Association Between Adherence to a 3-Month Cardiac Rehabilitation Program and Long-Term Clinical Outcomes in Japanese Patients With Cardiac Implantable Electronic Devices

PURPOSE

The objective of this study was to evaluate the association between comprehensive cardiac rehabilitation (CCR) completion and long-term clinical outcomes in patients with cardiac implantable electronic devices (CIED).

METHODS

This retrospective cohort study included 834 patients with CIED who participated in CCR, which included a cardiopulmonary exercise test or 6-min walk test. Patients with a left ventricular ejection fraction ≤40%, predicted peak oxygen uptake ≤80%, or B-type natriuretic peptide level ≥80 pg/mL were eligible. The primary outcome was all-cause mortality.

RESULTS

After excluding 241 patients with duplicate records and 69 who underwent CCR in the outpatient department, the data of 524 patients were analyzed. Mean age was 64 ± 15 yr, 389 (74%) patients were men, left ventricular ejection fraction was 31 ± 15%, and 282 (54%) patients had a history of hospitalization for worsening heart failure. Of the patients referred for CCR, 294 (56%) completed the program, and an additional 230 patients started but did not complete CCR. Over a 3.7-yr median follow-up period, all-cause mortality occurred in 156 (30%) patients. Completers had lower all-cause mortality rates than non-completers (log-rank 15.77, P < .001). After adjusting for prognostic baseline characteristics, completers had 58% lower all-cause mortality risks than non-completers (HR = 0.42; 95% CI, 0.27-0.64, P < .001).

CONCLUSIONS

Three-mo CCR program completion was associated with lower mortality risks in patients with CIED. New programs or management methods are needed to decrease mortality risks, especially for those who cannot complete CCR programs.

Impact of Changes in Rectus Femoris Cross-Sectional Area Measured by Ultrasound on the Prognosis of Patients With Acute Heart Failure

BACKGROUND

Low muscle mass in patients with acute heart failure (AHF) is associated with poor prognosis; however, this is based on a single baseline measurement, with little information on changes in muscle mass during hospitalization and their clinical implications. This study investigated the relationship between changes in rectus femoris cross-sectional area (RFCSA) on ultrasound and the prognosis of patients with AHF.

METHODS AND RESULTS

This is a retrospective evaluation of 284 AHF patients (mean [±SD] age 79.1±11.9 years; 116 female). RFCSA assessments at admission (pre-RFCSA), ∆RFCSA (i.e., the percentage change in RFCSA from admission to 2 weeks), and composite prognosis (all-cause death and heart failure-related readmission) within 1 year were determined. Patients were divided into 4 groups according to their median pre-RFCSA and ∆RFCSA after sex stratification: Group A, higher pre-RFCSA/better ∆RFCSA; Group B, higher pre-RFCSA/worse ∆RFCSA; Group C, lower pre-RFCSA/better ∆RFCSA; Group D, lower pre-RFCSA/worse ∆RFCSA. In the Cox regression analysis, with Group A as the reference, the cumulative event rate of Group C (hazard ratio [HR] 3.39; 95% confidence interval [CI] 0.71-16.09; P=0.124) did not differ significantly; however, the cumulative event rates of Group B (HR 7.93; 95% CI 1.99-31.60; P=0.003) and Group D (HR 9.24; 95% CI 2.57-33.26; P<0.001) were significantly higher.

CONCLUSIONS

∆RFCSA during hospitalization is useful for risk assessment of prognosis in patients with AHF.

Relationship of maximum walking speed with peak oxygen uptake and anaerobic threshold in male patients with heart failure

This retrospective observational study aimed to examine the relationships of maximum walking speed (MWS) with peak oxygen uptake (peak VO2) and anaerobic threshold (AT) obtained by cardiopulmonary exercise testing (CPX) in patients with heart failure. The study participants were 104 consecutive men aged ≥ 20 years who had been hospitalized or had undergone outpatient care at our hospital for heart failure between February 2019 and January 2023. MWS was measured in a 5-m section with a 1-m run-up before and after the course. Multivariable analysis was used to examine the association between MWS and peak VO2 and AT by CPX. The Pearson correlation coefficient showed that MWS was positively correlated with percent-predicted peak VO2 and percent-predicted AT (r = 0.463, p < 0.001; and r = 0.485, p < 0.001, respectively). In the multiple linear regression analysis employing percent-predicted peak VO2 and percent-predicted AT as the objective variables, only MWS demonstrated a significant positive correlation (standardized β: 0.471, p < 0.001 and 0.362, p < 0.001, respectively). Multiple logistic regression analyses, using an 80% cutoff in percent-predicted peak VO2 and AT, revealed that only MWS was identified as a significant factor in both cases (odds ratio [OR]: 1.239, 95% confidence interval [CI]: 1.071-1.432, p = 0.004 and OR: 1.469, 95% CI: 1.194-1.807, p < 0.001, respectively). MWS was correlated with peak VO2 and AT in male patients with heart failure. The MWS measurement as a screening test for exercise tolerance may provide a simple means of estimating peak VO2 and AT in heart failure patients.

Effects of beta-hydroxy beta-methyl butyrate calcium combined with exercise therapy in patients with cardiac disease: a study protocol for clinical trial

INTRODUCTION

The current treatment for heart disease consists of exercise therapy in addition to pharmacotherapy, nutritional support and lifestyle guidance. In general, nutritional support focuses on protein, salt and energy restrictions, with no active protein or amino acid intake in cases involving moderate or higher renal failure. From this perspective, patients with cardiac disease are at high risk of frailty.Beta-hydroxy beta-methyl butyrate (HMB) is a metabolite of leucine. HMB is widely used for muscle strengthening and can be safely ingested even by patients with renal failure. The proposed study protocol will investigate the effects of HMB-calcium (HMB-Ca) administered in combination with comprehensive cardiac rehabilitation for muscle strength, muscle mass and cardiac function in patients with cardiac disease during the convalescent period. The primary outcome will be knee extensor strength. Secondary outcomes will be gross isometric limb strength and skeletal muscle mass.

METHODS AND ANALYSIS

This study will be a single-blinded, randomised, controlled trial with parallel comparisons between two groups. The study period will be 60 days from the start of outpatient cardiac rehabilitation. Participants will be randomly divided into two groups: an HMB group consuming HMB-Ca one time per day for 60 days; and a Placebo group consuming reduced maltose once one time per day for 60 days. Exercise therapy will be performed by both groups.

ETHICS AND DISSEMINATION

The study protocol will be published in a peer-reviewed journal. Ethics approval was provided by the Showa University Clinical Research Review Board.

TRIAL REGISTRATION NUMBER

jRCTs031220139; Japan Registry of Clinical Trails.

Development and appropriateness of a scoring method for International Classification of Functioning, Disabilities, and Health assessment in older patients with heart failure: a Delphi survey of expert panel in Japan

OBJECTIVE

The number of older patients with heart failure (HF) is increasing in Japan and has become a social problem. There is an urgent need to develop a comprehensive assessment methodology based on the common language of healthcare; the International Classification of Functioning, Disability and Health (ICF). The purpose of this study was to develop and confirm the appropriateness of a scoring methodology for 43 ICF categories in older people with HF.

DESIGN

Cross-sectional survey. We applied the RAND/University of California at Los Angeles (UCLA) Appropriateness Method with a modified Delphi method.

SETTING AND PARTICIPANTS

We included a panel of 26 multidisciplinary experts on HF care consisting of home physicians, cardiovascular physicians, care managers, nurses, physical therapists, a pharmacist, occupational therapist, nutritionist and a social worker.

MEASURES

We conducted a literature review of ICF linking rules and developed a questionnaire on scoring methods linked to ICF categories in older people with HF. In the Delphi rounds, we sent the expert panel a questionnaire consisting of three questions for each of the 43 ICF categories. The expert panel responded to the questionnaire items on a 1 (very inappropriate) - 9 (very appropriate) Likert scale and repeated rounds until a consensus of 'Appropriate' and 'Agreement' was reached on all items.

RESULTS

A total of 21 panel members responded to all the Delphi rounds. In the first Delphi round, six question items in four ICF categories did not reach a consensus of 'Agreement', but the result of our modifications based on panel members' suggestions reached to a consensus of 'Appropriate' and 'Agreement' on all questions in the second Delphi round.

CONCLUSION

The ICF-based scoring method for older people with HF developed in this study was found to be appropriate. Future work is needed to clarify whether comprehensive assessment and information sharing based on ICF contributes to preventing readmissions.

Association of adherence to a 3 month cardiac rehabilitation with long-term clinical outcomes in heart failure patients

Aims

Although comprehensive cardiac rehabilitation (CCR) is recommended for patients with heart failure (HF), participants often show low adherence. The aim of this study was to evaluate the association of CCR completion and response with long‐term clinical outcomes.

Methods and results

We screened 824 HF patients who participated in a 3 month CCR programme and underwent baseline assessment, including cardiopulmonary exercise testing (CPX). After excluding 52 participants who experienced all‐cause death or HF hospitalization within 180 days, long‐term outcomes were compared between those who attended 3 month follow‐up assessment including CPX (completers) and those who did not (non‐completers). We also compared the prognostic value of the changes in peak oxygen uptake (VO₂) vs. quadriceps muscle strength (QMS) during the 3 month CCR programme. Among the 772 study patients, there were no significant differences in baseline characteristics, including left ventricular ejection fraction, B‐type natriuretic peptide levels, and peak VO₂, between the completers (n = 561) and non‐completers (n = 211), except for a higher age (63.2 ± 14.2 vs. 59.4 ± 16.2 years; P = 0.0015) and proportion of females (27% vs. 17%; P = 0.0030) among the completers. During a median follow‐up of 55.4 months, the completers had lower rates of the composite of all‐cause death or HF hospitalization (34.4% vs. 44.6%; P = 0.0015) and all‐cause death (16.9% vs. 24.6%; P = 0.0037) than the non‐completers. After adjustment for prognostic baseline characteristics, including age and sex, CCR completion was associated with 34% and 44% reductions in the composite outcome and all‐cause death, respectively. Among the completers, peak VO₂ and QMS increased significantly (8.9 ± 15.8% and 10.5 ± 17.9%, respectively) over 3 months. Patients who had an increase in peak VO₂ ≥ 6.3% (median value) during the CCR programme had significantly lower rates of the composite outcome (27.0% vs. 33.8%; P = 0.048) and all‐cause mortality (10.0% vs. 17.4%; P = 0.0069) than those who did not. No statistically significant difference was observed in the composite outcome (30.5% vs. 30.4%; P = 0.76) or all‐cause mortality (13.0% vs. 14.4%; P = 0.39) between those with and without an increase in QMS ≥8.3% (median value).

Conclusions

In HF patients who participated in a 3 month CCR programme, its completion was associated with lower risks of subsequent HF hospitalization and death. Within the group of patients who completed the programme, the improvement in exercise capacity, but not in skeletal muscle strength, over the 3‐month period was associated with better outcomes. These findings highlight the importance of the post‐CCR follow‐up assessment, including CPX, to identify a patient's adherence and response to the CCR programme.

Effects of sitagliptin on exercise capacity and hemodynamics in patients with type 2 diabetes mellitus and coronary artery disease

Sitagliptin attenuates left ventricular (LV) dysfunction and may improve oxygen uptake in animals. The effects of sitagliptin on oxygen uptake (VO₂) and exercise hemodynamics have been unclear in patients with type 2 diabetes mellitus (T2DM) and coronary artery disease (CAD). Thirty patients with T2DM and CAD were randomized into a sitagliptin (50 mg/day) or voglibose (0.6 mg/day) group. Patients underwent maximal cardiopulmonary exercise testing. VO₂ and hemodynamics were evaluated at rest, anaerobic threshold and peak exercise. Resting LV diastolic function (E', peak early diastolic mitral annular velocity) and geometry were evaluated by echocardiography, and endothelial function by reactive hyperemia peripheral arterial tonometry. A total of 24 patients (69 ± 9 years) completed 6 months of intervention. Peak VO₂ in the sitagliptin and voglibose groups (25.3 ± 7.3 vs. 24.0 ± 7.4, 22.7 ± 4.8 vs. 22.1 ± 5.2 ml/kg/min) was slightly decreased after 6 months (time effect p = 0.051; group × time effect p = 0.49). No effects were observed on LV ejection fraction, E', or reactive hyperemia index in either group. Heart rate during exercise was unaffected in both groups. Systolic blood pressure was unchanged by sitagliptin at rest and during exercise, but slightly lowered by voglibose at anaerobic threshold and peak exercise. In patients with T2DM and CAD, sitagliptin had little effect on resting LV and arterial function, exercise capacity, or exercise hemodynamics. Further studies need to be conducted with more patients as the number of the patients in this study was limited.

Combination of Peak Exercise Systolic Blood Pressure and Left Atrial Diameter as a Novel Non-Spirometry Prognostic Predictor Comparable to Peak Oxygen Uptake for Heart Failure With Reduced Ejection Fraction

BACKGROUND

Although peak oxygen uptake (pV̇O₂) is a well-established powerful prognostic predictor in heart failure (HF) patients, implementation of cardiopulmonary exercise testing (CPX) is limited by its complex analysis. We aimed to develop a new bivariate predictor obtained without respiratory gas measurement, comparable to pV̇O₂.Methods and Results:We studied 560 consecutive HF patients with ejection fraction (EF) <45% who underwent CPX. During a median follow-up of 49.0 months, the composite of all-cause death or HF hospitalization occurred in 228 patients (40.7%) and all-cause death in 111 (19.8%). pV̇O₂was the strongest single predictor of the composite outcome (chi-square, 99.3). Among the bivariate non-spirometry parameters, the ratio of systolic blood pressure at peak exercise to left atrial diameter (pSBP/LAD) was the strongest predictor (chi-square, 112.4). Patients with pSBP/LAD <2.8 mmHg/mm, compared with those with pSBP/LAD ≥2.8 mmHg/mm, had a hazard ratio of 3.84 (95% confidence interval, 2.95-5.04) for the composite outcome and 3.66 (2.50-5.37) for all-cause death. In the subgroup with pV̇O₂<14 mL/kg/min (n=149), where pV̇O₂had no further predictive value, pSBP was the strongest single predictor, and the predictive power of pSBP/LAD was more enhanced.

CONCLUSIONS

pSBP/LAD was a new powerful predictor of HF hospitalization and death, comparable to pV̇O₂, in HF with reduced EF. Because of its simplicity and high availability, this index has the potential for more widespread use than pV̇O₂.

Efficacy of Cardiac Rehabilitation in Heart Failure Patients With Low Body Mass Index

BACKGROUND

Low body mass index (BMI) is a relevant prognostic factor for heart failure (HF), but HF patients with low BMI are reported to be at risk of not receiving optimal drug treatment. We sought to evaluate the efficacy of cardiac rehabilitation (CR) in patients with low vs. normal BMI. Methods and Results: We studied 152 consecutive patients (low BMI, n=32; normal BMI, n=119) who participated in a 3-month CR program. Low BMI was defined as <18.5 kg/m²and normal BMI, as 18.5≤BMI<25 kg/m². All patients underwent cardiopulmonary exercise testing and muscle strength testing at the beginning and end of the 3-month CR program. After CR, a significantly greater proportion of HF patients with low BMI had a positive change in peak V̇O₂than in the normal BMI group (91% vs. 70%; P=0.010). Average percent change in peak V̇O₂was significantly greater in patients with low vs. normal BMI (17.1±2.8% vs. 7.8±1.5%; P<0.001). In addition, on multivariable logistic regression, low BMI was an independent predictor of a positive change in peak V̇O₂after CR (OR, 3.97; 95% CI: 1.10-14.31; P=0.035).

CONCLUSIONS

CR has a greater effect in patients with low than normal BMI, and low BMI is an independent predictor of a positive change in peak V̇O₂. Thus, CR should be strongly recommended for HF patients with low BMI.

Effect of Exercise Training in Heart Failure Patients Without Echocardiographic Response to Cardiac Resynchronization Therapy

Background: Cardiac resynchronization therapy (CRT) is an effective treatment of heart failure (HF) with ventricular dyssynchrony, but not all patients respond to a similar extent. We investigated the efficacy and safety of exercise training (ET) in patients without response to CRT.

Methods and Results: Thirty-four patients who participated in a 3-month ET program and underwent cardiopulmonary exercise testing at baseline and after the program were divided into 17 responders and 17 non-responders based on echocardiographic response criteria: either an increase in ejection fraction (EF) ≥10% or a reduction in left ventricular (LV) end-systolic volume ≥10%. Baseline characteristics including peak oxygen uptake (V̇O₂) and isometric knee extensor muscle strength (IKEMS) were similar in both groups, but non-responders had lower EF and larger LV. During the ET program, neither group had exercise-related adverse event including life-threatening ventricular arrhythmia. Peak V̇O₂ and IKEMS were significantly improved in both groups and there was no significant difference in change in peak V̇O₂ or IKEMS between responders and non-responders. On multiple regression analysis, change in IKEMS was an independent predictor of change in peak V̇O₂, whereas the response to CRT was not.

Conclusions: In HF patients undergoing CRT implantation, ET safely improved exercise capacity regardless of response to CRT, suggesting that even advanced HF patients without response to CRT can possibly benefit from ET.

Catheter Ablation of Atrial Fibrillation in Patients With Heart Failure

Atrial fibrillation (AF) and heart failure (HF) both have become major cardiovascular epidemics, adversely affecting quality of life, decreasing longevity, and imparting a large economic burden on the healthcare system. Both share similar risk factors and frequently coexist, leading to increased morbidity and mortality relative to patients with either condition alone. Although evidence-based treatment guidelines for both diseases exist, consensus treatment strategies are less clear when AF and HF co-occur. Given the risks of antiarrhythmic drugs and their incomplete success in maintaining sinus rhythm, catheter ablation has become an increasingly popular alternative to pharmacologic rhythm control in symptomatic patients with AF with normal cardiac function. Although multiple studies have demonstrated the efficacy of catheter ablation in AF, studies examining the use of catheter ablation specifically in patients with HF have recently begun to emerge and provide some guidance in this group of patients. In this review, we examine the effects of catheter ablation of AF in patients with HF on maintenance of sinus rhythm, left ventricular ejection fraction, exercise capacity, quality of life, hospitalization, and mortality rates. Data regarding both HF with reduced ejection fraction and preserved ejection fraction are discussed.

Protein acetylation in skeletal muscle mitochondria is involved in impaired fatty acid oxidation and exercise intolerance in heart failure

BACKGROUND

Exercise intolerance is a common clinical feature and is linked to poor prognosis in patients with heart failure (HF). Skeletal muscle dysfunction, including impaired energy metabolism in the skeletal muscle, is suspected to play a central role in this intolerance, but the underlying mechanisms remain elusive. Lysine acetylation, a recently identified post-translational modification, has emerged as a major contributor to the derangement of mitochondrial metabolism. We thus investigated whether mitochondrial protein acetylation is associated with impaired skeletal muscle metabolism and lowered exercise capacity in both basic and clinical settings of HF.

METHODS

We first conducted a global metabolomic analysis to determine whether plasma acetyl-lysine is a determinant factor for peak oxygen uptake (peak VO₂ ) in HF patients. We then created a murine model of HF (n = 11) or sham-operated (n = 11) mice with or without limited exercise capacity by ligating a coronary artery, and we tested the gastrocnemius tissues by using mass spectrometry-based acetylomics. A causative relationship between acetylation and the activity of a metabolic enzyme was confirmed in in vitro studies.

RESULTS

The metabolomic analysis verified that acetyl-lysine was the most relevant metabolite that was negatively correlated with peak VO₂ (r = -0.81, P < 0.01). At 4 weeks post-myocardial infarction HF, a treadmill test showed lowered work (distance × body weight) and peak VO₂ in the HF mice compared with the sham-operated mice (11 ± 1 vs. 23 ± 1 J, P < 0.01; 143 ± 5 vs. 159 ± 3 mL/kg/min, P = 0.01; respectively). As noted, the protein acetylation of gastrocnemius mitochondria was 48% greater in the HF mice than the sham-operated mice (P = 0.047). Acetylproteomics identified the mitochondrial enzymes involved in fatty acid β-oxidation (FAO), the tricarboxylic acid cycle, and the electron transport chain as targets of acetylation. In parallel, the FAO enzyme (β-hydroxyacyl CoA dehydrogenase) activity and fatty acid-driven mitochondrial respiration were reduced in the HF mice. This alteration was associated with a decreased expression of mitochondrial deacetylase, Sirtuin 3, because silencing of Sirtuin 3 in cultured skeletal muscle cells resulted in increased mitochondrial acetylation and reduced β-hydroxyacyl CoA dehydrogenase activity.

CONCLUSIONS

Enhanced mitochondrial protein acetylation is associated with impaired FAO in skeletal muscle and reduced exercise capacity in HF. Our results indicate that lysine acetylation is a crucial mechanism underlying deranged skeletal muscle metabolism, suggesting that its modulation is a potential approach for exercise intolerance in HF.

Peak V'O2 is an independent predictor of survival in patients with cardiac amyloidosis

INTRODUCTION

Cardiopulmonary exercise testing (CPET) has repeatedly been reported to reliably predict adverse outcomes in different forms of heart failure. However, it has not been elucidated in detail in cardiac amyloidosis (CA). Therefore, we evaluated the predictive value of CPET parameters in patients with CA regarding disease severity and prediction of mortality.

METHODS

Twenty-seven consecutive patients with CA were assessed noninvasively, including electrocardiography, echocardiography, CPET, and laboratory tests. Clinical data were correlated with CPET findings. Univariate and multivariate analyses were performed to evaluate predictors of mortality.

RESULTS

Within median follow-up period of 38 (IQR 43) months 19 (70%) deaths occurred. Patient initially presented with signs and symptoms of congestive heart failure NYHA 3 (IQR 1), reduced exercise capacity (peak V'O₂ 15.2 mL/kg body weight) and inefficient ventilation in CPET (V'E/V'CO₂ slope (30 (IQR 3)), markedly elevated cardiac biomarkers (NT-proBNP 1791 (IQR 3249) ng/mL) and echocardiographic signs of morphological (septum thickness 18 (IQR 6) mm) and functional cardiac involvement (TAPSE 19 (IQR 8) mm). Patients with peak V'O₂ below median value presented with significantly longer QTc interval when compared to patients with peak V'O₂ above the median. Further these patients tend to have more pronounced impairment of longitudinal function as indicated by lower MAPSE, TAPSE, and elevation of cardiac biomarkers. Multivariate analysis revealed peak V'O₂ slope as the only independent predictor of survival.

CONCLUSIONS

We identified reduced peak V'O₂ as an independent predictor of mortality in patients with cardiac involvement in different forms of systemic amyloidosis.

Physical fitness and physical activity in fatigued and non-fatigued inflammatory bowel disease patients

OBJECTIVE

To assess physical fitness and physical activity in inflammatory bowel disease (IBD) patients and whether fatigue is associated with impaired physical fitness and impaired physical activity.

MATERIALS AND METHODS

Ten patients with quiescent IBD and fatigue (fatigue group [FG]) based on the Checklist Individual Strength-Fatigue score of ≥35 were matched for age (±5 years) and sex with a non-fatigue group (NFG) with IBD. Physical fitness was measured with a cyclo-ergometric-based maximal exercise test, a submaximal 6-min walk test, and a dynamometer test to quantify the isokinetic muscle strength of the knee extensors and flexors. Level of physical activity was measured with an accelerometer-based activity monitor.

RESULTS

The patients in both groups did not differ in regard to medication use, clinical characteristics, and body composition. However, medium-to-large effect sizes for impaired physical fitness (both cardiorespiratory fitness and muscle strength) and physical activity were seen between the patients in the FG and the NFG. Especially, intensity of physical activity was significantly lower in the FG patients compared with the NFG patients (effect size: 1.02; p = 0.037). Similar results were seen when outcomes of the FG and NFG were compared with reference values of the normal population.

CONCLUSION

Fatigued IBD patients show an impaired physical fitness and physical activity compared with non-fatigued IBD patients. This gives directions for a physical component in fatigue in IBD patients. Therefore, these new insights into fatigue indicate that these patients might benefit from an exercise program to improve physical fitness and physical activity.

Usefulness of anaerobic threshold to peak oxygen uptake ratio to determine the severity and pathophysiological condition of chronic heart failure

BACKGROUND

Anaerobic threshold (AT) and peak oxygen uptake (V˙O₂) are well known as indicators of severity and prognosis of heart failure. Since these parameters are regulated by many factors, multiple organ dysfunction may occur in chronic heart failure, and these two parameters would vary among patients. However, it is not clear whether AT and peak V˙O₂ deteriorate similarly. Therefore, we planned to compare the degree of deterioration of these two parameters using a ratio of AT and peak V˙O₂ (%AT/peak), and evaluated its significance in heart failure subjects.

METHODS

One hundred ninety-four stable heart failure patients who had optimal medical treatment for at least 3 months were enrolled. Cardiopulmonary exercise testing, echocardiography, and blood sampling were examined within one week. Since %AT/peak varied from 50.3% to 108.5%, we divided patients into tertiles of %AT/peak [Group A, 50.1-70.0 (n=112), Group B, 70.1-90.0 (n=64), Group C, 90.1-110.0 (n=18)], and compared factors relating with skeletal muscle and heart failure among these 3 groups.

RESULTS

In Group A, ratio of measured AT against predicted value (%AT) and measured peak V˙O₂ against predicted value (%peak V˙O₂) were similar (80.3±19.0% and 80.4±17.1%, respectively). Peak V˙O₂ became lower as %AT/peak increased (Group B; 65.6±14.8%, p<0.01 vs. Group A, Group C; 38.3±9.7%, p<0.01 vs. Group B). On the other hand, %AT in Group B (77.1±18.5%) was similar to Group A, and diminished in Group C (58.0±8.2%, p<0.05 vs. Group B). Peak work rate and lean body mass were smaller in Group B than those in Group A. Although, left ventricular ejection fraction and E/E' deteriorated in Group B compared with Group A, plasma B-type natriuretic peptide and estimated glomerular filtration rate stayed constant in Group B and deteriorated in Group C.

CONCLUSIONS

%AT/peak showed negative correlation with peak V˙O₂. In chronic heart failure, muscle weakness occurs at an early stage, and this can be evaluated using %AT/peak.