Effect of ivabradine on exercise capacity in individuals with heart failure with preserved ejection fraction.

The prevalence of heart failure with preserved ejection fraction (HFpEF) is about 30-75% of the patients living with heart failure. A hallmark symptom of these patients is exercise intolerance. Ivabradine can, eventually, increase exercise capacity by heart rate control. However, clinical trials show conflicting results about the effects of ivabradine on exercise capacity, an important prognostic variable. The aim of this study was to investigate the effects of ivabradine on exercise capacity in individuals with HFpEF. This study was conducted following the Preferred Reporting Items for Systematic Reviews and Meta-Analyses statement and supplemented by guidance from the Cochrane Collaboration Handbook for Systematic Reviews of Interventions. For the meta-analysis, a forest plot was used to graphically present the effect sizes and the 95% CIs. Four randomized controlled trials were included. Ivabradine did not change exercise capacity expressed by peak VO2 and 6MWT (MD = 0.8; 95% CI - 2.5 to 4.3; P = 0.62) (Fig. 4a). In our secondary analysis, the ivabradine group showed a significant resting HR reduction when compared with placebo (MD = - 13.2; 95% CI - 16.6 to -9.8; P < 0.00001) and ivabradine showed increased values of E/e' ratio compared with placebo (MD = 0.8; 95% CI 0.0 to 1.6; P = 0.04). Current available evidence suggests that there is no effect of ivabradine on exercise capacity in patients with HFpEF. Also, questions about negative effects on E/e' values and adverse events associated with ivabradine treatment need to be considered in future studies.

Comment on: "exercise training and cardiac autonomic function following coronary artery bypass grafting: a systematic review and meta-analysis".

BACKGROUND: Low cardiorespiratory fitness is associated with poor prognosis in individuals with coronary artery disease and after coronary artery bypass grafting surgery. Thus, we comment about a meta-analysis that adds important information about the effect of exercise training on cardiac autonomic function in individuals following coronary artery bypass grafting surgery. MAIN BODY: The study by Kushwaha et al. showed positive effects for heart rate variability and heart rate recovery in subjects after coronary artery bypass grafting surgery in response to acute physical training. These data are relevant, since heart rate variability is an independent predictor of for all-cause and cardiovascular mortality for individuals with cardiovascular disorders. Additionally, attenuated heart rate recovery is associated with increased risk for the same outcomes. Moreover, we summarize the quantitative data from studies that compared the effect of physical training in comparison with control group in cardiorespiratory fitness in adults following coronary artery bypass grafting. CONCLUSIONS: Our findings suggest that improvements in peak oxygen consumption result in an additional benefit in adults following coronary artery bypass grafting. Considered that, the increased cardiorespiratory fitness is an independent predictor of longer survival in coronary artery disease.

Water-Based Exercises on Peak Oxygen Consumption, Exercise Time, and Muscle Strength in Patients with Coronary Artery Disease: A Systematic Review with Meta-Analysis.

Background: There is a growing use of water-based exercises in cardiac rehabilitation programs. However, there is little data concerning the effects of water-based exercise on the exercise capacity of coronary artery disease (CAD) patients. Objective: To perform a systematic review to investigate the effects of water-based exercise on peak oxygen consumption, exercise time, and muscle strength in patients with CAD. Methods: Five databases were searched to find randomized controlled trials that evaluated the effects of water-based exercise for coronary artery disease patients. Mean differences (MD) and 95% confidence intervals (CIs) were calculated, and heterogeneity was assessed using the I2 test. Results: Eight studies were included. Water-based exercise resulted in an improvement in peak VO2 of 3.4 mL/kg/min (95% CI, 2.3 to 4.5; I2 = 0%; 5 studies, N = 167), exercise time of 0.6 (95% CI, 0.1 to 1.1; I2 = 0%; 3 studies, N = 69), and total body strength of 32.2 kg (95% CI, 23.9 to 40.7; I2 = 3%; 3 studies, N = 69) when compared to no exercising controls. Water-based exercise resulted in an improvement in peak VO2 of 3.1 mL/kg/min (95% CI, 1.4 to 4.7; I2 = 13%; 2 studies, N = 74), when compared to the plus land exercise group. No significant difference in peak VO2 was found for participants in the water-based exercise plus land exercise group compared with the land exercise group. Conclusions: Water-based exercise may improve exercise capacity and should be considered as an alternative method in the rehabilitation of patients with CAD.

Effect of High-Intensity Interval Training on Aerobic Capacity and Heart Rate Control of Heart Transplant Recipients: a Systematic Review with Meta-Analysis.

INTRODUCTION: Heart transplantation (HTx) is the gold standard procedure for selected individuals with refractory heart failure. Highintensity interval training (HIIT) is safe and allows patients to exercise in high intensity for longer time when compared to moderateintensity continuous training (MICT). The primary aim of this study was to perform a systematic review and meta-analysis about the effect of HIIT compared to MICT on exercise capacity, peak heart rate, and heart rate reserve in HTx recipients. Secondarily, we pooled data comparing MICT and no exercise training in these patients. METHODS: This systematic review followed the standardization of the Preferred Reporting Items for Systematic Reviews and Metaanalyses statement and the Cochrane Collaboration Handbook. We presented the treatment effects of HIIT on the outcomes of interest as mean difference (MD) and 95% confidence interval (CI). Metaanalysis was performed using the random-effects, generic inverse variance method. RESULTS: HIIT improved peak oxygen consumption (peakVO2) (MD = 2.1; 95% CI 1.1, 3.1; P<0.0001), peak heart rate (MD = 3.4; 95% CI 0.8, 5.9; P=0.009), and heart rate reserve (MD = 4.8; 95% CI -0.05, 9.6; P=0.05) compared to MICT. Improvements on peakVO2 (MD = 3.5; 95% CI 2.3, 4.7; P<0.00001) and peak heart rate (MD = 5.6; 95% CI 1.6, 9.6; P=0.006) were found comparing HIIT and no exercise training. CONCLUSION: Current available evidence suggests that HIIT leads to improvements on peakVO2, peak heart rate, and heart rate reserve compared to MICT in HTx recipients. However, the superiority of HIIT should be tested in isocaloric protocols.

Effect of high-intensity interval training on aerobic capacity and heart rate control of heart transplant recipients: a systematic review with meta-analysis

Abstract Introduction: Heart transplantation (HTx) is the gold standard procedure for selected individuals with refractory heart failure. High-intensity interval training (HIIT) is safe and allows patients to exercise in high intensity for longer time when compared to moderate-intensity continuous training (MICT). The primary aim of this study was to perform a systematic review and meta-analysis about the effect of HIIT compared to MICT on exercise capacity, peak heart rate, and heart rate reserve in HTx recipients. Secondarily, we pooled data comparing MICT and no exercise training in these patients. Methods: This systematic review followed the standardization of the Preferred Reporting Items for Systematic Reviews and Meta-analyses statement and the Cochrane Collaboration Handbook. We presented the treatment effects of HIIT on the outcomes of interest as mean difference (MD) and 95% confidence interval (CI). Meta-analysis was performed using the random-effects, generic inverse variance method. Results: HIIT improved peak oxygen consumption (peakVO2) (MD = 2.1; 95% CI 1.1, 3.1; P<0.0001), peak heart rate (MD = 3.4; 95% CI 0.8, 5.9; P=0.009), and heart rate reserve (MD = 4.8; 95% CI -0.05, 9.6; P=0.05) compared to MICT. Improvements on peakVO2 (MD = 3.5; 95% CI 2.3, 4.7; P<0.00001) and peak heart rate (MD = 5.6; 95% CI 1.6, 9.6; P=0.006) were found comparing HIIT and no exercise training. Conclusion: Current available evidence suggests that HIIT leads to improvements on peakVO2, peak heart rate, and heart rate reserve compared to MICT in HTx recipients. However, the superiority of HIIT should be tested in isocaloric protocols.