An Stevens

Determinants of the effects of physical training and of the complications requiring resuscitation during exercise in patients with cardiovascular disease.

Background Benefits of cardiac rehabilitation with exercise therapy are well-established, although individual reactions are heterogeneous. The identification of determinants of training effects is useful from a prognostic point of view, but data regarding this are scarce. Furthermore, limited data exist on the determinants of complications during exercise in cardiac patients. This study aimed to investigate the determinants (1) of training effects in cardiac rehabilitation and (2) of complications requiring resuscitation during exercise activities at the hospital and during continued exercise at a sports club for cardiac patients. Design Clinical association study. Methods Determinants of changes in peak oxygen uptake (VO2) after 3 months of cardiac rehabilitation were determined by multiple regression analysis (n = 1909). Determinants of events requiring resuscitation (n = 21) were assessed by logistic regression analysis. Results Improvements in peak VO2 and exercise duration averaged 26%. Eighteen per cent of the variance in absolute improvements of peak VO2 was explained, with age and training characteristics as the strongest determinants. Twenty-one per cent of the variation in relative improvements was explained, with baseline exercise performance and training characteristics being the strongest determinants. The intake of anti-arrhythmics (odds ratio = 5.5; P<0.001) and the presence of ST-segment depression (> 1 mm) at baseline exercise testing (odds ratio = 1.6; P< 0.001) were predictive for serious complications. The occurrence of events requiring resuscitation was higher at the sports club (1/16 533 versus 1/29 214 patient-hours). Conclusions Age, baseline exercise performance and training characteristics were predictive for training effects in cardiac rehabilitation. Anti-arrhythmics and ST-segment depression at baseline exercise testing were predictive for complications.

Exercise training improves insulin release during glucose tolerance testing in stable chronic heart failure patients.

PURPOSE: Chronic heart failure (CHF) patients often present with (pre)diabetes, which negatively influences prognosis. Unlike the proven effect of exercise on glucose regulation in the general population, its effect in CHF is unclear. Therefore, this study aimed at investigating the effect of exercise training on glucose regulation in stable CHF patients. METHODS: Twenty-two CHF patients were randomized into training (EX, n = 15) and control (CON, n = 7) groups. Before and after a 12-week training intervention involving endurance and resistance training, glucose tolerance (2-hour oral glucose tolerance test), exercise tolerance (cardiopulmonary exercise test), muscle strength (isokinetic dynamometer), heart function (echocardiography), glycated hemoglobin, body composition (dual-energy x-ray absorptiometry), and quality of life (EQ5D) were assessed. RESULTS: At baseline, glucose levels 2 hours after glucose intake were elevated in both groups. Whereas area under the glucose curve did not change, area under the insulin curve decreased following training (EX, −13 ± 23% vs CON, +22 ± 33%; P < .05). Changes in the ratio of mitral peak velocity of early filling/early diastolic mitral annular velocity and waist-to-hip fat mass ratio were related to changes in the insulin curve. Exercise training resulted in improved oxygen uptake at the second ventilatory threshold (EX, +10 ± 5% vs CON, −8 ± 5%; P < .05) and isokinetic strength endurance of the upper leg (EX, +25 ± 9% vs CON, −6 ± 5%; P < 0.05). Lean body tissue was increased by 2.2 ± 0.5% in EX versus 0.2 ± 0.6% in CON (P < .05). CONCLUSION: Our data suggest that exercise training attenuates worsening of glucose regulation typically seen in a stable CHF population.