Achieving Cardiovascular Risk Management Goals and Patient Quality of Life

(1) Background: Eliminating or reducing the severity of modifiable risk factors of cardiovascular disease (CVD) and undertaking health-promoting behaviors is the basis for prevention. (2) Methods: This study included 200 subjects without a history of CVD, aged 18 to 80 years, who had been diagnosed with hypertension, hypercholesterolemia, or diabetes 6 to 24 months before study enrolment. (3) Results: The median 10-year CV risk assessed by the SCORE2 and SCORE2-OP algorithms was 3.0 (IQR 1.5-7.0). An increase in mean cardiovascular risk in the range from low and moderate to very high was associated with a decrease in quality of life both in individual subscales and the overall score. The median number of controlled risk factors was 4.0 (IQR 3.0-5.0). As the mean number of controlled risk factors increased, the quality of life improved in both of HeartQoL questionnaire subscales (emotional p = 0.0018; physical p = 0.0004) and the overall score (global p = 0.0001). The median number of reported health-promoting behaviors undertaken within 3 years before study enrolment was 3.0 (IQR 2.0-4.0). The highest quality of life in each of the studied dimensions was found in people who reported undertaking three health-promoting behaviors. (4) Conclusions: Controlling CVD risk factors and undertaking health-promoting behaviors has a positive impact on the quality of life of patients without a history of atherosclerotic CVD.

Rates of compliance and adherence to high-intensity interval training: a systematic review and Meta-analyses

BACKGROUND

To determine rates of compliance (i.e., supervised intervention attendance) and adherence (i.e., unsupervised physical activity completion) to high-intensity interval training (HIIT) among insufficiently active adults and adults with a medical condition, and determine whether compliance and adherence rates were different between HIIT and moderate-intensity continuous training (MICT).

METHODS

Articles on adults in a HIIT intervention and who were either insufficiently active or had a medical condition were included. MEDLINE, EMBASE, PsychINFO, SPORTDiscus, CINAHL, and Web of Science were searched. Article screening and data extraction were completed by two independent reviewers. Risk of bias was assessed using RoB 2.0 or ROBINS-I. Meta-analyses were conducted to discern differences in compliance and adherence between HIIT vs. MICT. Sensitivity analyses, publication bias, sub-group analyses, and quality appraisal were conducted for each meta-analysis.

RESULTS

One hundred eighty-eight unique studies were included (n = 8928 participants). Compliance to HIIT interventions averaged 89.4% (SD:11.8%), while adherence to HIIT averaged 63% (SD: 21.1%). Compliance and adherence to MICT averaged 92.5% (SD:10.6%) and 68.2% (SD:16.2%), respectively. Based on 65 studies included in the meta-analysis, compliance rates were not different between supervised HIIT and MICT interventions [Hedge's g = 0.015 (95%CI: - 0.088-0.118), p = .78]. Results were robust and low risk of publication bias was detected. No differences were detected based on sub-group analyses comparing medical conditions or risk of bias of studies. Quality of the evidence was rated as moderate over concerns in the directness of the evidence. Based on 10 studies, adherence rates were not different between unsupervised HIIT and MICT interventions [Hedge's g = - 0.313 (95%CI: - 0.681-0.056), p = .096]. Sub-group analysis points to differences in adherence rates dependent on the method of outcome measurement. Adherence results should be interpreted with caution due to very low quality of evidence.

CONCLUSIONS

Compliance to HIIT and MICT was high among insufficiently active adults and adults with a medical condition. Adherence to HIIT and MICT was relatively moderate, although there was high heterogeneity and very low quality of evidence. Further research should take into consideration exercise protocols employed, methods of outcome measurement, and measurement timepoints.

REGISTRATION

This review was registered in the PROSPERO database and given the identifier CRD42019103313.

Research trends and hotspots of exercise therapy in Panvascular disease: A bibliometric analysis

Panvascular diseases are a group of vascular system diseases, mainly including the heart, brain, neck, and other parts of the vascular lesions. As a non-pharmacological intervention, exercise therapy could prevent and treat Panvascular diseases. However, few bibliometric analyses of exercise therapy in Panvascular disease exist. This study aimed to analyze the trends and hotspots over the past decade and provide insights into the latest state of the art in global research, thereby contributing to further research in the field. We systematically searched the Web of Science Core Collection (WOSCC) for articles on exercise therapy and Panvascular disease. The acquired information from the reports was analyzed using CiteSpace and VOSviewer software to assess and forecast this field hottest areas and trends. The final analysis included 294 articles by our specified inclusion criteria. The number of publications has gradually increased over the past decade. Stroke was one of the most studied Panvascular diseases. China and the University of Sao Paulo were the country es and institutions that contributed the most to the field. Mary M. McDermott was the most prolific researcher, and the Journal of Vascular Surgery published the most articles. The 6-minute walk test, skeletal muscle, oxidative stress, and supervised exercise therapy were hot topics from 2019 to 2023. In conclusion, exploring exercise therapy programs and exercise mechanisms for Panvascular diseases has been ongoing. This study revealed the current status and trends of research in the field and identified hot topics. It was helpful for scholars to understand exercise therapy critical role in treating and preventing Panvascular diseases and provided a reference for clinical decision-making and further research.

High-intensity interval training versus moderate-intensity continuous training on patient quality of life in cardiovascular disease: a systematic review and meta-analysis

This systematic review and meta-analysis aimed to compare the effects of high-intensity interval training (HIIT) and moderate-intensity continuous training (MICT) on the quality of life (QOL) and mental health (MH) of patients with cardiovascular disease (CVDs). Web of Science, Medline, Embase, Cochrane (CENTRAL), CINAHL, China National Knowledge Infrastructure, Wanfang, and China Science and Technology Journal databases were searched from their date of establishment to July, 2023. A total of 5798 articles were screened, of which 25 were included according to the eligibility criteria. The weighted mean difference (WMD) and standardized mean difference (SMD) were used to analyze data from the same and different indicator categories, respectively. The fixed-effects model (FE) or random-effects model (RE) combined data based on the between-study heterogeneity. There were no statistically significant differences regarding QOL, physical component summary (PCS), mental component summary (MCS), and MH, including depression and anxiety levels, between the HIIT and MICT groups [SMD = 0.21, 95% confidence interval (CI)  - 0.18-0.61, Z = 1.06, P = 0.290; SMD = 0.10, 95% CI  - 0.03-0.23, Z = 1.52, P = 0.128; SMD = 0.07, 95% CI  - 0.05-0.20, Z = 1.13, P = 0.25; SMD = - 0.08, 95% CI  - 0.40-0.25, Z = - 0.46, P = 0.646; WMD = 0.14. 95% CI  - 0.56-0.84, Z = 0.39, P = 0.694, respectively]. HIIT significantly improved PCS in the coronary artery disease (CAD) population subgroup relative to MICT. HIIT was also significantly superior to MICT for physical role, vitality, and social function. We conclude that HIIT and MICT have similar effects on QOL and MH in patients with CVD, while HIIT is favorable for improving patients' self-perceived physiological functioning based on their status and social adjustment, and this effect is more significant in patients with CAD.

Effects of high-intensity interval training on vascular function in patients with cardiovascular disease: a systematic review and meta-analysis

Background: Exercise training improves endothelial function in patients with cardiovascular disease (CVD). However, the influence of training variables remains unclear. The aim of this study was to evaluate the effect of high-intensity interval training (HIIT), compared to moderate intensity training (MIT) and other exercise modalities (i.e., resistance and combined exercise), on endothelial function, assessed by arterial flow-mediated dilation (FMD) or endothelial progenitor cells (EPCs), in patients with CVD. Secondly, we investigated the influence of other training variables (i.e., HIIT protocol). Methods: The PICOS strategy was used to identify randomised and non-randomised studies comparing the effect of HIIT and other exercise modalities (e.g., MIT) on endothelial function in patients with CVD. Electronic searches were carried out in Pubmed, Embase, and Web of Science up to November 2022. The TESTEX scale was used to evaluate the methodological quality of the included studies. Random-effects models of between-group mean difference (MD) were estimated. A positive MD indicated an effect in favour of HIIT. Heterogeneity analyses were performed by the chi-square test and I 2 index. Subgroup analyses evaluated the influence of potential moderator variables. Results: Fourteen studies (13; 92.9% randomised) were included. Most of the studies trained 3 days a week for 12 weeks and performed long HIIT. No statistically significant differences were found between HIIT and MIT for improving brachial FMD in patients with coronary artery disease (CAD) and heart failure with reduced ejection fraction (HFrEF) (8 studies; MD+ = 0.91% [95% confidence interval (CI) = -0.06, 1.88]). However, subgroup analyses showed that long HIIT (i.e., > 1 min) is better than MIT for enhancing FMD (5 studies; MD+ = 1.46% [95% CI = 0.35, 2.57]), while no differences were found between short HIIT (i.e., ≤ 1 min) and MIT (3 studies; MD+ = -0.41% [95% CI = -1.64, 0.82]). Insufficient data prevented pooled analysis for EPCs, and individual studies failed to find statistically significant differences (p > .050) between HIIT and other exercise modalities in increasing EPCs. Discussion: Poor methodological quality could limit the precision of the current results and increase the inconsistency. Long HIIT is superior to MIT for improving FMD in patients with CAD or HFrEF. Future studies comparing HIIT to other exercise modalities, as well as the effect on EPCs and in HF with preserved ejection fraction are required. Systematic Review Registration: https://www.crd.york.ac.uk/PROSPERO/#myprospero, identifier CRD42022358156.

Physical Activity as a Lifestyle Modification in Patients With Multiple Comorbidities: Emphasizing More on Obese, Prediabetic, and Type 2 Diabetes Mellitus Patients

In this research, physical activity (PA) was shown to be inversely associated with the incidence of diabetes. This emphasizes the relevance of PA in diabetes prevention lifestyle intervention initiatives and encourages healthcare practitioners to advise high-risk patients on a healthy lifestyle combining PA for the reduction of weight in prediabetic, obese, and type 2 diabetes mellitus (T2DM) patients. The link between PA and diabetes was stronger in people with moderate or higher baseline PA, reflecting national recommendations that imply increasing activity levels may provide larger advantages for those who are comparatively less active. An intensive lifestyle intervention of eating healthier foods and increasing PA resulted in an effective decrease in weight and waist circumference after one year, which has high potential in the long term to prevent T2DM and different comorbidities such as obesity. Studies such as PRomotion Of Physical activity through structured Education with differing Levels of ongoing Support for those with prediabetes (PROPELS) demonstrate that the combination of PA interventions with telemedicine follow-ups results in ambulatory activity changes in the first year, but these changes do not last longer than four years. Acute PA practicing regularly will reduce postprandial glucose excursions. However, it is unknown what type of PA routine will benefit the most from reducing postprandial glucose levels. There are no discernible variations in the effects of different disciplines of training on glucose levels, mainly when the data are compared across time. The combination of a healthy diet and lifestyle with programs based on diabetes prevention results in comparable and clinically significant mean weight reduction with cardiometabolic advantages. Based on the reviewed and cited studies, PA in patients at high risk of T2DM and obese and non-obese patients with T2DM results in favorable outcomes in the first few months. There is a large gap in investigations of the effects of PA in these patients and the benefits of other lifestyle modifications in long-term-based studies. However, in this study, we emphasize the importance of lifestyle modifications, putting in perspective principally the PA that the majority of patients with comorbidities do not practice, especially those with obesity, prediabetes, and T2DM. Thus, it would be necessary to conduct long-interval studies such as randomized clinical trials, where a better outcome can be given about intervals based on daily exercise times and the type of exercise in conjunction with diets that will have the greatest benefit, focusing more on the subjects that our research mentioned.

Improving Metabolic Syndrome in Ghanaian Adults with Type 2 Diabetes through a Home-Based Physical Activity Program: A Feasibility Randomised Controlled Trial

There is a high prevalence of metabolic syndrome (MetS) among people with type 2 diabetes mellitus (T2DM). Physical activity has the potential to improve health outcomes for individuals with type 2 diabetes. Our study aim was to determine the effect of a 12-week culturally appropriate home-based physical activity program on metabolic syndrome markers and quality of life in Ghanaian adults with T2DM. A secondary objective was to examine the feasibility of implementing the PA program. A feasibility randomised controlled trial (RCT) was conducted. A purposive sample of 87 adults with T2DM at the Korle-Bu Teaching Hospital, Ghana, were randomized into either the control group (CG) (n = 43) or the intervention group (IG) (n = 44). Participants in the IG received the physical activity program in addition to their usual diabetes care; those in the CG received their usual diabetes care. Measurements for feasibility, MetS markers, and quality of life (SF-12) were performed at baseline and 12-week follow-up. Following the 12-week program, participants in the IG showed a significant improvement in fasting blood glucose (2.4% vs. 0.4%, p < 0.05), waist circumference (5.4% vs. 0.4%, p < 0.05), and systolic blood pressure (9.8% vs. 1.5%, p < 0.05). There were no statistical differences between the IG and CG regarding high-density lipoprotein, triglycerides, and diastolic blood pressure at the 12-week follow-up. Classification of MetS were reduced in the IG compared to the CG (51.2% vs. 83.3%, p < 0.05). The MetS severity score improved in the IG compared to the CG (8.8% vs. 0.5%, p < 0.05). The IG improved in two of the eight SF-12 dimensions (physical function and vitality, p < 0.05) compared to the CG. Thirty-two (72.7%) participants completed all 36 exercise sessions. Another 11 (25%) participants completed 80% of the exercise sessions. No adverse events were reported. In conclusion, a 12-week home-based physical activity program is feasible and safe. The intervention has the potential to improve MetS and quality of life in Ghanaian adults with T2DM. The preliminary findings of this study need to be confirmed in a large-scale multi-centre RCT.

The Effect of High-Intensity Interval Training on Exercise Capacity in Patients with Coronary Artery Disease: A Systematic Review and Meta-Analysis

Background

The optimal exercise prescription for coronary artery disease (CAD) remains under debate. The aim of our meta-analysis is to investigate the efficacy of high-intensity interval training (HIIT) versus moderate-intensity continuous training (MICT) of coronary artery disease patients.

Methods

Electronic databases were searched from their inception date until October 23, 2021, and the articles include randomized controlled trials. The mean differences and 95% confidence intervals were calculated, and heterogeneity was assessed using the I ² test.

Results

The study standards were met by seventeen studies. The pooled studies included 902 patients. HIIT resulted in improvement in peak oxygen uptake (1.50 ml/kg/min, 95% confidence interval: 0.48 to 2.53, n = 853 patients, and low quality evidence) compared with MICT. There was no discernible difference between the individuals in the HIIT group and the MICT group in terms of systolic/diastolic blood pressure or peak/resting heart rate.

Conclusion

This systematic review and meta-analysis reported the superiority of HIIT versus MICT in enhancing peak oxygen uptake in CAD patients.

HIGH-INTENSITY INTERVAL TRAINING POSES NO RISK TO HYPERTENSIVE WOMEN

ABSTRACT Introduction: The aim of this study was to evaluate whether a single session of high-intensity interval training (HIIT) would promote a hypotensive effect and cardiovascular risk in hypertensive women, in addition to increasing the bioavailability of nitric oxide. Methods: The sample consisted of 10 hypertensive women (63.7 ± 10.34 years; 66 ± 7.67 kg and 153.7 ± 9.08 cm) and the training load was established at 60% of the maximum aerobic speed. Results: We observed a very high hypotensive effect between the interaction moments during the intervention (Int. Pre: 122.40 ± 18.58; Int. Post: 143.00 ± 24.90; Int. Post 60min: 121.40 ± 13.87; p<0.001, η2P = 0.569). No cardiovascular risk was observed during the intervention (DP = Int. Pre: 9138.20 ± 1805.34; Int. Post: 14849.70 ± 3387.94; Int. Post 60min: 9615.90 ± 1124.41, p< 0.001, η2P = 0.739) and there was no increase in the bioavailability of nitric oxide. Conclusion: In conclusion, this work reveals that an HIIT session is capable of generating a hypotensive effect while not posing cardiovascular risk in hypertensive women. Level of evidence I; High-quality randomized clinical trial with or without statistically significant difference, but with narrow confidence intervals .

Extraordinary claims in the literature on high-intensity interval training (HIIT): IV. Is HIIT associated with higher long-term exercise adherence?

Nonadherence to and dropout from regular exercise and physical activity are important reasons why the field of exercise science has yet to fulfill its promise of improving public health on a global scale. Researchers have claimed that High-Intensity Interval Training (HIIT) is a feasible and sustainable exercise modality that may result in higher long-term adherence than moderate-intensity continuous exercise. If true, this would be a breakthrough discovery that could unlock the potential of exercise as a health-promoting intervention. We performed a systematic search of the literature and identified eight trials comparing HIIT to moderate-intensity continuous exercise, all of which involved follow-up periods of at least 12 months (i.e., SWIFT, Small Steps for Big Changes, SAINTEX-CAD, SMARTEX-HF, Generation 100, FITR, OptimEx-Clin, HITTS). Findings from these trials demonstrate that, while unsupervised, individuals initially assigned to HIIT tend to exercise at lower-than-prescribed intensities and HIIT groups demonstrate no advantage in long-term adherence.

Effect of exercise training on cardiac mitochondrial respiration, biogenesis, dynamics, and mitophagy in ischemic heart disease

Objective

Cardiac mitochondrial dysfunction was found in ischemic heart disease (IHD). Hence, this study determined the effects of exercise training (ET) on cardiac mitochondrial respiration and cardiac mitochondrial quality control in IHD.

Methods

A narrative synthesis was conducted after searching animal studies written in English in three databases (PubMed, Web of Science, and EMBASE) until December 2020. Studies that used aerobic exercise as an intervention for at least 3 weeks and had at least normal, negative (sedentary IHD), and positive (exercise-trained IHD) groups were included. The CAMARADES checklist was used to check the quality of the included studies.

Results

The 10 included studies (CAMARADES score: 6–7/10) used swimming or treadmill exercise for 3–8 weeks. Seven studies showed that ET ameliorated cardiac mitochondrial respiratory function as manifested by decreased reactive oxygen species (ROS) production and increased complexes I-V activity, superoxide dismutase 2 (SOD2), respiratory control ratio (RCR), NADH dehydrogenase subunits 1 and 6 (ND1/6), Cytochrome B (CytB), and adenosine triphosphate (ATP) production. Ten studies showed that ET improved cardiac mitochondrial quality control in IHD as manifested by enhanced and/or controlled mitochondrial biogenesis, dynamics, and mitophagy. Four other studies showed that ET resulted in better cardiac mitochondrial physiological characteristics.

Conclusion

Exercise training could improve cardiac mitochondrial functions, including respiration, biogenesis, dynamics, and mitophagy in IHD.

Systematic review registration

https://www.crd.york.ac.uk/prospero/display_record.php?RecordID=226817, identifier: CRD42021226817.

Exercise and obstructive sleep apnoea: a 24-week follow-up study

Objective

Report on long-term follow-up results in the apnoea hypopnea index (AHI) and self-reported daytime sleepiness in participants with moderate to severe obstructive sleep apnoea at 12 weeks after completion of a high-intensity exercise training or control intervention.

Methods

Twenty-six participants with obstructive sleep apnoea (body mass index (BMI) 37 (36-39) kg/m, age 52 (49-55) years, apnoea-hypopnoea index 40.5 (31.3-50.2) events/hour), randomised to either 12 weeks of supervised high-intensity interval training (HIIT) (4×4 min of treadmill running or walking at 90%-95% of maximal heart rate) or no intervention (control), underwent a sleep evaluation follow-up 24 weeks after intervention initiation. Respiratory measures during sleep were registered at baseline, 12 weeks (postintervention) and 24 weeks (long-term follow-up).

Results

At the 24-week follow-up, there were no statistically significant differences between the groups in the AHI (HIIT 30.7 (17.2-44.1) and control 38.7 (22.8-54.5) events/hour), Epworth score (HIIT 7.0 (4.7-9.3) and control 5.5 (3.9-7.0)), mean oxygen saturation (HIIT 93.2 (92.5-93.9) and control 92.0 (91.1-92.8)) or oxygen desaturation events (HIIT 32.9 (20.4-45.4) and control 44.3 (27.3-61.3) n/hour). BMI remained unchanged from the baseline in both groups. In the HIIT group, only two participants reported having continued with HIIT at 24 weeks.

Conclusion

The effect of 12 weeks of supervised high-intensity exercise training on AHI and self-reported daytime sleepiness was lost at the 24-week follow-up.

Short- and Long-Term Effects of High-Intensity Interval Training vs. Moderate-Intensity Continuous Training on Left Ventricular Remodeling in Patients Early After ST-Segment Elevation Myocardial Infarction—The HIIT-EARLY Randomized Controlled Trial

Aim

Due to insufficient evidence on the safety and effectiveness of high-intensity interval training (HIIT) in patients early after ST-segment elevation myocardial infarction (STEMI), we aimed to compare short- and long-term effects of randomized HIIT or moderate-intensity continuous training (MICT) on markers of left ventricular (LV) remodeling in STEMI patients receiving optimal guideline-directed medical therapy (GDMT).

Materials and Methods

Patients after STEMI (<4 weeks) enrolled in a 12-week cardiac rehabilitation (CR) program were recruited for this randomized controlled trial (NCT02627586). During a 3-week run-in period with three weekly MICT sessions, GDMT was up-titrated. Then, the patients were randomized to HIIT or isocaloric MICT for 9 weeks. Echocardiography and cardiopulmonary exercise tests were performed after run-in (3 weeks), end of CR (12 weeks), and at 1-year follow-up. The primary outcome was LV end-diastolic volume index (LVEDVi) at the end of CR. Secondary outcomes were LV global longitudinal strain (GLS) and cardiopulmonary fitness.

Results

Seventy-three male patients were included, with the time between STEMI and start of CR and randomization being 12.5 ± 6.3 and 45.8 ± 10.8 days, respectively. Mixed models revealed no significant group × time interaction for LVEDVi at the end of CR (p = 0.557). However, there was a significantly smaller improvement in GLS at 1-year follow-up in the HIIT compared to the MICT group (p = 0.031 for group × time interaction). Cardiorespiratory fitness improved significantly from a median value of 26.5 (1st quartile 24.4; 3rd quartile 1.1) ml/kg/min at randomization in the HIIT and 27.7 (23.9; 31.6) ml/kg/min in the MICT group to 29.6 (25.3; 32.2) and 29.9 (26.1; 34.9) ml/kg/min at the end of CR and to 29.0 (26.6; 33.3) and 30.6 (26.0; 33.8) ml/kg/min at 1 year follow-up in HIIT and MICT patients, respectively, with no significant group × time interactions (p = 0.138 and 0.317).

Conclusion

In optimally treated patients early after STEMI, HIIT was not different from isocaloric MICT with regard to short-term effects on LVEDVi and cardiorespiratory fitness. The worsening in GLS at 1 year in the HIIT group deserves further investigation, as early HIIT may offset the beneficial effects of GDMT on LV remodeling in the long term.

Evaluation of Maintained PhysicAl CaPacity 1-yr After Coronary Patient Cardiac Rehabilitation (EMAP): A FRENCH MULTICENTER STUDY

PURPOSE

Data are scarce concerning the sustainable effects of cardiac rehabilitation (CR), on cardiorespiratory fitness (CRF) of patients with coronary artery disease (CAD). This study, carried out using data from a French multicenter study, aimed to clarify the evolution of the CRF of patients with CAD 1 yr after the end of a CR stay.

METHODS

Patients were included after an acute coronary syndrome (77%) and/or coronary revascularization, occurring <3 mo beforehand. All underwent a CR program with CRF evaluation by exercise testing (ET) on a cycle ergometer at the beginning of CR (ET1), at its end (ET2), and 1 yr later (ET3)-all ETs were performed with medication.

RESULTS

Two hundred fifty-nine patients were included (age 60 ± 10 yr, 89% male) in 16 French CR centers. Left ventricular ejection fraction was 55.3 ± 9%. Revascularization was complete (82%). Maximal workloads were 110 ± 37 (ET1), 139 ± 43 (ET2), and 144 ± 46 W (ET3) (P< .001). The estimated metabolic equivalents of the task (METs) were respectively 5.3 ± 1.4, 6.4 ± 1.6 (P< .001), and 6.6 ± 1.7 (P< .002). One year later, 163 patients (63%) improved or maintained their CRF (ET3 ≥ ET2), 73 (28%) decreased (ET1 < ET3 < ET2), and 23 (9%) lost the benefit of CR (ET3 ≤ ET1).

CONCLUSION

Among completers who agreed to enroll in this study, most patients with CAD seem to maintain their CRF 1 yr after CR.

Effects of High-Intensity Interval vs. Moderate-Intensity Continuous Training on Cardiac Rehabilitation in Patients With Cardiovascular Disease: A Systematic Review and Meta-Analysis

Background

Studies have shown that high-intensity interval training (HIIT) is superior to moderate-intensity continuous training (MICT) for increasing peak oxygen uptake (VO_2peak) and reducing cardiovascular disease (CVD) and mortality. To our knowledge, previously published systematic reviews have neither compared different HIIT models with MICT nor investigated intervention frequencies of HIIT vs. MICT for purposes of improving cardiorespiratory fitness in patients with CVD.

Objective

The purpose of this meta-analysis was to compare the effects of different training models, intervention frequencies and weeks of HIIT vs. MICT on changes in cardiorespiratory fitness during cardiac rehabilitation (CR).

Methods

A systematic search was carried out for research articles on randomized controlled trials (RCTs) indexed in the PubMed, Cochrane Library, Web of Science, Embase and Scopus databases for the period up to December 2021. We searched for RCTs that compared the effect of HIIT vs. MICT on cardiorespiratory fitness in patients with CVD.

Results

Twenty-two studies with 949 participants (HIIT: 476, MICT: 473) met the inclusion criteria. Sensitivity analysis revealed that HIIT increased VO_2peak more than MICT (MD = 1.35). In the training models and durations, there was a greater increase in VO_2peak with medium-interval HIIT (MD = 4.02) and more than 12 weeks duration (MD = 2.35) than with MICT. There were significant improvements in VO_2peak with a HIIT frequency of 3 times/week (MD = 1.28). Overall, one minor cardiovascular and four non-cardiovascular adverse events were reported in the HIIT group, while six non-cardiovascular adverse events were reported in the MICT group.

Conclusion

HIIT is safe and appears to be more effective than MICT for improving cardiorespiratory fitness in patients with CVD. Medium-interval HIIT 3 times/week for more than 12 weeks resulted in the largest improvement in cardiorespiratory fitness during CR.

Systematic Review Registration

https://www.crd.york.ac.uk/prospero/display_record.php?ID=CRD42021245810, identifier: CRD42021245810.

State of Knowledge on Molecular Adaptations to Exercise in Humans: Historical Perspectives and Future Directions

For centuries, regular exercise has been acknowledged as a potent stimulus to promote, maintain, and restore healthy functioning of nearly every physiological system of the human body. With advancing understanding of the complexity of human physiology, continually evolving methodological possibilities, and an increasingly dire public health situation, the study of exercise as a preventative or therapeutic treatment has never been more interdisciplinary, or more impactful. During the early stages of the NIH Common Fund Molecular Transducers of Physical Activity Consortium (MoTrPAC) Initiative, the field is well-positioned to build substantially upon the existing understanding of the mechanisms underlying benefits associated with exercise. Thus, we present a comprehensive body of the knowledge detailing the current literature basis surrounding the molecular adaptations to exercise in humans to provide a view of the state of the field at this critical juncture, as well as a resource for scientists bringing external expertise to the field of exercise physiology. In reviewing current literature related to molecular and cellular processes underlying exercise-induced benefits and adaptations, we also draw attention to existing knowledge gaps warranting continued research effort. © 2021 American Physiological Society. Compr Physiol 12:3193-3279, 2022.

The High-Intensity Exercise Study to Attenuate Limitations and Train Habits in Older Adults With HIV (HEALTH): A Research Protocol

ABSTRACT

The High-Intensity Exercise Study to Attenuate Limitations and Train Habits in Older Adults With HIV (HEALTH), which incorporates an exercise and biobehavioral coaching intervention, has the following overall goals: (a) to determine whether high-intensity interval training (HIIT) mitigates physical function impairments, fatigue, and impairments in mitochondrial bioenergetics of older people living with HIV (PLWH) to a greater extent than continuous moderate exercise (CME); and (b) to determine whether a biobehavioral coaching and mobile health text messaging intervention after HIIT or CME can promote long-term adherence to physical activity. The HEALTH study is a randomized trial of 100 older PLWH (≥50 years of age) who self-report fatigue and have a sedentary lifestyle. Enrolled participants will be randomized to 16 weeks of supervised HIIT or CME training, followed by a 12-week maintenance phase, involving a mobile health coaching intervention. Outcomes of the HEALTH study will inform the development of scalable, effective exercise recommendations tailored to the unique needs of aging PLWH.

Exercise intensity assessment and prescription in cardiovascular rehabilitation and beyond: why and how: a position statement from the Secondary Prevention and Rehabilitation Section of the European Association of Preventive Cardiology

A proper determination of the exercise intensity is important for the rehabilitation of patients with cardiovascular disease (CVD) since it affects the effectiveness and medical safety of exercise training. In 2013, the European Association of Preventive Cardiology (EAPC), together with the American Association of Cardiovascular and Pulmonary Rehabilitation and the Canadian Association of Cardiac Rehabilitation, published a position statement on aerobic exercise intensity assessment and prescription in cardiovascular rehabilitation (CR). Since this publication, many subsequent papers were published concerning the determination of the exercise intensity in CR, in which some controversies were revealed and some of the commonly applied concepts were further refined. Moreover, how to determine the exercise intensity during resistance training was not covered in this position paper. In light of these new findings, an update on how to determine the exercise intensity for patients with CVD is mandatory, both for aerobic and resistance exercises. In this EAPC position paper, it will be explained in detail which objective and subjective methods for CR exercise intensity determination exist for aerobic and resistance training, together with their (dis)advantages and practical applications.

High level physical activity in cardiac rehabilitation: Implications for exercise training and leisure-time pursuits

IMPORTANCE

Regular moderate-to-vigorous physical activity and increased levels of cardiorespiratory fitness (CRF) are widely promoted as cardioprotective measures in secondary prevention interventions.

OBSERVATIONS

A low level of CRF increases the risk of cardiovascular disease (CVD) to a greater extent than merely being physically inactive. An exercise capacity <5 metabolic equivalents (METs), generally corresponding to the bottom 20% of the fitness continuum, indicates a higher mortality group. Accordingly, a key objective in early cardiac rehabilitation (CR) is to increase the intensity of training to >3 METs, to empower patients to vacate this "high risk" group. Moreover, a "good" exercise capacity, expressed as peak METs, identifies individuals with a favorable long-term prognosis, regardless of the underlying extent of coronary disease. On the other hand, vigorous-to-high intensity physical activity, particularly when unaccustomed, and some competitive sports are associated with a greater incidence of acute cardiovascular events. Marathon and triathlon training/competition also have limited applicability and value in CR, are associated with acute cardiac events each year, and do not necessarily provide immunity to the development of or the progression of CVD. Furthermore, extreme endurance exercise regimens are associated with an increased incidence of atrial fibrillation and accelerated coronary artery calcification.

CONCLUSIONS AND RELEVANCE

High-intensity training offers a time-saving alternative to moderate intensity continuous training, as well as other potential advantages. Additional long-term studies assessing safety, adherence, and morbidity and mortality are required before high-intensity CR training can be more widely recommended, especially in previously sedentary patients with known or suspected CVD exercising in non-medically supervised settings.

Optimizing Outcomes in Cardiac Rehabilitation: The Importance of Exercise Intensity

Exercise based cardiac rehabilitation (CR) is recognized internationally as a class 1 clinical practice recommendation for patients with select cardiovascular diseases and heart failure with reduced ejection fraction. Over the past decade, several meta-analyses have generated debate regarding the effectiveness of exercise-based CR for reducing all-cause and cardiovascular mortality. A common theme highlighted in these meta-analyses is the heterogeneity and/or lack of detail regarding exercise prescription methodology within CR programs. Currently there is no international consensus on exercise prescription for CR, and exercise intensity recommendations vary considerably between countries from light-moderate intensity to moderate intensity to moderate-vigorous intensity. As cardiorespiratory fitness [peak oxygen uptake (VO₂peak)] is a strong predictor of mortality in patients with coronary heart disease and heart failure, exercise prescription that optimizes improvement in cardiorespiratory fitness and exercise capacity is a critical consideration for the efficacy of CR programming. This review will examine the evidence for prescribing higher-intensity aerobic exercise in CR, including the role of high-intensity interval training. This discussion will highlight the beneficial physiological adaptations to pulmonary, cardiac, vascular, and skeletal muscle systems associated with moderate-vigorous exercise training in patients with coronary heart disease and heart failure. Moreover, this review will propose how varying interval exercise protocols (such as short-duration or long-duration interval training) and exercise progression models may influence central and peripheral physiological adaptations. Importantly, a key focus of this review is to provide clinically-relevant recommendations and strategies to optimize prescription of exercise intensity while maximizing safety in patients attending CR programs.

Can high-intensity interval training improve mental health outcomes in the general population and those with physical illnesses? A systematic review and meta-analysis

OBJECTIVE

High-intensity interval training (HIIT) is a safe and feasible form of exercise. The aim of this meta-analysis was to investigate the mental health effects of HIIT, in healthy populations and those with physical illnesses, and to compare the mental health effects to non-active controls and other forms of exercise.

DESIGN

Random effects meta-analyses were undertaken for randomised controlled trials (RCTs) comparing HIIT with non-active and/or active (exercise) control conditions for the following coprimary outcomes: mental well-being, symptoms of depression, anxiety and psychological stress. Positive and negative affect, distress and sleep outcomes were summarised narratively.

DATA SOURCES

Medline, PsycINFO, Embase and CENTRAL databases were searched from inception to 7 July 2020.

ELIGIBILITY CRITERIA FOR SELECTING STUDIES

RCTs that investigated HIIT in healthy populations and/or those with physical illnesses and reported change in mental well-being, depression, anxiety, psychological stress, positive/negative affect, distress and/or sleep quality.

RESULTS

Fifty-eight RCTs were retrieved. HIIT led to moderate improvements in mental well-being (standardised mean difference (SMD): 0.418; 95% CI: 0.135 to 0.701; n=12 studies), depression severity (SMD: -0.496; 95% CI: -0.973 to -0.020; n=10) and perceived stress (SMD: -0.474; 95% CI: -0.796 to -0.152; n=4) compared with non-active controls, and small improvements in mental well-being compared with active controls (SMD:0.229; 95% CI: 0.054 to 0.403; n=12). There was a suggestion that HIIT may improve sleep and psychological distress compared with non-active controls: however, these findings were based on a small number of RCTs.

CONCLUSION

These findings support the use of HIIT for mental health in the general population.

LEVEL OF EVIDENCE

The quality of evidence was moderate-to-high according to the Grading of Recommendations Assessment, Development and Evaluation) criteria.

PROSPERO REGISTRATION NUMBER

CRD42020182643.

Genome wide association study of response to interval and continuous exercise training: the Predict-HIIT study

BACKGROUND

Low cardiorespiratory fitness (V̇O_2peak) is highly associated with chronic disease and mortality from all causes. Whilst exercise training is recommended in health guidelines to improve V̇O_2peak, there is considerable inter-individual variability in the V̇O_2peak response to the same dose of exercise. Understanding how genetic factors contribute to V̇O_2peak training response may improve personalisation of exercise programs. The aim of this study was to identify genetic variants that are associated with the magnitude of V̇O₂peak response following exercise training.

METHODS

Participant change in objectively measured V̇O₂peak from 18 different interventions was obtained from a multi-centre study (Predict-HIIT). A genome-wide association study was completed (n = 507), and a polygenic predictor score (PPS) was developed using alleles from single nucleotide polymorphisms (SNPs) significantly associated (P < 1 × 10^-5) with the magnitude of V̇O₂peak response. Findings were tested in an independent validation study (n = 39) and compared to previous research.

RESULTS

No variants at the genome-wide significance level were found after adjusting for key covariates (baseline V̇O₂peak_, individual study, principal components which were significantly associated with the trait). A Quantile-Quantile plot indicates there was minor inflation in the study. Twelve novel loci showed a trend of association with V̇O₂peak response that reached suggestive significance (P < 1 × 10^-5). The strongest association was found near the membrane associated guanylate kinase, WW and PDZ domain containing 2 (MAGI2) gene (rs6959961, P = 2.61 × 10^-7). A PPS created from the 12 lead SNPs was unable to predict V̇O₂peak response in a tenfold cross validation, or in an independent (n = 39) validation study (P > 0.1). Significant correlations were found for beta coefficients of variants in the Predict-HIIT (P < 1 × 10^-4) and the validation study (P <  × 10^-6), indicating that general effects of the loci exist, and that with a higher statistical power, more significant genetic associations may become apparent.

CONCLUSIONS

Ongoing research and validation of current and previous findings is needed to determine if genetics does play a large role in V̇O₂peak response variance, and whether genomic predictors for V̇O₂peak response trainability can inform evidence-based clinical practice. Trial registration Australian New Zealand Clinical Trials Registry (ANZCTR), Trial Id: ACTRN12618000501246, Date Registered: 06/04/2018, http://www.anzctr.org.au/Trial/Registration/TrialReview.aspx?id=374601&isReview=true .

Adherence to High-Intensity Interval Training in Cardiac Rehabilitation: A REVIEW AND RECOMMENDATIONS

PURPOSE

High-intensity interval training (HIIT) is gaining popularity as a training approach for patients attending cardiac rehabilitation (CR). While the literature has focused on the efficacy of HIIT for improving cardiorespiratory fitness (CRF), particularly when compared with moderate intensity exercise, less emphasis has been placed on adherence to HIIT. The aim of this review was to summarize the current literature regarding adherence to HIIT in CR patients with coronary artery disease.

REVIEW METHODS

A review identified 36 studies investigating HIIT in CR patients with coronary artery disease. Methods and data were extracted for exercise or training adherence (to attendance, intensity, and duration), feasibility of protocols, and CRF. The review summarizes reporting of adherence; adherence to HIIT and comparator/s; the influence of adherence on changes in CRF; and feasibility of HIIT.

SUMMARY

Adherence to the attendance of HIIT sessions was high and comparable with moderate-intensity exercise. However, adherence to the intensity and duration of HIIT was variable and underreported, which has implications for determining the treatment effect of the exercise interventions being compared. Furthermore, additional research is needed to investigate the utility of home-based HIIT and long-term adherence to HIIT following supervised programs. This review provides recommendations for researchers in the measurement and reporting of adherence to HIIT and other exercise interventions to facilitate a sufficient and consistent approach for future studies. This article also highlights strategies for clinicians to improve adherence, feasibility, and enjoyment of HIIT for their patients.

Effect of self-tailored high-intensity interval training versus moderate-intensity continuous exercise on cardiorespiratory fitness after myocardial infarction: A randomized controlled trial

BACKGROUND

Whether high-intensity interval training (HIIT) is more efficient than moderate-intensity continuous exercise (MICE) to increase cardiorespiratory fitness in patients with acute coronary syndrome at moderate-to-high cardiovascular risk is controversial. The best approach to guide training intensity remains to be determined.

OBJECTIVE

We aimed to assess intensities achieved with self-tailored HIIT and MICE according to perceived exertion and to compare the effect on cardiorespiratory fitness in patients early after ST-elevation myocardial infarction (STEMI).

METHODS

We included 69 males starting cardiac rehabilitation within 4 weeks after STEMI. After a 3-week run-in phase with MICE, 35 patients were randomized to 9 weeks of HIIT (2×HIIT and 1×MICE per week) and 34 patients to MICE (3×MICE). Training workload for MICE was initially set at the patients' first ventilatory threshold (VT). HIIT consisted of 4×4-min intervals with a workload above the second VT in high intervals. Training intensity was adjusted weekly to maintain the perceived exertion (Borg score 13-14 for MICE, ≥15 for HIIT). Session duration was 38 min in both groups. Peak oxygen consumption (VO2) was measured by cardiopulmonary exercise testing pre- and post-intervention.

RESULTS

Both groups improved peak VO2 (ml/kg/min) (HIIT +1.9, p<0.001; MICE +3.2, p<0.001, Cohen's d -0.4), but changes in VO2 were not significantly different between groups (p=0.104). Exercise regimes did not differ between groups in terms of energy expenditure or training time, but perceived exertion was higher with HIIT.

CONCLUSIONS

Self-tailored HIIT was feasible in patients early after STEMI. It was more strenuous but not superior nor more time efficient than MICE in improving peak VO2.

Secondary prevention through comprehensive cardiovascular rehabilitation: From knowledge to implementation. 2020 update. A position paper from the Secondary Prevention and Rehabilitation Section of the European Association of Preventive Cardiology

Secondary prevention through comprehensive cardiac rehabilitation has been recognized as the most cost-effective intervention to ensure favourable outcomes across a wide spectrum of cardiovascular disease, reducing cardiovascular mortality, morbidity and disability, and to increase quality of life. The delivery of a comprehensive and 'modern' cardiac rehabilitation programme is mandatory both in the residential and the out-patient setting to ensure expected outcomes. The present position paper aims to update the practical recommendations on the core components and goals of cardiac rehabilitation intervention in different cardiovascular conditions, in order to assist the whole cardiac rehabilitation staff in the design and development of the programmes, and to support healthcare providers, insurers, policy makers and patients in the recognition of the positive nature of cardiac rehabilitation. Starting from the previous position paper published in 2010, this updated document maintains a disease-oriented approach, presenting both well-established and more controversial aspects. Particularly for implementation of the exercise programme, advances in different training modalities were added and new challenging populations were considered. A general table applicable to all cardiovascular conditions and specific tables for each clinical condition have been created for routine practice.

Cardiac rehabilitation of elderly patients in eight rehabilitation units in western Europe: Outcome data from the EU-CaRE multi-centre observational study

Aims

The European Cardiac Rehabilitation in the Elderly (EU-CaRE) HORIZON 2020 project compares the sustainable effects of cardiac rehabilitation (CR) in elderly patients.

Methods and results

A total of 1633 patients with coronary artery disease (CAD) or heart valve replacement (HVR), with or without revascularization, aged 65 or above, who participated in CR were included. Peak oxygen uptake (VO2peak), smoking, body mass index, diet, physical activity, serum lipids, psychological distress and medication were assessed before and after CR (T0 and T1) and after 12 months (T2). Patients undergoing coronary artery bypass surgery or surgical HVR had lower VO2peak at T0 and a greater increase to T1 and T2 (2.8 and 4.4 ml/kg/min, respectively) than CAD patients undergoing percutaneous or no revascularization (1.6 and 1.4 ml/kg/min, respectively). After multivariable adjustment, earlier CR uptake was associated with greater improvements in VO2peak. The proportion of CAD patients with three or more uncontrolled risk factors declined from 58.4% at T0 to 40.1% at T2 ( p < 0.0001). Psychological distress scores all improved and adherence to medication was overall good at all sites. There were significant differences in risk factor burden across sites, but no CR program was superior to others.

Conclusions

The outcomes of VO2peak in CR programs across Europe seemed mainly determined by timing of uptake and were maintained or even further improved at 1-year follow-up. Despite significant improvements, 40.1% of CAD patients still had three or more risk factors not at target after 1 year. Differences across sites could not be ascribed to characteristics of the CR programs offered.

Home-based exercise with telemonitoring guidance in patients with coronary artery disease: Does it improve long-term physical fitness?

BACKGROUND

Home-based interventions might facilitate the lifelong uptake of a physically active lifestyle following completion of a supervised phase II exercise-based cardiac rehabilitation. Yet, data on the long-term effectiveness of home-based exercise training on physical activity and exercise capacity are scarce.

OBJECTIVE

The purpose of the TeleRehabilitation in Coronary Heart disease (TRiCH) study was to compare the long-term effects of a short home-based phase III exercise programme with telemonitoring guidance to a prolonged centre-based phase III programme in coronary artery disease patients. The primary outcome was exercise capacity. Secondary outcomes included physical activity behaviour, cardiovascular risk profile and health-related quality of life.

METHODS

Ninety coronary artery disease patients (80 men) were randomly assigned to 3 months of home-based (30), centre-based (30) or a control group (30) on a 1:1:1 basis after completion of their phase II ambulatory cardiac rehabilitation programme. Outcome measures were assessed at discharge of the phase II programme and after one year.

RESULTS

Eighty patients (72 (91%) men; mean age 62.6 years) completed the one-year follow-up measurements. Exercise capacity and secondary outcomes were preserved in all three groups (P_time > 0.05 for all), irrespective of the intervention (P_interaction > 0.05 for all). Eighty-five per cent of patients met the international guidelines for physical activity (P_time < 0.05). No interaction effect was found for physical activity.

CONCLUSION

Overall, exercise capacity remained stable during one year following phase II cardiac rehabilitation. Our home-based exercise intervention was as effective as centre-based and did not result in higher levels of exercise capacity and physical activity compared to the other two interventions.

TRIAL REGISTRATION

ClinicalTrials.gov NCT02047942. https://clinicaltrials.gov/ct2/show/NCT02047942.

Exercise as a prescription for patients with various diseases

A growing understanding of the benefits of exercise over the past few decades has prompted researchers to take an interest in the possibilities of exercise therapy. Because each sport has its own set of characteristics and physiological complications that tend to occur during exercise training, the effects and underlying mechanisms of exercise remain unclear. Thus, the first step in probing the effects of exercise on different diseases is the selection of an optimal exercise protocol. This review summarizes the latest exercise prescription treatments for 26 different diseases: musculoskeletal system diseases (low back pain, tendon injury, osteoporosis, osteoarthritis, and hip fracture), metabolic system diseases (obesity, type 2 diabetes, type 1 diabetes, and nonalcoholic fatty liver disease), cardio-cerebral vascular system diseases (coronary artery disease, stroke, and chronic heart failure), nervous system diseases (Parkinson's disease, Huntington's disease, Alzheimer's disease, depression, and anxiety disorders), respiratory system diseases (chronic obstructive pulmonary disease, interstitial lung disease, and after lung transplantation), urinary system diseases (chronic kidney disease and after kidney transplantation), and cancers (breast cancer, colon cancer, prostate cancer, and lung cancer). Each exercise prescription is displayed in a corresponding table. The recommended type, intensity, and frequency of exercise prescriptions are summarized, and the effects of exercise therapy on the prevention and rehabilitation of different diseases are discussed.

Interval Endurance and Resistance Training as Part of a Community-Based Secondary Prevention Program for Patients With Diabetes Mellitus and Coronary Artery Disease

PURPOSE

High-intensity interval training (HIIT) has been observed to improve health and fitness in patients with cardiovascular disease. High-intensity interval training may not be appropriate in community-based settings. Moderate-intensity interval training (MIIT) and resistance training (RT) are emerging as effective alternatives to HIIT. These have not been well investigated in a community-based cardiac maintenance program.

METHODS

Patients with coronary artery disease and/or diabetes mellitus participated in clinical examinations and a 6-mo exercise program. Center-based MIIT and home-based moderate continuous intensity exercise were performed for 3-5 d/wk for 30-40 min/session. RT, nutritional counseling, coping, and behavioral change strategies were offered to all patients. Within-group changes in clinical metrics and exercise performance were assessed on a per-protocol basis after 6 mo.

RESULTS

Two hundred ninety-two patients (74%) concluded the 6-mo program. There were no serious adverse events. The peak oxygen uptake and peak workload increased significantly, 21.8 ± 6.1 to 22.8 ± 6.3 mL/kg/min and 128 ± 39 to 138 ± 43 W, respectively (both P < .001). Submaximal exercise performance increased from 68 ± 19 to 73 ± 22 W (P < .001). Glycated hemoglobin decreased from 6.57 ± 0.93% to 6.43 ± 0.12%, (P = .023). Daily injected insulin dosage was reduced from 42 IU (interquartile range: 19.0, 60.0) to 26 IU (interquartile range: 0, 40.3, P < .001).

CONCLUSIONS

MIIT and RT were feasible and effective in a community-based cardiac maintenance program for patients with cardiovascular disease, improving exercise performance, and blood glucose control.

Benefits and Risks of High-Intensity Interval Training in Patients With Coronary Artery Disease

Exercise-based cardiac rehabilitation is integral to secondary prevention in patients with coronary artery disease. Recently, the effectiveness and "superiority" of high-intensity interval training (HIIT) is a purported time-saving alternative to "traditional" moderate-intensity continuous training (MICT) in cardiac rehabilitation. The rationale for HIIT adoption is, however, not fully substantiated in the scientific literature. Established guidelines for exercise testing and training, when carefully adhered to, reduce the likelihood of triggering a cardiac event or inducing musculoskeletal injury. Clinicians should likewise consider patient risk stratification and introduce HIIT as an alternative to MICT only after patients exhibit stable and asymptomatic responses to vigorous exercise training. Although HIIT adherence appears comparable with MICT during outpatient rehabilitation, compliance drops dramatically for unsupervised exercise. Despite the enthusiasm surrounding HIIT, its main advantage over MICT appears to be short-term exercise performance outcomes and indices of vascular function. Regarding benefits to cardiovascular disease risk factor modification, management of vital signs, and measures of cardiac performance, current evidence indicates that HIIT does not outperform MICT. Long-term outcomes to HIIT are currently uncertain and logistical constraints to HIIT incorporation need additional clarification. Based on these limited findings, derived from facilities and clinicians at the forefront of cardiac rehabilitation, the routine adoption of HIIT should be viewed cautiously. In conclusion, the current review highlights numerous specific research directives that are needed before the safety and effectiveness of HIIT can be confirmed and widely adopted in patients with known or suspected coronary artery disease, especially in unsupervised, nonmedical settings.

A Multi-Center Comparison of O2peak Trainability Between Interval Training and Moderate Intensity Continuous Training

There is heterogeneity in the observed O_2peak response to similar exercise training, and different exercise approaches produce variable degrees of exercise response (trainability). The aim of this study was to combine data from different laboratories to compare O_2peak trainability between various volumes of interval training and Moderate Intensity Continuous Training (MICT). For interval training, volumes were classified by the duration of total interval time. High-volume High Intensity Interval Training (HIIT) included studies that had participants complete more than 15 min of high intensity efforts per session. Low-volume HIIT/Sprint Interval Training (SIT) included studies using less than 15 min of high intensity efforts per session. In total, 677 participants across 18 aerobic exercise training interventions from eight different universities in five countries were included in the analysis. Participants had completed 3 weeks or more of either high-volume HIIT (n = 299), low-volume HIIT/SIT (n = 116), or MICT (n = 262) and were predominately men (n = 495) with a mix of healthy, elderly and clinical populations. Each training intervention improved mean O_2peak at the group level (P < 0.001). After adjusting for covariates, high-volume HIIT had a significantly greater (P < 0.05) absolute O_2peak increase (0.29 L/min) compared to MICT (0.20 L/min) and low-volume HIIT/SIT (0.18 L/min). Adjusted relative O_2peak increase was also significantly greater (P < 0.01) in high-volume HIIT (3.3 ml/kg/min) than MICT (2.4 ml/kg/min) and insignificantly greater (P = 0.09) than low-volume HIIT/SIT (2.5 mL/kg/min). Based on a high threshold for a likely response (technical error of measurement plus the minimal clinically important difference), high-volume HIIT had significantly more (P < 0.01) likely responders (31%) compared to low-volume HIIT/SIT (16%) and MICT (21%). Covariates such as age, sex, the individual study, population group, sessions per week, study duration and the average between pre and post O_2peak explained only 17.3% of the variance in O_2peak trainability. In conclusion, high-volume HIIT had more likely responders to improvements in O_2peak compared to low-volume HIIT/SIT and MICT.

Interventions to promote patient utilisation of cardiac rehabilitation

BACKGROUND

International clinical practice guidelines routinely recommend that cardiac patients participate in rehabilitation programmes for comprehensive secondary prevention. However, data show that only a small proportion of these patients utilise rehabilitation.

OBJECTIVES

First, to assess interventions provided to increase patient enrolment in, adherence to, and completion of cardiac rehabilitation. Second, to assess intervention costs and associated harms, as well as interventions intended to promote equitable CR utilisation in vulnerable patient subpopulations.

SEARCH METHODS

Review authors performed a search on 10 July 2018, to identify studies published since publication of the previous systematic review. We searched the Cochrane Central Register of Controlled Trials (CENTRAL); the National Health Service (NHS) Centre for Reviews and Dissemination (CRD) databases (Health Technology Assessment (HTA) and Database of Abstracts of Reviews of Effects (DARE)), in the Cochrane Library (Wiley); MEDLINE (Ovid); Embase (Elsevier); the Cumulative Index to Nursing and Allied Health Literature (CINAHL) (EBSCOhost); and Conference Proceedings Citation Index - Science (CPCI-S) on Web of Science (Clarivate Analytics). We checked the reference lists of relevant systematic reviews for additional studies and also searched two clinical trial registers. We applied no language restrictions.

SELECTION CRITERIA

We included randomised controlled trials (RCTs) in adults with myocardial infarction, with angina, undergoing coronary artery bypass graft surgery or percutaneous coronary intervention, or with heart failure who were eligible for cardiac rehabilitation. Interventions had to aim to increase utilisation of comprehensive phase II cardiac rehabilitation. We included only studies that measured one or more of our primary outcomes. Secondary outcomes were harms and costs, and we focused on equity.

DATA COLLECTION AND ANALYSIS

Two review authors independently screened the titles and abstracts of all identified references for eligibility, and we obtained full papers of potentially relevant trials. Two review authors independently considered these trials for inclusion, assessed included studies for risk of bias, and extracted trial data independently. We resolved disagreements through consultation with a third review author. We performed random-effects meta-regression for each outcome and explored prespecified study characteristics.

MAIN RESULTS

Overall, we included 26 studies with 5299 participants (29 comparisons). Participants were primarily male (64.2%). Ten (38.5%) studies included patients with heart failure. We assessed most studies as having low or unclear risk of bias. Sixteen studies (3164 participants) reported interventions to improve enrolment in cardiac rehabilitation, 11 studies (2319 participants) reported interventions to improve adherence to cardiac rehabilitation, and seven studies (1567 participants) reported interventions to increase programme completion. Researchers tested a variety of interventions to increase utilisation of cardiac rehabilitation. In many studies, this consisted of contacts made by a healthcare provider during or shortly after an acute care hospitalisation.Low-quality evidence shows an effect of interventions on increasing programme enrolment (19 comparisons; risk ratio (RR) 1.27, 95% confidence interval (CI) 1.13 to 1.42). Meta-regression revealed that the intervention deliverer (nurse or allied healthcare provider; P = 0.02) and the delivery format (face-to-face; P = 0.01) were influential in increasing enrolment. Low-quality evidence shows interventions to increase adherence were effective (nine comparisons; standardised mean difference (SMD) 0.38, 95% CI 0.20 to 0.55), particularly when they were delivered remotely, such as in home-based programs (SMD 0.56, 95% CI 0.37 to 0.76). Moderate-quality evidence shows interventions to increase programme completion were also effective (eight comparisons; RR 1.13, 95% CI 1.02 to 1.25), but those applied in multi-centre studies were less effective than those given in single-centre studies, leading to questions regarding generalisability. A moderate level of statistical heterogeneity across intervention studies reflects heterogeneity in intervention approaches. There was no evidence of small-study bias for enrolment (insufficient studies to test for this in the other outcomes).With regard to secondary outcomes, no studies reported on harms associated with the interventions. Only two studies reported costs. In terms of equity, trialists tested interventions designed to improve utilisation among women and older patients. Evidence is insufficient for quantitative assessment of whether women-tailored programmes were associated with increased utilisation, and studies that assess motivating women are needed. For older participants, again while quantitative assessment could not be undertaken, peer navigation may improve enrolment.

AUTHORS' CONCLUSIONS

Interventions may increase cardiac rehabilitation enrolment, adherence and completion; however the quality of evidence was low to moderate due to heterogeneity of the interventions used, among other factors. Effects on enrolment were larger in studies targeting healthcare providers, training nurses, or allied healthcare providers to intervene face-to-face; effects on adherence were larger in studies that tested remote interventions. More research is needed, particularly to discover the best ways to increase programme completion.

Differential effects of endurance, interval, and resistance training on telomerase activity and telomere length in a randomized, controlled study

Aims

It is unknown whether different training modalities exert differential cellular effects. Telomeres and telomere-associated proteins play a major role in cellular aging with implications for global health. This prospective training study examines the effects of endurance training, interval training (IT), and resistance training (RT) on telomerase activity and telomere length (TL).

Methods and results

One hundred and twenty-four healthy previously inactive individuals completed the 6 months study. Participants were randomized to three different interventions or the control condition (no change in lifestyle): aerobic endurance training (AET, continuous running), high-intensive IT (4 × 4 method), or RT (circle training on 8 devices), each intervention consisting of three 45 min training sessions per week. Maximum oxygen uptake (VO2max) was increased by all three training modalities. Telomerase activity in blood mononuclear cells was up-regulated by two- to three-fold in both endurance exercise groups (AET, IT), but not with RT. In parallel, lymphocyte, granulocyte, and leucocyte TL increased in the endurance-trained groups but not in the RT group. Magnet-activated cell sorting with telomerase repeat-ampliflication protocol (MACS-TRAP) assays revealed that a single bout of endurance training-but not RT-acutely increased telomerase activity in CD14+ and in CD34+ leucocytes.

Conclusion

This randomized controlled trial shows that endurance training, IT, and RT protocols induce specific cellular pathways in circulating leucocytes. Endurance training and IT, but not RT, increased telomerase activity and TL which are important for cellular senescence, regenerative capacity, and thus, healthy aging.

Aerobic Interval vs. Continuous Training in Patients with Coronary Artery Disease or Heart Failure: An Updated Systematic Review and Meta-Analysis with a Focus on Secondary Outcomes

BACKGROUND

In a previous meta-analysis including nine trials comparing aerobic interval training with aerobic continuous training in patients with coronary artery disease, we found a significant difference in peak oxygen uptake favoring aerobic interval training.

OBJECTIVE

The objective of this study was to (1) update the original meta-analysis focussing on peak oxygen uptake and (2) evaluate the effect on secondary outcomes.

METHODS

We conducted a systematic review with a meta-analysis by searching PubMed and SPORTDiscus databases up to March 2017. We included randomized trials comparing aerobic interval training and aerobic continuous training in patients with coronary artery disease or chronic heart failure. The primary outcome was change in peak oxygen uptake. Secondary outcomes included cardiorespiratory parameters, cardiovascular risk factors, cardiac and vascular function, and quality of life.

RESULTS

Twenty-four papers were identified (n = 1080; mean age 60.7 ± 10.7 years). Aerobic interval training resulted in a higher increase in peak oxygen uptake compared with aerobic continuous training in all patients (1.40 mL/kg/min; p < 0.001), and in the subgroups of patients with coronary artery disease (1.25 mL/kg/min; p = 0.001) and patients with chronic heart failure with reduced ejection fraction (1.46 mL/kg/min; p = 0.03). Moreover, a larger increase of the first ventilatory threshold and peak heart rate was observed after aerobic interval training in all patients. Other cardiorespiratory parameters, cardiovascular risk factors, and quality of life were equally affected.

CONCLUSION

This meta-analysis adds further evidence to the clinically significant larger increase in peak oxygen uptake following aerobic interval training vs. aerobic continuous training in patients with coronary artery disease and chronic heart failure. More well-designed randomized controlled trials are needed to establish the safety of aerobic interval training and the sustainability of the training response over longer periods.

Resistance Exercise Training Is More Effective than Interval Aerobic Training in Reducing Blood Pressure During Sleep in Hypertensive Elderly Patients

Bertani, RF, Campos, GO, Perseguin, DM, Bonardi, JMT, Ferriolli, E, Moriguti, JC, and Lima, NKC. Resistance exercise training is more effective than interval aerobic training in reducing blood pressure during sleep in hypertensive elderly patients. J Strength Cond Res 32(7): 2085-2090, 2018-An appropriate fall in blood pressure (BP) during sleep is known to be related to a lower cardiovascular risk. The objective of this study was to compare the effect of different types of training on hypertensive elderly patients under treatment in terms of pressure variability assessed by the nocturnal decline in BP. Hypertensive elderly subjects under pharmacological treatment were randomly assigned to the following groups: 12 weeks of continuous aerobic training, interval aerobic training (IA), resistance training (R), or control (C). All subjects underwent ambulatory BP monitoring before and 24 hours after the last exercise session. The results were assessed using the mixed effects model. A greater nocturnal decline in diastolic BP compared with the wakefulness period was observed in R in comparison with C (11.0 ± 4.1 vs. 6.0 ± 5.7 mm Hg and p = 0.01) and with IA (11.0 ± 4. vs. 6.5 ± 5.1 mm Hg and p = 0.02). No fall in BP during a 24-hour period was observed in training groups compared with C, perhaps because the subjects were mostly nondippers, for whom the effect of training on BP is found to be lower. In conclusion, resistance training promoted a greater nocturnal fall in BP among hypertensive elderly subjects under treatment compared with IA subjects.

Home-Based Rehabilitation With Telemonitoring Guidance for Patients With Coronary Artery Disease (Short-Term Results of the TRiCH Study): Randomized Controlled Trial

Background

Cardiac rehabilitation (CR) is an essential part of contemporary coronary heart disease management. However, patients exiting a center-based CR program have difficulty retaining its benefits.

Objective

We aimed to evaluate the added benefit of a home-based CR program with telemonitoring guidance on physical fitness in patients with coronary artery disease (CAD) completing a phase II ambulatory CR program and to compare the effectiveness of this program in a prolonged center-based CR intervention by means of a randomized controlled trial.

Methods

Between February 2014 and August 2016, 90 CAD patients (unblinded, mean age 61.2 years, SD 7.6; 80/90, 89.0% males; mean height 1.73 m, SD 0.7; mean weight 82.9 kg, SD 13; mean body mass index 27.5 kg/m², SD 3.4) who successfully completed a 3-month ambulatory CR program were randomly allocated to one of three groups: home-based (30), center-based (30), or control group (30) on a 1:1:1 basis. Home-based patients received a home-based exercise intervention with telemonitoring guidance consisting of weekly emails or phone calls; center-based patients continued the standard in-hospital CR, and control group patients received the usual care including the advice to remain physically active. All the patients underwent cardiopulmonary exercise testing for assessment of their peak oxygen uptake (VO₂ P) at baseline and after a 12-week intervention period. Secondary outcomes included physical activity behavior, anthropometric characteristics, traditional cardiovascular risk factors, and quality of life.

Results

Following 12 weeks of intervention, the increase in VO₂ P was larger in the center-based (P=.03) and home-based (P=.04) groups than in the control group. In addition, oxygen uptake at the first (P-interaction=.03) and second (P-interaction=.03) ventilatory thresholds increased significantly more in the home-based group than in the center-based group. No significant changes were observed in the secondary outcomes.

Conclusions

Adding a home-based exercise program with telemonitoring guidance following completion of a phase II ambulatory CR program results in further improvement of physical fitness and is equally as effective as prolonging a center-based CR in patients with CAD.

Trial Registration

ClinicalTrials.gov NCT02047942; https://clinicaltrials.gov/ct2/show/NCT02047942 (Archived by WebCite at http://www.webcitation.org/70CBkSURj)

Long-term effect of exercise training in patients after transcatheter aortic valve implantation: Follow-up of the SPORT:TAVI randomised pilot study

Background Increased exercise capacity favourably influences clinical outcomes after transcatheter aortic valve implantation. In our SPORT:TAVI randomised pilot trial, eight weeks of endurance and resistance training (training group, TG) shortly after transcatheter aortic valve implantation resulted in significantly improved exercise capacity, muscular strength and quality of life compared to usual care (UC). However, the long-term clinical benefits of such an intervention are unknown. Design A randomised controlled trial. Methods SPORT:TAVI participants underwent reassessment of trial endpoints 24 ± 6 months after baseline: maximal oxygen uptake (VO₂peak) and anaerobic threshold (VO₂AT) were assessed with cardiopulmonary exercise testing, muscular strength with one-repetition maximum testing, quality of life with the Kansas City cardiomyopathy and medical outcomes study 12-item short-form health survey questionnaires, and prosthetic aortic valve function with echocardiography. Results Of 27 original participants (TG 13; UC 14; age 81 ± 6 years), more patients had died during follow-up in UC ( n = 5) than in TG ( n = 2; P = 0.165); three further patients (TG 1; UC 2) were unavailable for other reasons. In the remaining patients (TG 10; UC 7), a significant between-group difference in favour of TG was observed for change in VO₂AT from baseline (2.7 ml/min/kg (95% confidence interval 0.8-4.6); P = 0.008), but not for change in VO₂peak (2.1 ml/min/kg (-1.1-5.4); P = 0.178). Changes in muscular strength and quality of life did not differ between groups over time. Overall, prosthetic valve function remained intact in both groups. Conclusions Eight weeks of exercise training shortly after transcatheter aortic valve implantation resulted in preserved long-term improvements in VO₂AT, but not VO₂peak, muscular strength or quality of life compared to usual care. The findings emphasise the importance of ongoing exercise interventions following transcatheter aortic valve implantation to maintain initial improvements long term. Clinical Trial Registration (original trial): Clinicaltrials.gov NCT01935297.

High-intensity interval training versus moderate-intensity continuous training within cardiac rehabilitation: a systematic review and meta-analysis

BACKGROUND

Aerobic capacity has been shown to be inversely proportionate to cardiovascular mortality and morbidity and there is growing evidence that high-intensity interval training (HIIT) appears to be more effective than moderate-intensity continuous training (MICT) in improving cardiorespiratory fitness within the cardiac population. Previously published systematic reviews in cardiovascular disease have neither investigated the effect that the number of weeks of intervention has on cardiorespiratory fitness changes, nor have adverse events been collated.

OBJECTIVE

We aimed to undertake a systematic review and meta-analysis of randomized controlled trials (RCTs) within the cardiac population that investigated cardiorespiratory fitness changes resulting from HIIT versus MICT and to collate adverse events.

METHODS

A critical narrative synthesis and meta-analysis was conducted after systematically searching relevant databases up to July 2017. We searched for RCTs that compared cardiorespiratory fitness changes resulting from HIIT versus MICT interventions within the cardiac population.

RESULTS

Seventeen studies, involving 953 participants (465 for HIIT and 488 for MICT) were included in the analysis. HIIT was significantly superior to MICT in improving cardiorespiratory fitness overall (SMD 0.34 mL/kg/min; 95% confidence interval [CI; 0.2-0.48]; p<0.00001; I2=28%). There were no deaths or cardiac events requiring hospitalization reported in any study during training. Overall, there were more adverse events reported as a result of the MICT (n=14) intervention than the HIIT intervention (n=9). However, some adverse events (n=5) were not classified by intervention group.

CONCLUSION

HIIT is superior to MICT in improving cardiorespiratory fitness in participants of cardiac rehabilitation (CR). Improvements in cardiorespiratory fitness are significant for CR programs of >6-week duration. Programs of 7-12 weeks' duration resulted in the largest improvements in cardiorespiratory fitness for patients with coronary artery disease. HIIT appears to be as safe as MICT for CR participants.

Amount or intensity? Potential targets of exercise interventions in patients with heart failure with preserved ejection fraction

AIMS

Heart failure with preserved ejection fraction (HFpEF) remains a common condition with no pharmacological treatment. Physical activity (PA) improves symptoms and quality of life (QoL), but no clear recommendations exist on PA in HFpEF patients. We investigated the association of PA (amount/intensity) on clinical phenotype in HFpEF.

METHODS AND RESULTS

The Aldosterone in Diastolic Heart Failure trial investigated spironolactone vs. placebo in stable HFpEF patients. At baseline, all patients underwent detailed phenotypization including echocardiography, cardiopulmonary exercise testing, 6 minute walking test (6MWT), and QoL assessment (36-item Short-Form questionnaire). PA was assessed by a self-report questionnaire, classified in metabolic equivalents of task (MET) and analysed with regard to exercise capacity, diastolic function, and QoL. Four hundred twenty-two patients (52% women, age 67 ± 8 years, New York Heart Association II and III) were classified by weekly MET hours into a low (<70), middle (70-140), or high (>140) level of PA. Total PA correlated positively with 6MWT distance (r = 0.17; P = 0.002) and physical function of QoL (r = 0.10; P = 0.05), but not with peak oxygen uptake (peakVO₂ ). In contrast, both 6MWT distance and peakVO₂ were significantly higher in patients who performed high-intensity PA for >8 h/week (P < 0.001, P = 0.02, respectively). Time of high-intensity PA was related to higher 6MWT distance (r = 0.21, P < 0.001), peakVO₂ , and better physical function of QoL (both r = 0.13, P = 0.01), whereas low-intensity PA did not show significant associations. Interestingly, PA was not related to any measure of diastolic function.

CONCLUSIONS

A higher amount of PA is related to higher submaximal exercise capacity and physical function of QoL. Regarding maximal exercise capacity, only high-intensity PA showed significant association in HFpEF patients.

High-intensity interval training versus moderate-intensity continuous training on exercise capacity and quality of life in patients with coronary artery disease: A systematic review and meta-analysis

Background Exercise is an effective strategy for reducing total and cardiovascular mortality in patients with coronary artery disease. However, it is not clear which modality is best. We performed a meta-analysis to investigate the effects of high-intensity interval versus moderate-intensity continuous training of coronary artery disease patients. Methods We searched MEDLINE, PEDro, LILACS, SciELO and the Cochrane Library (from the earliest date available to November 2016) for controlled trials that evaluated the effects of high-intensity interval versus moderate-intensity continuous training for coronary artery disease patients. Weighted mean differences and 95% confidence intervals were calculated, and heterogeneity was assessed using the I² test. Results Twelve studies met the study criteria, including 609 patients. High-intensity interval training resulted in improvement in peak oxygen uptake weighted mean difference (1.3 ml/kg/min, 95% confidence interval: 0.6-1.9, n = 594) compared with moderate-intensity continuous training. No significant difference in physical, emotional, and social domain of quality of life was found for participants for participants in the high-intensity interval training group compared with the moderate-intensity continuous training group. Sub-analysis of three studies with isocaloric exercise training showed no significant difference in peak oxygen uptake weighted mean difference (0.4 ml/kg/min, 95% confidence interval: -0.1-0.9, n = 137) for participants in the high-intensity interval training group compared with moderate-intensity continuous training group. Conclusions High-intensity interval training may improve peak oxygen uptake and should be considered as a component of care of coronary artery disease patients. However, this superiority disappeared when isocaloric protocol is compared.

A scoping review of the psychological responses to interval exercise: is interval exercise a viable alternative to traditional exercise?

While considerable evidence suggests that interval exercise confers numerous physiological adaptations linked to improved health, its psychological consequences and behavioural implications are less clear and the subject of intense debate. The purpose of this scoping review was to catalogue studies investigating the psychological responses to interval exercise in order to identify what psychological outcomes have been assessed, the research methods used, and the results. A secondary objective was to identify research issues and gaps. Forty-two published articles met the review inclusion/exclusion criteria. These studies involved 1258 participants drawn from various active/inactive and healthy/unhealthy populations, and 55 interval exercise protocols (69% high-intensity interval training [HIIT], 27% sprint interval training [SIT], and 4% body-weight interval training [BWIT]). Affect and enjoyment were the most frequently studied psychological outcomes. Post-exercise assessments indicate that overall, enjoyment of, and preferences for interval exercise are equal or greater than for continuous exercise, and participants can hold relatively positive social cognitions regarding interval exercise. Although several methodological issues (e.g., inconsistent use of terminology, measures and protocols) and gaps (e.g., data on adherence and real-world protocols) require attention, from a psychological perspective, the emerging data support the viability of interval exercise as an alternative to continuous exercise.

Interval and continuous aerobic exercise training similarly increase cardiac function and autonomic modulation in infarcted mice

The present study aimed to compare the effects of moderate-intensity continuous and high-intensity interval exercise training (ET) on exercise tolerance, cardiac morphometry and function, hemodynamic, and cardiac autonomic modulation in myocardial infarcted mice. Wild-type mice (WT) were divided into four groups: sedentary WT (S); WT myocardium infarction sedentary (IS); WT myocardium infarction underwent to moderate-intensity continuous ET (MICT), and WT myocardium infarction underwent to high-intensity interval ET (MIIT). After 60 days of descending coronary artery ligation, moderate-intensity continuous ET consisted of running at 60% of maximum, while the high-intensity interval training consisted of eight sprints of 4 min at 80% of maximum and a 4-min recovery at 40% of maximum. Both exercises were performed 1 hr a day, 5 days a week, during 8 weeks. Results demonstrated that IS showed elevated exercise tolerance, as well as decreased hemodynamic and heart function, and autonomic control. On the other hand, both programs of ET were equally effective to increase all parameters, without further differences between the groups. In conclusion, the results of the present study showed that myocardial infarction leads to damage in both investigated strains and the two types of physical exercise attenuated the major impairments provoked by myocardial infarction in exercise tolerance, cardiac structure, cardiac function, hemodynamic and cardiac autonomic modulation.

Prioritizing Functional Capacity as a Principal End Point for Therapies Oriented to Older Adults With Cardiovascular Disease: A Scientific Statement for Healthcare Professionals From the American Heart Association

Adults are living longer, and cardiovascular disease is endemic in the growing population of older adults who are surviving into old age. Functional capacity is a key metric in this population, both for the perspective it provides on aggregate health and as a vital goal of care. Whereas cardiorespiratory function has long been applied by cardiologists as a measure of function that depended primarily on cardiac physiology, multiple other factors also contribute, usually with increasing bearing as age advances. Comorbidity, inflammation, mitochondrial metabolism, cognition, balance, and sleep are among the constellation of factors that bear on cardiorespiratory function and that become intricately entwined with cardiovascular health in old age. This statement reviews the essential physiology underlying functional capacity on systemic, organ, and cellular levels, as well as critical clinical skills to measure multiple realms of function (eg, aerobic, strength, balance, and even cognition) that are particularly relevant for older patients. Clinical therapeutic perspectives and patient perspectives are enumerated to clarify challenges and opportunities across the caregiving spectrum, including patients who are hospitalized, those managed in routine office settings, and those in skilled nursing facilities. Overall, this scientific statement provides practical recommendations and vital conceptual insights.

High-intensity interval training versus moderate-intensity steady-state training in UK cardiac rehabilitation programmes (HIIT or MISS UK): study protocol for a multicentre randomised controlled trial and economic evaluation

INTRODUCTION

Current international guidelines for cardiac rehabilitation (CR) advocate moderate-intensity exercise training (MISS, moderate-intensity steady state). This recommendation predates significant advances in medical therapy for coronary heart disease (CHD) and may not be the most appropriate strategy for the 'modern' patient with CHD. High-intensity interval training (HIIT) appears to be a safe and effective alternative, resulting in greater improvements in peak oxygen uptake (VO_{2 peak}). To date, HIIT trials have predominantly been proof-of-concept studies in the laboratory setting and conducted outside the UK. The purpose of this multicentre randomised controlled trial is to compare the effects of HIIT and MISS training in patients with CHD attending UK CR programmes.

METHODS AND ANALYSIS

This pragmatic study will randomly allocate 510 patients with CHD to 8 weeks of twice weekly HIIT or MISS training at 3 centres in the UK. HIIT will consist of 10 high-intensity (85-90% peak power output (PPO)) and 10 low-intensity (20-25% PPO) intervals, each lasting 1 min. MISS training will follow usual care recommendations, adhering to currently accepted UK guidelines (ie, >20 min continuous exercise at 40-70% heart rate reserve). Outcome measures will be assessed at baseline, 8 weeks and 12 months. The primary outcome for the trial will be change in VO_{2 peak} as determined by maximal cardiopulmonary exercise testing. Secondary measures will assess physiological, psychosocial and economic outcomes.

ETHICS AND DISSEMINATION

The study protocol V.1.0, dated 1 February 2016, was approved by the NHS Health Research Authority, East Midlands-Leicester South Research Ethics Committee (16/EM/0079). Recruitment will start in August 2016 and will be completed in June 2018. Results will be published in peer-reviewed journals, presented at national and international scientific meetings and are expected to inform future national guidelines for exercise training in UK CR.

TRIAL REGISTRATION NUMBER

NCT02784873; pre-results.