High Intensity Aerobic Interval Training With Mediterranean Diet Recommendations in Post-Myocardial Infarct Patients

Effects of Combined High Intensity Aerobic Interval Training Program and Mediterranean Diet Recommendations in Post-Myocardial Infarct Patients: INTERFARCT Controlled Trial

Acute myocardial infarction (MI) continues remains to be a major cause of death and disability worldwide. Exercise therapy has long been used for rehabilitation purposes and the benefit of regular physical exercise is also well established. The intensity of aerobic exercise training is a key issue in cardiac rehabilitation programmes.Endurance aerobic training is typically performed as continuous training at moderate to-high exercise intensity in steady-state conditions of aerobic energetic yield. However, interval training (i.e., repeated bouts of short-duration, high to severe- or severe to extreme-intensity exercise, separated by brief periods of lower-intensity) has been proposed to be more effective than continuous exercise for improving exercise capacity. Adding to that, health-related adaptations to low-volume and high intensity interval training have been presented.

On the other hand, the Mediterranean Diet has been widely reported to be a model of healthy eating for its contribution to a favourable health status and a better quality of life, reducing in overall mortality from cardiovascular diseases.

Considering all the above mentioned in MI population, the principal objective for the INTERFARCT study will be to assess the effects of different programs of high intensity aerobic interval training and Mediterranean Diet recommendations in the clinical condition, cardio-respiratory fitness, biomarkers, ventricular function and perception of quality of life after myocardial infarction.

Methods/Design: One hundred and fifty people after suffering acute MI will perform different assessments to evaluate clinical history, physical, biochemical and nutritional condition, and quality of life before and after 16-week of follow-up. All participants will receive Mediterranean diet recommendations and will be randomly assigned to attention control group (diet and physical activity recommendations) or exercise groups (diet recommendations plus high-intensity aerobic interval exercise). Participants assigned to an exercise group will train 2 days/week under supervision (day 1-treadmill and day 2-bike protocol). There will be two aerobic exercise groups: 1) high-intensity interval training and high-volume (HV-HIIT) group, and 2) high-intensity interval training and low-volume (LV-HIIT) group.

The management of acute myocardial infarction (MI) continues to undergo major changes, because it remains to be a major cause of death and disability worldwide. Myocardial infarction may be the first manifestation of coronary artery disease or it may occur, repeatedly, in patients with established disease. The term "myocardial infarction" may have major psychological and legal implications for the individual and society. It is an indicator of one of the leading health problems in the world and it is an outcome measure in clinical trials.

Coronary heart disease is a chronic condition and patients are at high risk for new events and premature death. Several evidence-based interventions can improve prognosis. Lifestyle changes should be explained and proposed to the patients before discharge, including cessation of smoking, blood pressure control, and advice regarding diet and weight control, and the encouragement of physical activity. Exercise therapy has long been used for rehabilitation purposes and the benefit of regular physical exercise is also well established. 1 The intensity of aerobic exercise training is a key issue in cardiac rehabilitation programmes. Exercise intensity is directly linked to both the amount of improvement in exercise capacity and the risk of adverse events during exercise, and intensity ranges for aerobic training prescription and design are included in several guidelines and publications regarding secondary prevention and cardiac rehabilitation. Aerobic fitness is recognized as a robust indicator of cardiovascular health and a well-established predictor of total and cardiovascular mortality in subjects with and without coronary heart disease. Direct measurements of peak oxygen uptake (VO2peak) and ventilatory thresholds are considered the gold standard references for the evaluation of aerobic metabolism function and, consequently, for aerobic exercise intensity assessment and design. The increase of VO2peak after a period of exercise training depends of the components of frequency, intensity, time or volume, and type or modality (FITT principle), which constitute the key to achieve a safe exercise training effect. Endurance aerobic training is typically performed as continuous training at moderate to-high exercise intensity in steady-state conditions of aerobic energetic yield. However, interval training (i.e., repeated bouts of short-duration, high to severe- or severe to extreme-intensity exercise, separated by brief periods of lower-intensity) has been proposed to be more effective than continuous exercise for improving exercise capacity. Adding to that, health-related adaptations to low-volume and high intensity interval training have been presented. This type of training is characterized by sessions that involve a relatively small total amount of exercise at high-intensity (i.e., ≤10 min). To our knowledge, there are no studies that compare HIIT with different volume exercise in patients who have suffered MI.

On the other hand, the relevance of overall high-quality food patterns, rather than focus on single nutrients and foods, has emerged as a powerful paradigm to address the diet and to assess their potential cardiovascular disease preventive effects. The Mediterranean Diet, representing the dietary pattern usually consumed among the populations bordering the Mediterranean sea, has been widely reported to be a model of healthy eating for its contribution to a favourable health status and a better quality of life, reducing in overall mortality from cardiovascular diseases.

Considering all the above mentioned in MI population: 1) the combination of the Mediterranean Diet with exercise seems critical in greater reduction of mortality from cardiovascular disease and improved cardiovascular biomarkers, 2) no previous studies have compared the effects of a combined dietary recommendations specific to people after MI with exercise training at high intensity interval training and different volumes (i.e., high- and low-volume).INTERFARCT study is designed to investigate what effect different 16-week aerobic INTERval exercise programs with Mediterranean Diet recommendations will have in people after suffering an acute myocardial inFARCTion.

PRIMARY OBJECTIVE:

To assess the effects of different programs of high intensity aerobic interval training and Mediterranean Diet recommendations in the clinical condition, cardio-respiratory fitness, biomarkers, ventricular function and perception of quality of life after myocardial infarction.

SECONDARY OBJECTIVES

1. To analyze the differences in the studied variables between the two high intensity aerobic interval training programs (high volumen vs low volume) with Mediterranean Diet recommendations to observe the effect of exercise volume.
2. To analyze whether a treatment with only recommendations (exercise and diet) is effective in the secondary prevention of cardiovascular disease comparing to supervised exercise.

Inclusion Criteria:

• Two months to 10 years from the cardiovascular event.
• Left ventricular ejection fraction > 30%
• Ability to undertake regular physical activity (walking and biking)

Exclusion Criteria:

• Moderate to severe heart valvular disease.
• Atrial fibrilation.
• Uncontrolled atrial or ventricular arrhythmias.
• Exercise induced myocardial ischaemia.
• Pericardial disease.
• Uncontrolled hypertension.
• Insulin dependent diabetes mellitus.
• Moderate to severe chronic lung disease (Vital capacity and/or forced expiratory volume during the first second <80% to that expected for the age).
• Severe kidney disease (renal creatinine clearance <30 mL/min, calculated by Cockcroft-Gault formula).
• Anaemia (haemoglobin <12 g/dL).
• Life expectancy less than one year.