Does the 6-minute walk test predict the prognosis in patients with NYHA class II or III chronic heart failure?

Psychological Distress Affects Performance during Exercise-Based Cardiac Rehabilitation

BACKGROUND

It is known that psychosocial distress affects the morbidity and mortality of patients with cardiovascular disease of every age. The aim of this study was to produce novel information on how psychological distress can influence cardiovascular performance in patients after cardiac surgery undergoing multidisciplinary cardiac rehabilitation.

METHODS

Patients (n = 57) admitted after cardiac surgery for valvular or coronary disease underwent, within 5 days of admission, the Symptom Checklist-90-Revised (SCL-90-R) self-report questionnaire to measure psychiatric symptoms and the 12-item General Health Questionnaire (GHQ-12) to assess the level of psychological distress. The Positive Symptom Distress Index (PSDI) was measured to indicate the amplitude of symptom distress. Cardiovascular performance was assessed by a 6 min walking test (6MWT) at admission and discharge, and oxygen consumption (VO2 max) was derived.

RESULTS

Within the SCL-90-R score, somatic symptoms (47.4%), depressive and anxiety symptoms (36.8% and 33.3%, respectively), symptoms of phobic anxiety (21.1%), and psychoticism (24.6%) were over-represented. As for the GHQ-12, 75.4% of the sample reported an abnormally negative perception of their health status. An inverse correlation was shown between the variation in 6MWT and SCL depression (p = 0.048), PSDI (p = 0.022), and the GHQ-12 (p = 0.040). Similarly, an inverse correlation was shown between the variation in the VO2 max, GHQ-12 (p = 0.041), and the PSDI (p = 0.023).

CONCLUSIONS

Post-cardiac surgery cardiac rehabilitation was associated with increased symptoms of psychological discomfort, as compared with the general population. The amplitude of psychological distress, depression, and hostility are associated with limited improvement in performance. These data strengthen the need for psychological support during cardiac rehabilitation programs.

Association between fingertip-measured advanced glycation end products and cardiovascular events in outpatients with cardiovascular disease

BACKGROUND

The accumulation of advanced glycation end products (AGEs) is associated with cardiovascular events in patients with cardiovascular disease (CVD). However, the relationship between the AGEs measured by an AGEs sensor noninvasively at the fingertip and prognosis in patients with CVD remains unclear. Therefore, this study aimed to determine the relationship between AGEs score and prognosis among patients with CVD.

METHODS

A total of 191 outpatients with CVD were included. AGEs score were measured using an AGEs sensor and the patients were classified into groups by the median value of AGEs score. The incidence of major adverse cardiovascular and cerebrovascular events (MACCE) at 30 months was compared between high- and low-AGEs score groups. In addition, receiver operating characteristic (ROC) curve analysis was used to calculate cutoff value for the AGEs score, which discriminates the occurrence of MACCE. Cox regression analysis was performed to identify the factors associated with the presence of MACCE. MACCE included cardiac death, myocardial infarction, percutaneous coronary intervention, heart failure, and stroke.

RESULTS

AGEs score was normally distributed, with a median value of 0.51. No significant intergroup differences were found in laboratory findings, physical functions, or medications. The high-AGEs score group had a significantly higher incidence of MACCE than the low-AGEs score group (27.1 vs. 10.5%, P = 0.007). A high-AGEs score was a risk factor for MACCE (hazard ratio, 2.638; 95% confidence interval, 1.271-5.471; P = 0.009). After the adjustment for confounders other than 6-min walking distance, the AGEs score remained a factor associated with the occurrence of MACCE. The best cutoff AGEs score for the detection of MACCE was 0.51 (area under the curve, 0.642; P = 0.008; sensitivity, 72.2%; specificity, 54.8%).

CONCLUSIONS

AGEs score measured at the fingertip in patients with CVD is associated with MACCE. AGEs score, which can be measured noninvasively and easily, may be useful as an assessment for the secondary prevention of CVD in patients with CVD.

A Simple Equation to Estimate Maximal Oxygen Uptake in Older Adults Using the 6 min Walk Test, Sex, Age and Body Mass Index

PURPOSE

The 6 min walk test (6MWT) is used in clinical and epidemiological practice as a simple tool to evaluate the maximal aerobic exercise capacity (VO2max). To date, little evidence has been provided regarding regression equation models to predict VO2max in older adults. Therefore, the main purpose of the study was to develop a reference equation to estimate objectively measured VO2max, based on the 6MWT, sex, age and body mass index (BMI).

PATIENTS AND METHODS

In this observational prospective study, we collected the data from 233 asymptomatic participants aged 60-80 years (52.4% women). VO2max and the 6MWT were measured using standardized protocols. BMI was calculated as weight (kg) divided by height squared (m2). To be able to develop the predictive equation for VO2max, we used linear generalized estimating equations (GEE).

RESULTS

Older men performed better in VO2max (30.9 ± 8.8 vs. 26.3 ± 6.3 mL/kg/min, p < 0.001) and the 6MWT (673.9 ± 58.7 vs. 642.3 ± 48.0 m, p < 0.001), compared to women. VO2max was correlated with the 6MWT (r = 0.71, p < 0.001), sex (r = -0.29, p < 0.001), age (r = -0.62, p < 0.001) and BMI (r = -0.38, p < 0.001). The model to predict VO2max included: VO2max (mL/kg/min) = 59.44 - 3.83 *, sex (1-men; 2-women) - 0.56 *, age (years) - 0.48 *, BMI (kg/m2) + 0.04 *, and the 6MWT (m) (R = 0.85; R2 = 72.3%, SEE = 3.99 mL/kg/min, p < 0.001).

CONCLUSION

The newly developed regression equation can be a guideline in clinical and epidemiological practice to predict the VO2max in apparently healthy older adults.

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.

Prognostic importance of the 6 min walk test in light chain (AL) amyloidosis

OBJECTIVES

In AL amyloidosis, organ response assessment is based on surrogates (eg, cardiac biomarkers). An objective functional test, such as the 6 min walk test (6MWT), capturing overall clinical improvement, is required. We aimed to evaluate the prognostic impact of the 6MWT at baseline and change following chemotherapy.

METHODS

This study evaluated the outcomes of patients who enrolled in a prospective observational study at the UK National Amyloidosis Centre (2012-2017). Patients underwent comprehensive assessments inclusive of blood testing, echocardiogram and 6MWT at baseline and annually thereafter.

RESULTS

In total, 799 patients were included within the study. Median baseline 6 min walk distance (6MWD) was 362 m (IQR: 231 m). 6MWD progressively decreased with worsening cardiac disease stage (458 m, 404 m, 331 m and 168 m for cardiac Mayo stages I, II, IIIa and IIIb, respectively (p<0.0001)). In patients with a baseline 6MWT of ≥350 m, the median overall survival was not reached (vs 30.0 (95% CI 23.2 to 36.8) months if <350 m and 5.0 (95% CI 2.8 to 7.2) months if unable to attempt 6MWT (p<0.0001). Following chemotherapy, only patients in a complete haematological response improved their 6MWD by 12 months (p=0.001). Improvement in 6MWD prolonged survival in patients with cardiac amyloidosis (p=0.005).

CONCLUSION

The 6MWT is prognostic in AL amyloidosis. A baseline distance of ≥350 m independently predicts better survival. These data suggest that 6MWT has utility in AL amyloidosis for baseline prognosis and assessing response.

Prognostic value of 6-min walk test compared to cardiopulmonary exercise test in patients with severe heart failure

AIMS

The 6-min walk test (6MWT) and cardiopulmonary exercise test (CPET) are both predictive in heart failure (HFrEF). Although 6MWT substitutes for CPET in HFrEF patients, as submaximal testing may be preferable, its prognostic superiority still needs to be verified, particularly in regard to beta blockers (BBs). We aimed to compare the prognostic role of CPET and 6MWT and investigate whether BB therapy influences the predictive value.

METHODS

This is a single-center, retrospective study. Advanced HFrEF patients were followed up for 3 years: events were cardiovascular death or urgent heart transplantation. We analyzed the predictive capacity of CPET and 6MWT in patients, and subdivided according to use of BBs.

RESULTS

In a group of 251 HFrEF patients, we found a correlation between meters and peak VO2 (r2 = 0.94). Over the 3-year follow-up, 74 events were recorded. Both CPET and 6MWT variables were correlated with outcome at univariate analysis (meter and VE/VCO2 slope, peak VO2, VO2 at ventilatory anaerobic threshold, percentage predicted of peak VO2), but only percentage predicted of peak VO2 (pppVO2) was an independent predictor. In 103 HFrEF patients on BBs (23 nonsurvivors), neither pppVO2 nor meter were predictive, while in 148 patients not treated with BB (51 with events) pppVO2 was selected as an independent prognostic parameter (P = 0.001).

CONCLUSIONS

6MWT is a valid alternative to CPET, although the percentage of predicted of peak VO2 emerged as the strongest predictor. Nonetheless, our results suggest that both functional derived parameters are not predictive among those patients treated with BBs. Further studies are necessary to confirm these findings.

Reply to "Six-minute walking test performance is associated with survival in cirrhotic patients" to the editor

Use of the six-minute walk test has been proposed as a prognostic marker in liver cirrhosis. In the Letter to the Editor presented here, the authors highlight some important points, which were raised after the article was published in the November issue of the World Journal of Hepatology.

Postoperative Pulmonary Complications in Patients With Transcatheter Tricuspid Valve Implantation—Implications for Physiotherapists

Objectives

To investigate the incidence of postoperative pulmonary complications (PPCs) and short-term recovery after transcatheter tricuspid valve implantation (TTVI).

Methods

A total of 17 patients diagnosed with severe tricuspid regurgitation who received a LuX-valve TTVI were included in this study. Spirometry lung function, maximal inspiratory pressure (MIP), and 6-min walk test distance (6MWD) were recorded. Prior to surgery, patients were stratified into high or low pulmonary risk groups based on published predefined criteria. A physiotherapist provided all patients with education on thoracic expansion exercises, effective cough and an inspiratory muscle training protocol at 50% of MIP for 3 days preoperatively. All patients received standard post-operative physiotherapy intervention including positioning, thoracic expansion exercises, secretion removal techniques and mobilization. Patients were assessed for PPCs as defined by the Melbourne-Group Score-version 2. Clinical characteristics and hospital stay, cost, functional capacity, and Kansas City Cardiomyopathy Questionnaire (KCCQ) heart failure score were recorded at admission, 1-week, and 30-days post-op.

Results

The mean (SD) age of the 17 patients was 68.4 (8.0) years and 15 (88%) were female. Pre-surgical assessment identified 8 patients (47%) at high risk of PPCs. A total of 9 patients (53%) developed PPCs between the 1st and 3rd day post-surgery, and 7 of these 9 patients were amongst the 8 predicted as “high risk” prior to surgery. One patient died before the 30 day follow up. Pre-operative pulmonary risk assessment score, diabetes mellitus, a low baseline MIP and 6MWD were associated with a high incidence of PPCs. Compared to those without PPCs, patients with PPCs had longer ICU and hospital stay, and higher hospitalization cost. At 30 days post-surgery, patients without PPCs maintained higher MIP and 6MWD compared to those with PPCs, but there were no significant between-group differences in other lung function parameters nor KCCQ.

Conclusion

This is the first study to report the incidence of PPCs post TTVI. Despite a 3-day prehabilitation protocol and standard post-operative physiotherapy, PPCs were common among patients after TTVI and significantly impacted on hospital and short-term recovery and outcomes. In the majority of patients, PPCs could be accurately predicted before surgery. A comprehensive prehabilitation program should be considered for patients prior to TTVI.

Clinical Trial Registration

[www.ClinicalTrials.gov], identifier [ChiCTR2000039671].

Changes Observed in the 6-minute Walk Test in Response to Exercise-based Cardiac Rehabilitation

Objectives: The six-minute walk test (6MWT) is widely used in exercise based cardiac rehabilitation (EBCR) for assessment of functional capacity. The purpose of this study was to assess the effect of structured exercise in an EBCR program on 6MWT change and to determine the significance of age, gender, body mass index (BMI), pathology and exercise attendance on influencing this outcome.Methods: Data from a single centre 6-week (twice weekly exercise and education of one-hour duration) exercise-based cardiac rehabilitation program were analysed. Between 2006 and 2019, 2524 patients (males 1923, females 601, mean age 63.5 ± 11.2 years) with cardiovascular disease completed a pre and post 6MWT. Analysis included the effect of age, gender, pathology, BMI and exercise attendance on 6MWT outcome.Results: The group mean improvement in the 6MWT was 21.8% (pre 6MWT 432 ± 83, post 6MWT 527 ± 102 metres). The age-related improvement showed that both males and females achieved a post 6MWT results equivalent to the pre 6MWT result of patients two decades younger with improvement in the 6MWT unrelated to exercise attendance.Conclusions: The 6MWT provides simple safe method for assessment of functional capacity in an out-of-hospital environment being suitable for all ages. The post EBCR 6MWT results showed a group mean improvement in excess of 20% for both sexes. The decline per decade in 6MWT distance is less than 20 metres up to the sixth decade with a more marked decline from the sixth to the eighth decade, the decline being approximately 40-metres for both sexes in the eighth decade.

Six-minute walking test performance is associated with survival in cirrhotic patients

BACKGROUND

Patients with cirrhosis are at risk of cirrhotic cardiomyopathy, with resulting cardiac dysfunction and exercise limitations. Six minute walking test (6MWT) assesses functional status and predicts morbidity and mortality in cardiopulmonary diseases.

AIM

To determine if it associates with mortality by analyzing 6MWT performance in patients with liver cirrhosis.

METHODS

A cohort of 106 cirrhotic patients was evaluated in the outpatient setting with echocardiogram and 6MWT and follow up for one year to document hepatic decompensation and mortality. The distance in meters was recorded at the end of 6 min (6MWD).

RESULTS

This cohort had a mean age of 51 years and 56% male; patients were staged as Child A in 21.7%, B 66% and C 12.3%. Walk distance inversely correlated with Child scores, and was significantly reduced as Child stages progresses. Patients who died (10.4%) showed shorter mean 6MWD (P = 0.006). Low 6MWD was an independent predictor of mortality (P = 0.01).

CONCLUSION

6MWT is a noninvasive inexpensive test whose result is related to Child scores and mortality. It is useful to identify patients with liver cirrhosis at high risk of mortality for closer monitoring and potential early intervention.

Prognostic value of 6-minute walk test and cardiopulmonary exercise test in acute heart failure (from the ESCAPE trial)

Introduction

We aim to study the utility of 6-minute walk distance (6MWD) and cardiopulmonary exercise testing (CPET) in patients with acute systolic heart failure (HF) in predicting post-discharge outcomes.

Methods

The ESCAPE trial data was utilized to examine the prognostic role of 6MWD and CPET in predicting 6-month all-cause mortality and rehospitalization in acute HF.

Results

The average 6MWD recorded in 271 and 292 patients on admission and discharge was 597 and 765 ft., respectively. Compared with non-survivors, survivors had significantly higher 6MWD on admission (624 vs. 463 ft., P = 0.006) and discharge (789 vs. 636 ft., P = 0.006). Admission and discharge 6MWD had an AUC of 0.629 (P = 0.0047) and 0.628 (P = 0.0093) in predicting mortality. The combination of optimal 6MWD cutoff values of >288 ft. on admission and > 320 ft. on discharge was associated with significantly lower mortality (11.1% vs. 28.3%, OR 0.316, P = 0.002). When dividing the sample into quartiles of increasing walking distance, patients in the 1st quartile had significantly higher mortality on admission (OR 3.59, 95% CI 1.396-9.282, P = 0.008) and discharge (OR 3.66, 95% CI 1.357-9.839, P = 0.01) compared with 4th quartile. P-value for the trend in mortality across quartiles of 6MWD on admission and discharge was 0.016 and 0.047, respectively. Cox proportional hazard analysis revealed that admission (HR 0.632, 95% CI 0.449-0.890, P = 0.009) and discharge 6MWD (HR 0.657, 95% CI 0.467-0.926, P = 0.016) were independent mortality determinants after adjustment for age, creatinine, sodium, systolic blood pressure and NYHA class, all on admission. CPET-derived variables did not predict either outcomes.

Conclusion

6MWD is an independent mortality determinant in advanced systolic HF.

Physical functional performance and prognosis in patients with heart failure: a systematic review and meta-analysis

BACKGROUND

Patients with Heart Failure (HF) show impaired functional capacities which have been related to their prognosis. Moreover, physical functional performance in functional tests has also been related to the prognosis in patients with HF. Thus, it would be useful to investigate how physical functional performance in functional tests could determine the prognosis in patients with HF, because HF is the leading cause of hospital admissions for people older than 65 years old. This systematic review and meta-analysis aims to summarise and synthesise the evidence published about the relationship between physical functional performance and prognosis in patients with HF, as well as assess the risk of bias of included studies and the level of evidence per outcome.

METHODS

Major electronic databases, such as PubMed, AMED, CINAHL, EMBASE, PEDro, Web of Science, were searched from inception to March 2020 for observational longitudinal cohort studies (prospective or retrospective) examining the relationship between physical functional performance and prognosis in patients with HF.

RESULTS

44 observational longitudinal cohort studies with a total of 22,598 patients with HF were included. 26 included studies reported a low risk of bias, and 17 included studies showed a moderate risk of bias. Patients with poor physical functional performance in the Six Minute Walking Test (6MWT), in the Short Physical Performance Battery (SPPB) and in the Gait Speed Test showed worse prognosis in terms of larger risk of hospitalisation or mortality than patients with good physical functional performance. However, there was a lack of homogeneity regarding which cut-off points should be used to stratify patients with poor physical functional performance from patients with good physical functional performance.

CONCLUSION

The review includes a large number of studies which show a strong relationship between physical functional performance and prognosis in patients with HF. Most of the included studies reported a low risk of bias, and GRADE criteria showed a low and a moderate level of evidence per outcome.

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.

Reliability of the six-minute walk test in individuals with stroke: systematic review and meta-analysis

PURPOSE

The six-minute walking test (6MWT) is a simple and widely used measure of functional capacity. The aim of this systematic review is to summarize findings on reliability of 6MWT in subjects who have had a stroke.

METHODS

Two independent investigators conducted an extensive search in multidisciplinary electronic databases from inception to August 2019, and selected complete original studies on the reliability of the 6MWT used to assess individuals with stroke. Two reviewers independently extracted data and evaluated methodological quality. Outcome for meta-analysis was reliability, measured by intraclass correlation coefficient (ICC). In addition, standard error of measurement (SEM) and minimal detectable change (MDC) were recorded.

RESULTS

Of the 241 potentially relevant articles screened, 6 met inclusion criteria and 5 of them were included in meta-analysis. Combined correlation coefficient of .98 (confidence interval .98-.99) was found for test-retest reliability. Only one study investigated inter-rater and intra-rater reliability. SEM and MDC values were rarely reported.

CONCLUSIONS

The 6MWT has high test-retest reliability, when used to assess individuals with stroke. Other types of reliability and SEM and MDC need further investigations in populations with a stroke.

Utility of 6-Minute Walk Test to Predict Response to Cardiac Resynchronization Therapy in Patients With Mild Heart Failure

Clinical studies of heart failure (HF) generally utilize the 6-minute walk test (6MWT) for functional capacity (FC) assessment. However, data on the impact of cardiac resynchronization therapy (CRT) on 6MWT and its role to predict long-term outcomes in mild HF patients with CRT are lacking. We studied 1,381 subjects with mild HF enrolled in Multicenter Automatic Defibrillator Implantation Trial - Cardiac Resynchronization Therapy with 6MWT data at baseline and 1 year. We assessed the effects of CRT-D on percent change in 6MWT at 1 year by left bundle branch block (LBBB) status, identified independent predictors of 6MWT at 1 year, and evaluated the association between changes in 6MWT and risk for HF or death. Treatment with CRT-D versus implantable cardiac defibrillator (ICD) was not associated with a significant improvement in 6MWT at 1-year in LBBB subjects (2.2 % vs 0.0%, p = 0.428, but it was associated with a deterioration in 6MWT in non-LBBB subjects (4.1% vs 0.0%, p = 0.308). Multivariate analysis showed that each 5% reduction in 6MWT was independently associated with a corresponding 3% increase in the risk of subsequent HF or death (p = 0.014). In conclusion, our findings suggest that 6MWT has limited utility to identify CRT response in mild HF subjects with LBBB. However, 6MWT showed a signal toward deterioration in mild HF subjects with non-LBBB, and this was predictive of subsequent increased risk of HF or death.

Short-Term Effect of Self-Selected Training Intensity on Ambulatory Blood Pressure in Hypertensive Older Women: A Randomized Controlled Trial

PURPOSE

To investigate the short-term effect of self-selected training intensity (SSTI) on ambulatory blood pressure (BP) in hypertensive older women.

PARTICIPANTS AND METHODS

This is a randomized, single-blind, two-arm, parallel-group controlled trial that included 40 medicated hypertensive older women (64.4±3.6 years; resting systolic 118±19 and diastolic BP 68±9 mmHg). SSTI intervention was performed three times per week, 30-50 minutes per session (n=20). The control group participated in health education meetings once per week (n=20). Ambulatory BP (primary outcome) and six-minute walking test performance (secondary outcome) were assessed at baseline and following 8 weeks of intervention. Heart rate (HR), rating of perceived exertion (RPE, 6-20), and affective valence (ie, feeling scale, -5/+5) were recorded during all SSTI sessions. Intention-to-treat and per-protocol analyses were used for data analyses.

RESULTS

Fifteen participants from the SSTI group and 17 from the control group completed the study. No differences in ambulatory BP (24-h, awake, and asleep) were observed between SSTI and control groups (intention-to-treat and per-protocol analyses; p>0.05). The SSTI group showed a greater six-minute walking test performance than the control group in the intention-to-treat and per-protocol analyses (p<0.05). The participants exercised at 52±10% of HR reserve reported an RPE of 11±1 and an affective valence of 3.4±1.1 over the 8-week period.

CONCLUSION

SSTI is a feasible approach to induce a more active lifestyle and increase health-related fitness in hypertensive older women, although it does not improve BP control over a short-term period.

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.

Predictors of Physical Capacity 6 Months After Implantation of a Full Magnetically Levitated Left Ventricular Assist Device: An Analysis From the ELEVATE Registry

BACKGROUND

In patients with a continuous-flow left ventricular assist device, preimplant predictors of poor physical performance are not well-described. We aimed to identify predictors of inability to walk more than 300 m on 6-minute walk test (6MWT) 6 months after HeartMate 3 implantation.

METHODS AND RESULTS

Using data from the European Registry of Patients Implanted With a Full Magnetically Levitated LVAD, patients with available 6MWT at 6 months after implantation were included (N = 194) and grouped according to 6MWT distance (6MWD) of >300 m (n = 150) or 6MWD of <300 m (n = 44). Patients walking <300 m were older (60 ± 10 vs 52 ± 12 years; P < .001), more often New York Heart Association functional class IV (63% vs 42%; P = .03), and more often had type 2 diabetes (43% vs 17%; P < .001) at implantation. Atrial fibrillation was seen in 57% in those with a 6MWT of <300 m vs 31% in those walking longer (P < .002). Further, hemoglobin and estimated glomerular filtration rate was lower in those walking <300 m (both P < .01). In multivariable regression analysis, independent predictors of a 6MWD of <300 m were: atrial fibrillation (odds ratio [OR], 3.22; 95% confidence interval [CI], 1.12-8.67), older age (OR for 10-year increment, 2.81; 95% CI, 1.55-5.07), New York Heart Association functional class IV (OR, 3.37; 95% CI, 1.27-8.98), and Interagency Registry for Mechanically Assisted Circulatory Support profile 1 or 2 (OR, 6.53; 95% CI, 1.92-22.19).

CONCLUSIONS

Six months after HeartMate 3 implantation, 77% of patients walked >300 meters in 6 minutes. Apart from age and measures of heart failure severity, atrial fibrillation at implantation is an independent predictor of low 6MWD at 6 months after implantation.

Does the 6-minute walk test in hospitalized COPD patients exclusively correlate with lung function parameters or should psychological factors also be taken into account?

The 6-minute walk test is generally considered a standard test for the evaluation of short-term maximal physical performance. It has not been evaluated whether psychological factors, such as anxiety or depression, affect the performance or the results of the test. The main aim of this study was to investigate whether a correlation exists between psychological factors and the data from the 6-minute walking test. The study cohort consisted of 85 (♀ = 34 and ♂ = 51) 66 ± 10 (mean ± SD) year-old patients with chronic obstructive pulmonary disease (COPD) hospitalized for disease exacerbation. Forced Expiratory Volume in the first second (FEV₁) (% predicted) as predictor for lung function, as well as anxiety and depression symptoms assessed using the Hospital Anxiety and Depression Scale (HADS) as psychological predictors were collected. Bivariate correlations and hierarchical linear regression models were used to analyse the correlations. Walking distance was on average 260m ± 107m and ranged from 64m to 480m. HADS was negatively correlated with 6-min walking distance (r = 0.441, p = .0009, r = -.523, p = 00006). Hierarchical linear regression showed that FEV₁ alone explained 33%, and together with the psychological variables anxiety and depression explained 42% of the variance of results from the 6-minute walking test. These findings demonstrated that 11% of the data correlated with the psychological variables alone (p = .011). The effect size for lung function (f² = .717) and psychological variables (f² = .352) were high, whereas the socio-demographic variables sex, age, educational level and BMI could not explain any additional variance in our cohort. In conclusion, our study indicates that psychological factors such as symptoms of depression and anxiety are associated with lower physical functional performance in the 6-minute walking test. As such, these factors should also be assessed. Future research is needed to show if treatments of anxiety and depression can improve the walking distance in COPD patients.

Physical Activity Is Higher in Patients with Left Ventricular Assist Device Compared with Chronic Heart Failure

PURPOSE

Left ventricular assist devices (LVAD) are associated with an increased aerobic capacity in patients with chronic heart failure (CHF). However, studies evaluating the impact of LVAD implantation on physical activity (PA) are lacking. The aim of this study was to compare daily PA levels in participants with LVAD with well-matched CHF participants.

METHODS

Sixteen participants with an LVAD (age, 59.1 ± 10.8 yr) were case-matched to 16 participants with advanced CHF (age, 58.3 ± 8.7 yr), who were listed or being considered for cardiac transplantation. Participants underwent a cardiopulmonary exercise test to determine peak oxygen consumption (V˙O2 peak). Physical activity was monitored continuously for seven consecutive days with an Actiheart monitor.

RESULTS

V˙O2 peak in the CHF group (12.3 ± 3.5 mL·kg·min) was not significantly different to the LVAD group before LVAD implantation (10.4 ± 2.1 mL·kg·min), but was lower than in the LVAD group after implantation (15.8 ± 4.3 mL·kg·min; P < 0.05). Physical activity was higher in the LVAD (19.7 ± 6.4 kJ·kg·d) compared with the CHF group (11.6 ± 6.9 kJ·kg·d; P = 0.001). The LVAD participants spent more time performing moderate-intensity PA than their CHF counterparts (median, 26 min·d; interquartile range, 24-40 min·d vs median, 12 min·d; interquartile range, 9-16 min·d; P < 0.001). Physical activity was correlated with V˙O2 peak (r = 0.582; P = 0.001) across participants in the CHF and LVAD groups.

CONCLUSIONS

Higher levels of PA were observed in participants with LVAD compared with patients with advanced CHF. This may be due to a higher V˙O2 peak, resulting in an improved capacity to perform activities of daily living with less symptoms.

Associação entre consumo de oxigênio de pico e teste de caminhada de seis minutos em pacientes após cirurgia cardíaca

RESUMO Pacientes submetidos a cirurgia de revascularização do miocárdio (CRM) apresentam redução da capacidade funcional cardiorrespiratória após o procedimento. Uma avaliação adequada no período pós-operatório desses indivíduos se faz fundamental, tendo em vista uma melhor prescrição para a reabilitação cardiopulmonar fase II e retorno às atividades de vida diária. Nosso objetivo foi verificar a associação entre a distância percorrida no teste de caminhada de 6 minutos (TC6) e o consumo de oxigênio de pico (VO2 pico) obtido no teste cardiopulmonar de exercício (TCPE) em pacientes 40 dias após a CRM. Nesse estudo observacional transversal, foram incluídos pacientes submetidos a CRM. A avaliação ocorreu 40 dias após a realização da cirurgia em ambiente hospitalar. Os testes realizados foram o TCPE, o protocolo em esteira rolante e o TC6, de acordo com as normas da American Thoracic Society. Para a análise dos resultados, utilizamos o teste de correlação de Pearson. A amostra contém 39 pacientes, dos quais 28 (71,8%) são do sexo masculino, com idade média de 58 anos. Foi possível observar predominância de sedentarismo (74,4%), uso de tabaco (74,4%) e alta prevalência de hipertensão arterial sistêmica (82,1%). Nos testes realizados, a distância média percorrida no TC6 foi de 494m±70m, e no TCPE o VO2 pico médio foi de 19,5±3,6ml/kg/min. A correlação linear observada entre eles foi r=0,48; p=0,02. Concluindo, houve correlação moderada e estatisticamente significativa entre distância percorrida no TC6 e o VO2 pico em pacientes 40 dias após CRM.

Using Physical Function to Predict Hospital Readmission within 1 Year in Patients with Heart Failure

OBJECTIVE

The aim of this study was to investigate which method of evaluating physical function could predict 1-year readmission due to worsening of heart failure (HF) in newly diagnosed HF patients.

METHODS

One hundred sixteen consecutive patients with HF who underwent cardiac rehabilitation at our hospital between May 2012 and September 2015 were retrospectively enrolled. Participants were divided into two groups based on whether they were readmitted for worsening HF within 1 year. Logistic regression analysis was used to evaluate whether physical function at the time of discharge was related to HF readmission within 1 year.

RESULTS

After a mean follow-up period of 327 days, 22 patients were readmitted because of worsening HF. In the readmission group, the results of the 6-Minute Walk Test (6MWT), One-Leg Standing Test, and 30-Second Chair-Stand Test at initial discharge were significantly worse than those in the non-readmission group. In a multivariable logistic regression model, after adjusting for age and sex, a lower 6MWT distance was independently associated with increased risk of readmission within 1 year (odds ratio: 0.990, 95% confidence interval: 0.985-0.996). The 6MWT showed better prognostic value (area under the receiver operating characteristic curve: 0.696) than other evaluation methods of physical function. The 1-year non-readmission rates were 90% for 6MWT ≥382.5 m, 68% for 6MWT <382.5 m, and 53% for those unable to walk 200 m independently (P <0.001).

CONCLUSION

Physical function, particularly the 6MWT distance at time of discharge, can be used to predict the likelihood of readmission within 1 year for patients with HF.

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.

The baseline speed of 10-m gait predicts ambulatory discharge for hospitalized frail elderly after DOPPO rehabilitation

The discharge of elderly patients from hospital on the basis of their independent gait program (DOPPO) is a new rehabilitation strategy for physically frail hospitalized elderly that aims to recover independent gait and to achieve ambulatory discharge. We retrospectively investigated baseline determinants of physical measures associated closely with the 6-min walking distance (6MWD) after DOPPO. Participants were 137 consecutive elderly inpatients, irrespective of the causative disease (mean age: 82±7 years; 76 women), who had a Short Physical Performance Battery (SPPB) score of less than 12 and low independent walking capacity. The rehabilitation comprised muscle stretching, muscle strengthening, balance training, and endurance exercise, including walking. The exercises were gradually increased until the goal of ambulatory discharge was attained. The SPPB, isometric knee-extension muscle strength (IKEMS), functional reach test (FRT), one-leg stance time (OLST), and the 10-m gait speed (TMGS) were measured, before and after the DOPPO intervention, and their association with the 6MWD was evaluated. All participants achieved ambulatory discharge, requiring on average 35±19 hospital days and 32±18 h of rehabilitation. The SPPB, IKEMS, FRT, OLST, and TMGS improved. The SPPB scores increased from 7.1 at baseline to 9.2 at discharge. Eighty-eight patients completed the 6MWD. The SPPB, IKEMS, FRT, OLST, and TMGS were strongly associated with the 6MWD. Only the baseline TMGS and SPPB predicted the 6MWD, with a cut-off TMGS value of 0.84 m/s providing the best prediction of achieving a distance of more than 300 m on the 6MWD. Thus, the baseline TMGS is the best prediction of the ambulatory outcome after the present DOPPO rehabilitation.

Clinical correlates and outcome associated with changes in 6-minute walking distance in patients with heart failure: findings from the BIOSTAT-CHF study

BACKGROUND

The 6-minute walk test (6MWT) is a simple and inexpensive way of measuring exercise capacity in patients with heart failure (HF) that predicts morbidity and mortality. However, there are few reports from large multicentre cohorts assessing the predictive value of baseline and changing walk distance.

METHODS AND RESULTS

In BIOSTAT-CHF, a 6MWT was performed at baseline (n = 1714) and 9 months (n = 1520). Cox proportional hazards models were used to assess the associations between 6MWT distance and the composite of HF hospitalization and/or death. Median follow-up was 21 months. The median (pct_25-75 ) of the 6MWT distance at baseline was 300 m (200-388 m). Independent predictors of a shorter 6MWT distance included older age, female sex, higher heart rate, New York Heart Association class III/IV, orthopnoea, ischaemic heart disease, a previous stroke, current malignancy, and higher N-terminal pro-B-type natriuretic peptide (all P < 0.05). Patients in the lowest baseline 6MWT tertile (≤ 240 m) were less likely to receive guideline-recommended doses of disease-modifying therapies (P < 0.05). Compared to patients in the highest baseline 6MWT tertile (> 360 m), those in the lowest and middle tertiles had a worse prognosis [adjusted hazard ratio (HR) 1.73, 95% confidence interval (CI) 1.38-2.18]. Patients with a decrease in the distance walked had a worse prognosis (adjusted HR for each 50 m decrease 1.09, 95% CI 1.06-1.12). 6MWT distance was not modified by treatment up-titration nor the 6MWT improved the BIOSTAT-CHF prognostic models.

CONCLUSIONS

The 6-minute walk test distance at baseline and a decline in walking distance were both associated with worse prognosis but did not improve the prognostic models. 6MWT distance was not modified by treatment up-titration and its use for assessing the benefits of pharmacologic treatment up-titration may be limited.

Association between Pulmonary Function and Stair-Climbing Test Results after Lung Resection: A Pilot Study

Background

The stair-climbing test was used to assess the exercise capacity before lung resection in subjects with lung cancer. However, few studies have systematically evaluated the role of this exercise methodology as a postoperative test. The aim of the present study was to assess whether the stair-climbing test findings reflect the postoperative decrease in pulmonary function.

Methods

Twenty subjects with non-small-cell lung cancer who underwent lung resection were enrolled in the study. Perioperative functional evaluation comprised the pulmonary function test, stair-climbing test, and 6-min walk distance test (6MWD). A correlation analysis was performed between the postoperative percentages of pulmonary function with respect to preoperative values and the exercise capacity.

Results

No correlation was noted between the percentage changes in pulmonary function and those in 6MWD. However, there was a significant correlation between the percentage changes in forced expiratory volume in 1 s and those in the altitude reached in the stair-climbing test (r=0.46, p < 0.05) and between the percentage changes in carbon monoxide lung diffusion capacity and those in the altitude (r=0.54, p < 0.05).

Conclusions

The stair-climbing test findings might be effective at detecting changes in exercise capacity induced by postoperative decrease in pulmonary function.

Efficacy of heart failure reversal treatment in patients with low ejection fraction

BACKGROUND

Heart failure reversal therapy (HFRT) is designed to enhance cardiorespiratory fitness of chronic heart failure (CHF) patients.

OBJECTIVE(S)

The present study was designed to evaluate efficacy of HFRT that uses herbal procedure (panchakarma) and allied therapies, in CHF patients with low ejection fraction.

METHODS

This efficacy study was conducted in CHF patients (aged: 25-65 years, ejection fraction (EF) 10-30%) wherein HFRT (60-75 min) consisting of snehana (external oleation), swedana (passive heat therapy), hrudaydhara (concoction dripping treatment) and basti (enema) was administered twice daily for 7 days. During this therapy and next 30 days, patients followed the study dinarcharya and were prescribed ARJ kadha in addition to their conventional treatment. The primary endpoint of this study was evaluation of maximum aerobic capacity uptake (MAC) as assessed by 6 min walk distance (6MWD) using Cahalins equation from baseline, at the end of 7 day treatment, follow-up after 30 days and 90 days. EF was assessed by 2D Echo at baseline and after 30 days of follow-up.

RESULTS

Fifty-two CHF patients with 10-30% EF (mean [SD] age: 58.8 [10.8], 85% men) were enrolled in the study. There was a 100% compliance to study therapy. A significant improvement was observed in MAC levels (7.11%, p = 0.029), at the end of 7 day therapy as compared to baseline. This improvement was maintained at two follow-up visits. Moreover ejection fraction was observed to be increased by 6.38%, p = 0.012 as compared to baseline at day 7 of the therapy.

CONCLUSION

This 90 day follow up study highlights the benefit of HFRT, as a part of maintenance treatment for CHF patients with reduced ejection fraction.

Utility of Walk Tests in Evaluating Functional Status Among Participants in an Outpatient Cardiac Rehabilitation Program

PURPOSE

Although walk tests are frequently used in cardiac rehabilitation (CR), no prior study has evaluated the capacity of these measures to predict peak oxygen uptake during exercise testing ((Equation is included in full-text article.)O2peak). This study evaluated the interrelationship of objective measures of exercise performance (walk and exercise testing) among patients entering CR as well as a novel measure of functional status assessment for use in CR.

METHODS

Forty-nine patients (33 males) referred to an outpatient CR program were evaluated with objective measures of ambulatory functional status (peak oxygen uptake [(Equation is included in full-text article.)O2peak], 6-minute walk test [6MWT], and 60-ft walk test [60ftWT]).

RESULTS

All measures of functional status were moderately to highly intercorrelated (r values from 0.50 to 0.88; P values < .05). The relationship among measures differed by sex, but not by age or diagnosis. Among men, results were generally consistent with the full sample. Among women, the magnitude of correlations was generally lower and there was no relationship between (Equation is included in full-text article.)O2peak and other measures.

CONCLUSIONS

Measures of functional status, including (Equation is included in full-text article.)O2peak, 6MWT, and 60ftWT, were highly correlated among CR patients, suggesting the plausibility of using them interchangeably to fit the needs of the patient and testing environment. Among women, walk tests may not be appropriate substitutes for (Equation is included in full-text article.)O2peak. Because of the brevity of the 60ftWT, it may be particularly useful for measuring functional status in patients with greater symptoms and those with comorbidities limiting walking.

Comparison of the long-term reproducibility of the walk test and of exercise peak oxygen consumption in patients with preserved exercise capacity

Short-term and long-term reproducibility of the cardiopulmonary (CPX) exercise test have been established. Though short and mid-term reproducibility of the walk test has been ascertained, this was not extensively done for the long-term reproducibility. The aim of the study was to examine the long-term reproducibility of distance walked in an allotted time and to check the stability of the relationship between walked distance and exercise peak VO₂ (pVO₂).

METHODS

Forty six subjects (33 men; 57 ± 14 years), referred for functional capacity assessment, were studied twice by CPX and walking test. On the same day, CPX was performed on a bicycle or a treadmill and walk test in a corridor as required by specific guidelines. We performed a 12-minute walk test and the distance covered in six minutes was systematically taken down. A free time interval of 1.5 hours was observed between the exercise tests. Distance walked in the allotted time and pVO₂ were analysed. Reproducibility was assessed according to Bland and Altman plots and intra-class coefficient correlation (ICC). The relationship between distance ambulated and pVO₂ was analysed by the Spearman coefficient correlation.

RESULTS

The time interval between the two evaluations was 290 ± 10 days. During this meantime, for those subjects having drug treatment, no change was recorded in their regimen. BMI remained stable for the entire studied population (28 ± 5 kg/m²). Minute walked distance was respectively 522 ± 83 and 527 ± 76 m in six minutes, 1033 ± 182 and 1041 ± 153 m in 12 minutes. pVO₂ was 21 ± 7 and 22 ± 7 ml/kg/min (all p = NS). The walk test was reproducible in the long-term, regardless of the modality (6 or 12-minute walk) as shown by the Bland-Altman plots and the high ICC of .89. Spearman's rho coefficient between distance ambulated and pVO₂ was modest and remained stable over time whatever the allotted time: Spearman's r = .54; p = .0011 (1st evaluation) and Spearman's r = .51; p = .0019 (2nd evaluation) between 6-minute distance walked and pVO₂.

CONCLUSIONS

The walking distance in an allotted time seems highly reproducible in the long-term. Its relationship with pVO₂ remains stable over time. It could be of value for repeated assessment of patients' exercise capacity in a first step. Further evaluation in a larger population is needed to confirm our result and its usefulness in clinical practice.

Evaluation of the Keeogo™ Dermoskeleton

Purpose: (1) To determine the specific functional characteristics of individuals with neurological impairments that may predict successful use of Keeogo™ dermoskeleton and (2) to quantify the specific benefit Keeogo™ provides to a regular user of the device. Methods: Thirteen individuals (seven males; six females; 52 ± 4.6 years old) with mobility impairments due to neurological disease or injury were recruited. Berg Balance Sale (BBS) score and Timed Up and Go (TUG) performance were used to identify baseline characteristics in participants. The 6-min walk test (6MWT) and 25-foot walk test (25FWT) were performed with the participants wearing and not wearing the dermoskeleton; a successful user of Keeogo™ displayed a ≥ 5% improvement in walking performance while wearing the device. A chronic stroke survivor (hemiparesis on left side) completed the stair climb test (SCT) and the 30-second chair stand test (30CST) with and without Keeogo™. Muscle activity, kinetics and postural control were analyzed during the sit-to-stand (sitTS), and compared to an age- and sex-matched healthy control. Results: Successful users of Keeogo™ have a moderate level of functionality (BBS: 46-51 s and/or TUG: 8-12 s). Wearing Keeogo™ improved performance on the 30CST, SCT and improved motor control, postural control and movement kinetics during the sitTS task in a chronic stroke survivor with significant hemiparesis. Conclusion: This is the first study providing data to help to identify which individuals with neurological impairment might benefit from using Keeogo™ dermoskeleton, together with new information quantifying its functional benefit to the user. Implications for Rehabilitation Keeogo™ is a user-initiated dermoskeleton that has been designed to assist individuals with mobility impairments to participate more effectively in activities of daily living (ADLs). Moderately impaired individuals have the greatest potential to benefit from using the device. Benefits of wearing the device include improvements in walking speed and endurance, performance on ADLs, motor control, kinetics, and postural control.

Natriuretic Peptides, 6-Min Walk Test, and Quality-of-Life Questionnaires as Clinically Meaningful Endpoints in HF Trials

The Expedited Access for Premarket Approval and De Novo Medical Devices Intended for Unmet Medical Need for Life Threatening or Irreversibly Debilitating Diseases or Conditions document was issued as a guidance for industry and for the Food and Drug Administration. The Expedited Access Pathway was designed as a new program for medical devices that demonstrated the potential to address unmet medical needs for life threatening or irreversibly debilitating conditions. The Food and Drug Administration would consider assessments of a device's effect on intermediate endpoints that, when improving in a congruent fashion, are reasonably likely to predict clinical benefit. The purpose of this review is to provide evidence to support the use of 3 such intermediate endpoints: natriuretic peptides, such as N-terminal pro-B-type natriuretic peptide/B-type natriuretic peptide, the 6-min walk test distance, and health-related quality of life in heart failure.

Comparison between stair-climbing test and six-minute walk test after lung resection using video-assisted thoracoscopic surgery lobectomy

[Purpose] Currently, the six-minute walk distance (6MWD) is used to evaluate exercise capacity in people following lung resection for non-small cell lung cancer. However, it is unclear whether the 6MWD can detect changes in cardiorespiratory fitness induced by exercise training or lung resection. Conversely, the stair-climbing test is used frequently for the preoperative evaluation of lung resection candidates. It is considered a sensitive method for detecting changes associated with training, but is not used to evaluate exercise capacity after lung resection. The purpose of this study was to compare the stair-climbing test and the six-minute walk test (6MWT) after lung resection. [Subjects and Methods] Fourteen patients undergoing lung resection completed the stair-climbing test and the 6MWT preoperatively, and one month postoperatively. The postoperative values and the percentage change in the stair-climbing test and the 6MWT were evaluated. [Results] The stair-climbing test results showed a significant deterioration at one month after lung resection; however, a significant change in the 6MWD was not observed. [Conclusion] When compared with the 6MWT, the stair-climbing test was more sensitive in detecting lung resection-induced changes in cardiorespiratory fitness.

A New Clinically Applicable Measure of Functional Status in Patients With Heart Failure: The 60-Foot Walk Test

OBJECTIVES

This study reports the development and predictive value of the 60-foot walk test (60ftWT), a brief functional status measure for patients with heart failure (HF). The goal was to develop a test suitable for clinical settings and appropriate for patients with walking impairments.

BACKGROUND

The 6-min walk test (6MWT) has considerable predictive value, but requires a long walking course and has limited utility in patients with mobility-related comorbidities. A shorter, more clinically practical test is therefore needed.

METHODS

A total of 144 patients (age 57.4 ± 11.4 years; 111 males) with symptomatic HF received baseline assessments using the 60ftWT, 6MWT, and self-reported symptom and health status. Patients were tested 3 months later to determine stability of assessments. HF hospitalizations or death from any cause were recorded for 3.5 years following baseline.

RESULTS

Median 60ftWT completion time was 26 s (interquartile range: 22 to 31 s). Longer 60ftWT time was associated with shorter 6MWT distance (r = -0.75; p < 0.001), and with higher symptom severity at baseline (r = -0.40; p < 0.001). Longer 60ftWT times also predicted increases in 6MWT and symptoms from baseline to 3 months (p < 0.01). Both WTs predicted long-term clinical outcomes, with patients taking longer than 31 s to complete the 60ftWT at greatest risk for HF hospitalization or death (hazard ratio: 2.13; 95% confidence interval: 1.18 to 3.84; p = 0.01).

CONCLUSIONS

The 60ftWT is an easily administered functional status measure that predicts adverse events, symptoms, and health status. It has the potential for considerable clinical utility to help identify patients at risk for future events and to calibrate treatments designed to improve functional status and quality of life.

Six-minute walk test predicts all-cause mortality and technique failure in ambulatory peritoneal dialysis patients

AIM

This study investigated the associated factors of 6-min walk test (6MWT) and its predictive value of outcome in patients undergoing peritoneal dialysis (PD).

METHODS

This is a single centre prospective observational cohort study. Stable ambulatory PD patients in our centre between 1 May 2010 and 30 April 2011 were enrolled in this study. All included subjects performed 6MWT, and 6-min walk distances (6MWDs) were recorded. Patients were divided into two groups according to 6MWD and prospectively followed up until death, cessation of PD or to the end of the study (30 September 2012).

RESULTS

A total of 145 patients were enrolled, including 63 (43%) males. Multiple stepwise regression showed that age (β = -0.295, P = 0.001), diastolic blood pressure (DBP) (β = 0.292, P = 0.001), left ventricular ejection fraction (LVEF) (β = 0.198, P = 0.019) were independently associated with lower 6MWD. By the end of the study, six (8%) patients died in long 6MWD group while 15 (20%) died in the short 6MWD group, a significantly lower patient survival was observed in short 6MWD group (Log-rank = 4.983, P = 0.026). Patients with short 6MWD also showed inferior technique survival (Log-rank = 4.838, P = 0.028). There was no significant difference in peritonitis-free survival between the two groups (Log-rank = 0.801, P = 0.371). However, more patients in short 6MWD group had been transferred to hemodialysis due to peritonitis (25% vs 4.2%, P = 0.013).

CONCLUSION

Age, diastolic blood pressure, LVEF are independent associated factors of 6MWD in patients undergoing PD. Having the advantages of easy applicability and safety, 6MWT may be proposed as an important predictor of outcome in ambulatory PD patients.

Reliability, construct validity and determinants of 6-minute walk test performance in patients with chronic heart failure

BACKGROUND

In-depth analyses of the measurement properties of the 6-minute walk test (6MWT) in patients with chronic heart failure (CHF) are lacking. We investigated the reliability, construct validity, and determinants of the distance covered in the 6MWT (6MWD) in CHF patients.

METHODS

337 patients were studied (median age 65years, 70% male, ejection fraction 35%). Participants performed two 6MWTs on subsequent days. Demographics, anthropometrics, clinical data, ejection fraction, maximal exercise capacity, body composition, lung function, and symptoms of anxiety and depression were also assessed. Construct validity was assessed in terms of convergent, discriminant and known-groups validity. Stepwise linear regression was used.

RESULTS

6MWT was reliable (ICC=0.90, P<0.0001). The learning effect was 31m (95%CI 27, 35m). Older age (≥65years), lower lung diffusing capacity (<80% predicted) and higher NYHA class (NYHA III) were associated with a lower likelihood of a meaningful increase in the second test (OR 0.45-0.56, P<0.05 for all). The best 6MWD had moderate-to-good correlations with peak exercise capacity (r_s=0.54-0.69) and no-to-fair correlations with body composition, lung function, ejection fraction, and symptoms of anxiety and depression (r_s=0.04-0.49). Patients with higher NYHA classes had lower 6MWD. 6MWD was independently associated with maximal power output during maximal exercise, estimated glomerular filtration rate and age (51.7% of the variability).

CONCLUSION

6MWT was found to be reliable and valid in patients with mild-to-moderate CHF. Maximal exercise capacity, renal function and age were significant determinants of the best 6MWD. These findings strengthen the clinical utility of the 6MWT in CHF.

Prognostic Usefulness of the 6-Minute Walk Test in Patients With Severe Aortic Stenosis

The 6-minute walk test distance (6MWD) has been shown to predict prognosis in selected cohorts of patients with heart failure and outcomes after surgical or transcatheter aortic valve implantation (AVI) in patients with symptomatic severe aortic stenosis (AS). Our objective was to evaluate the association between the 6MWD and outcome in patients with severe AS while remaining under medical treatment. In a prospective observational cohort study, a total of 149 patients diagnosed with severe AS by Doppler echocardiography underwent a 6-minute walk test. The single end point was a composite of all-cause death or hospitalization for heart failure. Patients receiving an AVI were censored from follow-up at the time of their AVI, so that only the events that occurred while the patients remained under medical treatment were included in the analysis. During follow-up (median 12.9 months), the end point occurred in 65 patients (43.6%). Univariate analysis showed an association between the 6MWD and the end point (p <0.001). After adjustment for symptoms, left ventricular ejection fraction, aortic valve area, Charlson co-morbidity score, and anemia, the 6MWD independently predicted the end point (adjusted hazard ratio 0.63; 95% confidence interval 0.45 to 0.89; p = 0.010). The incidence of the composite end point was 12 per 100 patient-years in patients with a 6MWD >331 m compared to 86 per 100 patient-years in those with a 6MWD ≤331 m (p <0.001). In conclusion, although patients with severe AS remain under medical treatment, the 6MWD is independently associated with all-cause death or hospitalization for heart failure.

Biomaterial-Enhanced Cell and Drug Delivery: Lessons Learned in the Cardiac Field and Future Perspectives

Heart failure is a significant clinical issue. It is the cause of enormous healthcare costs worldwide and results in significant morbidity and mortality. Cardiac regenerative therapy has progressed considerably from clinical and preclinical studies delivering simple suspensions of cells, macromolecule, and small molecules to more advanced delivery methods utilizing biomaterial scaffolds as depots for localized targeted delivery to the damaged and ischemic myocardium. Here, regenerative strategies for cardiac tissue engineering with a focus on advanced delivery strategies and the use of multimodal therapeutic strategies are reviewed.

A Home-Based Diaphragmatic Breathing Retraining in Rural Patients With Heart Failure

Dyspnea limits physical activity and functional status in heart failure patients. This feasibility study examined effects of a diaphragmatic breathing retraining (DBR) intervention delivered over 8 weeks with follow-up at 5 months. The intervention group (n = 18) was trained at baseline and received four telephone calls. An attention control group (n = 18) received four telephone calls with general health information. Results from linear mixed model analysis with effect sizes (η(2)) showed dyspnea improved in both groups, with little difference between groups. Compared with attention alone, the intervention increased physical activity (calories expended; η(2) = .015) and functional status (η(2) = .013) across the 5-month follow-up and increased activity counts at 8 weeks (η(2) = .070). This intervention was feasible and demonstrated promising effects on activity and function but not by reducing dyspnea. Patients may have increased physical activity because of instructions to use DBR during activities of daily living. Further exploration of the intervention's underlying physiological effect is needed.

[Assessment of exercise capacity in congenital heart disease]

For many years, the treatment of congenital heart diseases has been a field in which, based on the seriousness of these conditions, treatment options were viewed with the greatest deference. This has conditioned, in many cases, the interventions to be undertaken in each. In this sense, exercise was thought to have a negative impact and thus the practise of almost any physical activity was limited. Although there has recently been a change in the paradigm with respect to exercise, this idea continues to hold sway. For many cardiopathies, the information obtained through a stress test is essential in order to implement and supervise an exercise program. The aim of this study is to analyze the parameters within the stress test which allow for an adequate stratification of the risk to subjects with congenital heart diseases who undertake exercise, as well as their values in accordance with the type of pathology, the gravity of such, and the age of the patients. Furthermore, these parameters will be analyzed for both their survival markers and the protocols that can best be adjusted for patients with these characteristic.

Skeletal Muscle Changes in Chronic Cardiac Disease and Failure

Peak exercise performance in healthy man is limited not only by pulmonary or skeletal muscle function but also by cardiac function. Thus, abnormalities in cardiac function will have a major impact on exercise performance. Many cardiac diseases affect exercise performance and indeed for some cardiac conditions such as atherosclerotic heart disease, exercise testing is frequently used not only to measure functional capacity but also to make a diagnosis of heart disease, evaluate the efficacy of treatment, and predict prognosis. Early in the course of cardiac diseases, exercise performance will be minimally affected but with disease progression impairment in exercise capacity will become apparent. Ejection fraction, that is, the percent of blood volume ejected with each cardiac cycle is often used as a measure of cardiac performance but frequently there is a dissociation between the ejection fraction and exercise capacity in patients with heart disease. How abnormalities in cardiac function impacts the muscles, vasculature, and lungs to impact exercise performance will here be reviewed. The focus of this work will be on patients with systolic heart failure as the incidence and prevalence of heart failure is reaching epidemic proportions and heart failure is the end result of many other chronic cardiac diseases. The prognostic role of exercise and benefits of exercise training will also be discussed.

Frailty may be a risk marker for adverse outcome in patients with congestive heart failure

Aims

To examine the availability of frailty concept with objective criteria for risk stratification in patients with congestive heart failure (CHF).

Methods and results

Study design was secondary analysis of our CHF cohort. We selected 181 patients who completed clinical assessments and were successfully followed 2‐year post discharge. To set frailty criteria, grip strength <26 kg in men and <17 kg in women (weakness) and performance measure for activities of daily living‐8 ≧21 points (exhaustion) were defined for predicting 6 min walking distance <300 m (slowness) by the receiver‐operating characteristics. During 2 years of follow up, subjects who met all the criteria had a 4 times greater risk of cardiac event compared with those with no frailty criteria.

Conclusion

The findings of present study suggest that frailty criteria may serve as a new clinical marker for management of patients with CHF.