Background: Small studies have suggested that high-intensity interval training (HIIT) is superior to moderate continuous training (MCT) in reversing cardiac remodeling and increasing aerobic capacity in patients with heart failure with reduced ejection fraction. The present multicenter trial compared 12 weeks of supervised interventions of HIIT, MCT, or a recommendation of regular exercise (RRE). Methods: Two hundred sixty-one patients with left ventricular ejection fraction ≤35% and New York Heart Association class II to III were randomly assigned to HIIT at 90% to 95% of maximal heart rate, MCT at 60% to 70% of maximal heart rate, or RRE. Thereafter, patients were encouraged to continue exercising on their own. Clinical assessments were performed at baseline, after the intervention, and at follow-up after 52 weeks. Primary end point was a between-group comparison of change in left ventricular end-diastolic diameter from baseline to 12 weeks. Results: Groups did not differ in age (median, 60 years), sex (19% women), ischemic pathogenesis (59%), or medication. Change in left ventricular end-diastolic diameter from baseline to 12 weeks was not different between HIIT and MCT ( P =0.45); left ventricular end-diastolic diameter changes compared with RRE were −2.8 mm (−5.2 to −0.4 mm; P =0.02) in HIIT and −1.2 mm (−3.6 to 1.2 mm; P =0.34) in MCT. There was also no difference between HIIT and MCT in peak oxygen uptake ( P =0.70), but both were superior to RRE. However, none of these changes was maintained at follow-up after 52 weeks. Serious adverse events were not statistically different during supervised intervention or at follow-up at 52 weeks (HIIT, 39%; MCT, 25%; RRE, 34%; P =0.16). Training records showed that 51% of patients exercised below prescribed target during supervised HIIT and 80% above target in MCT. Conclusions: HIIT was not superior to MCT in changing left ventricular remodeling or aerobic capacity, and its feasibility remains unresolved in patients with heart failure. Clinical Trial Registration: URL: http://www.clinicaltrials.gov . Unique identifier: NCT00917046.
1 December 2007 in European Journal of Preventive Cardiology
Valid and reliable experimental models are essential to gain insight into the cellular and molecular mechanisms underlying the beneficial effects of exercise in...
Endothelial dysfunction is an important marker for prognosis in patients with coronary heart disease. However, there are no reference values for endothelial function in a healthy population. Our aim was to determine the distribution of flow-mediated dilation (FMD) values by gender and age in healthy adults. FMD was measured by ultrasound during reactive hyperaemia in the brachial artery of 4739 adults aged 20–89 years, who were free from self-reported cardiovascular or pulmonary disease. Differences in FMD across age and gender were analysed by multiple linear regression. Total mean ± SD FMD was 4.8 ± 4.2%, with corresponding estimates of 4.3 ± 3.9% for men and 5.3 ± 4.5% for women (p < 0.001). In total, 17% had FMD ≤0%, indicating endothelial dysfunction. FMD decreased with increasing age in both genders up to 70 years for men and 80 for women (p < 0.001). In women, age-related decline in FMD was steepest after age 45; in men, a steady decline after age 30. In men 80 years and older, FMD was higher than in men aged 50–79 years. The distribution of FMD in this study is representative of the respective age and gender groups of a healthy population and may be a useful reference for future studies. The high proportion of endothelial dysfunction came as a surprise. Its age and gender distribution suggest that FMD ≤0% precedes cardiovascular disease and that it may be a powerful non-invasive biomarker for identifying high-risk individuals.
Nondirective meditation techniques are practiced with a relaxed focus of attention that permits spontaneously occurring thoughts, images, sensations, memories and emotions to emerge and pass freely, without any expectation that mind wandering should abate. These techniques are thought to facilitate mental processing of emotional experiences, thereby contributing to wellness and stress management. The present study assessed brain activity by functional magnetic resonance imaging in 14 experienced practitioners of Acem meditation in two experimental conditions. In the first, nondirective meditation was compared to rest. Significantly increased activity was detected in areas associated with attention, mind wandering, retrieval of episodic memories and emotional processing. In the second condition, participants carried out concentrative practicing of the same meditation technique, actively trying to avoid mind wandering. The contrast nondirective meditation > concentrative practicing was characterized by higher activity in the right medial temporal lobe (parahippocampal gyrus and amygdala). In conclusion, the present results support the notion that nondirective meditation, which permits mind wandering, involves more extensive activation of brain areas associated with episodic memories and emotional processing, than during concentrative practicing or regular rest.