Home-based exercise in patients with coronary heart disease : effects on physical fitness and physical activity

Coronary arterial disease is responsible for approximately 18 million deaths worldwide including more than four million in Europe. Although mortality is decreasing, its prevalence is rising. After a cardiac event, secondary prevention plans such as cardiac rehabilitation are recommended. Cardiac rehabilitation is a multidisciplinary program that includes dietary modification, lipid control, smoking cessation, psychological counselling, pharmacological therapies and structural exercise training as the core component. Its effects on reducing mortality, prevention of hospital readmissions and improvement of quality of life are highly proved. However, it is still underutilized partially because one model does not fit all patients. Hence, innovative ways of delivering cardiac rehabilitation have been studied. One of those technologies is tele-monitoring; through cardiac tele-rehabilitation some traditional barriers of cardiac rehabilitation programs can be address and it represents an alternative or a supplement to conventional centre-based services. Thus, patients would not be restricted to the hospital or rehabilitation centre and could be controlled at a distance. Cardiac tele-rehabilitation has shown to be as effective as traditional centre-based cardiac rehabilitation on early stages of the program. However, the information regarding the maintenance phase is scarce. Thus, the main purpose of this doctoral research was to investigate the short and long-term effectiveness of a home-based exercise program guided through tele-monitoring in patients starting the maintenance phase (phase III) of cardiac rehabilitation compared to a centre-based group as well as a control group through an intervention study (TRiCH = Tele-rehabilitation in Coronary Heart Disease study). From our results in the short-term (3 months) we can conclude that a home-based cardiac rehabilitation program with tele-monitoring guidance is as effective as centre-based cardiac rehabilitation for improving exercise capacity measured as peak exercise capacity (VO2P). During the intervention, exercise capacity increased in home-based and centre-based groups with on average 4 to 5% with clinical significance while it remained stable in the control group. In the long-term, we did not obtain further increases although exercise capacity remained stable in all three groups. This result might be related to the maintenance of physical activity levels of our population. In the TRiCH study, 85% of patients meet the guidelines of the World Health Organization of at least 150 minutes of physical activity per week at a moderate intensity. Being physically active is one of the cornerstones on lifestyle changes for primary and secondary prevention of coronary artery disease and new technologies are useful tracking patient’s training. During the development of this PhD research, facing the wide variety of tracking products available to the public, we explored the accuracy of some devices. Our interest was also increased by the scarcity of published literature related to validity and reliability of such devices. We concluded that Fitbit Charge HR and MIO Fuse are valid and reliable to measure number of steps in a cardiac population, however, when it comes to energy expenditure we documented a noteworthy inability including also the SenseWear Armband Mini and the Actiheart to estimate it accurately. Nutrition is also considered a part of the lifestyle changes for coronary artery disease patients and a number of nutritional supplements have flooded the market in a similar manner as that of activity trackers. Resveratrol is a natural antioxidant present in red wine that has proved beneficial effects in the cardiovascular system of animals (specially rats), however, when it comes to human studies, few information has been published. Based on the cardio protective effect shown in animal models we intended to study if an acute supplementation with high doses of RV would improve endothelial function measured through flow-mediated dilation in cardiac patients on phase III of cardiac rehabilitation. We concluded that resveratrol impaired flow mediated dilation in patients who underwent percutaneous coronary intervention. However, given the few number of participants, our results must be interpreted cautiously.