-95%)]: mulheres [2,06 (1,42-2,99); p=0,01]; insuficiência renal crônica [3,39 (2,13-5,42); p<0,001]; idosos [2,09 (1,37-3,19) p<0,001]; diabéticos [1,55 (1,04-2,29); p=0,02]; obesos 1,56 [(1,01-2,40); p=0,04]; acidente vascular cerebral prévio [2,01 (1,02-3,96); p=0,04] correlacionaram-se com maiores taxas de mortalidade. CONCLUSÃO: Apesar das mais altas taxas de mortalidade em alguns subgrupos, disparidade significativa persiste nas mulheres, com atrasos no reconhecimento dos sintomas e trombólise imediata. Destaca-se a aplicabilidade do escore Killip-Kimball na predição, independentemente da apresentação clínica.

In patients with heart failure, enhanced ventilatory response to exercise is associated with severe obstructive sleep apnea.

STUDY OBJECTIVES: Patients with congestive heart failure (CHF) frequently exhibit an elevated ratio of minute ventilation over CO2 output (VE/VCO2 slope) while undergoing exercise tests. One of the factors contributing to this elevated slope is an increased chemosensitivity to CO2 in that this slope significantly correlates with the slope of the ventilatory response to CO2 rebreathing at rest. A previous study in patients with CHF and central sleep apnea showed that the highest VE/VCO2 slope during exercise was associated with the most severe central sleep apnea. In the current study, we tested the hypothesis that in patients with CHF and obstructive sleep apnea (OSA), the highest VE/VCO2 slope is also associated with the most severe OSA. If the hypothesis is correct, then it implies that in CHF, augmented instability in the negative feedback system controlling breathing predisposes to both OSA and central sleep apnea. METHODS: This preliminary study involved 70 patients with stable CHF and a spectrum of OSA severity who underwent full-night polysomnography, echocardiography, and cardiopulmonary exercise testing. Peak oxygen consumption and the VE/VCO2 slope were calculated. RESULTS: There was significant positive correlation between the apnea-hypopnea index and the VE/VCO2 slope (r = .359; P = .002). In the regression model, involving the relevant variables of age, body mass index, sex, VE/VCO2 slope, peak oxygen consumption, and left ventricular ejection fraction, the apnea-hypopnea index retained significance with VE/VCO2. CONCLUSIONS: In patients with CHF, the VE/VCO2 slope obtained during exercise correlates significantly to the severity of OSA, suggesting that an elevated CO2 response should increase suspicion for the presence of severe OSA, a treatable disorder that is potentially associated with excess mortality. CLINICAL TRIAL REGISTRATION: Registry: ClinicalTrials.gov; Name: Comparison Between Exercise Training and CPAP Treatment for Patients With Heart Failure and Sleep Apnea; URL: https://clinicaltrials.gov/ct2/show/record/NCT01538069; Identifier: NCT01538069. CITATION: Bittencourt L, Javaheri S, Servantes DM, Pelissari Kravchychyn AC, Almeida DR, Tufik S. In patients with heart failure, enhanced ventilatory response to exercise is associated with severe obstructive sleep apnea. J Clin Sleep Med. 2021;17(X):1875-1880.

Effects of inspiratory muscle training combined with aerobic exercise training on neurovascular control in chronic heart failure patients.

AIMS: We tested the hypothesis that the effects of combined inspiratory muscle training and aerobic exercise training (IMT + AET) on muscle sympathetic nerve activity (MSNA) and forearm blood flow in patients with heart failure with reduced ejection fraction are more pronounced than the effects of AET alone. METHODS AND RESULTS: Patients aged 30-70 years, New York Heart Association Functional Class II-III, and left ventricular ejection fraction ≤40% were randomly assigned to four groups: IMT (n = 11), AET (n = 12), IMT + AET (n = 9), and non-training (NT; n = 10). MSNA was recorded using microneurography. Forearm blood flow was measured by venous occlusion plethysmography and inspiratory muscle strength by maximal inspiratory pressure. IMT consisted of 30 min sessions, five times a week, for 4 months. Moderate AET consisted of 60 min sessions, three times a week for 4 months. AET (-10 ± 2 bursts/min, P = 0.03) and IMT + AET (-13 ± 4 bursts/min, P = 0.007) reduced MSNA. These responses in MSNA were not different between AET and IMT + AET groups. IMT (0.22 ± 0.08 mL/min/100 mL, P = 0.03), AET (0.27 ± 0.09 mL/min/100 mL, P = 0.01), and IMT + AET (0.35 ± 0.12 mL/min/100 mL, P = 0.008) increased forearm blood flow. No differences were found between groups. AET (3 ± 1 mL/kg/min, P = 0.006) and IMT + AET (4 ± 1 mL/kg/min, P = 0.001) increased peak oxygen consumption. These responses were similar between these groups. IMT (20 ± 3 cmH2 O, P = 0.005) and IMT + AET (18 ± 3 cmH2 O, P = 0.01) increased maximal inspiratory pressure. No significant changes were observed in the NT group. CONCLUSIONS: IMT + AET causes no additive effects on neurovascular control in patients with heart failure with reduced ejection fraction compared with AET alone. These findings may be, in part, because few patients had inspiratory muscle weakness.

Proportional Assist Ventilation Improves Leg Muscle Reoxygenation After Exercise in Heart Failure With Reduced Ejection Fraction.

BACKGROUND: Respiratory muscle unloading through proportional assist ventilation (PAV) may enhance leg oxygen delivery, thereby speeding off-exercise oxygen uptake ( V . ⁢ O 2 ) kinetics in patients with heart failure with reduced left ventricular ejection fraction (HFrEF). METHODS: Ten male patients (HFrEF = 26 ± 9%, age 50 ± 13 years, and body mass index 25 ± 3 kg m2) underwent two constant work rate tests at 80% peak of maximal cardiopulmonary exercise test to tolerance under PAV and sham ventilation. Post-exercise kinetics of V . ⁢ O 2 , vastus lateralis deoxyhemoglobin ([deoxy-Hb + Mb]) by near-infrared spectroscopy, and cardiac output (Q T ) by impedance cardiography were assessed. RESULTS: PAV prolonged exercise tolerance compared with sham (587 ± 390 s vs. 444 ± 296 s, respectively; p = 0.01). PAV significantly accelerated V . ⁢ O 2 recovery (τ = 56 ± 22 s vs. 77 ± 42 s; p < 0.05), being associated with a faster decline in Δ[deoxy-Hb + Mb] and Q T compared with sham (τ = 31 ± 19 s vs. 42 ± 22 s and 39 ± 22 s vs. 78 ± 46 s, p < 0.05). Faster off-exercise decrease in Q T with PAV was related to longer exercise duration (r = -0.76; p < 0.05). CONCLUSION: PAV accelerates the recovery of central hemodynamics and muscle oxygenation in HFrEF. These beneficial effects might prove useful to improve the tolerance to repeated exercise during cardiac rehabilitation.

Acute Hemodynamic Index Predicts In-Hospital Mortality in Acute Decompensated Heart Failure. / Índice Hemodinâmico Agudo Prediz Mortalidade Intra-Hospitalar de Pacientes com Insuficiência Cardíaca Aguda Descompensada.

BACKGROUND: The physical examination enables prognostic evaluation of patients with decompensated heart failure (HF), but lacks reliability and relies on the professional's clinical experience. Considering hemodynamic responses to "fight or flight" situations, such as the moment of admission to the emergency room, we proposed the calculation of the acute hemodynamic index (AHI) from values of heart rate and pulse pressure. OBJECTIVE: To evaluate the in-hospital prognostic ability of AHI in decompensated HF. METHODS: A prospective, multicenter, registry-based observational study including data from the BREATHE registry, with information from public and private hospitals in Brazil. The prognostic ability of the AHI was tested by receiver-operating characteristic (ROC) analyses, C-statistics, Akaike's information criteria, and multivariate regression analyses. p-values < 0.05 were considered statistically significant. RESULTS: We analyzed data from 463 patients with heart failure with low ejection fraction. In-hospital mortality was 9%. The median AHI value was used as cut-off (4 mmHg⋅bpm). A low AHI (≤ 4 mmHg⋅bpm) was found in 80% of deceased patients. The risk of in-hospital mortality in patients with low AHI was 2.5 times that in patients with AHI > 4 mmHg⋅bpm. AHI independently predicted in-hospital mortality in acute decompensated HF (sensitivity: 0.786; specificity: 0.429; AUC: 0.607 [0.540-0.674]; p = 0.010) even after adjusting for comorbidities and medication use [OR: 0.061 (0.007-0.114); p = 0.025). CONCLUSIONS: The AHI independently predicts in-hospital mortality in acute decompensated HF. This simple bed-side index could be useful in an emergency setting. (Arq Bras Cardiol. 2021; 116(1):77-86).

FUNDAMENTO: O exame físico permite a avaliação prognóstica de pacientes com insuficiência cardíaca (IC) descompensada, porém não é suficientemente confiável e depende da experiência clínica do profissional. Considerando as respostas hemodinâmicas a situações do tipo "luta ou fuga" tais como a admissão no serviço de emergência, foi proposto o índice hemodinâmico agudo (IHA), calculado a partir da frequência cardíaca e pressão de pulso. OBJETIVO: avaliar a capacidade prognóstica intra-hospitalar do IHA na IC descompensada. MÉTODOS: estudo prospectivo, multicêntrico e observacional baseado no registro BREATHE, incluindo dados de hospitais públicos e privados no Brasil. Foram utilizadas análises ROC (Receiver Operating Characteristic), de estatística c e de regressão multivariada, assim como o critério de informação de Akaike, para testar a capacidade prognóstica do IHA. O valor-p < 0,05 foi considerado estatisticamente significativo. RESULTADOS: Foram analisados dados de 463 pacientes com IC com fração de ejeção reduzida a partir do registro BREATHE. A mortalidade intra-hospitalar foi de 9%. A mediana do IHA foi considerada o valor de corte (4 mmHg⋅bpm). Um baixo IHA (≤ 4 mmHg⋅bpm) foi encontrado em 80% dos pacientes falecidos. O risco de mortalidade intra-hospitalar em pacientes com baixo IHA foi 2,5 vezes maior que aquele para pacientes com IHA > 4 mmHg⋅bpm. O IHA foi capaz de predizer independentemente a mortalidade intra-hospitalar na IC aguda descompensada [sensibilidade: 0,786; especificidade: 0,429; AUC (área sob a curva): 0,607 (0,540-0,674), p = 0,010] mesmo depois dos ajustes para comorbidades e uso de medicamentos [razão de chances (RC): 0,061 (0,007-0,114), p = 0,025]. CONCLUSÕES: O IHA é capaz de predizer independentemente a mortalidade intra-hospitalar na IC aguda descompensada. Esse índice simples e realizado à beira do leito pode se mostrar útil em serviços de emergência. (Arq Bras Cardiol. 2021; 116(1):77-86).

Inspiratory Muscle Weakness is Related to Poor Short-Term Outcomes for Heart Transplantation.

INTRODUCTION: In heart transplantation (HT) recipients, several factors are critical to promptly adopting appropriate rehabilitation strategies and may be important to predict outcomes way after surgery. This study aimed to determine preoperative patient-related risk factors that could adversely affect the postoperative clinical course of patients undergoing HT. METHODS: Twenty-one hospitalized patients with heart failure undergoing HT were evaluated according to respiratory muscle strength and functional capacity before HT. Mechanical ventilation (MV) time, reintubation rate, and intensive care unit (ICU) length of stay were recorded, and assessed postoperatively. RESULTS: Inspiratory muscle strength as absolute and percentpredicted values were strongly correlated with MV time (r=-0.61 and r=-0.70, respectively, at P<0.001). Concerning ICU length of stay, only maximal inspiratory pressure (MIP) absolute and percent-predicted values were significantly associated. The absolute |MIP| was significantly negatively correlated with ICU length of stay (r=-0.58 at P=0.006) and the percent-predicted MIP was also significantly negatively correlated with ICU length of stay (r=-0.68 at P=0.0007). No associations were observed between preoperative functional capacity, age, sex, and clinical characteristics and MV time and ICU length of stay in the cohort included in this study. Patients with respiratory muscle weakness had a higher prevalence of prolonged MV, reintubation, and delayed ICU length of stay. CONCLUSION: An impairment of preoperative MIP was associated with poorer short-term outcomes following HT. As such, inspiratory muscle strength is an important clinical preoperative marker in patients undergoing HT.

Accuracy of Post-thrombolysis ST-segment Reduction as an Adequate Reperfusion Predictor in the Pharmaco-Invasive Approach. / Acurácia da Redução do Segmento-ST Pós-Trombólise como Preditor de Reperfusão Adequada em Estratégia Fármaco-Invasiva.

BACKGROUND: Primary percutaneous coronary intervention is considered the "gold standard" for coronary reperfusion. However, when not available, the drug-invasive strategy is an alternative method and the electrocardiogram (ECG) has been used to identify reperfusion success. OBJECTIVES: Our study aimed to assess ST-Segment changes in post-thrombolysis and their power to predict recanalization and using the angiographic scores TIMI-flow and Myocardial Blush Grade (MBG) as an ideal reperfusion criterion. METHODS: 2,215 patients with ST-Segment Elevation Myocardial Infarction (STEMI) undergoing fibrinolysis [(Tenecteplase)-TNK] and referred to coronary angiography within 24 h post-fibrinolysis or immediately referred to rescue therapy were studied. The ECG was performed pre- and 60 min-post-TNK. The patients were categorized into 2 groups: those with ideal reperfusion (TIMI-3 and MBG-3) and those with inadequate reperfusion (TIMI and MBG <3). The ECG reperfusion criterion was defined by the reduction of the ST-Segment >50%. A p-value <0.05 was considered for the analyses, with bicaudal tests. RESULTS: The ECG reperfusion criterion showed a positive predictive value of 56%; negative predictive value of 66%; sensitivity of 79%; and specificity of 40%. There was a weak positive correlation between ST-Segment reduction and ideal reperfusion angiographic data (r = 0.21; p <0.001) and low diagnostic accuracy, with an AUC of 0.60 (95%CI: 0.57-0.62). CONCLUSION: The ST-Segment reduction was not able to accurately identify patients with adequate angiographic reperfusion. Therefore, even patients with apparently successful reperfusion should be referred to angiography soon, to ensure adequate macro and microvascular coronary flow.

FUNDAMENTO: A intervenção coronária percutânea primária é considerada o "padrão-ouro" para reperfusão coronária. Entretanto, quando não disponível, a estratégia fármaco-invasiva é método alternativo, e o eletrocardiograma (ECG) tem sido utilizado para identificar sucesso na reperfusão. OBJETIVOS: Nosso estudo teve como objetivo examinar alterações no segmento-ST pós-lise e seu poder de prever a recanalização, usando os escores angiográficos TIMI e blush miocárdio (MBG) como critério de reperfusão ideal. MÉTODOS: Foram estudados 2.215 pacientes com infarto agudo do miocárdio com supra-ST submetidos à fibrinólise [(Tenecteplase)-TNK] e encaminhados para angiografia coronária em até 24 h pós-fibrinólise ou imediatamente encaminhados à terapia de resgate. O ECG foi realizado pré-TNK e 60 min-pós. Os pacientes foram categorizados em dois grupos: aqueles com reperfusão ideal (TIMI-3 e MBG-3) e aqueles com reperfusão inadequada (fluxo TIMI <3). Foi definido o critério de reperfusão do ECG pela redução do segmento ST >50%. Consideramos p-valor <0,05 para as análises, com testes bicaudais. RESULTADOS: O critério de reperfusão pelo ECG apresentou valor preditivo positivo de 56%; valor preditivo negativo de 66%; sensibilidade de 79%; e especificidade de 40%. Houve fraca correlação positiva entre a redução do segmento-ST e os dados angiográficos de reperfusão ideal (r = 0,21; p <0,001) e baixa precisão diagnóstica, com AUC de 0,60 (IC-95%; 0,57-0,62). CONCLUSÃO: Em nossos resultados, a redução do segmento-ST não conseguiu identificar com precisão os pacientes com reperfusão angiográfica apropriada. Portanto, mesmo pacientes com reperfusão aparentemente bem-sucedida devem ser encaminhados à angiografia brevemente, a fim de garantir fluxo coronário macro e microvascular adequados.

Implications for Clinical Practice from a Multicenter Survey of Heart Failure Management Centers.

OBJECTIVES: This observational, cross-sectional study based aimed to test whether heart failure (HF)-disease management program (DMP) components are influencing care and clinical decision-making in Brazil. METHODS: The survey respondents were cardiologists recommended by experts in the field and invited to participate in the survey via printed form or email. The survey consisted of 29 questions addressing site demographics, public versus private infrastructure, HF baseline data of patients, clinical management of HF, performance indicators, and perceptions about HF treatment. RESULTS: Data were obtained from 98 centers (58% public and 42% private practice) distributed across Brazil. Public HF-DMPs compared to private HF-DMP were associated with a higher percentage of HF-DMP-dedicated services (79% vs 24%; OR: 12, 95% CI: 94-34), multidisciplinary HF (MHF)-DMP [84% vs 65%; OR: 3; 95% CI: 1-8), HF educational programs (49% vs 18%; OR: 4; 95% CI: 1-2), written instructions before hospital discharge (83% vs 76%; OR: 1; 95% CI: 0-5), rehabilitation (69% vs 39%; OR: 3; 95% CI: 1-9), monitoring (44% vs 29%; OR: 2; 95% CI: 1-5), guideline-directed medical therapy-HF use (94% vs 85%; OR: 3; 95% CI: 0-15), and less B-type natriuretic peptide (BNP) dosage (73% vs 88%; OR: 3; 95% CI: 1-9), and key performance indicators (37% vs 60%; OR: 3; 95% CI: 1-7). In comparison to non- MHF-DMP, MHF-DMP was associated with more educational initiatives (42% vs 6%; OR: 12; 95% CI: 1-97), written instructions (83% vs 68%; OR: 2: 95% CI: 1-7), rehabilitation (69% vs 17%; OR: 11; 95% CI: 3-44), monitoring (47% vs 6%; OR: 14; 95% CI: 2-115), GDMT-HF (92% vs 83%; OR: 3; 95% CI: 0-15). In addition, there were less use of BNP as a biomarker (70% vs 84%; OR: 2; 95% CI: 1-8) and key performance indicators (35% vs 51%; OR: 2; 95% CI: 91,6) in the non-MHF group. Physicians considered changing or introducing new medications mostly when patients were hospitalized or when observing worsening disease and/or symptoms. Adherence to drug treatment and non-drug treatment factors were the greatest medical problems associated with HF treatment. CONCLUSION: HF-DMPs are highly heterogeneous. New strategies for HF care should consider the present study highlights and clinical decision-making processes to improve HF patient care.

Effects of aerobic and inspiratory training on skeletal muscle microRNA-1 and downstream-associated pathways in patients with heart failure.

BACKGROUND: The exercise intolerance in chronic heart failure with reduced ejection fraction (HFrEF) is mostly attributed to alterations in skeletal muscle. However, the mechanisms underlying the skeletal myopathy in patients with HFrEF are not completely understood. We hypothesized that (i) aerobic exercise training (AET) and inspiratory muscle training (IMT) would change skeletal muscle microRNA-1 expression and downstream-associated pathways in patients with HFrEF and (ii) AET and IMT would increase leg blood flow (LBF), functional capacity, and quality of life in these patients. METHODS: Patients age 35 to 70 years, left ventricular ejection fraction (LVEF) ≤40%, New York Heart Association functional classes II-III, were randomized into control, IMT, and AET groups. Skeletal muscle changes were examined by vastus lateralis biopsy. LBF was measured by venous occlusion plethysmography, functional capacity by cardiopulmonary exercise test, and quality of life by Minnesota Living with Heart Failure Questionnaire. All patients were evaluated at baseline and after 4 months. RESULTS: Thirty-three patients finished the study protocol: control (n = 10; LVEF = 25 ± 1%; six males), IMT (n = 11; LVEF = 31 ± 2%; three males), and AET (n = 12; LVEF = 26 ± 2%; seven males). AET, but not IMT, increased the expression of microRNA-1 (P = 0.02; percent changes = 53 ± 17%), decreased the expression of PTEN (P = 0.003; percent changes = -15 ± 0.03%), and tended to increase the p-AKTser473 /AKT ratio (P = 0.06). In addition, AET decreased HDAC4 expression (P = 0.03; percent changes = -40 ± 19%) and upregulated follistatin (P = 0.01; percent changes = 174 ± 58%), MEF2C (P = 0.05; percent changes = 34 ± 15%), and MyoD expression (P = 0.05; percent changes = 47 ± 18%). AET also increased muscle cross-sectional area (P = 0.01). AET and IMT increased LBF, functional capacity, and quality of life. Further analyses showed a significant correlation between percent changes in microRNA-1 and percent changes in follistatin mRNA (P = 0.001, rho = 0.58) and between percent changes in follistatin mRNA and percent changes in peak VO2 (P = 0.004, rho = 0.51). CONCLUSIONS: AET upregulates microRNA-1 levels and decreases the protein expression of PTEN, which reduces the inhibitory action on the PI3K-AKT pathway that regulates the skeletal muscle tropism. The increased levels of microRNA-1 also decreased HDAC4 and increased MEF2c, MyoD, and follistatin expression, improving skeletal muscle regeneration. These changes associated with the increase in muscle cross-sectional area and LBF contribute to the attenuation in skeletal myopathy, and the improvement in functional capacity and quality of life in patients with HFrEF. IMT caused no changes in microRNA-1 and in the downstream-associated pathway. The increased functional capacity provoked by IMT seems to be associated with amelioration in the respiratory function instead of changes in skeletal muscle. ClinicalTrials.gov (Identifier: NCT01747395).

Microvascular oxygen delivery-to-utilization mismatch at the onset of heavy-intensity exercise in optimally treated patients with CHF.

Impaired muscle blood flow at the onset of heavy-intensity exercise may transiently reduce microvascular O(2) pressure and decrease the rate of O(2) transfer from capillary to mitochondria in chronic heart failure (CHF). However, advances in the pharmacological treatment of CHF (e.g., angiotensin-converting enzyme inhibitors and third-generation beta-blockers) may have improved microvascular O(2) delivery to an extent that intramyocyte metabolic inertia might become the main locus of limitation of O(2) uptake (Vo(2)) kinetics. We assessed the rate of change of pulmonary Vo(2) (Vo(2)(p)), (estimated) fractional O(2) extraction in the vastus lateralis (approximately Delta[deoxy-Hb+Mb] by near-infrared spectroscopy), and cardiac output (Qt) during high-intensity exercise performed to the limit of tolerance (Tlim) in 10 optimally treated sedentary patients (ejection fraction = 29 + or - 8%) and 11 controls. Sluggish Vo(2)(p) and Qt kinetics in patients were significantly related to lower Tlim values (P < 0.05). The dynamics of Delta[deoxy-Hb+Mb], however, were faster in patients than controls [mean response time (MRT) = 15.9 + or - 2.0 s vs. 19.0 + or - 2.9 s; P < 0.05] with a subsequent response "overshoot" being found only in patients (7/10). Moreover, tauVo(2)/MRT-[deoxy-Hb+Mb] ratio was greater in patients (4.69 + or - 1.42 s vs. 2.25 + or - 0.77 s; P < 0.05) and related to Qt kinetics and Tlim (R = 0.89 and -0.78, respectively; P < 0.01). We conclude that despite the advances in the pharmacological treatment of CHF, disturbances in "central" and "peripheral" circulatory adjustments still play a prominent role in limiting Vo(2)(p) kinetics and tolerance to heavy-intensity exercise in nontrained patients.