Six minute corridor walk test as an outcome measure for the assessment of treatment in randomized, blinded intervention trials of chronic heart failure: a systematic review

Heart rate reactivity, recovery, and endurance of the incremental shuttle walk test in patients prone to heart failure

AIMS

Few randomized trials assessed the changes over time in the chronotropic heart rate (HR) reactivity (CHR), HR recovery (HRR) and exercise endurance (EE) in response to the incremental shuttle walk test (ISWT). We addressed this issue by analysing the open HOMAGE (Heart OMics in Aging) trial.

METHODS

In HOMAGE, 527 patients prone to heart failure were randomized to usual treatment with or without spironolactone (25-50 mg/day). The current sub-study included 113 controls and 114 patients assigned spironolactone (~70% on beta-blockers), who all completed the ISWT at baseline and at Months 1 and 9. Within-group changes over time (follow-up minus baseline) and between-group differences at each time point (spironolactone minus control) were analysed by repeated measures ANOVA, unadjusted or adjusted for sex, age and body mass index, and additionally for baseline for testing 1 and 9 month data.

RESULTS

Irrespective of randomization, the resting HR and CHR did not change from baseline to follow-up, with the exception of a small decrease in the HR immediately post-exercise (-3.11 b.p.m.) in controls at Month 9. In within-group analyses, HR decline over the 5 min post-exercise followed a slightly lower course at the 1 month visit in controls and at the 9 month visits in both groups, but not at the 1 month visit in the spironolactone group. Compared with baseline, EE increased by two to three shuttles at Months 1 and 9 in the spironolactone group but remained unchanged in the control group. In the between-group analyses, irrespective of adjustment, there were no HR differences at any time point from rest up to 5 min post-exercise or in EE. Subgroup analyses by sex or categorized by the medians of age, left ventricular ejection fraction or glomerular filtration rate were confirmatory. Combining baseline and Months 1 and 9 data in both treatment groups, the resting HR, CHR and HRR at 1 and 5 min averaged 61.5, 20.0, 9.07 and 13.8 b.p.m. and EE 48.3 shuttles.

CONCLUSIONS

Spironolactone on top of usual treatment compared with usual treatment alone did not change resting HR, CHR, HRR and EE in response to ISWT. Beta-blockade might have concealed the effects of spironolactone. The current findings demonstrate that the ISWT, already used in a wide variety of pathological conditions, is a practical instrument to measure symptom-limited exercise capacity in patients prone to developing heart failure because of coronary heart disease.

Assessment of Mobility Trajectories Using Wearable Inertial Sensors During Autologous Hematopoietic Cell Transplant

OBJECTIVE

This study aimed to characterize mobility patterns using wearable inertial sensors and serial assessment across autologous hematopoietic cell transplant (autoHCT) and investigate the relation between mobility and perceived function in patients with hematologic cancer.

DESIGN

Prospective longitudinal study.

SETTING

Hospital adult transplant clinic followed by discharge.

PARTICIPANTS

78 patients with hematological cancer receiving autoHCT.

MAIN OUTCOME MEASURES

Mobility was measured across 3 clinical phases (pretransplant, pre-engraftment, and post-engraftment) in using inertial sensors worn during prescribed performance tests in the hospital. Perceived function was assessed using validated provider-reported (Eastern Cooperative Oncology Group [ECOG] Performance Status Scale) and patient-reported [European Organization for Research and Treatment of Cancer Quality of Life Questionnaire [EORTC QLQ-C30]) measures. Trajectories of 5 selected mobility characteristics (turn duration, gait speed, stride time variability, double support time, and heel strike angle) across the clinical phases were also evaluated using piecewise linear mixed-effects models.

RESULTS

Using Principal Components Analysis, 4 mobility patterns were identified pretransplant: Gait Limitation, Sagittal Sway, Coronal Sway, and Balance Control. Gait Limitation measured pretransplant was significantly inversely associated with perceived function reported by the provider- (β = -0.11; 95% CI: -0.19, -0.02) and patient- (β = -4.85; 95% CI: -7.72, -1.99) post-engraftment in age-adjusted linear regression models. Mobility characteristics demonstrated immediate declines early pre-engraftment with stabilization by late pre-engraftment.

CONCLUSION

Patients with hematological cancer experiencing gait limitations pretransplant are likely to have worse perceived function post-engraftment. Mobility declines in early phases post-transplant and may not fully recover, indicating an opportunity for timely rehabilitation referrals. Wearable inertial sensors can be used to identify early mobility problems and patients who may be at risk for future functional decline who may be candidates for early physical rehabilitation.

Effect of Dapagliflozin Versus Placebo on Symptoms and 6-Minute Walk Distance in Patients With Heart Failure: The DETERMINE Randomized Clinical Trials

BACKGROUND

Sodium-glucose cotransporter 2 inhibitors reduce the risk of worsening heart failure (HF) and cardiovascular death in patients with HF irrespective of left ventricular ejection fraction. It is important to determine whether therapies for HF improve symptoms and functional capacity.

METHODS

The DETERMINE (Dapagliflozin Effect on Exercise Capacity Using a 6-Minute Walk Test in Patients With Heart Failure) double-blind, placebo-controlled, multicenter trials assessed the efficacy of the sodium-glucose cotransporter 2 inhibitor dapagliflozin on the Total Symptom Score (TSS) and Physical Limitation Scale (PLS) of the Kansas City Cardiomyopathy Questionnaire (KCCQ) and 6-minute walk distance (6MWD) in 313 patients with HF with reduced ejection fraction (DETERMINE-Reduced) and in 504 patients with HF with preserved ejection fraction (DETERMINE-Preserved) with New York Heart Association class II or III symptoms and elevated natriuretic peptide levels. The primary outcomes were changes in the KCCQ-TSS, KCCQ-PLS, and 6MWD after 16 weeks of treatment.

RESULTS

Among the 313 randomized patients with HF with reduced ejection fraction, the median placebo-corrected difference in KCCQ-TSS from baseline at 16 weeks was 4.2 (95% CI, 1.0, 8.2; P=0.022) in favor of dapagliflozin. The median placebo-corrected difference in KCCQ-PLS was 4.2 (95% CI, 0.0, 8.3; P=0.058). The median placebo-corrected difference in 6MWD from baseline at 16 weeks was 3.2 meters (95% CI, -6.5, 13.0; P=0.69). In the 504 patients with HF with preserved ejection fraction, the median placebo-corrected 16-week difference in KCCQ-TSS and KCCQ-PLS was 3.2 (95% CI, 0.4, 6.0; P=0.079) and 3.1 (-0.1, 5.4; P=0.23), respectively. The median 16-week difference in 6MWD was 1.6 meters (95% CI, -5.9, 9.0; P=0.67). In an exploratory post hoc analysis of both trials combined (DETERMINE-Pooled), the median placebo-corrected difference from baseline at 16 weeks was 3.7 (1.5, 5.9; P=0.005) for KCCQ-TSS, 4.0 (0.3, 4.9; P=0.036) for KCCQ-PLS, and 2.5 meters (-3.5, 8.4; P=0.50) for 6MWD.

CONCLUSIONS

Dapagliflozin improved the KCCQ-TSS in patients with HF with reduced ejection fraction but did not improve KCCQ-PLS or 6MWD. Dapagliflozin did not improve these outcomes in patients with HF with preserved ejection fraction. In a post hoc analysis including all patients across the full spectrum of ejection fraction, there was a beneficial effect of dapagliflozin on KCCQ-TSS and KCCQ-PLS but not 6MWD.

REGISTRATION

URL: https://www.clinicaltrials.gov; Unique identifiers: NCT03877237 and NCT03877224.

Systematic Review of the Use of the 6-Minute Walk Test in Measuring and Improving Prognosis in Patients With Ischemic Heart Disease

Introduction

The 6-minute walk test (6MWT) has been used for over 30 years to assess exercise capacity in patients with respiratory disease, and more recently, in those with heart failure. However, despite being a simple and reproducible test of real-world exercise capacity, its use in patients with ischemic heart disease (IHD) is less well accepted. We sought to review systematically the evidence surrounding the 6MWT in IHD.

Methods

We searched the Medline, PubMed, Embase, and Scopus databases for the following key terms: "six minute walk test/6 minute walk test/6MWT" and "angina/coronary artery disease/coronary disease/IHD/ischemic heart disease." We followed Preferred Reporting Items for Systematic Reviews and Meta-analysis (PRISMA) guidelines to select publications for full-text review and analyzed the collated data.

Results

A total of 1228 unique papers were found, of which 71 were chosen for full-text review and 37 for detailed analysis. Most (23) concerned the effect on 6MWT distance (6MWTd) of cardiac rehabilitation, with measurements commenced after an intervention (acute myocardial infarction, n = 4; open heart surgery (OHS), n = 5; percutaneous coronary intervention (PCI), n = 3; or other, n = 11). The effect on 6MWTd of OHS was investigated in 6 studies and of PCI in one study. The 6MWT is a useful measurement of physical capacity; data are limited on its ability to assess benefit following PCI.

Conclusions

The 6MWT has been studied inconsistently in IHD. The majority of data are on patients before and after CR. Data are limited concerning the effect on 6MWTd of OHS or PCI. The available data support the 6MWT as a measure of change in performance status following coronary intervention. More work is required to confirm this hypothesis.

No-Implant Interatrial Shunt for HFpEF: 6-Month Outcomes From Multicenter Pilot Feasibility Studies

BACKGROUND

Most approaches to the creation of an interatrial shunt require placement of a permanent implant to maintain patency.

OBJECTIVES

The goal of this study was to investigate the safety and efficacy of a no-implant interatrial shunt for patients with heart failure with preserved ejection fraction (HFpEF) and heart failure with mildly reduced ejection fraction (HFmrEF).

METHODS

This was a multicenter, uncontrolled study of patients with HFpEF/HFmrEF and NYHA functional class ≥II, ejection fraction >40%, and pulmonary capillary wedge pressure (PCWP) during supine exercise ≥25 mm Hg with PCWP-to-right atrial gradient ≥5 mm Hg. Follow-up was through 6 months with imaging to assess shunt durability.

RESULTS

A total of 28 patients were enrolled: mean age was 68 ± 9 years, and 68% were female. Baseline resting and peak exercise PCWP were 19 ± 7 mm Hg and 40 ± 11 mm Hg, respectively. All procedures displayed technical success with confirmation of left-to-right flow (shunt diameter 7.1 ± 0.9 mm). At 1 month, peak exercise PCWP decreased 5.4 ± 9.6 mm Hg (P = 0.011) with no change in right atrial pressure. There were no serious device or procedure-related adverse events through 6 months. Mean 6-minute walk distance increased 101 ± 71 meters (P < 0.001); Kansas City Cardiomyopathy Questionnaire Overall Summary Score increased 26 ± 19 points (P < 0.001); N-terminal pro-B-type natriuretic peptide decreased 372 ± 857 pg/mL (P = 0.018); and shunt patency was confirmed with unchanged diameter.

CONCLUSIONS

In these feasibility studies of a no-implant interatrial shunt, HFpEF/HFmrEF shunts exhibited stability with favorable safety and early efficacy signals. The results show promise toward this new approach for treating patients with HFpEF/HFmrEF and an appropriate hemodynamic profile. (Evaluation of the Safety and Feasibility of a Percutaneously Created Interatrial Shunt to Alleviate Heart Failure Symptoms in Patients With Chronic Heart Failure and Preserved or Mid-Range Left Ventricular Ejection Fraction [ALLEVIATE-HF-1]; NCT04583527; Evaluation of the Safety and Effectiveness of a Percutaneously Created Interatrial Shunt to Alleviate Heart Failure Symptoms in Patients With Chronic Heart Failure and Preserved or Mid-Range Left Ventricular Ejection Fraction [ALLEVIATE-HF-2]; NCT04838353).

Bone Marrow Mesenchymal Stem Cells for Heart Failure Treatment: A Systematic Review and Meta-Analysis

AIM

Bone marrow-derived mesenchymal stem cells (BM-MSCs) are the most well-studied and characterised stem cell types. This review was undertaken of the current available phase II/III randomised clinical trials (RCTs) that delivered BM-MSCs to treat patients with cardiomyopathy, and to assess their performance.

METHODS

The Preferred Reporting Items for Systematic Reviews and Meta-Analysis guidelines were followed during the systematic review and meta-analysis. Eligible studies were reviewed, and their data charted. To assess the efficacy of BM-MSCs, the outcome was improvement in left ventricular ejection fraction (LVEF) and 6-minute walking distance (6MWD).

RESULTS

The pooled weighted mean difference (WMD) showed that BM-MSCs treatment improved the 6MWD by 27.86 m (95% CI 0.11-55.6 m) compared with the control groups. The pooled WMD showed that BM-MSCs treatment improved the LVEF by 6.37% (95% CI 5.48%-7.26%) compared with the control groups.

CONCLUSION

BM-MSCs treatment is an effective intervention for managing patients with heart failure, but it requires larger and more robust clinical trials to support its routine use in clinics.

Cardiac MRI-based right-to-left ventricular blood pool T2 relaxation times ratio correlates with exercise capacity in patients with chronic heart failure

BACKGROUND

MRI T2 mapping has been proven to be sensitive to the level of blood oxygenation. We hypothesized that impaired exercise capacity in chronic heart failure is associated with a greater difference between right (RV) to left ventricular (LV) blood pool T2 relaxation times due to a higher level of peripheral blood desaturation, compared to patients with preserved exercise capacity and to healthy controls.

METHODS

Patients with chronic heart failure (n = 70) who had undergone both cardiac MRI (CMR) and a 6-min walk test (6MWT) were retrospectively identified. Propensity score matched healthy individuals (n = 35) served as control group. CMR analyses included cine acquisitions and T2 mapping to obtain blood pool T2 relaxation times of the RV and LV. Following common practice, age- and gender-adjusted nominal distances and respective percentiles were calculated for the 6MWT. The relationship between the RV/LV T2 blood pool ratio and the results from 6MWT were evaluated by Spearman's correlation coefficients and regression analyses. Inter-group differences were assessed by independent t-tests and univariate analysis of variance.

RESULTS

The RV/LV T2 ratio moderately correlated with the percentiles of nominal distances in the 6MWT (r = 0.66) while ejection fraction, end-diastolic and end-systolic volumes showed no correlation (r = 0.09, 0.07 and - 0.01, respectively). In addition, there were significant differences in the RV/LV T2 ratio between patients with and without significant post-exercise dyspnea (p = 0.001). Regression analyses showed that RV/LV T2 ratio was an independent predictor of the distance walked and the presence of post-exercise dyspnea (p < 0.001).

CONCLUSION

The proposed RV/LV T2 ratio, obtained by two simple measurements on a routinely acquired four-chamber T2 map, was superior to established parameters of cardiac function to predict exercise capacity and the presence of post-exercise dyspnea in patients with chronic heart failure.

Functional outcome after cardiac rehabilitation and its association with survival in heart failure across the spectrum of ejection fraction

BACKGROUND

There is limited evidence regarding the effects of cardiac rehabilitation (CR) in patients with heart failure and preserved ejection fraction (HFpEF).

METHODS

We studied 1784 patients admitted to inpatient CR. The patients were grouped into HFpEF (EF≥0.50), HF with mildly reduced EF (HFmrEF; EF 41-49), and HF with reduced EF (HFrEF; EF≤0.40). A standardized 6-min walking test was performed at admission and discharge. Measures of functional outcome were: (1) absolute increase in 6-min walking distance (6MWD) from admission to discharge >50 m and (2) increase in 6MWD to ≥300 among the patients who walked <300 m at admission.

RESULTS

After adjustment, the patients with HFpEF or HFmrEF were as likely as those with HFrEF to achieve an increase in 6MWD >50 m (odds ratio 0.95 [95%CI 0.71-1.24; p=0.648] and 1.04 [95%CI 0.77-1.41; p=0.769], respectively) or an increase in 6MWD to ≥300 m (odds ratio 0.79 [95%CI 0.51-1.23; p=0.299] and 0.65 [95%CI 0.38-1.12; p=0.118], respectively). The adjusted hazard ratio of 5-year mortality for patients who achieved an increase in 6MWD >50 m was 0.60 (95%CI 0.51-0.71; p<0.001) and that for patients who achieved an increase in 6MWD at discharge to ≥300 m 0.61 (95%CI 0.48-0.79; p<0.001). In each EF group, both outcomes remained independently associated with improved survival.

CONCLUSIONS

Our data suggest that patients with HFpEF or HFmrEF are as likely as those with HFrEF to benefit from CR in terms of functional improvement. Functional improvement was independently associated with improved long-term survival, regardless of EF.

Predicting hospitalization from real-world measures in patients with chronic kidney disease: A proof-of-principle study

Objective

To investigate if in-clinic measures of physical function and real-world measures of physical behavior and mobility effort are associated with one another and to determine if they predict future hospitalization in participants with chronic kidney disease (CKD).

Methods

In this secondary analysis, novel real-world measures of physical behavior and mobility effort, including the best 6-minute step count (B6SC), were derived from passively collected data from a thigh worn actigraphy sensor and compared to traditional in-clinic measures of physical function (e.g. 6-minute walk test (6MWT). Hospitalization status during 2 years of follow-up was determined from electronic health records. Correlation analyses were used to compare measures and Cox Regression analysis was used to compare measures with hospitalization.

Results

One hundred and six participants were studied (69  ±  13 years, 43% women). Mean  ±  SD baseline measures for 6MWT was 386  ±  66 m and B6SC was 524  ±  125 steps. Forty-four hospitalization events over 224 years of total follow-up occurred. Good separation was achieved for tertiles of 6MWT, B6SC and steps/day for hospitalization events. This pattern persisted in models adjusted for demographics (6MWT: HR  =  0.63 95% CI 0.43-0.93, B6SC: HR  =  0.75, 95% CI 0.56-1.02 and steps/day: HR  =  0.75, 95% CI 0.50-1.13) and further adjusted for morbidities (6MWT: HR  =  0.54, 95% CI 0.35-0.84, B6SC: HR  =  0.70, 95% CI 0.49-1.00 and steps/day: HR  =  0.69, 95% CI 0.43-1.09).

Conclusion

Digital health technologies can be deployed remotely, passively, and continuously to collect real-world measures of physical behavior and mobility effort that differentiate risk of hospitalization in patients with CKD.

Using Wearable Inertial Sensors to Assess Mobility of Patients With Hematologic Cancer and Associations With Chemotherapy-Related Symptoms Before Autologous Hematopoietic Stem Cell Transplant: Cross-sectional Study

BACKGROUND

Wearable sensors could be a simple way to quantify and characterize mobility in patients with hematologic cancer scheduled to receive autologous hematopoietic stem cell transplant (autoHSCT) and how they may be related to common treatment-related symptoms and side effects of induction chemotherapy.

OBJECTIVE

We aimed to conduct a cross-sectional study comparing mobility in patients scheduled to receive autoHSCT with that in healthy, age-matched adult controls and determine the relationships between patient mobility and chemotherapy-related symptoms.

METHODS

Patients scheduled to receive autoHSCT (78/156, 50%) and controls (78/156, 50%) completed the prescribed performance tests using wearable inertial sensors to quantify mobility including turning (turn duration and number of steps), gait (gait speed, stride time, stride time variability, double support time, coronal trunk range of motion, heel strike angle, and distance traveled), and balance (coronal sway, coronal range, coronal velocity, coronal centroidal frequency, sagittal sway, sagittal range, sagittal velocity, and sagittal centroidal frequency). Patients completed the validated patient-reported questionnaires to assess symptoms common to chemotherapy: chemotherapy-induced peripheral neuropathy (Functional Assessment of Cancer Therapy/Gynecologic Oncology Group-Neurotoxicity subscale), nausea and pain (European Organization for Research and Treatment of Cancer Quality of Life Questionnaire), fatigue (Patient-Reported Outcomes Measurement Information System Fatigue Short Form 8a), vertigo (Vertigo Symptom Scale-short form), and depression (Center for Epidemiological Studies-Depression). Paired, 2-sided t tests were used to compare mobility between patients and controls. Stepwise multivariable linear regression models were used to evaluate associations between patient mobility and symptoms.

RESULTS

Patients aged 60.3 (SD 10.3) years had significantly worse turning (turn duration; P<.001), gait (gait speed, stride time, stride time variability, double support time, heel strike angle, stride length, and distance traveled; all P<.001), and balance (coronal sway; P<.001, range; P<.001, velocity; P=.02, and frequency; P=.02; and sagittal range; P=.008) than controls. In patients, high nausea was associated with worse stride time variability (ß=.001; P=.005) and heel strike angle (ß=-.088; P=.02). Pain was associated with worse gait speed (ß=-.003; P=.003), stride time variability (ß=.012; P=.02), stride length (ß=-.002; P=.004), and distance traveled (ß=-.786; P=.005). Nausea and pain explained 17% to 33% and 14% to 36% of gait variance measured in patients, respectively.

CONCLUSIONS

Patients scheduled to receive autoHSCT demonstrated worse mobility in multiple turning, gait, and balance domains compared with controls, potentially related in part to nausea and pain. Wearable inertial sensors used in the clinic setting could provide granular information about mobility before further treatment, which may in turn benefit from rehabilitation or symptom management. Future longitudinal studies are needed to better understand temporal changes in mobility and symptoms across the treatment trajectory to optimally time, design, and implement strategies, to preserve functioning in patients with hematologic cancer in the long term.

Improvements in Efficacy Measures With Tafamidis in the Tafamidis in Transthyretin Cardiomyopathy Clinical Trial

Background

Transthyretin amyloid cardiomyopathy (ATTR-CM) is a fatal disease. Tafamidis was approved to treat patients with ATTR-CM based on findings from the ATTR-ACT (Tafamidis in Transthyretin Cardiomyopathy Clinical Trial).

Objectives

This post hoc analysis examined the proportion of patients who experienced improved efficacy measures through 30 months of treatment with tafamidis or placebo in ATTR-ACT.

Methods

Patients with ATTR-CM were randomized to tafamidis (80 mg or 20 mg) or placebo. Change from baseline in 6-minute walk test distance, Kansas City Cardiomyopathy Questionnaire Overall Summary score, N-terminal pro-B-type natriuretic peptide concentration, patient global assessment of overall health, and New York Heart Association functional class were assessed at regular time points. The proportion of patients with improvement was summarized for each time point with odds ratio. Missing data were imputed as deterioration.

Results

Higher proportions of tafamidis-treated patients (n = 264) than placebo-treated patients (n = 177) showed improvement in all assessments. The odds ratio for improvement favored tafamidis for all measures and at all time points. It was significant (P < 0.001) at month 30 for 6-minute walk test distance (4.9; 95% CI: 2.28-10.69), Kansas City Cardiomyopathy Questionnaire Overall Summary score (3.3; 95% CI: 1.85-5.78), N-terminal pro-B-type natriuretic peptide concentration (5.3; 95% CI: 2.66-10.73), and patient global assessment of overall health (2.9; 95% CI: 1.69-4.95).

Conclusions

This analysis found that higher proportions of patients treated with tafamidis experienced improvement from baseline in measures of heart failure, functional capacity, and health-related quality of life than those treated with placebo during ATTR-ACT. These data provide further evidence of the clinical benefits of tafamidis in patients with ATTR-CM. (Safety and Efficacy of Tafamidis in Patients With Transthyretin Cardiomyopathy [ATTR-ACT]; NCT01994889).

Guidelines for physical activity in children with heart disease

Justification

In recent years, there has been increasing recognition of children with heart disease in our country. These children belong to different age groups and have untreated, partially treated, or completely treated heart disease. The role of physical activity for optimal physical, emotional, and psychosocial well-being for children is well understood. There is a challenge for the parents and the medical professionals to take a decision regarding the type of physical activity safe for the child as heart disease may affect the hemodynamic demands. Most of the existing international guidelines focus on competitive sports in operated heart disease children. This may be of limited use when we have a mixed population of children with heart disease, different types of sports in our country and where a larger subset is looking for recommendations to leisure time activities.

Process

The Pediatric Cardiac Society of India decided to formulate recommendations for physical activity in children with heart diseases. A committee of experts, who were well-versed with the subject of physical activity in children with heart disease, volunteered to take up the task of writing the guidelines. The recommendations emerged following deliberations of the committee members, on the virtual platform as well as mails. The final version of manuscript was approved by all committee members and all members are co-authors of this manuscript. The different types of physical activities were defined including leisure sports and competitive sports. The exercise was classified based on the mechanical action of muscles involved into dynamic and static components. Each type of exercise was then classified based on the intensity into low, medium, and high. Recommendations for the type of physical activity for individual heart lesions were decided based on the rationale available.

Objectives

The recommendations here are made with an intention to provide general guidelines for physical activity in children with operated and unoperated heart diseases, not excluding a need for individualizing a plan, serial assessment, and comprehensive checkup in special situations.

Recommendations

We hope the recommendations mentioned below would provide basic clarity in planning physical activity in children with heart disease. This is with the hope to encourage physically active life, at the same time ensuring a safety net.

TNF-α Predicts Endothelial Function and Number of CD34+ Cells after Stimulation with G-CSF in Patients with Advanced Heart Failure

Patients with advanced heart failure (HF) have reduced cardiac output and impaired peripheral blood flow, which diminishes endothelial shear stress and consequently flow-mediated dilatation (FMD). The aim of our study was to find out whether endothelial dysfunction is associated with the number of CD34+ cells and TNF-α levels in patients with ischemic and non-ischemic HF after stimulation with granulocyte colony-stimulating factor (G-CSF). We included 56 patients with advanced HF (LVEF < 35%). Eighteen patients (32.14%) had ischemic and 38 (67.86%) patients had non-ischemic HF. FMD of the brachial artery was performed before the patients underwent 5-day bone marrow stimulation with daily subcutaneous injections of G-CSF (5 μg/kg bid). On the fifth day peripheral blood CD34+ cell count was measured. No statistically significant differences were found between the patient groups in NT-proBNP levels ((1575 (425−2439) vs. 1273 (225−2239)) pg/mL; p = 0.40), peripheral blood CD34+ cell count ((67.54 ± 102.32 vs. 89.76 ± 71.21) × 106; p = 0.32), TNF-α ((8.72 ± 10.30 vs. 4.96 ± 6.16) ng/mL; p = 0.13) and FMD (6.7 ± 5.4 vs. 7.2 ± 5.9%; p = 0.76). In a linear regression model, only FMD (p = 0.001) and TNF-α (p = 0.003) emerged as statistically significant predictors of CD34+ cells counts. Our study suggests that TNF-α is a good predictor of impaired endothelial function and of CD34+ cells mobilization after G-CSF stimulation in patients with advanced HF of ischemic and non-ischemic origin.

A PILOT CLINICAL TRIAL OF CELL THERAPY IN HEART FAILURE WITH PRESERVED EJECTION FRACTION

Aims

We investigated the effects of CD34⁺ cell therapy in patients with heart failure with preserved ejection fraction (HFpEF).

Methods and results

In a prospective pilot study, we enrolled 30 patients with HFpEF. In Phase 1, patients were treated with medical therapy for 6 months. Thereafter, all patients underwent CD34⁺ cell transplantation. Using electroanatomical mapping, we measured local mechanical diastolic delay and myocardial viability to guide the targeting of cell injections. Patients were followed for 6 months after cell transplantation (Phase 2), and the primary endpoint was the difference in change in E/e′ between Phase 1 and Phase 2. In Phase 1, the decrease in E/e′ was significantly less pronounced than in Phase 2 (−0.33 ± 1.72 vs. −3.77 ± 2.66, p = 0.001). During Phase 1, there was no significant change in global systolic strain (GLS; from −12.5 ± 2.4% to −12.8 ± 2.6%, p = 0.77), N‐terminal pro‐B‐type natriuretic peptide (NT‐proBNP; from 1463 ± 1247 pg/ml to 1298 ± 931 pg/ml, p = 0.31), or 6‐min walk test (6MWT; from 391 ± 75 m to 402 ± 93 m, p = 0.42). In Phase 2, an improvement was noted in NT‐proBNP (from 1298 ± 931 pg/ml to 887 ± 809 pg/ml, p = 0.02) and 6MWT (from 402 ± 93 m to 438 ± 72 m, p = 0.02). Although GLS did not change significantly in Phase 2 (from −12.8 ± 2.6% to −13.8 ± 2.7%, p = 0.36), we found improved local systolic strain at cell injection sites (−3.4 ± 6.8%, p = 0.005).

Conclusions

In this non‐randomized trial, transendocardial CD34⁺ cell therapy in HFpEF was associated with an improvement in E/e′, NT‐proBNP, exercise capacity, and local myocardial strain at the cell injection sites.

Clinical Trial Registration: ClinicalTrials.gov NCT02923609.

Prognostic value of functional capacity after transitional rehabilitation in older patients hospitalized for heart failure

BACKGROUND

Poor functional status is highly prevalent among older patients hospitalized for HF and marks a downward inflection point in functional and prognostic trajectories. We assessed the prognostic value of 6-min walk test after transitional cardiac rehabilitation in older patients hospitalized for heart failure (HF).

METHODS

We studied 759 patients aged ≥60 years who had been transferred to six inpatient rehabilitation facilities (IRF) from acute care hospitals after a hospitalization for acute HF. The primary outcome was 3-year all-cause mortality. We used multivariable Cox analysis to determine the association between 6-min walk distance (6MWD) at discharge from the IRFs and the primary outcome, adjusting for established predictors of death. The optimal cutoff for 6MWD was considered as the one that maximized the chi-square statistic.

RESULTS

Mean age was 75 ± 8 years. 6MWD significantly increased from admission to discharge (145 to 210 m; p < 0.001). The optimal cutoff for 6MWD was 198 m. After full adjustment, the hazard ratio for each 50 m-increase in discharge 6MWD was 0.90 (0.87-0.94; p < 0.001) and that for discharge 6MWD dichotomized at the optimal cutoff 0.48 (0.38-0.60; p < 0.001). The incidence rate of death/100 person-years for the patients who walked >198 m was 13.0 (10.0-15.5) compared with 30.8 (26.9-35.4) for those who walked <198 m. A statistically significant interaction of discharge 6MWD with left ventricular ejection fraction (EF) on the risk of death was observed (p value for interaction 0.047).

CONCLUSIONS

A rehabilitation intervention provided in the critical hospital-to-home transition period to older patients hospitalized for HF resulted in improved functional capacity. Increasing levels of functional capacity following rehabilitation were closely associated with decreasing risk of death; this association was significantly stronger for the subgroup with preserved EF.

Adjuvant testosterone therapy in chronic heart failure (ATTIC): a randomised open-label trial

INTRODUCTION

Heart failure is a major contributor to morbidity and mortality in the geriatric population, with no promising therapy currently available with considerable benefit. Testosterone therapy is an emerging viable treatment option given its beneficial effects, including improving cardiac functional capacity, alleviating symptoms and low cost, among others.

METHODS

We have planned an open-label, parallel design, 1:1 randomised controlled trial, which aims to recruit 986 adult males above the age of 60 diagnosed with chronic stable heart failure fulfilling the eligibility criteria. The participants will be randomised into 2 groups of 493 each. Both groups will receive standard recommended treatment regimen of chronic stable heart failure and intervention arm participants will receive additional testosterone gel. All participants will be assessed at baseline, 4 weeks, 6 weeks and 12 weeks. The primary endpoints will assess the differences in functional capacity, frailty and quality of life at 3 months compared with baseline. The secondary endpoints will include the mean change from baseline at 3 months in cardiac remodelling using echocardiography, serum brain natriuretic peptide levels, the incidence of adverse drug reaction.

STATISTICAL ANALYSIS

The data will be analysed with the help of SPSS 23 software. Primary objectives of change in 6-minute walk test, frailty index and quality of life will be analysed using the student's t-test. The statistical significance will be defined as p value<0.05 and taking confidence level as 95%.

ETHICAL CLEARANCE

Institutional Ethics Committee clearance taken via letter no AIIMS/IEC/20/847, dated 21 November 2020. This study involves human participants and was approved by institutional ethical committee, DHR Reg: EC/NEW/Inst/2020/1046CDSCO, Reg No: ECR/736/Inst/UK/2015/RR-18. Participants gave informed consent to participate in the study before taking part.

TRIAL REGISTRATION NUMBER

(CTRI)-REF/2020/12/030292.

Heart-Focused Anxiety Affects Behavioral Cardiac Risk Factors and Quality of Life: A Follow-Up Study Using a Psycho-Cardiological Rehabilitation Concept

Background

Heart-focused anxiety (HFA) raises the risk for adverse outcomes in patients with heart disease. Despite this great importance, it is rarely assessed in clinical practice. Three dimensions are commonly defined in the context of HFA: heart-related fear, avoidance, and attention. The impact of these aspects on cardiac risk factors is essentially unclear. In this study, we investigated the relationship between HFA and behavioral cardiac risk factors as well as health-related quality of life (HRQoL), which represent important treatment outcomes of inpatient psycho-cardiological rehabilitation.

Methods

A prospective observational design was used to examine 238 rehabilitation inpatients with comorbidity of cardiac disease and psychiatric disorder. We assessed HFA using the Cardiac Anxiety Questionnaire (CAQ), HRQoL using the SF-12 Health Survey, exercise capacity using the 6-minute walk test, and smoking behavior, respectively at admission (t0) and discharge (t1). Physical activity was assessed at t0 and in a follow-up survey 6 months after discharge (t2) using the International Physical Activity Questionnaire (IPAQ). Multiple regression models were used to analyze the predictive value of HFA for the outcome variables at t0, t1, and t2, adjusted for socio-demographic factors and depression. Predictive values for changes over time were evaluated by the regressor variable approach.

Results

Exercise capacity and physical activity were negatively predicted by baseline heart-related avoidance, both cross-sectionally and prospectively. Avoidance at t1 also negatively predicted long-term changes over time in physical activity at t2. Total HFA and the subcomponent avoidance negatively predicted physical HRQoL both cross-sectionally and prospectively. Mental HRQoL was cross-sectionally predicted by heart-focused attention at t0, and prospectively predicted by total HFA and by avoidance. Regarding changes in the course of rehabilitation, baseline avoidance negatively predicted improvement in physical HRQoL during rehabilitation. Concerning smoking behavior, no associations with HFA were found.

Conclusions

HFA is a relevant inhibiting factor for the achievement of therapy goals in psycho-cardiological rehabilitation such as health behavior and HRQoL. Heart-related avoidance in particular, has a negative impact on exercise capacity, physical activity, and self-reported physical health. Its prospective negative predictive value for physical activity and physical health underlines the relevance of HFA for psycho-cardiological interventions.

Long-term preservation of functional capacity and quality of life in advanced heart failure patients with bridge to transplant therapy: A report from Japanese nationwide multicenter registry

BACKGROUND

Under the revised heart allocation system in the United States, bridge to transplant (BTT) patients with left ventricular assist device (LVAD) have a longer waitlist period, as they are now lowly prioritized. However, little is known regarding the long-term trajectory of functional capacity (FC) and health-related quality of life (HR-QOL) among BTT-LVAD patients.

METHODS

We retrospectively analyzed 442 consecutive patients with BTT-LVAD between April 2013 and May 2019 from a Japanese nationwide registry. FC (New York Heart Association [NYHA] functional class, peak oxygen uptake [VO₂], and 6-min walk test [6MWT]) and HR-QOL (European Quality of Life [EQ-5D index] and Visual Analogue Scale [EQ-VAS]) were assessed at baseline and for up to 60 months after LVAD implantation.

RESULTS

During the follow-up period of 30 months (IQR 18-42 months), 100 (22.6%) patients underwent transplantation, 37 (8.3%) died, and 14 (3.1%) underwent explantation for recovery. Mean peak VO₂, 6MWT distance, EQ-5D index, and EQ-VAS significantly improved 3 months after LVAD implantation (p = 0.0012, p = 0.0037, p < 0.001, p < 0.001, respectively). Furthermore, these improvements were sustained for up to 60 months following LVAD implantation. Major adverse events including device failure, infection, stroke, and bleeding, which occurred within the first 3 months after LVAD implantation may have not affected FC or HR-QOL for up to 60 months (p = 0.15, p = 0.22, respectively).

CONCLUSIONS

BTT patients showed long-term preservation of FC and HR-QOL, suggesting that BTT remains an option despite the long waiting time to HTx.

Deficiência de Ferro na Insuficiência Cardíaca com Fração de Ejeção Reduzida: Fisiopatologia, Diagnóstico e Tratamento

A deficiência de ferro (DF) ou ferropenia é uma importante comorbidade na insuficiência cardíaca com fração de ejeção reduzida (ICFER) estável, e muito prevalente tanto nos anêmicos como não anêmicos. A ferropenia na ICFER deve ser pesquisada por meio da coleta de saturação de transferrina e ferritina. Há dois tipos de ferropenia na IC: absoluta, em que as reservas de ferro estão depletadas; e funcional, onde o suprimento de ferro é inadequado apesar das reservas normais. A ferropenia está associada com pior classe funcional e maior risco de morte em pacientes com ICFER, e evidências científicas apontam melhora de sintomas e de qualidade de vida desses pacientes com tratamento com ferro parenteral na forma de carboximaltose férrica. O ferro exerce funções imprescindíveis como o transporte (hemoglobina) e armazenamento (mioglobina) de oxigênio, além de ser fundamental para o funcionamento das mitocôndrias, constituídas de proteínas à base de ferro, e local de geração de energia na cadeia respiratória pelo metabolismo oxidativo. A geração insuficiente e utilização anormal de ferro nas células musculares esquelética e cardíaca contribuem para a fisiopatologia da IC. A presente revisão tem o objetivo de aprofundar o conhecimento a respeito da fisiopatologia da ferropenia na ICFER, abordar as ferramentas disponíveis para o diagnóstico e discutir sobre a evidência científica existente de reposição de ferro.

Inertial Sensor Algorithm to Estimate Walk Distance

The “total distance walked” obtained during a standardized walking test is an integral component of physical fitness and health status tracking in a range of consumer and clinical applications. Wearable inertial sensors offer the advantages of providing accurate, objective, and reliable measures of gait while streamlining walk test administration. The aim of this study was to develop an inertial sensor-based algorithm to estimate the total distance walked using older subjects with impaired fasting glucose (Study I), and to test the generalizability of the proposed algorithm in patients with Multiple Sclerosis (Study II). All subjects wore two inertial sensors (Opals by Clario-APDM Wearable Technologies) on their feet. The walking distance algorithm was developed based on 108 older adults in Study I performing a 400 m walk test along a 20 m straight walkway. The validity of the algorithm was tested using a 6-minute walk test (6MWT) in two sub-studies of Study II with different lengths of a walkway, 15 m (Study II-A, n = 24) and 20 m (Study II-B, n = 22), respectively. The start and turn around points were marked with lines on the floor while smaller horizontal lines placed every 1 m served to calculate the manual distance walked (ground truth). The proposed algorithm calculates the forward distance traveled during each step as the change in the horizontal position from each foot-flat period to the subsequent foot-flat period. The total distance walked is then computed as the sum of walk distances for each stride, including turns. The proposed algorithm achieved an average absolute error rate of 1.92% with respect to a fixed 400 m distance for Study I. The same algorithm achieved an absolute error rate of 4.17% and 3.21% with respect to an averaged manual distance for 6MWT in Study II-A and Study II-B, respectively. These results demonstrate the potential of an inertial sensor-based algorithm to estimate a total distance walked with good accuracy with respect to the manual, clinical standard. Further work is needed to test the generalizability of the proposed algorithm with different administrators and populations, as well as larger diverse cohorts.

Is the six-minute walk test still reliable compared to cardiopulmonary exercise test for exercise capacity in children with congenital heart disease?

OBJECTIVES

We aimed to assess the validity of the six-minute walk test (6MWT) to reflect the functional capacity of children with congenital heart disease (CHD), evaluate a possible correlation between the 6MWT distance with cardiopulmonary exercise test (CPET) variables, as well as to find a cutoff value to stratification the physical fitness in this population.

METHODS

We enrolled 459 children with CHD, 6-18 years old, who performed a complete CPET and 6MWT on the same day in a cross-sectional observational study. Correlations between variables of CPET and six-minute walking distance (6MWD) were analyzed and cutoff values of 6MWD were identified for the classification of the physical fitness in the population.

RESULTS

The mean distance ambulated during the 6MWT was 578 ± 65 m, 590 ± 65 m for boys, and 562 ± 62 m for girls (p < 0.001). Both VO_2max and %predicted VO_2max showed a correlation with the 6MWT distance (r = 0.35, p < 0.001 and r = 0.51, p < 0.001, respectively), and an inverse correlation was found between VE/VCO2 slope and the 6MWT distance (r = -0.31; p < 0.001). There appeared to be a linear association between 6MWD and VO_2max up to a 6MWD of approximately 600 m. We divided the population into 4 subgroups (boys <130 cm; boys ≥130 cm; girls <130 cm; girls ≥130 cm), and get the cutoff values (554 m, 617 m, 549 m, 587 m) respectively equivalent to 80% of predicted VO_2max. The 6MWT distances of another 102 patients were applied for external verification of the cutoff values.

CONCLUSIONS

Our study provided evidence on when a 6MWT should be considered as a convincing complementary test in the pediatric population with CHD and explored the classification of exercise tolerance using a 6MWD value. The cut-off values for 6MWD may be qualified as an intervention target for exercise rehabilitation.

The Role of 6-Minute Walk Test Guided by Impedance Cardiography in the Rehabilitation Following Knee Arthroplasty: A Randomized Controlled Trial

Objective: To explore the effect of the 6-minute walk test (6MWT) guided by non-invasive cardiac output on the rehabilitation of patients with knee osteoarthritis following artificial total knee arthroplasty.

Methods: About 66 patients with knee osteoarthritis planned to undergo artificial total knee arthroplasty were included from March 2019 to October 2019, and randomly assigned to the intervention group or control group. Under the guidance of a clinical rehabilitation physician, orthopedic physician, and cardiologist, a home rehabilitation exercise program based on 6MWT and non-invasive cardiac output was formulated for patients with knee osteoarthritis. The participants of the intervention group conducted full rehabilitation training supervision and guidance through the WeChat platform to ensure their rehabilitation pieces of training were completed safely and effectively. As for the control group, patients were just given rehabilitation training manuals at the time of discharge and completed the training by themselves.

Results: At 6 months post-operatively, 6-minute walk distance (413.88 ± 44.61 vs. 375.00 ± 40.53 m, P < 0.05), active metabolic equivalent (4.13 ± 0.29 vs. 3.88 ± 0.27, P < 0.05), stroke volume after 6MWT (114.97 ± 12.05 vs. 98.38 ± 16.43 ml, P < 0.05), and cardiac output (11.92 ± 1.68 vs. 9.79 ± 1.82 l/min, P < 0.05) of the intervention group were significantly higher than those of the control group. The symptom evaluation scores of the intervention group were also better than those of the control group.

Conclusions: The multidisciplinary post-operative rehabilitation exercise training program is beneficial to the recovery of lower limb function and the improvement of exercise capacity after knee replacement, and it also helps to improve the non-invasive hemodynamic indicators related to the cardiac function of the patient.

Clinical Trial Registration:http://www.chictr.org.cn/index.aspx.

Predicting outcome in children with dilated cardiomyopathy: the use of repeated measurements of risk factors for outcome

Aims

We aimed to determine whether in children with dilated cardiomyopathy repeated measurement of known risk factors for death or heart transplantation (HTx) during disease progression can identify children at the highest risk for adverse outcome.

Methods and results

Of 137 children we included in a prospective cohort, 36 (26%) reached the study endpoint (SE: all‐cause death or HTx), 15 (11%) died at a median of 0.09 years [inter‐quartile range (IQR) 0.03–0.7] after diagnosis, and 21 (15%) underwent HTx at a median of 2.9 years [IQR 0.8–6.1] after diagnosis. Median follow‐up was 2.1 years [IQR 0.8–4.3]. Twenty‐three children recovered at a median of 0.6 years [IQR 0.5–1.4] after diagnosis, and 78 children had ongoing disease at the end of the study. Children who reached the SE could be distinguished from those who did not, based on the temporal evolution of four risk factors: stunting of length growth (−0.42 vs. −0.02 length Z‐score per year, P < 0.001), less decrease in N‐terminal pro‐B‐type natriuretic peptide (NT‐proBNP) (−0.26 vs. −1.06 2log pg/mL/year, P < 0.01), no decrease in left ventricular internal diastolic dimension (LVIDd; 0.24 vs. −0.60 Boston Z‐score per year, P < 0.01), and increase in New York University Pediatric Heart Failure Index (NYU PHFI; 0.49 vs. −1.16 per year, P < 0.001). When we compared children who reached the SE with those with ongoing disease (leaving out the children who recovered), we found similar results, although the effects were smaller. In univariate analysis, NT‐proBNP, length Z‐score, LVIDd Z‐score, global longitudinal strain (%), NYU PHFI, and age >6 years at presentation (all P < 0.001) were predictive of adverse outcome. In multivariate analysis, NT‐proBNP appeared the only independent predictor for adverse outcome, a two‐fold higher NT‐proBNP was associated with a 2.8 times higher risk of the SE (hazard ratio 2.78, 95% confidence interval 1.81–3.94, P < 0.001).

Conclusions

The evolution over time of NT‐proBNP, LVIDd, length growth, and NYU PHFI identified a subgroup of children with dilated cardiomyopathy at high risk for adverse outcome. In this sample, with a limited number of endpoints, NT‐proBNP was the strongest independent predictor for adverse outcome.

OUTSTEP-HF: randomised controlled trial comparing short-term effects of sacubitril/valsartan versus enalapril on daily physical activity in patients with chronic heart failure with reduced ejection fraction

AIMS

OUTSTEP-HF compared the effect of sacubitril/valsartan vs. enalapril on 6-min walk test (6MWT) distance, non-sedentary daytime physical activity and heart failure (HF) symptoms in patients with HF with reduced ejection fraction (HFrEF).

METHODS AND RESULTS

Ambulatory patients (n = 621) with stable symptomatic HFrEF were randomised 1:1 to sacubitril/valsartan (n = 310) or enalapril (n = 311). Changes in physical activity and mean daily non-sedentary daytime activity from baseline to Week 12 were measured using 6MWT and a wrist-worn accelerometer device, respectively. After 12 weeks, 6MWT improved by 35.09 m with sacubitril/valsartan [97.5% confidence interval (CI) 27.85, 42.32] and by 26.11 m with enalapril (97.5% CI 18.78, 33.43); however, there was no significant difference between groups [least squares means treatment difference: 8.98 m (97.5% CI -1.31, 19.27); P = 0.0503]. Mean daily non-sedentary daytime activity decreased by 27 min with sacubitril/valsartan and by 21 min with enalapril [least squares means treatment difference: -6 min (97.5% CI -25.7, 13.4), P = 0.4769] after 12 weeks. 6MWT improved by ≥30 m in 51% of patients in the sacubitril/valsartan group vs. 44% of patients treated with enalapril (odds ratio 1.251, 95% CI 0.895, 1.748). At Week 4, non-sedentary daytime activity increased by ≥10% in 58% of patients treated with sacubitril/valsartan vs. 64% with enalapril; 58% of patients treated with sacubitril/valsartan reported improved HF symptoms as assessed by patient global assessment vs. 43% with enalapril. However, these differences did not persist at Week 12.

CONCLUSION

After 12 weeks of treatment, there was no significant benefit of sacubitril/valsartan on either 6MWT or daytime physical activity measured by actigraphy compared with enalapril.

Six-minute walk test: prognostic value and effects of nebivolol versus placebo in elderly patients with heart failure from the SENIORS trial

BACKGROUND

There is limited information about the 6-min walk test (6MWT) in elderly patients with heart failure. We evaluated 6MWT and the effect of nebivolol on 6MWT from the SENIORS trial.

METHODS AND RESULTS

The SENIORS trial evaluated nebivolol versus placebo on death and hospitalisation in patients aged ≥ 70 years with heart failure. A total of 1982 patients undertook a 6MWT at baseline and 1716 patients at 6 months. Patients were divided into tertiles (≤ 200 m, 201 to ≤ 300 m and > 300 m) and to change in distance walked between baseline and 6 months (< 0 m, 0 to < 30 m and ≥ 30 m). The primary outcome was all-cause mortality and cardiovascular hospital admission. Secondary endpoint was all-cause mortality. Baseline walk distance of ≤ 200 m incurred a greater risk of the primary and secondary outcomes (HR 1.41, CI 95% 1.17-1.69, p < 0.001) and (HR 1.37, CI 95% 1.05-1.78, p = 0.019). A decline in walk distance over 6 months was associated with increased risk of clinical events. Nebivolol had no influence on change in walk distance over 6 months.

CONCLUSIONS

The 6MWT has prognostic utility in elderly patients. Those who walked less than 200 m were at highest risk. Nebivolol had no effect on 6MWT.

Larger End-Diastolic Volume Associates With Response to Cell Therapy in Patients With Nonischemic Dilated Cardiomyopathy

OBJECTIVE

To investigate the association of left ventricular end-diastolic volume (LVEDV) and the response to cell therapy in patients with nonischemic dilated cardiomyopathy (NICM).

PATIENTS AND METHODS

Five-year registry data from 133 consecutive patients with NICM who underwent CD34⁺ cell treatment were analyzed. All patients received granulocyte-colony stimulating factor; CD34⁺ cells were collected by apheresis and delivered by transendocardial injections. Patients with baseline LVEDV less than 200 mL (group A; n=72) and patients with LVEDV 200 to 370 mL (group B; n=54) were included. Patients with LVEDV greater than 370 mL were excluded (n=7). Favorable ejection fraction response was pre-defined by improvement in left ventricular ejection fraction (LVEF) greater than or equal to 5% at 1 y post-cell therapy.

RESULTS

At baseline, groups A and B were comparable with regards to age (52±11 y in group A vs 53±10 y in group B; P=.95), sex (male: 79% vs 83%, respectively; P=.55), creatinine (1.07±0.28 mg/dL vs 1.03±0.21 mg/dL, respectively; P=.21), or N-terminal probrain natriuretic peptide (1454±1658 pg/mL vs 1589±1338 pg/mL, respectively; P=.80). Baseline LVEF was higher in group A (32.8±8.7%) than in group B (30.2±8.7%; P=.03). During follow-up, there were four deaths in group A (5.6%), and 2 in group B (3.7%, P=.63). At 1-year post-cell therapy, LVEDV decreased significantly in group B (-56±30 mL; P=.003), but not in group A (+12±97 mL; P=.13). On multivariate analysis, baseline LVEDV was an independent correlate of favorable response in LVEF to therapy (P=.02).

CONCLUSION

Larger LVEDV was associated with more pronounced increase in LVEF after transendocardial CD34⁺ cell therapy in NICM patients, informing target individuals with the highest likelihood of regenerative response.

TRIAL REGISTRATION

clinicaltrials.gov identifier: NCT02445534.

Short-Term Exercise Progression of Cardiovascular Patients throughout Cardiac Rehabilitation: An Observational Study

Cardiac rehabilitation (CR) is a highly recommended secondary prevention measure for patients with diagnosed cardiovascular disease. Unfortunately, participation rates are low due to enrollment and adherence issues. As such, new CR delivery strategies are of interest, as to improve overall CR delivery. The goal of the study was to obtain a better understanding of the short-term progression of functional capacity throughout multidisciplinary CR, measured as the change in walking distance between baseline six-minute walking test (6MWT) and four consecutive follow-up tests. One-hundred-and-twenty-nine patients diagnosed with cardiovascular disease participated in the study, of which 89 patients who completed the whole study protocol were included in the statistical analysis. A one-way repeated measures ANOVA was conducted to determine whether there was a significant change in mean 6MWT distance (6MWD) throughout CR. A three-way-mixed ANOVA was performed to determine the influence of categorical variables on the progression in 6MWD between groups. Significant differences in mean 6MWD between consecutive measurements were observed. Two subgroups were identified based on the change in distance between baseline and end-of-study. Patients who increased most showed a linear progression. In the other group progression leveled off halfway through rehabilitation. Moreover, the improvement during the initial phase of CR seemed to be indicative for overall progression. The current study adds to the understanding of the short-term progression in exercise capacity of patients diagnosed with cardiovascular disease throughout a CR program. The results are not only of interest for CR in general, but could be particularly relevant in the setting of home-based CR.

Impaired Exercise Tolerance in Heart Failure With Preserved Ejection Fraction: Quantification of Multiorgan System Reserve Capacity

Exercise intolerance is a principal feature of heart failure with preserved ejection fraction (HFpEF), whether or not there is evidence of congestion at rest. The degree of functional limitation observed in HFpEF is comparable to patients with advanced heart failure and reduced ejection fraction. Exercise intolerance in HFpEF is characterized by impairments in the physiological reserve capacity of multiple organ systems, but the relative cardiac and extracardiac deficits vary among individuals. Detailed measurements made during exercise are necessary to identify and rank-order the multiorgan system limitations in reserve capacity that culminate in exertional intolerance in a given person. We use a case-based approach to comprehensively review mechanisms of exercise intolerance and optimal approaches to evaluate exercise capacity in HFpEF. We also summarize recent and ongoing trials of novel devices, drugs, and behavioral interventions that aim to improve specific exercise measures such as peak oxygen uptake, 6-min walk distance, heart rate, and hemodynamic profiles in HFpEF. Evaluation during the clinically relevant physiological perturbation of exercise holds promise to improve the precision with which HFpEF is defined and therapeutically targeted.

6 min walk test is a strong independent predictor of death in outpatients with heart failure

AIMS

The aim of this study was to examine the prognostic value of the 6 min walk test (6MWT) in a large cohort of outpatients with heart failure.

METHODS AND RESULTS

A total of 5519 outpatients with heart failure from the National Norwegian Heart Failure Registry (NNHFR), which is part of the Norwegian Cardiovascular Disease Registry, were included in this analysis. The NNHFR recommended the use of the 6MWT for prognostic assessment of all patients included in the registry. Patients were categorized according to the 6MWT: Category 1 walked the longest and Category 3 the shortest. During a median (25th-75th percentiles) follow-up of 24 (14-36), 12.9% of the patients died. Patients in Category 3 had the overall worst outcome than had patients in Categories 1 and 2. 6MWT used as a continuous variable was a highly significant independent predictor for mortality in a multivariate Cox regression model adjusted for 16 other variables with a hazard ratio of 0.979 [(95% confidence interval 0.972-0.986), P < 0.001]. The four most important predictors for mortality were active cancer in the last 5 years, age, 6MWT, and natriuretic peptides (all P < 0.001).

CONCLUSIONS

6MWT is a strong independent predictor of mortality in outpatients with HF. The findings support the use of the 6MWT in the prognostic assessment of patients with HF irrespective of HF aetiology.

Stability and Predictors of Poor 6-min Walking Test Performance over 2 Years in Patients with COPD

Poor performance in the 6-min walk test (6MWT < 350 m) is an important prognostic indicator of mortality and risk of exacerbations in patients with chronic obstructive pulmonary disease (COPD). Little is known about the stability of this state over time and what factors might predict a poor 6MWT performance. To determine the stability of 6MWT performance over a 2-year period in COPD patients participating in annual medical follow-up visits, and to assess the ability of several clinical, pulmonary, and non-pulmonary factors to predict poor 6MWT performance, we prospectively included 137 patients with stable COPD (mean age, 66.9 ± 8.3 years). The 6MWT was scored at baseline and 2-year follow-up. To evaluate clinical, pulmonary, and non-pulmonary variables as potential predictors of poor 6MWT performance, we used multiple logistic regression models adjusted for age, sex, weight, height, and 6MWT performance at baseline. Poor 6MWT performance was stable over 2 years for 67.4% of patients. Predictors of poor 6MWT performance included a five-repetition sit-to-stand test score ≤2 (OR, 3.01; 95% CI, 1.22-7.42), the percentage of mobility activities with limitations (OR, 1.03; 95% CI, 1.00-1.07), and poor 6MWT performance at baseline (OR, 4.64; 95% CI, 1.88-11.43). Poor 6MWT performance status was stable for the majority of COPD patients. Lower scores on the five-repetition sit-to-stand test and a higher number of mobility activities with limitations were relevant predictors of poor 6MWT performance over 2 years. Prognostic models based on these non-pulmonary factors can provide non-inferior discriminative ability in comparison with prognostic models based on only pulmonary factors.

Exercise Intolerance in Patients With Heart Failure: JACC State-of-the-Art Review

Exercise intolerance is the cardinal symptom of heart failure (HF) and is of crucial relevance, because it is associated with a poor quality of life and increased mortality. While impaired cardiac reserve is considered to be central in HF, reduced exercise and functional capacity are the result of key patient characteristics and multisystem dysfunction, including aging, impaired pulmonary reserve, as well as peripheral and respiratory skeletal muscle dysfunction. We herein review the different modalities to quantify exercise intolerance, the pathophysiology of HF, and comorbid conditions as they lead to reductions in exercise and functional capacity, highlighting the fact that distinct causes may coexist and variably contribute to exercise intolerance in patients with HF.

Does Repeated Measurement of a 6-Min Walk Test Contribute to Risk Prediction in Children with Dilated Cardiomyopathy?

A single 6-min walk test (6MWT) can be used to identify children with dilated cardiomyopathy (DCM) with a high risk of death or heart transplantation. To determine if repeated 6MWT has added value in addition to a single 6MWT in predicting death or heart transplantation in children with DCM. Prospective multicenter cohort study including ambulatory DCM patients ≥ 6 years. A 6MWT was performed 1 to 4 times per year. The distance walked was expressed as percentage of predicted (6MWD%). We compared the temporal evolution of 6MWD% in patients with and without the study endpoint (SE: all-cause death or heart transplantation), using a linear mixed effects model. In 57 patients, we obtained a median of 4 (IQR 2-6) 6MWTs per patient during a median of 3.0 years of observation (IQR 1.5-5.1). Fourteen patients reached a SE (3 deaths, 11 heart transplantations). At any time during follow-up, the average estimate of 6MWD% was significantly lower in patients with a SE compared to patients without a SE. In both patients groups, 6MWD% remained constant over time. An absolute 1% lower 6MWD% was associated with an 11% higher risk (hazard) of the SE (HR 0.90, 95% CI 0.86-0.95 p < 0.001). Children with DCM who died or underwent heart transplantation had systematically reduced 6MWD%. The performance of all patients was stable over time, so repeated measurement of 6MWT within this time frame had little added value over a single test.

Favorable Response to CD34+ Cell Therapy Is Associated with a Decrease of Galectin-3 Levels in Patients with Chronic Heart Failure

Background

Galectin-3 plasma levels (gal-3) were shown to correlate with the scar burden in chronic heart failure (CHF) setting. As scar burden predicts response to stem cell therapy, we sought to explore a correlation between gal-3 and response to CD34+ cell transplantation in patients with CHF.

Methods

We performed a post hoc analysis of patients, enrolled in 2 prospective trials investigating the clinical effects of CD34+ cell therapy in patients with ischemic cardiomyopathy (ICMP) and nonischemic dilated cardiomyopathy (DCMP). CD34+ cells were mobilized by G-CSF, collected via apheresis, and injected transendocardially using NOGA system. Patients were followed for 3 months and demographic, echocardiographic, and biochemical parameters and gal-3 were analyzed at baseline and at follow-up. Response to cell therapy was defined as an LVEF increase of ≥5%.

Results

61 patients were included in the analysis. The mean age of patients was 52 years and 83% were male. DCMP and ICMP were present in 69% and 31% of patients, respectively. The average serum creatinine was 86 ± 23 μmol/L, NT-proBNP 1132 (IQR 350-2279) pg/mL, and LVEF 30 ± 6%. Gal-3 at baseline and at 3 months did not differ significantly (13.4 ± 5.5 ng/mL vs. 13.1 ± 5.8 ng/mL; p = 0.72), and there were no differences in baseline gal-3 with respect to heart failure etiology (15.1 ± 7.2 ng/mL in ICMP vs. 12.7 ± 4.3 ng/mL in DCMP; p = 0.12). Comparing responders (N = 49) to nonresponders (N = 18), we found no differences in baseline gal-3 (13.6 ± 5.7 ng/mL vs. 13.2 ± 4.9 ng/mL; p = 0.80). However, responders had significantly lower gal-3 at 3-month follow-up (12.1 ± 4.0 ng/mL vs. 15.7 ± 8.4 ng/mL; p < 0.05). Also, responders demonstrated a significant decrease in gal-3 over 3 months, while in nonresponders, an increase in gal-3 occurred (−1.5 ± 5.4 ng/mL vs. +2.7 ± 4.3 ng/mL; p = 0.01).

Conclusions

In patients with chronic heart failure undergoing CD34+ cell therapy, a decrease in galectin-3 plasma levels is associated with beneficial response to this treatment modality. Further prospective data is warranted to confirm our findings and to deepen our understanding of the role of gal-3 in the field of stem cell therapy.

Sex-dependent changes in physical, mental, and quality of life outcomes in metoprolol-treated Chinese chronic heart failure patients

This study assessed sex differences in cardiac and motor functions, quality of life (QoL), and mental status in Chinese chronic heart failure (CHF) patients after metoprolol treatment.This single-center prospective study, conducted from February 2013 to April 2016, included CHF patients (men and women) with resting heart rate (HR) >80 beats/min using metoprolol continuous release tablets. Metoprolol-induced changes in cardiac and motor functions, QoL, and mental status at 1, 3, 6, 9, and 12 months from baseline, within and between the sexes, were analyzed. Descriptive data were represented as counts, percentages, and mean ± standard deviation. Differences at various follow-up periods were compared using repeated measures one-way analysis of variance, followed by post hoc Dunnett's multiple comparison test. Statistical significance was considered at P < .05.Compared with men, women reported significantly higher systolic blood pressure (SBP) (122.28 ± 6.76 vs 125.47 ± 6.67 mm Hg, P < .05) and Veterans Specific Activity Questionnaire score (8.16 ± 0.98 vs 8.47 ± 0.89, P = .05) at 12 months. Men reported higher Hospital Anxiety and Depression Scale scores for depression than women at 1 month (10.27 vs 8.83, P < .05) and for anxiety at 12 months (8.4 vs 7.72, P < .05). Metoprolol significantly decreased HR and Minnesota Living with Heart Failure Questionnaire score in men (64.5 ± 3.13 and 53.7 ± 8.00) and women (65.38 ± 3.32 and 53.85 ± 8.42, respectively). Ejection fraction (%, men: 50.00 ± 4.45, women: 50.72 ± 4.09), cardiac index (L/min/m, men: 2.70 ± 0.25, women: 2.78 ± 0.23), 6-minute walk test distance (m, men: 414.41 ± 20.84, women: 420.34 ± 20.35), and short form-8 questionnaire scores (men: 52.05 ± 1.94, women: 52.19 ± 2.58) increased significantly in both the sexes (P < .001 for all) at 12 months. Copenhagen Burnout Inventory score significantly increased in men (mean score 62.43, P < .05).Metoprolol treatment improves cardiac and motor functions, QoL, and anxiety scores but causes greater depression and burnout in men and women. Sex was seen to affect mental status of CHF patients the most.

CD34+ Cell Transplantation Improves Right Ventricular Function in Patients with Nonischemic Dilated Cardiomyopathy

We investigated the effects of CD34⁺ cell therapy on right ventricular (RV) function in patients with nonischemic dilated cardiomyopathy (DCM). We enrolled 60 patients with DCM who were randomized to CD34⁺ cell therapy (Stem Cells (SC) Group n = 30), or no cell therapy (Controls, n = 30). The SC Group received granulocyte‐colony stimulating factor, and CD34⁺ cells were collected by apheresis and injected transendocardially. Patients were followed for 6 months. At baseline, the groups did not differ in age, gender, left ventricular ejection fraction, N‐terminal probrain natriuretic peptide, or parameters of RV function. At 6 months, we found a significant improvement in RV function in the SC Group (tricuspid annular plane systolic excursion [TAPSE]: +0.44 ± 0.64 cm, p = .001; peak systolic tissue Doppler velocity of tricuspid annulus [St]: +1.5 ± 2.1 cm/s; p = .001; percent of fractional area change [FAC]: +8.6% ± 5%, p = .01), but not in Controls (TAPSE: −0.07 ± 0.32 cm, p = .40; St: −0.1 ± 1.2 cm/s; p = .44; FAC: −1.2% ± 3.2%, p = .50). On repeat electroanatomical mapping, we found an improvement in interventricular septum viability in 19 of 30 patients from the SC Group; this correlated with the improvements in RV function (13/19 in the improved septum group versus 3/11 in the remaining cohort, p = .029). These results suggest that patients with DCM, changes in RV function correlate with changes of viability of interventricular septum. CD34⁺ cell therapy appears to be associated with improved right ventricular function in this patient cohort. (Clinical Trial Registration Information: www.clinicaltrials.gov; NCT02248532). Stem Cells Translational Medicine2018;7:168–172

[Utility of the 6-minute walk test in assessing maintenance of physical activity after cardiac rehabilitation]

Evaluation of therapeutic patient education (TPE) is an integral part of cardiac rehabilitation programs. An important component of this involves assessing continued physical activity (PA) after rehabilitation. Few tools are available to assess the maintenance of physical activity, and we argue that use of a field test like the 6-minute walk test (6MWT) can provide some useful indicators. Objective: to study the utility of the 6MWT as a tool for assessing maintenance of PA in post-rehabilitation follow-up. Methods: we conducted a retrospective study of 168 patients (133 men and 35 women) with a mean age of 60.65 years (+/-9.7). First, we analyzed the data from a stress test (ST) and a 6MWT at the beginning and end of rehabilitation. We then analyzed the data from a 6MWT and an International Physical Activity Questionnaire (IPAQ) performed six months after the end of rehabilitation. Results: there was a significant correlation between the 6MWT and the initial and final ST (r=0.5456, p<0.001 for the initial ST, r= 0.604, p<0.001 for the final ST), confirming the validity of using this test in cardiac rehabilitation. We observed a slight correlation between the 6MWT and the IPAQ (r=0.3923, p<0.001) six months post-rehabilitation. The IPAQ results show that patients with a significant level of physical activity during the week maintain their 6MWT distance. Conclusion: the 6MWT is a reliable test in cardiac rehabilitation. It can be used in conjunction with the IPAQ to assess patient adherence to physical activity guidelines in post-rehabilitation follow-up.

6-minute walking test: a useful tool in the management of heart failure patients

Reduced functional ability and exercise tolerance in patients with heart failure (HF) are associated with poor quality of life and a worse prognosis. The 6-minute walking test (6MWT) is a widely available and well-tolerated test for the assessment of the functional capacity of patients with HF. Although the cardiopulmonary exercise test (a maximal exercise test) remains the gold standard for the evaluation of exercise capacity in patients with HF, the 6MWT (submaximal exercise test) may provide reliable information about the patient’s daily activity. The current review summarizes the value of 6MWT in patients with HF and identifies its usefulness and limitations in everyday clinical practice in populations of HF. We aimed to investigate potential associations of 6MWD with other measures of functional status and determinants of 6MWD in patients with HF as well as to review its prognostic role and changes to various interventions in these patients.

Transendocardial CD34+ Cell Therapy does not Increase the Risk of Ventricular Arrhythmias in Patients with Chronic Heart Failure

Ventricular arrhythmias (VA) are of major concern in the field of cell therapy, potentially limiting its safety and efficacy. We sought to investigate the effects of CD34⁺ cell therapy on VA burden in patients with chronic heart failure (CHF). We performed registry data analysis of patients with CHF and implanted ICD/CRT devices treated with transendocardial CD 34⁺ cell therapy. Demographic, echocardiographic, and biochemical parameters were analyzed. Device records were reviewed and the number and type of VA 1 year prior to and 1 year after cell therapy were analyzed. All patients underwent electroanatomical mapping, and myocardial scar was defined as unipolar voltage (UV) <8.3 mV and linear local shortening (LLS) <6%. Of 209 patients screened, 48 met inclusion criteria. The mean age of the patients was 52 years and 88% were male. Nonischemic and ischemic cardiomyopathy were present in 55% and 45% of patients. The average serum creatinine was 91±26 µmol/L, serum bilirubin 18±9 µmol/L, NT-proBNP 1767 (468, 2446) pg/mL, LVEF 27±9% and 6’ walk test 442±123 m. The average scar burden in patients with nonischemic and ischemic DCM was 58±15% and 51±25% (P=0.48). No significant difference in VA burden was observed before and after cell therapy (48% vs. 44%; P=0.68). ICD activation occurred in 19% and 27% of patients before and after cell therapy (P=0.33). According to our results, transendocardial CD34⁺ cell therapy does not appear to increase the risk of VA in chronic heart failure patients.

6MWT performance correlates with peripheral neuropathy but not with cardiac involvement in patients with hereditary transthyretin amyloidosis (hATTR)

Hereditary transthyretin amyloidosis (hATTR) is a life-threatening multisystemic disease with sensory-motor peripheral neuropathy, cardiomyopathy and dysautonomia. Although the six-minute walk test (6MWT) is one of the most popular clinical tests to assess functional exercise capacity in cardiopulmonary and neuromuscular diseases, little is known about 6MWT in evaluating hATTR patients. A prospective single-center pilot study was performed in twenty hATTR patients, comparing 6MWT with widely used outcome measures. After 18 months, fourteen patients were re-evaluated. 6MWT performance was highly related with familial amyloidotic polyneuropathy stage and polyneuropathy disability score, and with CMT examination score, neuropathy impairment score-lower limbs and Kumamoto score. There was no correlation with compound autonomic dysfunction test, modified body mass index and numerous indices of heart dysfunction. After 18 months, familial amyloidotic polyneuropathy stage and polyneuropathy disability score systems were not able to reveal any significant change, whereas all other outcome measures significantly worsened. Among the outcome measures monitoring the neuropathic disturbances, neuropathy impairment score-lower limbs showed the highest responsiveness to change (adjusted effect size: 0.79), followed by CMT examination score (0.67), Kumamoto scale (0.65), 6MWT (0.62). 10MWT showed a very small value (0.21). Compound autonomic dysfunction test had a large value (0.91) whereas modified body mass index a small/moderate value (0.49). 6MWT is a simple and sensitive tool to monitor neuropathic involvement but not cardiac dysfunction in hATTR course.

Pulmonary hypertension-targeted therapies in heart failure: A systematic review and meta-analysis

Background

Pulmonary hypertension (PH) due to left heart failure (HF) is the most common form of PH. However, treatment is unclear because there are conflicting results about safety and efficacy of PH-targeted therapies.

Objectives

To assess the effects of PH-targeted therapy on exercise capacity in HF patients.

Methods

MEDLINE, EMBASE and the Cochrane Library were searched from January 1990 to July 2017 for randomized controlled trials comparing PH-targeted therapies to conventional therapy in HF. The primary outcome was to assess the effects on exercise capacity. Secondary outcomes included mortality, hospitalisation, NT-proBNP levels, echocardiographic and hemodynamics parameters and discontinuation rate.

Results

22 studies were included (n = 5448), including 3, 8 and 11 studies with low, high and unknown risk of bias, respectively. PH-targeted therapies were associated with an improvement of exercise capacity (standardized mean difference 0.29;95%CI:0.08–0.50, p = 0.006). Pre-specified subgroup analyses found that this improvement was predominantly observed in studies evaluating phosphodiesterase-5 inhibitors and prostanoids and in patients with reduced ejection fraction. Moreover, systolic pulmonary artery pressure measured by echocardiography was improved (mean difference: -7.5mmHg; [95%CI]: -14.9,-0.1, p = 0.05), which was also entirely driven by studies evaluating phosphodiesterase-5 inhibitors. However, PH-targeted therapies were associated with an increased treatment discontinuation rates and a potential increase in mortality compared to standard treatment.

Conclusions

In conclusion, PH-targeted therapies and especially phosphodiesterase-5 inhibitors may improve exercise capacity in patients with HF. However, an increase in adverse outcomes was likely. Moreover, most studies were at high or unknown risk of bias, precluding confident conclusions about the effects of PH-targeted therapies.

Hormone treatments in congestive heart failure

The common ultimate pathological feature for all cardiovascular diseases, congestive heart failure (CHF), is now considered as one of the main public health burdens that is associated with grave implications. Neurohormonal systems play a critical role in cardiovascular homeostasis, pathophysiology, and cardiovascular diseases. Hormone treatments such as the newly invented dual-acting drug valsartan/sacubitril are promising candidates for CHF, in addition to the conventional medications encompassing beta receptor blockers, angiotensin-converting enzyme inhibitors, angiotensin receptor blockers, and mineralocorticoid receptor antagonists. Clinical trials also indicate that in CHF patients with low insulin-like growth factor-1 or low thyroid hormone levels, supplemental treatment with growth hormone or thyroid hormone seems to be cardioprotective; and in CHF patients with volume overload the vasopressin antagonists can relieve the symptoms superior to loop diuretics. Furthermore, a combination of selective glucocorticoid receptor agonist and mineralocorticoid receptor antagonist may be used in patients with diuretic resistance. Finally, the potential cardiovascular efficacy and safety of incretin-based therapies, testosterone or estrogen supplementation needs to be prudently evaluated in large-scale clinical studies. In this review, we briefly discuss the therapeutic effects of several key hormones in CHF.

Six-minute walk distance after coronary artery bypass grafting compared with medical therapy in ischaemic cardiomyopathy

Background

In patients with ischaemic left ventricular dysfunction, coronary artery bypass surgery (CABG) may decrease mortality, but it is not known whether CABG improves functional capacity.

Objective

To determine whether CABG compared with medical therapy alone (MED) increases 6 min walk distance in patients with ischaemic left ventricular dysfunction and coronary artery disease amenable to revascularisation.

Methods

The Surgical Treatment in Ischemic Heart disease trial randomised 1212 patients with ischaemic left ventricular dysfunction to CABG or MED. A 6 min walk distance test was performed both at baseline and at least one follow-up assessment at 4, 12, 24 and/or 36 months in 409 patients randomised to CABG and 466 to MED. Change in 6 min walk distance between baseline and follow-up were compared by treatment allocation.

Results

6 min walk distance at baseline for CABG was mean 340±117 m and for MED 339±118 m. Change in walk distance from baseline was similar for CABG and MED groups at 4 months (mean +38 vs +28 m), 12 months (+47 vs +36 m), 24 months (+31 vs +34 m) and 36 months (-7 vs +7 m), P>0.10 for all. Change in walk distance between CABG and MED groups over all assessments was also similar after adjusting for covariates and imputation for missing values (+8 m, 95% CI -7 to 23 m, P=0.29). Results were consistent for subgroups defined by angina, New York Heart Association class ≥3, left ventricular ejection fraction, baseline walk distance and geographic region.

Conclusion

In patients with ischaemic left ventricular dysfunction CABG compared with MED alone is known to reduce mortality but is unlikely to result in a clinically significant improvement in functional capacity.

Trial registration number

NCT00023595.

Resting and exercise haemodynamics in relation to six-minute walk test in patients with heart failure and preserved ejection fraction

AIMS

Patients with heart failure and preserved ejection fraction (HFpEF) are characterized by functional impairment and an abnormal haemodynamic response to exercise. The six-minute walk test (6MWT) serves as a standardized test for functional capacity quantification in heart failure patients, and is associated with cardiovascular outcomes. However, as the association between 6MWT and haemodynamic parameters during rest and exercise in HFpEF patients is unknown, we sought to elucidate this relationship.

METHODS AND RESULTS

Overall, 64 patients enrolled in the REDUCE LAP-HF trial completed a 6MWT at baseline. Univariate and multivariable linear regression models were used to assess the associations between 6MWT and measured or derived haemodynamic variables at baseline, during light/moderate exercise (20 W), and at peak supine exercise. The average 6MWT distance was 318 ± 106 m. At rest, in a multivariable model, only pulmonary capillary wedge pressure (PCWP) was significantly associated with 6MWT [coefficient: -5.4, 95% confidence interval (CI) -10.4, -0.5, P = 0.033]. During light/moderate exercise, mean pulmonary artery pressure was associated with 6MWT in a multivariable model (coefficient: -3.5, 95% CI -6.8, -0.3, P = 0.033). During peak exercise, central venous pressure, cardiac index (CI), and PCWP/CI correlated with 6MWT; however, workload corrected PCWP was the only variable independently associated with 6MWT (coefficient: -0.8, 95% CI -1.3, -0.4, P < 0.001). The variance in 6MWT was modestly explained by measured or derived haemodynamic variables at rest or at any stage of exercise (r²  = 7-17%).

CONCLUSION

Workload corrected PCWP correlated best with 6MWT performance in HFpEF patients. Baseline haemodynamic variables were modestly correlated with 6MWT, suggesting that 6MWT performance in HFpEF patients may be significantly influenced by extra-cardiac factors.

Correlation of 6-min walk test with left ventricular function and quality of life in heart failure due to Chagas disease

OBJECTIVES

To evaluate the correlation of the total distance walked during the six-minute walk test (6MWT) with left ventricular function and quality of life in patients with Chagas Disease (ChD) complicated by heart failure.

METHODS

This is a cross-sectional study of adult patients with ChD and heart failure diagnosed based on Framingham criteria. 6MWT was performed following international guidelines. New York Heart Association functional class, brain natriuretic peptide (BNP) serum levels, echocardiographic parameters and quality of life (SF-36 and MLHFQ questionnaires) were determined and their correlation with the distance covered at the 6MWT was tested.

RESULTS

Forty adult patients (19 male; 60 ± 12 years old) with ChD and heart failure were included in this study. The mean left ventricular ejection fraction was 35 ± 12%. Only two patients (5%) ceased walking before 6 min had elapsed. There were no cardiac events during the test. The average distance covered was 337 ± 105 metres. The distance covered presented a negative correlation with BNP (r = -0.37; P = 0.02), MLHFQ quality-of-life score (r = -0.54; P = 0.002), pulmonary artery systolic pressure (r = -0.42; P = 0.02) and the degree of diastolic dysfunction (r = -0.36; P = 0.03) and mitral regurgitation (r = -0.53; P = 0.0006) and positive correlation with several domains of the SF-36 questionnaire.

CONCLUSIONS

The distance walked during the 6MWT correlates with BNP, quality of life and parameters of left ventricular diastolic function in ChD patients with heart failure. We propose this test to be adopted in endemic areas with limited resources to aid in the identification of patients who need referral for tertiary centres for further evaluation and treatment.