High Intensity Interval Training vs Moderate Intensity and Continuous Training in Chronic Heart Failure

Study Overview
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Brief Summary
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Purpose: Exaggerated sympathetic nervous system (SNS) activity associated with low heart rate variability (HRV) is considered as a trigger of cardiac arrhythmias and sudden death. Regular exercise training is efficient to improve autonomic balance. In 2013, the investigators published that a single session of an optimized short-high intensity interval exercise with passive recovery (HIIT) protocol was efficient in chronic heart failure (CHF) patients for enhancing vagal tone and to decrease arrhythmias in the 24-h post exercise period when compared to a single session of moderate intensity continuous exercise (MICT). Nevertheless the effects of HIIT training performed on several weeks have never yet been studied on the parameters described by Coumel's triangle (the arrhythmogenic substrate, the trigger factor as premature ventricular contraction and the modulation factors of which the most common is the autonomic nervous system). The aim of this study was to verify the superiority of HIIT to enhance parasympathetic activity, cardiorespiratory fitness and cardiac function when compared to MICT in a short and intense cardiac rehabilitation program.

Detailed Description
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Before and after the Rehabilitation Program (RP), all patients underwent a 24-hour ECG recording, an echocardiography, a cardiopulmonary exercise test. The RP consisted of 2 types of exercise training according to the randomization: a short-high intensity interval exercise with passive recovery a classical moderate and continuous exercise training at 60% of peak power output The RP lasted 4 weeks.

Official Title
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Efficacy of High Intensity Interval Training vs Moderate Intensity and Continuous Training on Autonomic Nervous System Modulations in Chronic Heart Failure

Conditions
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Chronic Heart Failure

Intervention / Treatment
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* Behavioral: exercise training in heart failure with HIIT


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: stable chronic heart failure with NYHA functional class from I to III stable left ventricular ejection fraction (LVEF) < 45% over at least 6 months stable optimal medical therapy including a beta-blocker and an angiotensin-converting enzyme inhibitor or angiotensin receptor blockers for at least 6 weeks ability to perform a maximal cardiopulmonary exercise test admitted to the Rehabilitation Centre for a comprehensive Cardiovascular Rehabilitation Program Exclusion Criteria: any relative or absolute contraindications to exercise training according to current recommendations fixed-rate pacemaker with heart rate limits set lower than exercise training target major cardiovascular event or procedure within the 3 months preceding enrolment chronic atrial fibrillation heart failure secondary to significant uncorrected primary valve disease (except for mitral regurgitation secondary to left ventricular dysfunction) heart failure secondary to congenital heart disease or obstructive cardiomyopathy.

Ages Eligible for Study
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Minimum Age: 18 Years

Sexes Eligible for Study
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All

Accepts Healthy Volunteers
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No

Study Plan
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How is the study designed?
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Design Details

Primary Purpose: Supportive Care
Allocation: Randomized
Intervention Model: Parallel Assignment
Interventional Model Description: subjects were randomly assigned to one of the two groups: high intensity interval training moderate intensity and continuous training Block size = 4, allocation ratio 1:1
Masking: Double


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Experimental: high intensity interval training<br>high intensity interval training: two sets of 8-min intervals at 100% of peak power output (PPO). Each interval set was composed of repeated bouts of 30 s at 100% of PPO interspersed by 30 s of passive recovery in the seated position. Four minutes of passive recovery were allowed between the two sets. | Behavioral: exercise training in heart failure with HIIT<br>* to compare MICT vs HIIT 5 days/week during 4 weeks in a Cardiovascular Centre.<br>|
| Active Comparator: moderate intensity and continuous exercise<br>moderate intensity and continuous exercise: 30 minutes at 60% of PPO. | Behavioral: exercise training in heart failure with HIIT<br>* to compare MICT vs HIIT 5 days/week during 4 weeks in a Cardiovascular Centre.<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| High Frequency power in normalized units (HFnu%) | based on Heart Rate Variability, the power spectral density of the HF (0.15-0.40 Hz, ms2.Hz-1) bands were calculated. | Change from baseline through study completion, an average of 4 weeks (measured during the night period for stationary signal) | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| maximal oxygen consumption (VO2peak ml.min.kg) | VO2 at peak exercise was measured with Cardiopulmonary Exercise Test. | Change from baseline through study completion, an average of 4 weeks | 
| First ventilatory threshold (VT1) (ml.min.kg) | VO2 at VT1 was measured with Cardiopulmonary Exercise Test. | Change from baseline through study completion, an average of 4 weeks | 
| Heart Rate Recovery (beats per minute, bpm) | Heart Rate Recovery (with passive recovery) at 1, 2 and 3 minutes after peak exercise (in beats per minute, bpm) | Change from baseline through study completion, an average of 4 weeks | 
| Left Ventricular Ejection Fraction (LVEF, %) | LV volumes and ejection fraction were calculated from apical recordings by modified biplane Simpson's method. | Change from baseline through study completion, an average of 4 weeks | 
| premature ventricular contraction, (n/24h) | Ectopic ventricular beats were classified as isolated premature contractions, bigeminy, and salves. | Change from baseline through study completion, an average of 4 weeks | 
| NT-pro-BNP, (ng/L) | blood sample analysis | Change from baseline through study completion, an average of 4 weeks | 

 Terms related to the study
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Keywords Provided by Centre Hospitalier Valida
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exercise training, chronic heart failure, parasympathetic, autonomic nervous system, cardiorespiratory fitness, cardiac rehabilitation