Movement therapy in lung transplantation candidates assisted by a lightweight wearable robot.

The aim of this pilot-study was to investigate the safety, feasibility and tolerability of an assisted mobilization of patients with advanced pulmonary diseases, using a lightweight, exoskeleton-type robot (Myosuit, MyoSwiss AG, Zurich, Switzerland). Ten patients performed activities of daily life (ADL) both with and without the device. The mean age was 53.6 (±5.6) years; 70% were male. The assessment of outcome included the evaluation of vital signs, adverse events, rates of perceived exertion and dyspnea (PRE, PRD), the ability to perform ADL and the individual acceptability. Robotic-assisted mobilization was feasible in all patients. No adverse events occurred. RPE and RPD showed no significant difference with or without the Myosuit (mean difference in RPE -1.7, 95%-confidence interval (CI) -1.16, 4.49; p = 0.211; mean difference in RPD 0.00, 95%-CI -1.88, 1.88; p = 0.475). 80% of patients were interested to participate in a robotic-assisted training on a regular basis. A robotic exoskeleton-assisted mobilization is safe, feasible, well-tolerated and well-accepted. The results are highly encouraging to further pursue this highly innovative approach.

Supervised exercise training in patients with advanced heart failure and left ventricular assist device: A multicentre randomized controlled trial (Ex-VAD trial).

AIMS: Small studies and observations suggested that exercise training may improve peak oxygen consumption (peakVO2 ) in patients with advanced heart failure and left ventricular assist device (LVAD). We investigated whether in this patient group a supervised exercise training can improve exercise capacity. METHODS AND RESULTS: In this multicentre, prospective, randomized, controlled trial, patients with stable heart failure and LVAD were randomly assigned (2:1) to 12 weeks of supervised exercise training or usual care, with 12 weeks of follow-up. The primary endpoint was the change in peakVO2 after 12 weeks (51 patients provided a power of 90% with an expected group difference in peakVO2 of 3 ml/kg/min). Secondary endpoints included changes in submaximal exercise capacity and quality of life. Among 64 patients enrolled (97% male, mean age 56 years), 54 were included in the analysis. Mean difference in the change of peakVO2 after 12 weeks was 0.826 ml/min/kg (95% confidence interval [CI] -0.37, 2.03; p = 0.183). There was a positive effect of exercise training on 6-min walk distance with a mean increase in the intervention group by 43.4 m (95% CI 16.9, 69.9; p = 0.0024), and on the Kansas City Cardiomyopathy Questionnaire physical domain score (mean 14.3, 95% CI 3.7, 24.9; p = 0.0124), both after 12 weeks. The overall adherence was high (71%), and there were no differences in adverse events between groups. CONCLUSION: In patients with advanced heart failure and LVAD, 12 weeks of exercise training did not improve peakVO2 but demonstrated positive effects on submaximal exercise capacity and physical quality of life.

Left atrial strain predicts exercise capacity in heart failure independently of left ventricular ejection fraction.

AIMS: We hypothesized that left atrial (LA) remodelling and function are associated with poor exercise capacity as prognostic marker in chronic heart failure (CHF) across a broad range of left ventricular ejection fraction (LVEF). METHODS AND RESULTS: One hundred seventy-one patients with CHF were analysed [age 65 ± 11 years, 136 males (80%); 86 heart failure with reduced ejection fraction (HFrEF), 27 heart failure with mid-range ejection fraction (HFmrEF), 58 heart failure with preserved ejection fraction (HFpEF)]. All patients underwent echocardiography and maximal cardiopulmonary exercise testing and were classified according to a prognostic cut-off of peak VO2 (pVO2 ; 14 mL/kg/min). Seventy-seven (45%) patients reached pVO2  < 14 and 94 (55%) pVO2  ≥ 14 mL/kg/min. Between the two groups, there was a considerable difference in both left atrial volume (LAVi, 53 ± 24 vs. 44 ± 18 mL/m2 , P = 0.005) and function (LA reservoir strain 12 ± 5 vs. 20 ± 10%, P < 0.0001). Receiver-operating characteristic curves identified LA reservoir strain (area under the curve: 0.73 [0.65-0.80], P < 0.0001) as strong predictor for impaired pVO2 among all echocardiographic variables; LA reservoir strain < 23% had 37% specificity but a very high sensitivity (96%) in identifying a severely reduced pVO2 . In logistic regression analysis, LA reservoir strain < 23% was associated with a highly increased risk of pVO2  < 14 mL/kg/min (odds ratio 16.0 [4.7-54.6]; P < 0.0001). The multivariate analysis showed that a reduced LA reservoir strain was associated with pVO2  < 14 mL/kg/min after adjustment for age, body mass index (BMI), and clinical variables, that is, New York Heart Association class, atrial fibrillation, haemoglobin, and creatinine (b 0.22 [95% confidence interval, CI, 0.12-0.31]; P < 0.0001), and after adjustment for echocardiographic variables, that is, LVEF or left ventricular global longitudinal strain (LVGLS) and tricuspid annular plane systolic excursion (TAPSE) (b 0.16 [95% CI 0.08-0.24]; P < 0.0001). Patients with HFrEF, HFmrEF, and HFpEF were separately analysed. Among LA reservoir strain, LAVi, LVEF, LVGLS, and TAPSE, LA reservoir strain was the only one significantly associated with pVO2 in all subgroups (after adjustment for sex and BMI, P = 0.003, 0.04, and 0.01, respectively). CONCLUSIONS: In patients with CHF, an impaired LA reservoir function is independently associated with a severely reduced pVO2 . LA dysfunction represents a marker of poor prognosis across LVEF borders in the CHF population.

Movement therapy in advanced heart failure assisted by a lightweight wearable robot: a feasibility pilot study.

AIMS: The aim of this pilot study was to investigate the safety, feasibility, tolerability, and acceptability of an assisted mobilization of advanced heart failure patients, using a lightweight, exoskeleton-type robot (Myosuit, MyoSwiss AG, Zurich, Switzerland). METHODS AND RESULTS: Twenty patients in functional NYHA class III performed activities of daily life (ADL, n = 10) or participated in a single, standardized, 60 min rehabilitation exercise unit (REU, n = 10) with and without the Myosuit. The outcome assessment included the evaluation of vital signs, adverse events, rates of perceived exertion and dyspnoea (RPE, RPD), the ability to perform ADL or REU, and the individual acceptability. The mean age of the subjects was 49.4 (±11.0) years; 80% were male. The mean left ventricular ejection fraction was 22.1% (±7.4%) and the median NT-proBNP 2054 pg/mL (IQR 677, 3270 pg/mL). In all patients, mobilization with the Myosuit was feasible independently or with minor support. The mean individual difference in the total walking distance of the patients without and with robotic assistance was -26.5 m (95% confidence interval (CI) -142 to 78 m, P = 0.241). No adverse events occurred. RPE and RPD showed no significant difference with or without the device (ADL: RPE -0.1 m, 95% CI -1.42 to 1.62, P = 0.932 and RPD -0.95 m, 95% CI -0.38 to 2.28, P = 0.141; REU: RPE 1.1 m, 95% CI -2.90 to 0.70, P = 0.201 and RPD 0.5 m, 95% CI -2.02 to 1.02, P = 0.435). All median responses in the acceptability questionnaire were positive. The patients felt safe and enjoyed the experience; 85% would be interested in participating in robot-assisted training on a regular basis. CONCLUSION: This feasibility pilot trial provides first indications that a robotic exoskeleton-assisted mobilization of patients with advanced heart failure is safe, feasible, well-tolerated, and well-accepted. The results are highly encouraging to further pursue this innovative approach in rehabilitation programmes. This trial was registered at ClinicalTrials.gov: NCT04839133.

Nitric oxide metabolites: associations with cardiovascular biomarkers and clinical parameters in patients with HFpEF.

AIMS: Heart failure with preserved ejection fraction (HFpEF) is one of the most rapidly growing cardiovascular health burden worldwide, but there is still a lack of understanding about the HFpEF pathophysiology. The nitric oxide (NO) signalling pathway has been identified as a potential key element. The aim of our study was to investigate markers of NO metabolism [l-arginine (l-Arg), homoarginine (hArg), and asymmetric and symmetric dimethylarginine (ADMA and SDMA)], additional biomarkers [N-terminal pro-B-type natriuretic peptide (NT-proBNP), endothelin-1 (ET-1), mid-regional pro-adrenomedullin (MR-proADM), copeptin, and high-sensitivity C-reactive protein (hsCRP)], and the endothelial function in an integrated approach focusing on associations with clinical characteristics in patients with HFpEF. METHODS AND RESULTS: Seventy-three patients, prospectively enrolled in the 'German HFpEF Registry', were analysed. Inclusion criteria were left ventricular ejection fraction (LVEF) ≥ 50%; New York Heart Association functional class ≥ II; elevated levels of NT-proBNP > 125 pg/mL; and at least one additional criterion for structural heart disease or diastolic dysfunction. All patients underwent transthoracic echocardiography, cardiopulmonary exercise testing, and pulse amplitude tonometry (EndoPAT™). Patients were categorized in two groups based on their retrospectively calculated HFA-PEFF score. Serum concentrations of l-Arg, hArg, ADMA, SDMA, NT-proBNP, ET-1, MR-proADM, copeptin, and hsCRP were determined. Patients had a median age of 74 years, 47% were female, and median LVEF was 57%. Fifty-two patients (71%) had an HFA-PEFF score ≥ 5 (definitive HFpEF), and 21 patients (29%) a score of 3 to 4 (risk for HFpEF). Overall biomarker concentrations were 126 ± 32 µmol/L for l-Arg, 1.67 ± 0.55 µmol/L for hArg, 0.74 (0.60;0.85) µmol/L for SDMA, and 0.61 ± 0.10 µmol/L for ADMA. The median reactive hyperaemia index (RHI) was 1.55 (1.38;1.87). SDMA correlated with NT-proBNP (r = 0.291; P = 0.013), ET-1 (r = 0.233; P = 0.047), and copeptin (r = 0.381; P = 0.001). ADMA correlated with ET-1 (r = 0.250; P = 0.033) and hsCRP (r = 0.303; P = 0.009). SDMA was associated with the left atrial volume index (ß = 0.332; P = 0.004), also after adjustment for age, sex, and comorbidities. Biomarkers were non-associated with the RHI. A principal component analysis revealed two contrary clusters of biomarkers. CONCLUSIONS: Our findings suggest an impaired NO metabolism as one possible key pathogenic determinant in at least a subgroup of patients with HFpEF. We argue for further evaluation of NO-based therapies. Upcoming studies should clarify whether subgroups of HFpEF patients can take more benefit from therapies that are targeting NO metabolism and pathway.

Evaluation of the HFA-PEFF Score: results from the prospective DIAST-CHF cohort.

AIMS: Although the number of patients suffering from heart failure with preserved ejection fraction (HFpEF) increases, the routine diagnosis remains a challenge. In the absence of a pathognomonic sign for HFpEF or specific treatment strategies, a prognosis-based characterization of suspected patients remains promising for both the risk stratification of the patients and a disease definition. The Heart Failure Association (HFA) of the European Society of Cardiology has introduced an algorithm with different levels of likelihood regarding the diagnosis of HFpEF, the HFA-PEFF score. We aimed to evaluate the predictive value of this algorithm in a large cohort regarding mortality, symptom burden, and the functional status. METHODS AND RESULTS: DIAST-CHF is a multicentre, population-based, prospective, observational study in subjects with at least one risk factor for HFpEF between the age of 50 and 85. We calculated the HFA-PEFF score (n = 1668) and analysed the risk groups for overall mortality, cardiovascular hospitalization, and submaximal functional capacity (6-min walk distance) at baseline and after a follow-up period of 10 years. Patients with high HFA-PEFF score values 5&6 showed a higher mortality than those with an intermediate score (score values 2-4) and low score values (high 21.3% vs. intermediate 10.1% vs. low 4.3%, P < 0.001). Also, the burden of MACE (death, cardiovascular hospitalization, new myocardial infarction, first diagnosis of HF) was increased in the high score values group (high 40.7% vs. intermediate 25.9% vs. low 13.9%, P < 0.001). Similarly, patients with higher scores had higher cumulative incidences of cardiovascular hospitalizations (P = 0.011). Subjects with higher scores also had lower 6-min walk distance both at baseline and during follow-up. CONCLUSIONS: The HFA-PEFF score provides a reliable instrument to stratify suspected HFpEF patients by their risk for mortality, symptom burden, and functional status in cohort at risk with a follow-up period of 10 years. As high HFA-PEFF scores are associated with worse outcome, the HFA-PEFF algorithm describes a defining approach towards HFpEF.

Peak O2 -pulse predicts exercise training-induced changes in peak V̇O2 in heart failure with preserved ejection fraction.

AIMS: Exercise training (ET) has been consistently shown to increase peak oxygen consumption (V̇O2 ) in patients with heart failure with preserved ejection fraction (HFpEF); however, inter-individual responses vary significantly. Because it is unlikely that ET-induced improvements in peak V̇O2 are significantly mediated by an increase in peak heart rate (HR), we aimed to investigate whether baseline peak O2 -pulse (V̇O2  × HR-1 , reflecting the product of stroke volume and arteriovenous oxygen difference), not baseline peak V̇O2 , is inversely associated with the change in peak V̇O2 (adjusted by body weight) following ET versus guideline control (CON) in patients with HFpEF. METHODS AND RESULTS: This was a secondary analysis of the OptimEx-Clin (Optimizing Exercise Training in Prevention and Treatment of Diastolic Heart Failure, NCT02078947) trial, including all 158 patients with complete baseline and 3 month cardiopulmonary exercise testing measurements (106 ET, 52 CON). Change in peak V̇O2 (%) was analysed as a function of baseline peak V̇O2 and its determinants (absolute peak V̇O2 , peak O2 -pulse, peak HR, weight, haemoglobin) using robust linear regression analyses. Mediating effects on change in peak V̇O2 through changes in peak O2 -pulse, peak HR and weight were analysed by a causal mediation analysis with multiple correlated mediators. Change in submaximal exercise tolerance (V̇O2 at the ventilatory threshold, VT1) was analysed as a secondary endpoint. Among 158 patients with HFpEF (66% female; mean age, 70 ± 8 years), changes in peak O2 -pulse explained approximately 72% of the difference in changes in peak V̇O2 between ET and CON [10.0% (95% CI, 4.1 to 15.9), P = 0.001]. There was a significant interaction between the groups for the influence of baseline peak O2 -pulse on change in peak V̇O2 (interaction P = 0.04). In the ET group, every 1 mL/beat higher baseline peak O2 -pulse was associated with a decreased mean change in peak V̇O2 of -1.45% (95% CI, -2.30 to -0.60, P = 0.001) compared with a mean change of -0.08% (95% CI, -1.11 to 0.96, P = 0.88) following CON. None of the other factors showed significant interactions with study groups for the change in peak V̇O2 (P > 0.05). Change in V̇O2 at VT1 was not associated with any of the investigated factors (P > 0.05). CONCLUSIONS: In patients with HFpEF, the easily measurable peak O2 -pulse seems to be a good indicator of the potential for improving peak V̇O2 through exercise training. While changes in submaximal exercise tolerance were independent of baseline peak O2 -pulse, patients with high O2 -pulse may need to use additional therapies to significantly increase peak V̇O2 .