Association between VO₂ peak estimated by a 1-km treadmill walk and mortality. A 10-year follow-up study in patients with cardiovascular disease

Associations between mitochondrial copy number, exercise capacity, physiologic cost of walking, and cardiac strain in young adult survivors of childhood cancer

PURPOSE

Childhood cancer survivors are at risk for cardiac dysfunction and impaired physical performance, though underlying cellular mechanisms are not well studied. In this cross-sectional study, we examined the association between peripheral blood mitochondrial DNA copy number (mtDNA-CN, a proxy for mitochondrial function) and markers of performance impairment and cardiac dysfunction.

METHODS

Whole-genome sequencing, validated by quantitative polymerase chain reaction, was used to estimate mtDNA-CN in 1720 adult survivors of childhood cancer (48.5% female; mean age = 30.7 years, standard deviation (SD) = 9.0). Multivariable logistic regression was performed to evaluate the associations between mtDNA-CN and exercise intolerance, walking inefficiency, and abnormal global longitudinal strain (GLS), adjusting for treatment exposures, age, sex, and race and ethnicity.

RESULTS

The prevalence of exercise intolerance, walking inefficiency, and abnormal GLS among survivors was 25.7%, 10.7%, and 31.7%, respectively. Each SD increase of mtDNA-CN was associated with decreased odds of abnormal GLS (adjusted odds ratio (OR) = 0.88, p = 0.04) but was not associated with exercise intolerance (OR = 1.02, p = 0.76) or walking inefficiency (OR = 1.06, p = 0.46). Alkylating agent exposure was associated with increased odds of exercise intolerance (OR = 2.25, p < 0.0001), walking inefficiency (OR = 2.37, p < 0.0001), and abnormal GLS (OR = 1.78, p = 0.0002).

CONCLUSIONS

Increased mtDNA-CN is associated with decreased odds of abnormal cardiac function in childhood cancer survivors.

IMPLICATIONS FOR CANCER SURVIVORS

These findings demonstrate a potential role for mtDNA-CN as a biomarker of early cardiac dysfunction in this population.

Effectiveness of smartphone-assisted cardiac rehabilitation: a systematic review and meta-analysis

PURPOSE

To explore the effectiveness of smartphone-assisted home cardiac rehabilitation and whether it can be used as a remote detection method to promote home cardiac rehabilitation.

METHODS

Four databases were searched to collect randomized controlled trials (RCTs) about smartphone-assisted cardiac rehabilitation. The Cochrane risk-of-bias tool was used to assess the methodological quality of the included studies. Two independent investigators performed the literature screening, information extraction, and risk of bias assessment. Any disagreements were resolved by a third investigator. Meta-analysis and systematic review were performed. Sensitivity analysis and subgroup analysis were carried out to explore the sources of heterogeneity.

RESULTS

A total of 14 RCTs involving 1962 patients were included. Meta-analysis showed that compared with conventional cardiac rehabilitation/usual care, smartphone-assisted cardiac rehabilitation significantly improved VO2peak in patients with cardiovascular disease (WMD= 1.32, 95%CI:0.82 to 1.81, p > 0.05) and enhanced their treatment compliance (RR = 1.62, 95%CI:1.21 to 2.17, p > 0.05). There were no significant differences in six-minute walk distance (WMD = 12.88, 95%CI:-0.82 to 26.57, p > 0.05), body mass index (BMI) (WMD=-0.14, 95%CI:-0.34 to 0.06, p > 0.05), life quality, psychological status, and other cardiovascular risks.

CONCLUSION

Smartphone-assisted cardiac rehabilitation showed significant improvement in exercise capacity and treatment compliance in patients with cardiac rehabilitation but did not improve BMI, quality of life, psychological status, or reduce other cardiovascular risks. Smartphone-based cardiac rehabilitation is increasingly used as a remote detection method for cardiac rehabilitation in middle-income countries, which provides new insights into home cardiac rehabilitation.

Life's Essential 8 Cardiovascular Health Score and Cardiorespiratory Fitness in the Community

BACKGROUND

The relation of cardiorespiratory fitness (CRF) to lifestyle behaviors and factors linked with cardiovascular health remains unclear. We aimed to understand how the American Heart Association's Life's Essential 8 (LE8) score (and its changes over time) relate to CRF and complementary exercise measures in community-dwelling adults.

METHODS AND RESULTS

Framingham Heart Study (FHS) participants underwent maximum effort cardiopulmonary exercise testing for direct quantification of peak oxygen uptake (V̇O2). A 100-point LE8 score was constructed as the average across 8 factors: diet, physical activity, nicotine exposure, sleep, body mass index, lipids, blood glucose, and blood pressure. We related total LE8 score, score components, and change in LE8 score over 8 years with peak V̇O2 (log-transformed) and complementary CRF measures. In age- and sex-adjusted linear models (N=1838, age 54±9 years, 54% women, LE8 score 76±12), a higher LE8 score was associated favorably with peak V̇O2, ventilatory efficiency, resting heart rate, and blood pressure response to exercise (all P<0.0001). A clinically meaningful 5-point higher LE8 score was associated with a 6.0% greater peak V̇O2 (≈1.4 mL/kg per minute at sample mean). All LE8 components were significantly associated with peak V̇O2 in models adjusted for age and sex, but blood lipids, diet, and sleep health were no longer statistically significant after adjustment for all LE8 components. Over an ≈8-year interval, a 5-unit increase in LE8 score was associated with a 3.7% higher peak V̇O2 (P<0.0001).

CONCLUSIONS

Higher LE8 score and improvement in LE8 over time was associated with greater CRF, highlighting the importance of the LE8 factors in maintaining CRF.

Change in Peak Oxygen Uptake Predicted by the Moderate 1-km Treadmill Walking Test After Walking Training in Outpatients With Cardiovascular Disease

PURPOSE

The purpose of this study was to determine the ability of the moderate 1-km treadmill walking test (1km-TWT) to predict changes in peak oxygen uptake (V˙O 2peak ) in patients with stable cardiovascular disease (CVD) during an exercise-based secondary prevention program.

METHODS

Sixty-four male outpatients with stable CVD (age 64 [41-85] yr) performed the 1km-TWT before and after an 8-wk walking training program. Patient V˙O 2peak was estimated using a sex-specific equation including age, body mass index, 1km-TWT performance time, and heart rate (V˙O 2peakEST ). Forty-one patients completed a maximal cardiopulmonary treadmill test (CPX) for direct V˙O 2peak determination (V˙O 2peakMEAS ). The training prescription consisted of moderate-to-high intensity supervised walking for 30-40 min/session, and an additional 2-4 times/wk of unsupervised home moderate walking sessions between 20-60 min at the end of the program. The walking intensity was based on the results of the 1km-TWT.

RESULTS

Patients participated in an average of 14 of the 16 supervised sessions. An overall significant improvement in V˙O 2peakMEAS and weekly recreational physical activity levels were observed. No differences were observed between V˙O 2peakMEAS and V˙O 2peakEST . Compared with CPX results, the 1km-TWT underestimated the V˙O 2peak increase after the exercise intervention (mean difference -0.3 mL/kg/min, P > .05).

CONCLUSIONS

The 1km-TWT provides a reasonably accurate and simple tool to predict changes in V˙O 2peak due to moderate walking training in male outpatients with CVD. These findings contribute to the growing body of evidence supporting the use of the 1km-TWT for exercise testing and training purposes in the context of cardiac rehabilitation/secondary prevention programs.

A Moderate Walking Test Predicts Survival in Women With Cardiovascular Disease

INTRODUCTION

Cardiovascular disease (CVD) is the principal cause of death in U.S. women. Peak oxygen uptake is strongly related to mortality and CVD. This study aimed to investigate the association between estimated peak oxygen uptake, determined using a moderate 1-km walking test, and all-cause mortality in female patients with stable CVD.

METHODS

Of the 482 women in our registry between 1997 and 2020, we included 430 participants in the analysis (aged 67 [34-88] years). A Cox proportional hazard model was used to determine the variables significantly associated with mortality. On the basis of the peak oxygen uptake estimated using the 1-km walking test, the sample was subdivided into tertiles, and mortality risk was calculated. The discriminatory accuracy of peak oxygen uptake in estimating survival was assessed by receiver operating characteristic curves. All results were adjusted for demographic and clinical covariates.

RESULTS

A total of 135 deaths from any cause occurred over a median of 10.4 years (IQR=4.4-16.4), with an average annual mortality of 4.2%. Estimated peak oxygen uptake was a stronger predictor of all-cause mortality than demographic and clinical variables (c-statistic-0.767; 95% CI=0.72, 0.81; p<0.0001). The survival rate decreased from the highest tertile of fitness to the lowest. Compared with the lowest group, hazard ratios (95% CIs) for the second and third tertiles were 0.55 (0.37, 0.83) and 0.29 (0.16, 0.51), respectively (p for trend <0.0001).

CONCLUSIONS

Higher peak oxygen uptake levels were associated with a lower risk of all-cause mortality. The indirect estimation of peak oxygen uptake using the 1-km walking test is feasible and can be applied for risk stratification among female patients undergoing secondary prevention programs.

Exercise Training in Elderly Cancer Patients: A Systematic Review

Due to the aging of the population, in 70% of cases, a new cancer diagnosis equals a cancer diagnosis in a geriatric patient. In this population, beyond the concept of mortality and morbidity, functional capacity, disability, and quality of life remain crucial. In fact, when the functional status is preserved, the pathogenetic curve towards disability will stop or even regress. The present systematic review investigated the effectiveness of physical exercise, as part of a holistic assessment of the patient, for preventing disability and improving the patient’s quality of life, and partially reducing all-cause mortality. This evidence must point towards decentralization of care by implementing the development of rehabilitation programs for elderly cancer patients either before or after anti-cancer therapy.

Moderate walking speed and survival association across 23-years follow-up in female patients with cardiovascular disease

AIMS

To estimate the association between average walking speed (WS), determined using a moderate 1-km treadmill-walking test (1 k-TWT), and all-cause mortality in female patients with stable cardiovascular disease (CVD).

METHODS

A sample of 431 patients (age 67 [34-88] years), performed a 1 k-TWT and were followed for all-cause mortality for up to 23 years. Variables significantly associated with mortality were determined by Cox proportional hazard models. Based on average WS during the 1k_TWT the sample was subdivided into tertiles, and mortality risk was calculated. Receiver-operating-characteristic curves were constructed to assess the discriminatory accuracy of WS for estimating survival.

RESULTS

During a median follow-up of 10.4 years, a total of 135 deaths from any cause occurred, with an average mortality rate of 4.2%. The strongest predictor of mortality was WS (c-statistic for all-cause mortality 0.801, 95% confidence intervals: 0.51-1.11, p < 0.0001). Survival rate decreased from the fastest to the lowest tertile. Compared to the group with the lowest WS, the hazard ratios (95% confidence intervals) for the second and third tertiles were 0.73 (0.48-1.12) and 0.47 (0.25-0.91), respectively (p for trend <0.0001).

CONCLUSION

Average WS maintained during a moderate treadmill-walk is inversely related to survival in female patients with CVD. The 1 k-TWT is a simple and useful tool for assessing progress and stratifying risk in women undergoing secondary prevention programs.

Adherence to a guided walking program with amelioration of cognitive functions in subjects with schizophrenia even during COVID-19 pandemic

Background

Aim of the study was to enrol a group of individuals with schizophrenia in a long-term moderate-intensity physical activity program and to evaluate its effects on their cognitive functions and cardiovascular risk factors. An additional aim of the study was the comparison of the adherence to the physical activity program before and during the COVID-19 pandemic.

Methods

Forty sedentary patients diagnosed with schizophrenia (mean age 46.4 ± 9.6) followed by the Public Mental Health Department of Ferrara were included in the study. 28 of them followed a 1-year walking program consisting of two guided walking sessions/week, while 12 maintained their sedentary lifestyle and followed the usual Cognitive Rehabilitation program. To the participants following the walking program VO₂ peak and walking speed were assessed at baseline and at the end of the program. All participants were evaluated on blood pressure and anthropometric variable. Cognitive functions were assessed with the Screen for Cognitive Impairment in Psychiatry (SCIP) and with the Frontal Assessment Battery (FAB) questionnaires.

Results

The 20 participants completing the walking program displayed significant improvements in cognitive functions (d_ppc2 0.35 for SCIP and 0.26 for FAB), with a positive correlation between SCIP score and the number of sessions attended (R = 0.86, p < 0.001), evident in the patients attending to at least 75 of the 100 walking sessions. Walking speed and VO₂peak increased significantly and a decrease of body weight, BMI, systolic and diastolic blood pressure was also observed. The adherence to the walking program registered during Covid-19 period did not differ from that observed before the pandemic. The 12 CG (Control Group) patients maintaining the sedentary lifestyle did not display improvements of cognitive functions.

Conclusions

The main finding of this study is the improvement of cognitive functions which is significantly related to the number of walking sessions attended by participants with schizophrenia. The walking program, guided by exercise specialists, proved to be an enjoyable activity for people with mental disorder feasible even during the COVID-19 pandemic.

Trial registration Retrospectively registered on ISRCTN as non-randomized trial (n. ISRCTN14763786).

A moderate 200-m walk test estimates peak oxygen uptake in elderly outpatients with cardiovascular disease

BACKGROUND

A moderate 1-km treadmill walk test (1k-TWT) has been demonstrated to be a valid tool for estimating peak oxygen uptake (VO2peak) in outpatients with cardiovascular disease (CVD). The results obtained by the 1k-TWT predict survival and hospitalization in men and women with CVD. We aimed to examine whether shorter versions of the full 1k-TWT equally assess VO2peak in outpatients with CVD.

METHODS

One hundred eighteen outpatients with CVD, aged 70±9 years, referred to an exercise-based secondary prevention program, performed a moderate and perceptually-regulated (11-13/20 on the Borg Scale) 1k-TWT. Age, height, weight, heart rate, time to walk 100-m, 200-m, 300-m, and 400-m, and the full 1000-m, were entered into equations to estimate VO2peak.

RESULTS

The minimal distance providing similar VO2peak results of the full 1k-TWT was 200-m: 23.0±5.3 mL/kg/min and 23.0±5.5 mL/kg/min, respectively. The concordance correlation coefficient between the two was 0.97 (95%CI 0.96 to 0.98, P<0.0001). The slope and the intercept of the relationship between the values obtained by the 200-m and the full 1k-TWT were not different from the line of identity. Bland-Altman analysis did not show systematic or proportional error.

CONCLUSIONS

A moderate 200-m treadmill-walk is a reliable method for estimating VO2peak in elderly outpatients with CVD. A 200-m walk enables quick and easy cardiorespiratory fitness assessment, with low costs and low burden for health professionals and patients. These findings have practical implications for the transition of patients from clinically-based programs to fitness facilities or self-guided exercise programs.

Impact of Improvement in Walking Speed on Hospitalization and Mortality in Females with Cardiovascular Disease

Cardiovascular disease (CVD) is the principal cause of death in women. Walking speed (WS) is strongly related with mortality and CVD. The rate of all-cause hospitalization or death was assessed in 290 female outpatients with CVD after participation in a cardiac rehabilitation/secondary prevention program (CR/SP) and associated with the WS maintained during a moderate 1 km treadmill-walk. Three-year mortality rates were 57%, 44%, and 29% for the slow (2.1 ± 0.4 km/h), moderate (3.1 ± 0.3 km/h), and fast (4.3 ± 0.6 km/h) walkers, respectively, with adjusted hazard ratios (HRs) of 0.78 (p = 0.24) and 0.55 (p = 0.03) for moderate and fast walkers compared to the slow walkers. In addition, hospitalization or death was examined four to six years after enrollment as a function of the change in the WS of 176 patients re-assessed during the third year after baseline. The rates of hospitalization or death were higher across tertiles of reduced WS, with 35%, 50%, and 53% for the high (1.5 ± 0.3 km/h), intermediate (0.7 ± 0.2 km/h), and low tertiles (0.2 ± 0.2 km/h). Adjusted HRs were 0.79 (p = 0.38) for the intermediate and 0.47 (p = 0.02) for the high tertile compared to the low improvement tertile. Improved walking speed was associated with a graded decrease in hospitalization or death from any cause in women undergoing CR/SP.

Guided walking reduces blood pressure in hypertensive sedentary subjects including those with resistant hypertension

Hypertension poorly responsive to medications is defined resistant hypertension. We have previously shown that 1-year of guided walking is followed by highly significant reduction of systolic blood pressure in hypertensive subjects. Aim of this study was to assess the effect of a 1-year of guided walking on the blood pressure of sedentary hypertensive subjects including patients with resistant hypertension. Two hundred and fifty-nine sedentary subjects with systolic pressure ≥130 mmHg were subdivided in a group without blood pressure medications and in a group taking three or more antihypertensive drugs, including diuretics. Blood pressure, body weight, body mass index, waist circumference, and walking speed were determined at enrollment and after 1-year of walking, supervised by exercise physiologists. At baseline, systolic pressure was significantly higher in the subjects under therapy (144.6 ± 12.2 vs. 140.2 ± 10.7). Two hundred and three subjects (124 without and 79 with therapy) completed the program. During the 1-year program each subject walked ~220 h. After 1-year a significant decrease (P < 0.0001) of systolic pressure was observed in both groups. The decrease was significantly higher (P < 0.0001) in the subjects under therapy. The decrease of systolic pressure was directly proportional to baseline values. Diastolic blood pressure decreased significantly in both groups. In conclusion, habitual walking may lead to clinically significant reductions of blood pressure in therapy resistant hypertensive subjects.

Exercise intervention improves quality of life in older adults after myocardial infarction: randomised clinical trial

OBJECTIVE

To establish the benefits of an early, tailored and low-cost exercise intervention in older patients hospitalised for acute coronary syndrome (ACS).

METHODS

The study was a multicentre, randomised assessment of an exercise intervention in patients with ACS ≥70 years with reduced physical performance (as defined by the short physical performance battery (SPPB), value 4-9). The exercise intervention included four supervised sessions (1, 2, 3, 4 months after discharge) and home-based exercises. The control group attended a health education programme only. The outcomes were the 6-month and 1-year effects on physical performance, daily activities, anxiety/depression and quality of life. Finally, 1-year occurrence of adverse events was recorded.

RESULTS

Overall, 235 patients with ACS (median age 76 (73-81) years) were randomised 1 month after ACS. Exercise and control groups were well balanced. Exercise intervention improved 6-month and 1-year grip strength and gait speed. Exercise intervention was associated with a better quality of life (as measured by EuroQol-visual analogue scale at 6 months 80 (70-90) vs 70 (50-80) points, p<0.001 and at 1 year 75 (70-87) vs 65 (50-80) points, p<0.001) and with a reduced perception of anxiety and/or depression (6 months: 21% vs 42%, p=0.001; 1 year 32% vs 47%, p=0.03). The occurrence of cardiac death and hospitalisation for cardiac cause was lower in the intervention group (7.5% vs 17%, p=0.04).

CONCLUSIONS

The proposed early, tailored, low-cost exercise intervention improves mobility, daily activities, quality of life and outcomes in older patients with ACS. Larger studies are needed to confirm the clinical benefit.

TRIAL REGISTRATION NUMBER

NCT03021044.

Improvement in VO2peak predicts readmissions for cardiovascular disease and mortality in patients undergoing cardiac rehabilitation

Background

Improvement in exercise capacity is a main goal of cardiac rehabilitation but the effects are often lost at long-term follow-up and thus also the benefits on prognosis. We assessed whether improvement in VO2peak during a cardiac rehabilitation programme predicts long-term prognosis.

Methods and results

We performed a retrospective analysis of 1561 cardiac patients completing cardiac rehabilitation in 2011–2017 in Copenhagen. Mean age was 63.6 (11) years, 74% were male and 84% had coronary artery disease, 6% chronic heart failure and 10% heart valve replacement. The association between baseline VO2peak and improvement after cardiac rehabilitation and being readmitted for cardiovascular disease and/or all-cause mortality was assessed with three different analyses: Cox regression for the combined outcome, for all-cause mortality and a multi-state model. During a median follow-up of 2.3 years, 167 readmissions for cardiovascular disease and 77 deaths occurred. In adjusted Cox regression there was a non-linear decreasing risk of the combined outcome with higher baseline VO2peak and with improvement of VO2peak after cardiac rehabilitation. A similar linear association was seen for all-cause mortality. Applying the multi-state model, baseline VO2peak and change in VO2peak were associated with risk of a cardiovascular disease readmission and with all-cause mortality but not with mortality in those having an intermediate readmission for cardiovascular disease.

Conclusion

VO2peak as well as change in VO2peak were highly predictive of future risk of readmissions for cardiovascular disease and all-cause mortality. The predictive value did not extend beyond the next admission for a cardiovascular event.

Prognostic comparison of the FRIEND and Wasserman/Hansen peak VO2 equations applied to a submaximal walking test in outpatients with cardiovascular disease

AIMS

The aim of this study was to determine the ability to predict all-cause mortality using established per cent-predicted (%PRED) equations for peak oxygen consumption (VO2peak) estimated by a submaximal walk test in outpatients with cardiovascular disease.

METHODS

Male patients (N = 1491) aged 62 ± 10 years at baseline underwent a moderate and perceptually regulated (11-13 on the 6-20 Borg scale) 1-km treadmill-walking test to estimate VO2peak. %PRED was derived from the Fitness Registry and the Importance of Exercise: A National Data Base (FRIEND) and the Wasserman/Hansen equations.

RESULTS

There were 215 deaths during a median 9.4-year follow-up. The FRIEND prediction equation provided better prognostic information with receiver operating curve analysis showing significantly different areas under the curve (0.72 and 0.69 for the FRIEND and the Wasserman/Hansen equations respectively, p = 0.001). Overall mortality rate was higher across decreasing tertiles of %PRED using FRIEND, with 26%, 11% and 5% for the least fit, intermediate and high fit tertiles, respectively (p for trend < 0.0001). Compared with the least fit tertile, the adjusted hazard ratios for the second and third tertiles were 0.54 (95% confidence interval 0.34-0.87, p = 0.01) and 0.45 (95% confidence interval 0.25-0.81, p = 0.008), respectively. Each 1% increase in %PRED conferred a 3% improvement in survival (p = 0.0004).

CONCLUSION

Low %PRED VO2peak in cardiac outpatients determined by the FRIEND equation was associated with a high mortality rate independent of traditional cardiovascular risk factors and clinical history. The FRIEND equation may provide a suitable normal standard when applied to clinically stable outpatients with cardiovascular disease.

Physical activity intervention for elderly patients with reduced physical performance after acute coronary syndrome (HULK study): rationale and design of a randomized clinical trial

Background

Reduced physical performance and impaired mobility are common in elderly patients after acute coronary syndrome (ACS) and they represent independent risk factors for disability, morbidity, hospital readmission and mortality. Regular physical exercise represents a means for improving functional capacity. Nevertheless, its clinical benefit has been less investigated in elderly patients in the early phase after ACS. The HULK trial aims to investigate the clinical benefit of an early, tailored low-cost physical activity intervention in comparison to standard of care in elderly ACS patients with reduced physical performance.

Design

HULK is an investigator-initiated, prospective multicenter randomized controlled trial (NCT03021044). After successful management of the ACS acute phase and uneventful first 1 month, elderly (≥70 years) patients showing reduced physical performance are randomized (1:1 ratio) to either standard of care or physical activity intervention. Reduced physical performance is defined as a short physical performance battery (SPPB) score of 4–9. The early, tailored, low-cost physical intervention includes 4 sessions of physical activity with a supervisor and an home-based program of physical exercise. The chosen primary endpoint is the 6-month SPPB value. Secondary endpoints briefly include quality of life, on-treatment platelet reactivity, some laboratory data and clinical adverse events. To demonstrate an increase of at least one SPPB point in the experimental arm, a sample size of 226 patients is needed.

Conclusions

The HULK study will test the hypothesis that an early, tailored low-cost physical activity intervention improves physical performance, quality of life, frailty status and outcome in elderly ACS patients with reduced physical performance.

Trial registration

Clinicaltrials.gov, identifier NCT03021044, first posted January, 13th 2017.

Electronic supplementary material

The online version of this article (10.1186/s12872-018-0839-8) contains supplementary material, which is available to authorized users.

Outdoor Reproducibility of a 1-km Treadmill Walking Test to Predict Peak Oxygen Uptake in Cardiac Patients

INTRODUCTION

The aim of this study was to determine whether the 1-km treadmill walking test, previously developed to predict peak oxygen uptake ((Equation is included in full-text article.)O2peak) in stable cardiac outpatients, could be reproduced outdoors.

METHODS

Fifty male cardiac outpatients performed the 1-km walking test on a treadmill and on a flat track within 1 week. (Equation is included in full-text article.)O2peak was estimated for both testing conditions considering age, height, weight, walking speed, and heart rate.

RESULTS

Average walking speed was slightly higher during outdoor conditions (5.73 ± 0.77 km/h vs 5.55 ± 0.84 km/h), whereas mean heart rates were similar for both testing conditions (102 ± 18 beats/min vs 103 ± 16 beats/min). (Equation is included in full-text article.)O2peak values for treadmill and outdoor tests were not significantly different (26.4 ± 4.1 mL/kg/min vs 26.8 ± 4.5 mL/kg/min) and were strongly correlated (r = 0.93, P < .0001). The slope and the intercept of the (Equation is included in full-text article.)O2peak values were not different from the line of identity.

CONCLUSIONS

This moderate and perceptually regulated 1-km walking test administered outdoors gives similar results compared with a similar test performed on a treadmill. Therefore, (Equation is included in full-text article.)O2peak can be reasonably estimated using both testing modalities. This suggests that the outdoor 1-km test can be applied for indirect estimations of cardiorespiratory fitness in an outpatient setting.

A moderate 500-m treadmill walk for estimating peak oxygen uptake in men with NYHA class I-II heart failure and reduced left ventricular ejection fraction

Background

Maximal cardiopulmonary exercise testing (CPX) is the gold-standard for cardiorespiratory fitness assessment in chronic heart failure (CHF) patients. However, high costs, required medical supervision, and safety concerns make maximal exercise testing impractical for evaluating mobility-impaired adults. Thus, several submaximal walking protocols have been developed and currently used to estimate peak oxygen consumption (VO₂peak) in CHF patients. However, these tests have to be performed at close to maximum exercise intensity. The aim of this study was to examine the validity of a 500-m treadmill-walking test carried out at moderate intensity for estimating VO₂peak in community-dwelling adult and elderly patients with CHF and reduced left ventricular ejection fraction (HFrEF).

Methods

Forty-three clinically stable men with HFrEF (age 67.7 ± 9.2 years, and left ventricular ejection fraction, LVEF 38% ± 6%) underwent exercise testing during an outpatient cardiac rehabilitation/secondary prevention program. Each patients completed a CPX, and a moderate and self-paced (11–13/20 on the Borg scale) 500-m treadmill-walking test. Age, weight, height, walk time, and heart rate during the 500-m test were entered into prediction equations previously validated for VO₂peak estimation from a 1000-m walking test in patients with cardiovascular disease and preserved LVEF.

Results

Directly measured and estimated VO₂peak values were not different (21.6 ± 4.9 vs 21.7 ± 4.6 mL/kg/min). The comparison between measured and estimated VO₂peak values yielded a correlation of R = 0.97 (SEE = 0.7 mL/kg/min, P < 0.0001). The slope and the intercept coincided with the line of identity (Passing and Bablock analysis, P = 0.50). Residuals were normally distributed, and the examination of the Bland-Altman analysis do not show systematic or proportional error.

Conclusions

A moderate and self-regulated 500-m treadmill-walking test is a valid tool for VO₂peak estimation in patients with HFrEF. These findings may have practical implications in the context of transitioning from clinically based programs to fitness facilities or self-guided exercise programs in adults and elderly men with HFrEF.

Electronic supplementary material

The online version of this article (10.1186/s12872-018-0801-9) contains supplementary material, which is available to authorized users.

The utility of personal activity trackers (Fitbit Charge 2) on exercise capacity in patients post acute coronary syndrome [UP-STEP ACS Trial]: a randomised controlled trial protocol

Background

The benefits of physical activity and cardiovascular rehabilitation on the reduction of cardiovascular risk are well documented. Despite this, significant barriers and challenges remain in optimizing patient risk factors post acute coronary syndromes (ACS) and ensuring patient compliance. Consumer wearable personal activity trackers represent a cost effective and readily available technology that may aid in this endeavour.

Methods

UP-STEP ACS is a prospective single-blinded, two-arm, parallel, randomized control trial with an aim to enrol 200 patients all undertaking cardiac rehabilitation. It will assess the affect that personal activity monitors have on change in exercise capacity in patients post acute coronary syndromes primarily measured by a six-minute walk test (6MWT). Secondary end points will be the improvement in other cardiovascular risk factors, namely; blood lipid and glucose levels, weight, waist circumference, along with mood, quality of life and cardiac rehabilitation adherence. Patients will be randomized to either receive a personal activity tracker or standard post hospital care during their index event. After the 8- week intervention period, patients will return for a clinical review and repeat of baseline assessments including the 6MWT.

Discussion

The utility and impact on exercise capacity of personal activity trackers in patient’s post-acute coronary syndrome has not been assessed. This study aims to add to the scientific evidence emerging regarding the clinical utility and validity of these devices in different patient population groups. If proven to be of benefit, these devices represent a cost effective, easily accessible technology that could aid in the reduction of cardiovascular events.

Trial registration

The trial has been registered with the Australian New Zealand Clinical Trials Registry (ANZCTR). The registration number is ACTRN12617000312347 (28/02/2017).

Aqua walking as an alternative exercise modality during cardiac rehabilitation for coronary artery disease in older patients with lower extremity osteoarthritis

Background

The purpose of this study was to examine the effects of aqua walking (AW) on coronary artery disease (CAD) and cardiorespiratory fitness in older adults with osteoarthritis in the lower extremity and compare it with that of traditional over-ground walking.

Methods

Sixty consecutive eligible patients who had undergone percutaneous coronary intervention for CAD with limited ambulation due to lower extremity osteoarthritis were recruited. They were randomly assigned to the AW program group, treadmill/track walking (TW) program group, or non-exercise control group (CON). Assessments were performed before and after 24 weeks of medically supervised exercise training.

Results

Significant differences were observed in the change in %body fat (TW: −2.7%, AW: −2.8%, CON: −0.4%), total cholesterol level (TW: −23.6 mg/dL, AW: −27.2 mg/dL, CON: 15.8 mg/dL), resting heart rate (TW: −6.3 bpm, AW: −6.9 bpm, CON: 1.3 bpm), and cardiorespiratory fitness expressed as VO₂ peak (TW: 2.3 mL/kg·min⁻¹, AW: 2.0 mL/kg·min⁻¹, CON: −2.5 mL/kg·min⁻¹) over 24 weeks among the groups. However, no significant differences in the change in these measures were found between the TW and AW groups.

Conclusion

AW appears to be a feasible alternative exercise modality to over-ground walking for cardiac rehabilitation and can be recommended for older adults with CAD and osteoarthritis.

Effectiveness and safety of a home-based cardiac rehabilitation programme of mixed surveillance in patients with ischemic heart disease at moderate cardiovascular risk: A randomised, controlled clinical trial

BACKGROUND

Previous studies have documented the feasibility of home-based cardiac rehabilitation programmes in low-risk patients with ischemic heart disease, but a similar solution needs to be found for patients at moderate cardiovascular risk. The objective of this study was to analyse the effectiveness and safety of a home-based cardiac rehabilitation programme of mixed surveillance in patients with ischemic cardiopathology at moderate cardiovascular risk.

METHODS

A randomised, controlled clinical trial was designed wherein 28 patients with stable coronary artery disease at moderate cardiovascular risk, who met the selection criteria for this study, participated. Of these, 14 were assigned to the group undergoing traditional cardiac rehabilitation in hospital (control group) and 14 were assigned to the home-based mixed surveillance programme (experimental group). The patients in the experimental group went to the cardiac rehabilitation unit once a week and exercised at home, which was monitored with a remote electrocardiographic monitoring device (NUUBO®). The in-home exercises comprised of walking at 70% of heart rate reserve during the first month, and 80% during the second month, for 1 h per day at a frequency of 5 to 7 days per week. A two-way repeated measures analysis of variance (ANOVA) was performed to evaluate the effects of time (before and after intervention) and time-group interaction regarding exercise capacity, risk profile, cardiovascular complications, and quality of life.

RESULTS

No significant differences were observed between the traditional cardiac rehabilitation group and the home-based with mixed surveillance group for exercise time and METS achieved during the exertion test, and the recovery rate in the first minute (which increased in both groups after the intervention). The only difference between the two groups was for quality of life scores (10.93 [IC95%: 17.251, 3.334, p = 0.007] vs -4.314 [IC95%: -11.414, 2.787; p = 0.206]). No serious heart-related complications were recorded during the cardiac rehabilitation programme.

CONCLUSIONS

The home-based cardiac rehabilitation programme with mixed surveillance appears to be as effective and safe as the traditional model in patients with ischemic heart disease who are at moderate cardiovascular risk. However, the cardiac rehabilitation programmes carried out in hospital seems to have better results in improving the quality of life.

TRIAL REGISTRATION

Retrospectively registered NCT02796404 (May 23, 2016).

A Review of Interventions to Improve Enrolment and Adherence to Cardiac Rehabilitation Among Patients Aged 65 Years or Above

PURPOSE

This review provides an overview and quality assessment of existing interventions, assessing the intervention types that are most effective at increasing enrolment and adherence to cardiac rehabilitation in older patients aged ≥65 years Methods: The review of the literature was performed using electronic databases to search for randomised controlled trials that aimed to increase enrolment and/or adherence to cardiac rehabilitation in older patients aged ≥65 years. The main key words were cardiac rehabilitation, enrolment, adherence and older patients. Studies were included if; (1) the intervention targeted improving enrolment and/or adherence to at least one of the following components of the cardiac rehabilitation programme: exercise, education or maintaining lifestyle changes; (2) assess the effectiveness of an intervention on increasing enrolment and/or adherence to a cardiac rehabilitation programme or any of its components; (3) include measures for assessing enrolment and/or adherence to a cardiac rehabilitation programme or any of its components; (4) the study included patients with a mean age of ≥65 years who were deemed eligible to participate in a cardiac rehabilitation programme. Included studies could be published in any language and there were no date restrictions for included studies. Studies focusing on pharmaceutical adherence were not included for the purpose of this review.

RESULTS

Seven studies were included, with four investigating enrolment (1944 participants) and three assessing adherence to intervention programmes (410 participants). Three studies (1919 participants) reported higher enrolment to cardiac rehabilitation in the intervention group. Two studies that reported increases in enrolment to cardiac rehabilitation were deemed to have an unclear or high risk of bias. All three studies (410 participants) reported better adherence to cardiac rehabilitation in the intervention group when compared to the control group. Two studies that reported better completion of cardiac rehabilitation were deemed to have an unclear or high risk of bias. No formal meta-analysis was conducted due to the observed multiple heterogeneity among outcome measures, the low number of included studies and variability in study designs.

CONCLUSION

This review found only weak evidence to suggest that interventions can increase enrolment or adherence to cardiac rehabilitation programmes for patients aged ≥65 years, therefore no practice recommendations could be made and further high-quality research is needed in this population group.

Improved walking speed is associated with lower hospitalisation rates in patients in an exercise-based secondary prevention programme

OBJECTIVE

To determine the relationship between walking speed (WS) maintained during a 1 km test and its improvement on hospitalisation in cardiac outpatients who were referred to an exercise-based secondary prevention programme.

METHODS

Hospitalisation was assessed in 1791 patients 3 years after enrolment and related to the WS achieved during a 1 km walk at moderate intensity on a treadmill. Hospitalisation was also assessed during the fourth-to-sixth years as function of improvement in WS in 1111 participants who were re-evaluated 3 years after baseline.

RESULTS

Three-year hospitalisation rate across tertiles of baseline WS was 50% for the slow walkers (2.7±0.6 km/hour), 41% for the moderate (4.1±0.3 km/hour) and 25% for the fast walkers (5.2±0.5 km/hour) (p for trend <0.0001), with adjusted HRs (95% CI) of 0.93 (0.74 to 1.17, p=0.53) for intermediate and 0.58 (0.43 to 0.78, p=0.0003) for fast. Every 1 km/hour increase in WS was associated with a 21% reduction in hospitalisation (p<0.0001). Hospitalisation from the fourth-to-sixth years was lower across tertiles of improved WS, with 44% for the low (0.2±0.4 km/hour), 34% for the intermediate (0.8±0.2 km/hour) and 30% for the high tertile (1.6±0.4 km/hour) (p for trend <0.0001). Adjusted HRs were 0.68 (p=0.002) for the intermediate and 0.58 (p<0.0001) for the high tertile. Every 1 km/hour increase in WS was associated with a 35% reduction in hospitalisation (p<0.0001).

CONCLUSION

Improvement in WS is associated with a significant, dose-dependent lower rate of all-cause hospitalisation in cardiac outpatients. WS is a simple, easily applied and clinically useful tool for cardiac patients undergoing secondary prevention.