Effect of an intensive lifestyle intervention on the structural and functional substrate for atrial fibrillation in people with metabolic syndrome.

ABSTRACT

AIMS: To evaluate the effect of an intensive lifestyle intervention (ILI) on the structural and functional cardiac substrate of atrial fibrillation (AF) in overweight or obese people with metabolic syndrome (Mets). METHODS AND RESULTS: Participants of the PREvención con DIeta MEDiterranea-Plus trial (n = 6874) were randomized 11 to an ILI programme based on an energy-reduced Mediterranean diet, increased physical activity, and cognitive-behavioural weight management or to a control intervention of low-intensity dietary advice. A core echocardiography lab evaluated left atrial (LA) strain, function, and volumes in 534 participants at baseline, 3-year, and 5-year follow-ups. Mixed models were used to evaluate the effect of the ILI on LA structure and function. In the subsample, the baseline mean age was 65 years [standard deviation (SD) 5 years], and 40% of the participants were women. The mean weight change after 5 years was -3.9 kg (SD 5.3 kg) in the ILI group and -0.3 kg (SD 5.1 kg) in the control group. Over the 5-year period, both groups experienced a worsening of LA structure and function, with increases in LA volumes and stiffness index and decreases in LA longitudinal strain, LA function index, and LA emptying fraction over time. Changes in the ILI and control groups were not significantly different for any of the primary outcomes {LA emptying fraction -0.95% [95% confidence interval (CI) -0.93, -0.98] in the control group, -0.97% [95% CI -0.94, -1.00] in the ILI group, Pbetween groups = 0.80; LA longitudinal strain 0.82% [95% CI 0.79, 0.85] in the control group, 0.85% [95% CI 0.82, 0.89] in the ILI group, Pbetween groups = 0.24} or any of the secondary outcomes. CONCLUSION: In overweight or obese people with Mets, an ILI had no impact on the underlying structural and functional LA substrate measurements associated with AF risk.

This study evaluated whether an intervention-modifying lifestyle had an effect on the parts of the heart involved in the development of atrial fibrillation (AF), a common problem of the heart rhythm. This intervention was implemented in people who had excessive body weight and the metabolic syndrome (Mets), which is a combination of several cardiovascular risk factors. The lifestyle intervention included promoting a Mediterranean diet low in calories and increasing exercise to facilitate weight loss, and this intervention was compared with a control intervention to follow a healthy diet. We performed repeated studies of the heart structure and function with imaging over a period of 5 years. During the 5 years of the study, both study groups (intervention and control) showed changes in their heart consistent with ageing. However, these changes were not different in those who were receiving the lifestyle intervention. Also, participants who lost more weight, adhered better to the study diet, or did more physical activity, overall did not show any differences in their heart compared with those who did not achieve their lifestyle goals.In conclusion, a lifestyle intervention focusing on weight loss, better diet, and more exercise was not effective in improving parts of the heart potentially involved with the risk of AF.In people with metabolic syndrome, a weight control lifestyle intervention, based on an energy-reduced Mediterranean diet and physical activity, had no effect on the structural and functional cardiac substrate of atrial fibrillation.