Is the Clinical Delivery of Cardiac Rehabilitation in an Australian Setting Associated with Changes in Physical Capacity and Cardiovascular Risk and Are Any Changes Maintained for 12 Months?

Long-term maintenance of changes in cardiovascular risk factors and physical capacity once patients leave the supervised program environment have not previously been reported. This study investigated the changes in physical capacity outcomes and cardiovascular risk factors in an Australian cardiac rehabilitation setting, and the maintenance of changes in these outcomes in the 12 months following cardiac rehabilitation attendance. Improvements in mean (95% CI) cardiorespiratory fitness (16.4% (13.2-19.6%), p < 0.001) and handgrip strength (8.0% (5.4-10.6%), p < 0.001) were observed over the course of the cardiac rehabilitation program, and these improvements were maintained in the 12 months following completion. Waist circumference (p = 0.003) and high-density lipoprotein cholesterol (p < 0.001) were the only traditional cardiovascular risk factors to improve during the cardiac rehabilitation program. Vigorous-intensity aerobic exercise was associated with significantly greater improvements in cardiorespiratory fitness, Framingham risk score, and waist circumference in comparison to moderate-intensity exercise. An increase in the intensity of the exercise prescribed during cardiac rehabilitation in Australia is recommended to induce larger improvements in physical capacity outcomes and cardiovascular risk. A standardized exercise test at the beginning of the rehabilitation program is recommended to facilitate appropriate prescription of exercise intensity.

Evaluating Exercise Progression in an Australian Cardiac Rehabilitation Program: Should Cardiac Intervention, Age, or Physical Capacity Be Considered?

Progression of prescribed exercise is important to facilitate attainment of optimal physical capacity during cardiac rehabilitation. However, it is not clear how often exercise is progressed or to what extent. This study evaluated whether exercise progression during clinical cardiac rehabilitation was different between cardiovascular treatment, age, or initial physical capacity. The prescribed exercise of sixty patients who completed 12 sessions of outpatient cardiac rehabilitation at a major Australian metropolitan hospital was evaluated. The prescribed aerobic exercise dose was progressed using intensity rather than duration, while repetitions and weight lifted were utilised to progress resistance training dose. Cardiovascular treatment or age did not influence exercise progression, while initial physical capacity and strength did. Aerobic exercise intensity relative to initial physical capacity was progressed from the first session to the last session for those with high (from mean (95%CI) 44.6% (42.2-47.0) to 68.3% (63.5-73.1); p < 0.001) and moderate physical capacity at admission (from 53.0% (50.7-55.3) to 76.3% (71.2-81.4); p < 0.001), but not in those with low physical capacity (from 67.3% (63.7-70.9) to 85.0% (73.7-96.2); p = 0.336). The initial prescription for those with low physical capacity was proportionately higher than for those with high capacity (p < 0.001). Exercise testing should be recommended in guidelines to facilitate appropriate exercise prescription and progression.

Acute cardiovascular responses to interval exercise: A systematic review and meta-analysis.

Interval exercise training is increasingly recommended to improve health and fitness; however, it is not known if cardiovascular risk is different from continuous exercise protocols. This systematic review with meta-analyses assessed the effect of a single bout of interval exercise on cardiovascular responses that indicate risk of cardiac fibrillation and infarction compared to continuous exercise. Electronic databases Medline, CINAHL, Embase, Scopus and Cochrane were searched. Key inclusion criteria were: (1) intervals of the same intensity and duration followed by a recovery period and (2) reporting at least one of blood pressure, heart rate variability, arterial stiffness or function. Cochrane Risk of Bias tool and GRADE approach were used. Meta-analyses found that systolic blood pressure responses to interval exercise did not differ from responses to continuous exercise immediately (MD 8 mmHg [95% CI -32, 47], p = 0.71) or at 60 min following exercise (MD 0 mmHg [95% CI -2, 1], p = 0.79). However, reductions in diastolic blood pressure and flow-mediated dilation with interval exercise were observed 10-15 min post-exercise. The available evidence indicates that interval exercise does not convey higher cardiovascular risk than continuous exercise. Further investigation is required to establish the safety of interval exercise for clinical populations.

Is Exercise Prescription in Cardiac Rehabilitation Influenced by Physical Capacity or Cardiac Intervention?

This study investigated the influence of cardiac intervention and physical capacity of individuals attending an Australian outpatient cardiac rehabilitation program on the initial exercise prescription. A total of 85 patients commencing outpatient cardiac rehabilitation at a major metropolitan hospital had their physical capacity assessed by an incremental shuttle walk test, and the initial aerobic exercise intensity and resistance training load prescribed were recorded. Physical capacity was lower in surgical patients than nonsurgical patients. While physical capacity was higher in younger compared with older surgical patients, there was no difference between younger and older nonsurgical patients. The initial exercise intensity did not differ between surgical and nonsurgical patients. This study highlights the importance of preprogram exercise testing to enable exercise prescription to be individualized according to actual physical capacity, rather than symptoms, comorbidities and age, in order to maximize the benefit of cardiac rehabilitation.

Validation of the Fitbit One, Garmin Vivofit and Jawbone UP activity tracker in estimation of energy expenditure during treadmill walking and running.

OBJECTIVES: To determine the validity of energy expenditure estimation made by the Fitbit One, Garmin Vivofit and Jawbone UP activity trackers during treadmill walking and running. Determining validity of such trackers will inform the interpretation of the data they generate. DESIGN: Cross-sectional study. METHOD: Fourteen adults walked at 0.70, 1.25, 1.80 ms-1 and ran at 2.22, 2.78, 3.33 ms-1 on a treadmill wearing a Fitbit One, Garmin Vivofit and Jawbone UP. Estimation of energy expenditure from each tracker was compared to measurement from indirect calorimetry (criterion). Paired t-tests, correlation coefficients and Bland-Altman plots assessed agreement and proportional bias. Mean percentage difference assessed magnitude of difference between estimated and criterion energy expenditure for each speed. RESULTS: Energy expenditure estimates from the Fitbit One and Garmin Vivofit correlated significantly (p< 0.01; r= 0.702; 0.854) with criterion across all gait speeds (0.70-3.33 ms-1). Fitbit One, Garmin Vivofit and Jawbone UP correlated significantly (p < 0.05; r = 0.729; 0.711; 0.591) with criterion across all walking speeds (0.70-1.80 ms-1). However, only the Garmin Vivofit correlated significantly (p< 0.05; r = 0.346) with energy expenditure estimations from criterion across running speeds (2.22-3.33 ms-1). Bland-Altman plots showed proportional bias for the Fitbit One and Garmin Vivofit. Energy expenditure estimations of single speeds were overestimated by the Fitbit One and underestimated by the Garmin Vivofit. CONCLUSIONS: Energy expenditure reported by the devices distinguished between walking and running, with a general increase as exercise intensity increased. However, the reported energy expenditure from these devices should be interpreted with caution, given their potential bias and error. Practical implications Although devices report the same outcome of EE estimation, they are not equivalent to each other and differ from criterion measurements during walking and running. These devices are not suitable as research measurement tools for recording precise and accurate EE estimates but may be suitable for use in interventions of behaviour change as they provide feedback to user on trends in energy expenditure. If intending to use these devices in studies where precise measurements of energy expenditure are required, researchers need to undertake specific validation and reliability studies prior to interventions and the collection of cross-sectional data.

A review of guidelines for cardiac rehabilitation exercise programmes: Is there an international consensus?

BACKGROUND: Cardiac rehabilitation is an important component in the continuum of care for individuals with cardiovascular disease, providing a multidisciplinary education and exercise programme to improve morbidity and mortality risk. Internationally, cardiac rehabilitation programmes are implemented through various models. This review compared cardiac rehabilitation guidelines in order to identify any differences and/or consensus in exercise testing, prescription and monitoring. METHODS: Guidelines, position statements and policy documents for cardiac rehabilitation, available internationally in the English language, were identified through a search of electronic databases and government and cardiology society websites. Information about programme delivery, exercise testing, prescription and monitoring were extracted and compared. RESULTS: Leading cardiac rehabilitation societies in North America and Europe recommend that patients progress from moderate- to vigorous-intensity aerobic endurance exercise over the course of the programme, with resistance training included as an important adjunct, for maintaining independence and quality of life. North American and European guidelines also recommend electrocardiograph-monitored exercise stress tests. Guidelines for South America and individual European nations typically include similar recommendations; however, those in the United Kingdom, Australia and New Zealand specify lower-intensity exercise and less technical assessment of functional capacity. CONCLUSION: Higher-intensity aerobic training programmes, supplemented by resistance training, have been recommended and deemed safe for cardiac rehabilitation patients by many authorities. Based on research evidence, this may also provide superior outcomes for patients and should therefore be considered when developing an international consensus for exercise prescription in cardiac rehabilitation.

Violet/blue chrysanthemums--metabolic engineering of the anthocyanin biosynthetic pathway results in novel petal colors.

Chrysanthemums (Chrysanthemum×morifolium Ramat.) are an important cut-flower and potted plant crop in the horticultural industry world wide. Chrysanthemums express the flavonoid 3'-hydroxylase (F3'H) gene and thus accumulate anthocyanins derived from cyanidin in their inflorescences which appear pink/red. Delphinidin-based anthocyanins are lacking due to the deficiency of a flavonoid 3', 5'-hydroxylase (F3'5'H), and so violet/blue chrysanthemum flower colors are not found. In this study, together with optimization of transgene expression and selection of the host cultivars and gene source, F3'5'H genes have been successfully utilized to produce transgenic bluish chrysanthemums that accumulate delphinidin-based anthocyanins. HPLC analysis and feeding experiments with a delphinidin precursor identified 16 cultivars of chrysanthemums out of 75 that were predicted to turn bluish upon delphinidin accumulation. A selection of eight cultivars were successfully transformed with F3'5'H genes under the control of different promoters. A pansy F3'5'H gene under the control of a chalcone synthase promoter fragment from rose resulted in the effective diversion of the anthocyanin pathway to produce delphinidin in transgenic chrysanthemum flower petals. The resultant petal color was bluish, with 40% of total anthocyanidins attributed to delphinidin. Increased delphinidin levels (up to 80%) were further achieved by hairpin RNA interference-mediated silencing of the endogenous F3'H gene. The resulting petal colors were novel bluish hues, not possible by hybridization breeding. This is the first report of the production of anthocyanins derived from delphinidin in chrysanthemum petals leading to novel flower color.