Efficacy and safety of surgical energy devices for axillary node dissection: a systematic review and network meta-analysis.

Various surgical energy devices are used for axillary lymph-node dissection. However, those that reduce seroma during axillary lymph-node dissection are unknown. We aimed to determine the best surgical energy device for reducing seroma by performing a network meta-analysis to synthesize the current evidence on the effectiveness of surgical energy devices for axillary node dissection for breast cancer patients. We searched MEDLINE, Embase, CENTRAL, ClinicalTrials.gov, and World Health Organization International Clinical Trials Platform Search Portal. Two reviewers independently selected randomized controlled trials (RCTs) comparing electrosurgical bipolar vessel sealing (EBVS), ultrasonic coagulation shears (UCS), and conventional techniques for axillary node dissection. Primary outcomes were seroma, drained fluid volume (mL), and drainage duration (days). We analyzed random-effects and Bayesian network meta-analyses. We evaluated the confidence of each outcome using the CINeMA tool. We registered with PROSPERO (CRD42022335434). We included 34 RCTs with 2916 participants. Compared to the conventional techniques, UCS likely reduces seroma (risk ratio [RR], 0.61; 95% credible interval [CrI], 0.49-0.73), the drained fluid volume (mean difference [MD], - 313 mL; 95% CrI - 496 to - 130), and drainage duration (MD - 1.79 days; 95% CrI - 2.91 to - 0.66). EBVS might have little effect on seroma, the drained fluid volume, and drainage duration compared to conventional techniques. UCS likely reduce seroma (RR 0.44; 95% CrI 0.28-0.69) compared to EBVS. Confidence levels were low to moderate. In conclusion, UCS are likely the best surgical energy device for seroma reduction during axillary node dissection for breast cancer patients.

Age- and sex-stratified normal values for circulatory and ventilatory power during ramp exercise derived from a healthy Japanese population.

Circulatory power (CP) and ventilatory power (VP), obtained by cardiopulmonary exercise testing (CPX), have been suggested to be excellent prognostic markers for heart failure. However, the normal values of these parameters in healthy Japanese populations remain unknown; thus, we aimed to investigate these values in such a population. A total of 391 healthy Japanese participants, 20-78 years of age, underwent CPX with a cycle ergometer with ramp protocols. Systolic blood pressure (SBP), heart rate, oxygen uptake ([Formula: see text]O2) at peak exercise, and the slope of minute ventilation ([Formula: see text]E) versus carbon dioxide ([Formula: see text]CO2) ([Formula: see text]E vs. [Formula: see text]CO2 slope) were measured. CP was calculated by multiplying the peak [Formula: see text]O2 and SBP values, and VP was calculated by dividing the peak SBP value by the [Formula: see text]E versus [Formula: see text]CO2 slope. For males and females, the average CP values were 6119 ± 1280 (mean ± standard deviation) and 4775 ± 914 mmHg·mL/min/kg, respectively (p < 0.001). The average VP values for males and females were 8.0 ± 1.3 and 6.9 ± 1.3 mmHg (p < 0.001). CP decreased with age in both sexes. VP increased with age in females, with no significant change in males. We calculated the normal values for CP and VP in a healthy Japanese population. The results can contribute to the evaluation of patients' CPX results as a reference.

Effects of cardiac rehabilitation with motion assistance from a wearable cyborg hybrid assistive limb on patients with chronic heart failure: a randomized controlled trial with a one-year follow-up.

[Purpose] We have recently reported that using a wearable cyborg hybrid assistive limb improved the isometric knee extensor muscle strength of patients with chronic heart failure. Here, we investigated the long-term effects of a lumbar-type hybrid assistive limb for patients with chronic heart failure. [Participants and Methods] A total of 28 hospitalized patients with chronic heart failure (mean age, 73.1 ± 13.8 years) were randomly assigned to two groups: the hybrid assistive limb group or the control group, in which they performed a sit-to-stand exercise with or without the hybrid assistive limb, respectively. The cardiac rehabilitation therapy included this intervention, which was performed as many times as possible for 5-30 minutes per day for 6-10 days. Clinical assessments like lower-limb muscle strength, walking ability, etc., were measured before and after the intervention. Cardiac events were followed up for up to a year after discharge. [Results] No adverse events occurred during the study period in either group. In terms of long-term effects, the incidence of cardiac events was 23% and 45% in the hybrid assistive limb and the control groups, respectively. [Conclusion] Hybrid assistive limb-assisted exercise therapy may be a safe and feasible cardiac rehabilitation tool in patients with chronic heart failure. The lumbar-type wearable cyborg hybrid assistive limb may have a positive effect on heart failure prognosis by adding long-term exercise therapy.

Effects of Cardiac Rehabilitation With Lumbar-Type Hybrid Assistive Limb on Muscle Strength in Patients With Chronic Heart Failure　- A Randomized Controlled Trial.

BACKGROUND: Aiming to establish an effective tool in new cardiac rehabilitation programs, we investigated the use of a lumbar-type hybrid assistive limb (HAL) in patients with heart failure (HF) who had difficulty in walking at the usual speed of healthy subjects (≈80 m/min).Methods and Results:We randomly assigned 28 HF patients (age, 73.1±13.8 years) to perform a sit-to-stand exercise with or without HAL. The sit-to-stand exercise was repeated as many times as possible as cardiac rehabilitation therapy over a period of 6-10 days. We measured 5 parameters before and after the completion of cardiac rehabilitation: B-type natriuretic peptide, Short Physical Performance Battery (SPPB), 6-min walking distance (6MWD), 30-s chair-stand test (CS-30), and isometric knee extensor muscle strength. The SPPB and 6MWD were significantly improved, and the CS-30 score was somewhat improved, after the exercise therapy in both the HAL and non-HAL groups. The knee extensor muscle strength improved significantly in the HAL group (0.29±0.11 to 0.35±0.11 kgf/kg, P<0.01), but showed no change in the non-HAL group (0.35±0.11 to 0.35±0.13 kgf/kg, P=0.40). CONCLUSIONS: The improved knee extensor muscle strength in the HAL group suggests that the lumbar-type HAL may be an effective tool for cardiac rehabilitation in HF patients with frailty, which is a predictor of poor prognosis in HF.

Ventilatory efficiency during ramp exercise in relation to age and sex in a healthy Japanese population.

BACKGROUND: The current understanding of ventilator efficiency variables during ramp exercise testing in the normal Japanese population is insufficient, and the responses of tidal volume (VT) and minute ventilation (V̇E) to the ramp exercise test in the normal Japanese population are not known. METHODS: A total of 529 healthy Japanese subjects aged 20-78 years underwent cardiopulmonary exercise testing using a cycle ergometer with ramp protocols. VT and V̇E at rest, at anaerobic threshold, and at peak exercise were determined. The slope of V̇E versus carbon dioxide (V̇CO2) (V̇E vs. V̇CO2 slope), minimum V̇E/V̇CO2, and oxygen uptake efficiency slope (OUES) were determined. RESULTS: For males and females in their 20 s, peak VT (VTpeak) was 2192 ± 376 and 1509 ± 260 mL (p < 0.001), peak V̇E (V̇Epeak) was 80.6 ± 18.7 and 57.7 ± 13.9 L/min (sex differences p < 0.001), the V̇E vs. V̇CO2 slope was 24.4 ± 3.2 and 25.7 ± 3.2 (p = 0.035), the minimum V̇E/V̇CO2 was 24.2 ± 2.3 and 27.0 ± 2.8 (p < 0.001), and the OUES was 2452 ± 519 and 1991 ± 315 (p < 0.001), respectively. VTpeak and V̇Epeak decreased with age and increased with weight and height. The V̇E vs. V̇CO2 slope and minimum V̇E/V̇CO2 increased with age, while conversely, the OUES decreased with age. CONCLUSIONS: We have established the normal range of VT and V̇E responses, the V̇E vs. V̇CO2 slope, the minimum V̇E/V̇CO2, and the OUES for a healthy Japanese population. Some of these parameters were influenced by weight, height, sex, and age. These results provide useful reference values for interpreting the results of cardiopulmonary exercise testing in cardiac patients.

Pulse wave transit time during exercise testing reflects the severity of heart disease in cardiac patients.

The pulse wave transit time (PWTT) is easily measured as the time from the R wave of an electrocardiogram to the arrival of the pulse wave measured by an oxygen saturation monitor at the earlobe. We investigated whether the change of PWTT during exercise testing reflects cardiopulmonary function. Eighty-nine cardiac patients who underwent cardiopulmonary exercise testing (CPX) were enrolled. We analyzed the change of PWTT during exercise and the relationship between the shortening of the PWTT and CPX parameters. PWTT was significantly shortened from rest to peak exercise (204.6 ± 33.6 vs. 145.6 ± 26.4 msec, p < 0.001) in all of the subjects. The patients with heart failure had significantly higher PWTT at peak exercise than the patients without heart failure (152.7 ± 27.1 vs. 140.4 ± 24.8 msec, p = 0.031). The shortening of PWTT from rest to peak exercise showed significant positive correlations with the peak O2 uptake (VO2) (r = 0.56, p < 0.001), anaerobic threshold (r = 0.40, p = 0.016), and % increase of systolic blood pressure during exercise (r = 0.75, p < 0.001), and a negative correlation with the slope of the increase in ventilation versus the increase in CO2 output (VE-VCO2 slope) (r = - 0.42, p = 0.010) in the patients with heart failure. PWTT was shortened during exercise as the exercise intensity increased. In the patients with heart failure, the shortening of PWTT from rest to peak exercise was smaller in those with lower exercise capacity and those with higher VE-VCO2 slope, an established index known to reflect the severity of heart failure.

Efficacy of Cardiac Rehabilitation with Assistance from Hybrid Assistive Limb in Patients with Chronic Heart Failure: Protocol for a Randomized Controlled Study.

The hybrid assistive limb (HAL) provides motion assistance based on bioelectrical signals detected on the skin surface when muscle forces are generated. The lumbar-type HAL is expected to expand the therapeutic options for severe cardiac patients who have difficulty in moving on their own legs. We aim to compare the efficacy of exercise therapy performed with assistance from a lumbar-type HAL versus conventional training (sit-to-stand exercise without HAL) in patients with chronic heart failure. This investigation will be a randomized, nonblinded, controlled study. Sixty patients who satisfy the criteria to receive cardiac rehabilitation therapy under the Japanese national insurance system will be enrolled at the University of Tsukuba Hospital. Participants randomly assigned to 2 groups (HAL group and conventional group) at a 1:1 allocation ratio will perform exercise therapy either with HAL or without HAL for 5-30 min once a day for 6-10 days. Outcome parameters will be measured just before and after the completion of the exercise therapy and at 1 year after hospital discharge. The primary outcomes will be the heart rate, blood pressure, subjective ratings of exercise intensity during exercise (Borg scale), number of days from the start of exercise therapy to independent walking and to discharge, and prognosis (mortality and cardiovascular events) over the 1-year period after discharge. The secondary outcomes will be the assessment of heart failure severity, brain natriuretic peptide, grip strength, thigh muscle thickness, isometric knee extensor strength, standing ability, 10-meter walking speed, 6-min walking distance, short physical performance battery, and adverse events. Unpaired t tests will be used for baseline assessments and outcome measures. This is the first randomized controlled study to examine the efficacy and feasibility of lumbar-type HAL in patients with chronic heart failure. If the results confirm beneficial effects in the outcomes of patients with heart failure, this study will add more evidence in support of the use of the lumbar-type HAL as an effective tool in new cardiac rehabilitation programs.

Effects of a lumbar-type hybrid assistive limb on cardiopulmonary burden during squat exercise in healthy subjects.

The lumbar-type Hybrid Assistive Limb (HAL) is expected to expand the possibilities of exercise therapy for severe cardiac patients who have difficulty in moving on their own legs. We investigated whether motion assistance from HAL during squat exercise could effectively reduce the cardiopulmonary burden in healthy subjects. Twelve healthy subjects (33 ±â€¯11 years) performed squat exercise for 3 consecutive minutes at a repetition rate of 20 squats per minute with and without assistance from a lumbar-type HAL. The oxygen uptake (VO2), carbon dioxide output (VCO2), minute ventilation (VE), and the Borg Scale were monitored during exercise. VO2 (930 ±â€¯207 vs 992 ±â€¯169 mL/min, p < 0.05) and the Borg Scale rating (12.8 ±â€¯1.1 vs 13.7 ±â€¯0.8, p < 0.05) at the end of exercise were significantly lower when HAL was used. When 2 subjects who regularly perform high-intensity exercise for more than 10 h per week were excluded from the analyses, VO2, VCO2, VE, and the Borg Scale were significantly lower when HAL was used. Our results demonstrate that the lumbar-type HAL significantly reduces cardiopulmonary burden during squat exercise in healthy subjects. The effects were especially striking in sedentary subjects. Further studies on cardiac patients are expected to establish a new cardiac rehabilitation program using HAL.

Geriatric nutritional risk index predicts all-cause deaths in heart failure with preserved ejection fraction.

AIMS: The objective of the study was to evaluate whether the geriatric nutritional risk index (GNRI) at discharge may be helpful in predicting the long-term prognosis of patients hospitalized with heart failure (HF) with preserved ejection fraction (HFpEF, left ventricular ejection fraction ≥50%), a common HF phenotype in the elderly. METHODS AND RESULTS: Overall, 110 elderly HFpEF patients (≥65 years) from the Ibaraki Cardiovascular Assessment Study-HF (n = 838) were enrolled. The mean age was 78.5 ± 7.2 years, and male patients accounted for 53.6% (n = 59). All-cause mortality was compared between the low GNRI (<92) with moderate or severe nutritional risk group and the high GNRI (≥92) with no or low nutritional risk group. Cox proportional hazard regression models were constructed to evaluate the influence of the GNRI on all-cause death with the following covariates using forward stepwise selection: age, sex, nutritional status based on the GNRI as a categorical variable, history of HF hospitalization, haemoglobin level, estimated glomerular filtration rate, log brain natriuretic peptide levels (logBNP), history of hypertension, log C-reactive protein levels, left ventricular ejection fraction, left ventricular mass index, and the New York Heart Association functional classification (I/II or III class). The prognostic value of the GNRI was compared with that of serum albumin using C-statistics. The GNRI was added to the logBNP, serum albumin or the body mass index was added to the logBNP, and the C-statistic was compared using DeLong's test. Cox regression analysis revealed that age and a low GNRI were independent predictors of all-cause death (P < 0.05, n = 103; hazard ratio = 1.095, 95% confidence interval = 1.031-1.163, for age, and hazard ratio = 3.075, 95% confidence interval = 1.244-7.600, for the GNRI). DeLong's test for the two correlated receiver operating characteristic curves [area under the receiver operating characteristic curve (AUROC) of serum albumin, 0.71; AUROC of the GNRI, 0.75] demonstrated significant differences between the groups (P = 0.038). Adding the GNRI to the logBNP increased the AUROC for all-cause death significantly (0.71 and 0.80, respectively; P = 0.040, n = 105). The addition of serum albumin or the body mass index to the logBNP did not significantly increase the AUROC for all-cause death (P = 0.082 and P = 0.29, respectively). CONCLUSIONS: Nutritional screening using the GNRI at discharge is helpful to predict the long-term prognosis of elderly HFpEF patients.

Exercise training reduces ventricular arrhythmias through restoring calcium handling and sympathetic tone in myocardial infarction mice.

Exercise can improve morbidity and mortality in heart failure patients; however, the underlying mechanisms remain to be fully investigated. Thus, we investigated the effects of exercise on cardiac function and ventricular arrhythmias in myocardial infarction (MI) induced heart failure mice. Wild-type male mice underwent sham-operation or permanent left coronary artery ligation to induce MI. MI mice were divided into a sedentary (MI-Sed) and two intervention groups: MI-Ex (underwent 6-week treadmill exercise training) and MI-ßb (oral bisoprolol treatment (1 mg/kg/d) without exercise). Cardiac function and structure were assessed by echocardiography and histology. Exercise capacity and cardiopulmonary function was accepted as oxygen consumption at peak exercise (peak VO2 ). Autonomic nervous system function and the incidence of spontaneous ventricular arrhythmia were evaluated via telemetry recording. mRNA and protein expressions in the left ventricle (LV) were investigated by real-time PCR and Western blotting. There were no differences in survival rate, MI size, cardiac function and structure, while exercise training improved peak VO2 . Compared with MI-Sed, MI-Ex, and MI-ßb showed decreased sympathetic tone and lower incidence of spontaneous ventricular arrhythmia. By Western blot, the hyperphosphorylation of CaMKII and RyR2 were restored by exercise and ß-blocker treatment. Furthermore, elevated expression of miR-1 and decreased expression of its target protein PP2A were recovered by exercise and ß-blocker treatment. Continuous intensive exercise training can suppress ventricular arrhythmias in subacute to chronic phase of MI through restoring autonomic imbalance and impaired calcium handling, similarly to that for ß-blockers.

Safety and efficacy of in-hospital cardiac rehabilitation following antiarrhythmic therapy for patients with electrical storm.

BACKGROUND: Exercise-based in-hospital rehabilitation for patients with electrical storm (ventricular tachycardia/ventricular fibrillation, VT/VF) following antiarrhythmic therapy may prevent the deleterious outcomes of prolonged immobility, but the safety and efficacy of this strategy are still uncertain. We retrospectively investigated the rate of electrical storm recurrence in patients receiving rehabilitation. METHODS: Sixty-seven patients receiving therapy for electrical storm were included in this study. After treatment, patients were divided into rehabilitation (n=39) and non-rehabilitation (n=28) groups. RESULTS: Incidences of electrical storm recurrence and VT/VF requiring anti-tachycardia pacing or electrical defibrillation did not differ significantly between the rehabilitation and non-rehabilitation groups (13% vs. 21% and 28% vs. 25%, respectively). However, early mobilization initiated ≤2 days after primary therapy was disadvantageous for electrical storm and VT/VF recurrence compared to later mobilization (21% vs. 6% and 34% vs. 19%, respectively). Although the activities of daily living (ADL) at admission were significantly lower in the rehabilitation group, the scores were restored to the level of the non-rehabilitation group at the time of discharge. Univariate analysis revealed that high B-type natriuretic peptide (hazard ratio [HR]: 3.2; 95% confidence interval [CI]: 1.1-11), decreased left ventricular ejection fraction, and elevated E/E' (HR: 3.4; 95% CI: 1.1-11) were associated with VT/VF recurrence. CONCLUSIONS: The incidence of electrical storm relapse is substantial following antiarrhythmic therapy, but it is not increased by in-hospital rehabilitation. Although caution is urged for early mobilization, sustaining mobility to resume activity is recommended because ADL levels tend to deteriorate as a result of prolonged bed rest.

Effects of a cyborg-type robot suit HAL on cardiopulmonary burden during exercise in normal subjects.

BACKGROUND: The hybrid assistive limb (HAL) is the world's first cyborg-type robot suit that provides motion assistance to physically challenged patients. HAL is expected to expand the possibilities of exercise therapy for severe cardiac patients who have difficulty in moving on their own legs. As a first step, we examined whether or not the motion assistance provided by HAL during exercise could effectively reduce the cardiopulmonary burden in healthy subjects. METHODS: A total of ten healthy male adults (35 ± 12 years) underwent cardiopulmonary exercise testing (CPX) on a cycle ergometer with or without assistance from HAL. The CPX protocol consisted of four 3-min stages performed in a continuous sequence: rest, 0 W, 40 W, and 80 W. The heart rate (HR), blood pressure, oxygen uptake (VO2), minute ventilation (VE), and gas exchange ratio (R) were monitored during the CPX. RESULTS: At 0 W, the HR, VO2, and VE were significantly higher when HAL was used. At 80 W, however, the HR (107 ± 14 vs 114 ± 14 beats/min, p < 0.01), systolic blood pressure (141 ± 15 vs 155 ± 20 mmHg, p < 0.01), VO2 (17.6 ± 2.4 vs 19.0 ± 2.5 mL/min/kg, p < 0.05), and R (0.88 ± 0.04 vs 0.95 ± 0.09, p < 0.05) were significantly lower when HAL was used. CONCLUSIONS: HAL has the potential to reduce cardiopulmonary burden during moderate-intensity exercise and can, therefore, be used as a support for exercise therapy. Further studies on cardiac patients are expected to contribute to the establishment of a new exercise therapy program using HAL.

Clinical significance of respiratory compensation during exercise testing in cardiac patients.

Ventilation (VE) increases linearly with the increase of carbon dioxide output (VCO2) during cardiopulmonary exercise testing. VE-VCO2 slope rises in parallel with exercise intensity, reaches a turning point (called the RC point), then steepens because of respiratory compensation for lactic acidosis. While this RC point can be identified universally, it is undetectable in some patients. In this study we evaluated whether the respiratory compensation during exercise testing has clinical significance in cardiac patients. In total, 152 cardiac patients with a respiratory exchange ratio at peak exercise (peak R) of between 1.10 and 1.20 were enrolled. Cardiopulmonary parameters were compared between patients who manifested the RC point (n = 118) and those who did not (n = 34). The peak R did not significantly differ between these two groups. Compared to the patients without the RC point, those with the RC point had a higher oxygen uptake at peak exercise (peak VO2) (20.2 ± 5.3 vs 13.6 ± 3.4 mL/min/kg, p < 0.001), higher anaerobic threshold (AT) (12.4 ± 3.2 vs 9.2 ± 2.3 mL/min/kg, p < 0.001), and lower VE-VCO2 slope (31.7 ± 5.8 vs 37.8 ± 9.6, p = 0.001). Brain natriuretic peptide (BNP) tended to be lower in the patients with the RC point (175.4 ± 364.7 vs 327.9 ± 381.1 pg/mL, p = 0.067). Peak VO2, the marker of cardiopulmonary function, was found to be the independent predictor of the presence of the RC point. The present findings suggest that the phenomenon of respiratory compensation during heavy exercise indicates better cardiopulmonary function in cardiac patients within a prescribed range of effort.

Clinical Significance of the Presence of Oscillatory Breathing Both at Rest and During Exercise in Cardiac Patients.

Cardiac patients often experience nocturnal and daytime oscillatory breathing (OB). OB noted at rest sometimes becomes unclear or even disappears during exercise. We evaluated the physiological significance of OB by comparing the clinical characteristics of cardiac patients who manifested OB only at rest (group A), only during exercise (group B), and both at rest and during exercise (group C).Among 3,432 cardiac patients who underwent cardiopulmonary exercise testing (CPX), 114, 94, and 65 patients were identified as group A, B, and C, respectively. Left ventricular ejection function was 57 ± 17% in group A, 49 ± 20% in group B, and 41 ± 21% in group C (P < 0.05 for all comparisons among the 3 groups). The level of brain natriuretic peptide (BNP) was significantly higher in group C than in groups A and B. The peak VO2 was lower and the VE-VCO2 slope was higher in groups B and C than in group A.The present findings suggest that cardiac function is more impaired in cardiac patients who manifest OB both at rest and during exercise than in cardiac patients who manifest OB only at rest or only during exercise.

Utility of Nutritional Screening in Predicting Short-Term Prognosis of Heart Failure Patients.

Controlling nutritional status (CONUT) uses 2 biochemical parameters (serum albumin and cholesterol level), and 1 immune parameter (total lymphocyte count) to assess nutritional status. This study examined if CONUT could predict the short-term prognosis of heart failure (HF) patients.A total of 482 (57.5%) HF patients from the Ibaraki Cardiovascular Assessment Study-HF (n = 838) were enrolled (298 men, 71.7 ± 13.6 years). Blood samples were collected at admission, and nutritional status was assessed using CONUT. CONUT scores were defined as follows: 0-1, normal; 2-4, light; 5-8, moderate; and 9-12, severe degree of undernutrition. Accordingly, 352 (73%) patients had light-to-severe nutritional disturbances. The logarithmically transformed plasma brain natriuretic peptide (log BNP) concentration was significantly higher in the moderate-severe nutritional disturbance group (2.92 ± 0.42) compared to the normal group (2.72 ± 0.45, P < 0.01). CONUT scores were significantly higher in the in-hospital death patients [4 (3-8), n = 14] compared with patients who were discharged following symptom alleviation [3 (1-5), n = 446, P < 0.05]. With the exception of transferred HF patients (n = 22), logistic regression analysis that incorporated the CONUT score and the log BNP, showed that a higher CONUT score (P = 0.019) and higher log BNP (P = 0.009) were predictors of in-hospital death, and the median duration of hospital stay was 20 days.Our results demonstrate the usefulness of CONUT scores as predictors of short-term prognosis in hospitalized HF patients.

Mechanisms That Modulate Peripheral Oxygen Delivery during Exercise in Heart Failure.

Oxygen uptake ([Formula: see text]o2) measured at the mouth, which is equal to the cardiac output (CO) times the arterial-venous oxygen content difference [C(a-v)O2], increases more than 10- to 20-fold in normal subjects during exercise. To achieve this substantial increase in oxygen uptake [[Formula: see text]o2 = CO × C(a-v)O2] both CO and the arterial-venous difference must simultaneously increase. Although this occurs in normal subjects, patients with heart failure cannot achieve significant increases in cardiac output and must rely primarily on changes in the arterial-venous difference to increase [Formula: see text]o2 during exercise. Inadequate oxygen delivery to the tissue during exercise in heart failure results in tissue anaerobiosis, lactic acid accumulation, and reduction in exercise tolerance. H+ is an important regulatory and feedback mechanism to facilitate additional oxygen delivery to the tissue (Bohr effect) and further aerobic production of ATP when tissue anaerobic metabolism increases the production of lactate (anaerobic threshold). This H+ production in the muscle capillary promotes the continued unloading of oxygen (oxyhemoglobin desaturation) while maintaining the muscle capillary Po2 (Fick principle) at a sufficient level to facilitate aerobic metabolism and overcome the diffusion barriers from capillary to mitochondria ("critical capillary Po2," 15-20 mm Hg). This mechanism is especially important during exercise in heart failure where cardiac output increase is severely constrained. Several compensatory mechanisms facilitate peripheral oxygen delivery during exercise in both normal persons and patients with heart failure.

Nutritional screening based on the controlling nutritional status (CONUT) score at the time of admission is useful for long-term prognostic prediction in patients with heart failure requiring hospitalization.

The objective of the study was to clarify whether controlling nutritional status (CONUT) is useful for predicting the long-term prognosis of patients hospitalized with heart failure (HF). A total of 482 (57.5%) HF patients from the Ibaraki Cardiovascular Assessment Study-HF (N = 838) were enrolled (298 men, 71.7 ± 13.6 years). At admission, blood samples were collected and nutritional status assessed using CONUT. CONUT scores were defined as follows: 0-1, normal; 2-4, light; 5-8, moderate; and 9-12, severe undernutrition. Accordingly, 352 (73%) patients had light-to-severe nutritional disturbances. In the follow-up period [median 541.5 (range 354-786) days], 109 deaths were observed. A Kaplan-Meier analysis revealed that all-cause deaths occurred more frequently in HF patients with nutritional disturbances [n = 93 (26.4%)] than in those with normal nutrition [n = 16 (12.3%); log-rank p < 0.001]. The Cox proportional hazard analyses revealed that a per point increase in the CONUT score was associated with an increased risk of all-cause death (hazard ratio 1.142; 95% confidence interval, 1.044-1.249) after controlling simultaneously for age, sex, previous history of HF hospitalization, log brain natriuretic peptide, and use of therapeutic agents at admission (tolvaptan and aldosterone antagonists). This study suggests that nutritional screening using CONUT scores is helpful in predicting the long-term prognosis of patients hospitalized with HF in a multicenter registry setting.

Clinical significance of the overshoot phenomena of respiratory gas indices during recovery from maximal exercise testing.

BACKGROUND: Overshoot phenomena of the gas exchange ratio (R:VCO2/VO2), ventilatory equivalent for O2 (VE/VO2), and end-tidal O2 pressure (PETO2) are commonly observed during recovery from maximal cardiopulmonary exercise testing (CPX). We investigated the clinical significance of the overshoots of these indices by comparing their magnitudes between healthy subjects and cardiac patients with left ventricular dysfunction. METHODS: In total, 121 subjects (73 healthy subjects and 48 cardiac patients with left ventricular ejection fraction<40%) who underwent CPX and achieved peak R≥1.10 were enrolled. We evaluated and calculated the presence and magnitude of the overshoot phenomena of R, VE/VO2, and PETO2. RESULTS: The overshoot phenomena of R, VE/VO2, and PETO2 were observed in all the subjects. The magnitudes of the R (21.4±12.4% vs. 29.3±10.0%, p<0.001), VE/VO2 (45.5±23.5% vs. 77.5±28.5%, p<0.001), and PETO2 (5.3±3.4% vs. 10.1±4.2%, p<0.001) overshoots were significantly lower in cardiac patients than in healthy subjects. In cardiac patients, the magnitude of the PETO2 overshoot showed significant positive correlations with the peak O2 uptake (VO2) (r=0.52, p<0.001), anaerobic threshold (r=0.43, p=0.003), and ratio of the increase in VO2 to the increase in the work rate (r=0.41, p=0.005), and a negative correlation with the slope of the increase in ventilation versus the increase in CO2 output (r=-0.50, p<0.001). The magnitudes of the R and VE/VO2 overshoots showed the same patterns of significant correlation with the CPX indices. CONCLUSIONS: We concluded that the overshoots of R, VE/VO2, and PETO2 during recovery from maximal exercise reflect the natural cardiopulmonary adaptation after exercise and are more prominent in subjects with better cardiopulmonary function.