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Abstract: Purpose: Cardiac rehabilitation participation rates are low despite strong recommendations, and many chronic heart failure patients remain physically inactive. Rural living, long travel distance, costs, age, and frailty might be factors explaining this. To increase cardiac rehabilitation uptake, we designed an exercise-based randomized controlled telerehabilitation trial enabling chronic heart failure patients unable or unwilling to participate in outpatient cardiac rehabilitation to exercise at home. Aim was to evaluate the long-term effects of telerehabilitation on physical activity levels.Methods and results: CHF patients (n = 61) with reduced (≤40%), mildly reduced (41-49%), or preserved ejection fraction (≥50%) were randomized (1:1) to telerehabilitation (n = 31) with an initial 3-month group-based high-intensity exercise telerehabilitation program or control (n = 30), with regular follow-up visits over a 2-year period. All participants attended a "Living with heart failure" course. Outcomes were measures of physical activity, peak oxygen uptake, 6-minute walk test distance, quality of life, morbidity, and mortality. We found no significant differences between groups for long-term changes in moderate to vigorous activity (MVPA) or peak oxygen uptake from baseline to the 2-year follow-up. Nor quality of life differed between groups, but both groups had significant within-group improvements in score on the Minnesota living with heart failure questionnaire (p = 0.000) and improvement in EQ-5D VAS score was significant (p = 0.05) in the telerehabilitation group.Conclusions: Telerehabilitation performed as home-based real-time high-intensity exercise sessions provided by videoconferencing for participants unable or unwilling to participate in standard outpatient cardiac rehabilitation did not affect long-term physical activity levels or physical capacity as expected. Still, a positive effect on health-related quality of life was seen in both groups., Competing Interests: Conflict of Interest and Funding Source: The work was supported by funds from the Liaison Committee of Central Norway Regional Health Authority and the Norwegian University of Science and Technology and the National Association for Heart and Lung Diseases. The authors declare no conflicts of interest., (Copyright © 2024 by the American College of Sports Medicine.)

Exercise is an important component of rehabilitation care for patients with heart failure with preserved ejection fraction (HFpEF). However, it is unclear which type of physical rehabilitation exercise is most effective. Thus, the aim of this study was to determine the relative effects of different types of exercise interventions on aerobic capacity measured by peak oxygen consumption (VO 2 peak; in mL/kg·min) in patients with HFpEF. We searched different electronic databases until December 2020 for randomized controlled trials that evaluated the effects of different types of exercise interventions on VO 2 peak of patients with HFpEF. Mean difference, standardized mean difference (SMD), and 95% confidence intervals (CIs) were calculated. Fixed and random-effects Bayesian network meta-analysis was used to compare the relative effectiveness of the different exercise interventions. Nineteen studies met the study criteria, including 720 patients. Comparing the physical rehabilitation interventions with usual care (control group), inspiratory muscle training was the highest ranked exercise intervention with an SMD of 3.6 mL/kg·min (95% CI, 2.3-4.8), followed by the group undergoing high-intensity interval training with a significant pooled improvement in VO 2 peak 3.5 (95% CI, 2.6-4.4) and combined aerobic and resistance exercise with an SMD of 3.2 (95% CI, 1.4-5.0). The inspiratory muscle training, high-intensity interval training, and combined aerobic and resistance exercise were the highest ranked physical rehabilitation intervention to improve VO 2 peak. These interventions should be considered as a component in the care of patients with HFpEF. Registration: https://www.crd.york.ac.uk/PROSPERO/ ; Unique identifier: CRD42021256442., Competing Interests: Disclosure: The authors declare no conflict of interest., (Copyright © 2022 Wolters Kluwer Health, Inc. All rights reserved.)

Purpose: This study aimed to investigate baseline, exercise testing, and exercise training-mediated predictors of change in peak oxygen uptake (V˙O2peak) from baseline to 12-wk follow-up (ΔV˙O2peak) in a post hoc analysis from the SMARTEX Heart Failure trial., Methods: We studied 215 patients with heart failure with left ventricular ejection fraction (LVEF) ≤35%, and New York Heart Association (NYHA) classes II-III who were randomized to either supervised high-intensity interval training with exercise target intensity of 90%-95% of peak heart rate (HRpeak) or supervised moderate continuous training (MCT) with target intensity of 60%-70% of HRpeak, or who received a recommendation of regular exercise on their own. Predictors of ΔV˙O2peak were assessed in two models: a logistic regression model comparing highest and lowest tertiles (baseline parameters) and a multivariate linear regression model (test/training/clinical parameters)., Results: The change in V˙O2peak in response to the interventions (ΔV˙O2peak) varied substantially, from -8.50 to +11.30 mL·kg·min. Baseline NYHA (class II gave higher odds vs III; odds ratio (OR), 7.1 (2.0-24.9); P = 0.002), LVEF (OR per percent, 1.1 (1.0-1.2); P = 0.005), and age (OR per 10 yr, 0.5 (0.3-0.8); P = 0.003) were associated with ΔV˙O2peak.In the multivariate linear regression, 34% of the variability in ΔV˙O2peak was explained by the increase in exercise training workload, ΔHRpeak between baseline and 12-wk posttesting, age, and ever having smoked., Conclusion: Exercise training response (ΔV˙O2peak) correlated negatively with age, LVEF, and NYHA class. The ability to increase workload during the training period and increased ΔHRpeak between baseline and the 12-wk test were associated with a positive outcome.

Background: Small studies have suggested that high-intensity interval training (HIIT) is superior to moderate continuous training (MCT) in reversing cardiac remodeling and increasing aerobic capacity in patients with heart failure with reduced ejection fraction. The present multicenter trial compared 12 weeks of supervised interventions of HIIT, MCT, or a recommendation of regular exercise (RRE)., Methods: Two hundred sixty-one patients with left ventricular ejection fraction ≤35% and New York Heart Association class II to III were randomly assigned to HIIT at 90% to 95% of maximal heart rate, MCT at 60% to 70% of maximal heart rate, or RRE. Thereafter, patients were encouraged to continue exercising on their own. Clinical assessments were performed at baseline, after the intervention, and at follow-up after 52 weeks. Primary end point was a between-group comparison of change in left ventricular end-diastolic diameter from baseline to 12 weeks., Results: Groups did not differ in age (median, 60 years), sex (19% women), ischemic pathogenesis (59%), or medication. Change in left ventricular end-diastolic diameter from baseline to 12 weeks was not different between HIIT and MCT ( P =0.45); left ventricular end-diastolic diameter changes compared with RRE were -2.8 mm (-5.2 to -0.4 mm; P =0.02) in HIIT and -1.2 mm (-3.6 to 1.2 mm; P =0.34) in MCT. There was also no difference between HIIT and MCT in peak oxygen uptake ( P =0.70), but both were superior to RRE. However, none of these changes was maintained at follow-up after 52 weeks. Serious adverse events were not statistically different during supervised intervention or at follow-up at 52 weeks (HIIT, 39%; MCT, 25%; RRE, 34%; P =0.16). Training records showed that 51% of patients exercised below prescribed target during supervised HIIT and 80% above target in MCT., Conclusions: HIIT was not superior to MCT in changing left ventricular remodeling or aerobic capacity, and its feasibility remains unresolved in patients with heart failure., Clinical Trial Registration: URL: http://www.clinicaltrials.gov. Unique identifier: NCT00917046., (© 2017 The Authors.)

Introduction: Many studies suggest that cardiorespiratory fitness, measured as peak oxygen uptake (VO2peak), may be the single best predictor of cardiovascular morbidity and premature cardiovascular mortality. However, current reference values are either estimates of oxygen uptake or come from small studies, mainly of men. Therefore, the aims of this study were to directly measure VO2peak in healthy adult men and women and to assess the association with cardiovascular risk factor levels., Methods: A cross-sectional study of 4631 volunteering, free-living Norwegian men (n = 2368) and women (n = 2263) age 20-90 yr. The data collection was from June 2007 to June 2008. Participants were free from known pulmonary or cardiovascular disease. VO2peak was measured by ergospirometry during treadmill running. Associations (odds ratios, OR) with unfavorable levels of cardiovascular risk factors and a cluster of cardiovascular risk factors were assessed by logistic regression analysis., Results: Overall, mean VO2peak was 40.0 ± 9.5 mL·kg(-1)·min(-1). Women below the median VO2peak (<35.1 mL·kg(-1)·min(-1)) were five times (OR = 5.4, 95% confidence interval = 2.3-12.9) and men below the median (<44.2 mL·kg(-1)·min(-1)) were eight times (OR = 7.9, 95% confidence interval = 3.5-18.0) more likely to have a cluster of cardiovascular risk factors compared to those in the highest quartile of VO2peak (≥40.8 and ≥50.5 mL·kg(-1)·min(-1) in women and men, respectively). Each 5-mL·kg(-1)·min(-1) lower VO2peak corresponded to ∼56% higher odds of cardiovascular risk factor clustering., Conclusions: These data represent the largest reference material of objectively measured VO2peak in healthy men and women age 20-90 yr. Even in people considered to be fit, VO2peak was clearly associated with levels of conventional cardiovascular risk factors.

We hypothesized that high-intensity aerobic interval training results in a greater beneficial adaptation of the heart compared with that observed after low-to-moderate exercise intensity. This is supported by recent epidemiological, experimental, and clinical studies. Cellular and molecular mechanisms of myocardial adaptation to exercise training are discussed in this review.

Background: Physical fitness and level of regular exercise are closely related to cardiovascular health. A regimen of regular intensity-controlled treadmill exercise was implemented and withdrawn to identify cellular mechanisms associated with exercise capacity and maximal oxygen uptake (VO2max)., Methods and Results: Time-dependent associations between cardiomyocyte dimensions, contractile capacity, and VO2max were assessed in adult rats after high-level intensity-controlled treadmill running for 2, 4, 8, and 13 weeks and detraining for 2 and 4 weeks. With training, cardiomyocyte length, relaxation, shortening, Ca2+ decay, and estimated cell volume correlated with increased VO2max (r=0.92, -0.92, 0.88, -0.84, 0.73; P<0.01). Multiple regression analysis identified cell length, relaxation, and Ca2+ decay as the main explanatory variables for VO2max (R2=0.87, P<0.02). When training stopped, exercise-gained VO2max decreased 50% within 2 weeks and stabilized at 5% above sedentary controls after 4 weeks. Cardiomyocyte size regressed in parallel with VO2max and remained (9%) above sedentary after 4 weeks, whereas cardiomyocyte shortening, contraction/relaxation- and Ca2+-transient time courses, and endothelium-dependent vasorelaxation regressed completely within 2 to 4 weeks of detraining. Cardiomyocyte length, estimated cell volume, width, shortening, and Ca2+ decay and endothelium-dependent arterial relaxation all correlated with VO2max (r=0.85, 0.84, 0.75, 0.63, -0.54, -0.37; P<0.01). Multiple regression identified cardiomyocyte length and vasorelaxation as the main determinants for regressed VO2max during detraining (R2=0.76, P=0.02)., Conclusions: Cardiovascular adaptation to regular exercise is highly dynamic. On detraining, most of the exercise-gained aerobic fitness acquired over 2 to 3 months is lost within 2 to 4 weeks. The close association between cardiomyocyte dimensions, contractile capacity, arterial relaxation, and aerobic fitness suggests cellular mechanisms underlying these changes.