Evaluation of Skeletal Muscle Function and Effects of Early Rehabilitation during Acute Heart Failure: Rationale and Study Design

Age-Specific Changes in Physical Function in Patients with Acute Decompensated Heart Failure

Cardiac rehabilitation (CR) improves physical function in patients with acute decompensated heart failure (ADHF) and frailty. However, few studies have assessed physical function through multiple measures during hospitalization; moreover, the effect of age remains unclear. This study aimed to evaluate age-specific changes in physical function during the acute-phase treatment period in patients with ADHF. Patients with ADHF hospitalized between June 2018 and June 2023, who were aged ≥ 60 years and underwent CR, were included in the study. Physical function assessments at admission and discharge included grip strength, quadriceps isometric strength, short physical performance battery (SPPB), gait speed, and frailty. Changes in physical function from admission to discharge were assessed. The mean age of the 531 patients was 79.8 ± 9.0 years and 58% were male. Physical function at admission and discharge significantly decreased with age according to all measures. In patients aged ≥ 90 years, quadriceps isometric strength (0.27 ± 0.11 kgf/BW kg) and the SPPB score (4.5 ± 3.6 points) were severely impaired at admission. However, no significant differences were observed in changes in physical function according to age; the improvement in the SPPB score tended to increase with age (+1.7 ± 1.9, +2.3 ± 2.1, +2.2 ± 2.4, and +2.3 ± 1.8, in the 60-69-, 70-79-, 80-89-, and ≥ 90-year age groups, respectively). The improvement in frailty was similar in all groups. Although physical function declined with age, the changes in physical function were similar in patients with ADHF at any age above 60 years who underwent CR.

The Benefits of Early Rehabilitation for Patients With Acute Heart Failure Requiring IV Inotropic Drugs

OBJECTIVES

The benefits of early rehabilitation for patients with acute heart failure (HF) requiring IV inotropic drugs have yet to be determined. We investigated the association between early rehabilitation and short-term clinical outcomes in patients with acute HF requiring IV inotropic drugs.

DESIGN

Retrospective cohort study.

SETTING

This study used data including more than 90% of patients at a tertiary emergency hospital in Japan.

PATIENTS

This study included patients with acute HF who required IV inotropic drugs within 2 days of admission.

INTERVENTIONS

We compared patients who commenced rehabilitation within 2 days of admission (the early rehabilitation group) and those who did not (the control group).

MEASUREMENTS AND MAIN RESULTS

Propensity score matching was used to compare in-hospital mortality, 30-day all-cause and HF readmissions, length of stay, and Barthel Index (BI) at discharge between patients who received early rehabilitation and those who did not. Totally, 38,302 patients were eligible for inclusion; of these, 5,127 received early rehabilitation and 5,126 pairs were generated by propensity score matching. After propensity score matching, the patients who received early rehabilitation had a lower in-hospital mortality rate than those who did not (9.9% vs. 13.2%; p < 0.001). The relative risk (95% CI) of early rehabilitation for in-hospital mortality was 0.75 (0.67-0.83). Patients undergoing early rehabilitation exhibited a shorter mean length of stay (25.5 vs. 27.1; p < 0.001), lower 30-day all-cause (14.1% vs. 16.4%; p = 0.001) and HF (8.6% vs. 10.4%; p = 0.002) readmissions, and higher BI scores at discharge (68 vs. 67; p = 0.096). Consistent findings were observed across subgroups, including in patients 80 years old or older, those with a body mass index less than 18.5 kg/m 2 , and those with BI scores less than 60.

CONCLUSIONS

The early prescription of rehabilitation was associated with favorable short-term outcomes even for patients with acute HF requiring IV inotropic drugs.

Association of early acute-phase rehabilitation initiation on outcomes among patients aged ≥90 years with acute heart failure

BACKGROUND

Data on the potential benefit of acute-phase rehabilitation initiation in very old (aged ≥90) patients with acute heart failure (AHF) have been scarce.

METHODS

We retrospectively analyzed data from the Diagnosis Procedure Combination database, which is a nationwide inpatient database. This study included patients hospitalized for heart failure (HF) from January 2010 to March 2018, those aged ≥90 years, who had a length of stay of ≥3 days, New York Heart Association (NYHA) class of ≥II, and had not undergone major procedures under general anesthesia. Propensity score matching and generalized linear models were used to compare in-hospital mortality, length of stay, 30-day readmission rate due to HF, all-cause 30-day readmission, and improvement in activities of daily living (ADL) between patients with and without an acute-phase rehabilitation initiation, which is defined as the rehabilitation initiation within 2 days after hospital admission.

RESULTS

Acute-phase rehabilitation was initiated in 8588 of 41,896 eligible patients. Propensity score matching created 8587 pairs. Patients with acute-phase rehabilitation initiation have lower in-hospital mortality (9.0% vs. 11.2%, p < 0.001). Acute-phase rehabilitation initiation was associated with lower in-hospital mortality (odds ratio, 0.778; 95% confidence interval, 0.704-0.860). Patients with acute-phase rehabilitation initiation have a shorter median length of stay (17 days vs. 18 days, p < 0.001), lower 30-day readmission rate due to HF (5.5% vs. 6.4%, p = 0.011) and all-cause 30-day readmission (10.2% vs. 11.2%, p = 0.036), and better ADL improvement (49.7% vs. 46.9%, p < 0.001). Subgroup analysis revealed consistent results (sex, body mass index, NYHA class, and Barthel Index).

CONCLUSIONS

The acute-phase rehabilitation initiation was associated with improved short-term clinical outcomes in patients aged ≥90 years with AHF.

Relationship between high-sensitivity cardiac troponin T, B-type natriuretic peptide, and physical function in patients with heart failure

AIMS

High-sensitivity cardiac troponin T (hs-cTnT) and B-type natriuretic peptide (BNP) are associated with prognosis and severity in patients with heart failure (HF); however, their association with physical function is unclear. This study aimed to investigate whether hs-cTnT and BNP levels are associated with physical function in patients with HF.

METHODS AND RESULTS

Hs-cTnT, BNP, and physical function (maximal quadriceps isometric strength [QIS], usual gait speed, and 6-min walk distance [6MWD]) were evaluated in 363 consecutive patients with HF (median age, 70 [60-78] years). Patients were divided into four groups according to their median hs-cTnT and BNP levels. After adjusting for demographic characteristics, laboratory levels, and HF severity, higher hs-cTnT and BNP levels were significantly associated with lower physical function (log hs-cTnT, β = -0.162, P = 0.001, for maximal QIS; β = -0.175, P = 0.002, for usual gait speed, and β = -0.129, P = 0.004, for 6MWD; log BNP, β = -0.090, P = 0.092, for maximal QIS, β = 0.038, P = 0.516, for usual gait speed, and β = -0.108, P = 0.023, for 6MWD). In addition, the high hs-cTnT and high BNP group had significantly lower physical function (all P < 0.05) than the low hs-cTnT and low BNP group.

CONCLUSIONS

Higher hs-cTnT and BNP levels are both associated with lower physical function in patients with HF, but hs-cTnT levels showed a more consistent association. The combination of hs-cTnT and BNP may be effective for the stratification of physical function in patients with HF.

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

AIMS

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

METHODS AND RESULTS

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

CONCLUSION

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

Early cardiac rehabilitation for acute decompensated heart failure safely improves physical function (PEARL study): a randomized controlled trial

BACKGROUND

Improvements in the Short Physical Performance Battery (SPPB) rather than exercise tolerance reportedly lead to favorable prognosis in elderly patients with acute decompensated heart failure (ADHF). However, about 50% of heart failure shows heart failure with preserved ejection fraction, safe and effective interventions to improve SPPB for these types remain unclear. In addition, although a standard cardiac rehabilitation (CR) program for heart failure is widely used in Japan, whether this is sufficient to improve SPPB in elderly patients with ADHF remains unclear.

AIM

This study was to evaluate whether the addition of multidisciplinary physical interventions to the standard CR program would prove effective for improving SPPB among elderly patients with ADHF regardless types of heart failure.

DESING

Randomized, prospective study.

SETTING

Patients admitted to our hospital due to ADHF in Japan.

POPULATION

Elderly patients with ADHF between March 2019 and March 2020 were randomized to two groups, an Intervention group and a Control group.

METHODS

The Control group performed standard CR. The Intervention group received balance training and resistance training and used a cycling ergometer in addition to the standard CR program. The primary outcome was the improvement in SPPB after CR.

RESULTS

Seventy-five patients with ADHF were divided into the two groups (Intervention group, n=36; Control group, n=39). At baseline, both groups showed low physical performance and a high prevalence of frailty. Intervention size effect was an improvement in SPPB score of +2.2 (+3.7±1.1 vs. +1.5±1.7; p<0.001). Of the 3 components of SPPB, both gait speed and timed repeated chair rise were significantly improved in the Intervention group compared to the Control group, with intervention size effect of +0.76 and +0.94, respectively (p<0.001). Subgroup analysis of heart failure with preserved ejection fraction showed significant improvement in SPPB score in the Intervention group compared to the Control group (p<0.001).No adverse events were observed during the study period.

CONCLUSIONS

A multi-faceted intervention in addition to standard CR improved physical performance among elderly patients with ADHF regardless types of heart failure.

CLINICAL REHABILITATION IMPACT

We believe that use of a cycling ergometer and loadspecific resistance training provide specific CR for patients with ADHF during acute hospitalization and highlight the need for active intervention.

Research on Human Sports Rehabilitation Design Based on Object-Oriented Technology

In order to improve the effect of human motion rehabilitation, a design model of human motion rehabilitation based on object-oriented technology is proposed. The entire model design process includes the following steps. First, a visual dynamic tracking model for human motion rehabilitation is established, and then a fuzzy PID (Proportion Integration Differentiation) superheterodyne control method is used to design the bone training control for human motion rehabilitation. The bone tracking control and adaptive training are under the control of object-oriented technology; it is analyzed by collecting human activity data during training. The 6-DOF kinematics problem of human movement rehabilitation is decomposed into the bone training control problem in the subspace. Combining object-oriented technology, visual blur recognition of human sports rehabilitation training, and adopting an adaptive kinematics model to design sports rehabilitation can improve the control convergence and global stability of the human sports rehabilitation process. The simulation results show that the method has a good overall steady state and the sports rehabilitation training effect is obvious.

Early rehabilitation in older patients hospitalized with acute decompensated heart failure: A retrospective cohort study

Although hospitalized patients with acute decompensated heart failure (ADHF) have severe physical dysfunction, little data are available on the comparative effectiveness of early versus late rehabilitation. This study examined the relationship between early compared to late rehabilitation and physical function among older patients hospitalized for ADHF.

METHODS

In a retrospective cohort study, independent patients aged ≥65 years at baseline who were hospitalized for ADHF from 2012 to 2014 and underwent inpatient rehabilitation were identified using Emergency Department visit data and electronic medical records at two hospitals. Patients were classified into those who underwent early rehabilitation (initiated within 72 hours of admission) and late rehabilitation (after 72 hours). Primary outcome was length of time from admission until the patient was able to walk independently. Multivariable competing-risk regression with death as the competing event was used to adjust for potential confounding factors, and multiple imputation (MI) analysis was performed.

RESULTS

Of 259 individuals, 30 (11.6%) commenced rehabilitation within 72 hours after admission while 229 (88.4%) did so 72 hours after admission. Patients who received early rehabilitation had a higher rate of unassisted walking for at least 40 m by 30 days after admission (hazard ratio: 8.03; 95% confidence interval: 2.15 to 29.98; P = .002 in the multivariable adjusted model) than those who received late rehabilitation. Similar findings were observed on MI analysis.

CONCLUSION

Early rehabilitation therapy commenced within 72 hours of admission was associated with a higher rate of recovery of an activity of daily living (independent walking on a level surface).

Iron status, catabolic/anabolic balance, and skeletal muscle performance in men with heart failure with reduced ejection fraction

BACKGROUND

Metabolic derangements related to tissue energetics constitute an important pathophysiological feature of heart failure. We investigated whether iron deficiency and catabolic/anabolic imbalance contribute to decreased skeletal muscle performance in men with heart failure with reduced ejection fraction (HFrEF), and whether these pathologies are related to each other.

METHODS

We comprehensively examined 23 men with stable HFrEF (median age [interquartile range]: 63 [59-66] years; left ventricular ejection fraction: 28 [25-35]%; New York Heart Association class I/II/III: 17/43/39%). We analyzed clinical characteristics, iron status, hormones, strength and fatigability of forearm flexors and quadriceps (surface electromyography), and exercise capacity (6-minute walking test).

RESULTS

None of the patients had anemia whereas 8 were iron-deficient. Flexor carpi radialis fatigability correlated with lower reticulocyte hemoglobin content (CHR, p < 0.05), and there was a trend towards greater fatigability in patients with higher body mass index and lower serum ferritin (both p < 0.1). Flexor carpi ulnaris fatigability correlated with lower serum iron and CHR (both p < 0.05). Vastus medialis fatigability was related to lower free and bioavailable testosterone (FT and BT, respectively, both p < 0.05), and 6-minute walking test distance was shorter in patients with higher cortisol/FT and cortisol/BT ratio (both p < 0.05). Lower ferritin and transferrin saturation correlated with lower percentage of FT and BT. Men with HFrEF and iron deficiency had higher total testosterone, but lower percentage of FT and BT.

CONCLUSIONS

Iron deficiency correlates with lower bioactive testosterone in men with HFrEF. These two pathologies can both contribute to decreased skeletal muscle performance in such patients.

Human motion component and envelope characterization via wireless wearable sensors

BACKGROUND

The characterization of limb biomechanics has broad implications for analyzing and managing motion in aging, sports, and disease. Motion capture videography and on-body wearable sensors are powerful tools for characterizing linear and angular motions of the body, though are often cumbersome, limited in detection, and largely non-portable. Here we examine the feasibility of utilizing an advanced wearable sensor, fabricated with stretchable electronics, to characterize linear and angular movements of the human arm for clinical feedback. A wearable skin-adhesive patch with embedded accelerometer and gyroscope (BioStampRC, MC10 Inc.) was applied to the volar surface of the forearm of healthy volunteers. Arms were extended/flexed for the range of motion of three different regimes: 1) horizontal adduction/abduction 2) flexion/extension 3) vertical abduction. Data were streamed and recorded revealing the signal "pattern" of movement in three separate axes. Additional signal processing and filtering afforded the ability to visualize these motions in each plane of the body; and the 3-dimensional motion envelope of the arm.

RESULTS

Each of the three motion regimes studied had a distinct pattern - with identifiable qualitative and quantitative differences. Integration of all three movement regimes allowed construction of a "motion envelope," defining and quantifying motion (range and shape - including the outer perimeter of the extreme of motion - i.e. the envelope) of the upper extremity. The linear and rotational motion results from multiple arm motions match measurements taken with videography and benchtop goniometer.

CONCLUSIONS

A conformal, stretchable electronic motion sensor effectively captures limb motion in multiple degrees of freedom, allowing generation of characteristic signatures which may be readily recorded, stored, and analyzed. Wearable conformal skin adherent sensor patchs allow on-body, mobile, personalized determination of motion and flexibility parameters. These sensors allow motion assessment while mobile, free of a fixed laboratory environment, with utility in the field, home, or hospital. These sensors and mode of analysis hold promise for providing digital "motion biomarkers" of health and disease.

NIRS-EMG for Clinical Applications: A Systematic Review

In this review, we present an overview of the applications and computed parameters of electromyography (EMG) and near-infrared spectroscopy (NIRS) methods on patients in clinical practice. The eligible studies were those where both techniques were combined in order to assess muscle characteristics from the electrical and hemodynamic points of view. With this aim, a comprehensive screening of the literature based on related keywords in the most-used scientific data bases allowed us to identify 17 papers which met the research criteria. We also present a brief overview of the devices designed specifically for muscular applications with EMG and NIRS sensors (a total of eight papers). A critical analysis of the results of the review suggests that the combined use of EMG and NIRS on muscle has been only partially exploited for assessment and evaluation in clinical practice and, thus, this field shows promises for future developments.