Maximum oxygen uptake corrected for skeletal muscle mass accurately predicts functional improvements following exercise training in chronic heart failure.

BACKGROUND: Skeletal muscle mass and peak oxygen uptake are important predictors of functional status and outcome in patients with stable chronic heart failure. AIMS: To assess changes in skeletal muscle mass and peak oxygen uptake following an exercise training program. METHODS: Thirty-six patients with moderate stable chronic heart failure were randomly allocated to either a bicycle ergometer (bike) or functional electrical muscle stimulators (FES) applied to quadriceps and gastrocnemius muscles to be used daily for six weeks. Dual-energy X-ray absorptionometry (DEXA) scanning was performed before and after training along with symptom limited cardiopulmonary exercise test, quadriceps strength and fatigue resistance, and 6-min walk test. RESULTS: Both exercise modalities resulted in improvements in treadmill exercise time, leg strength, 6-min walk test and peak oxygen uptake per kilogram of skeletal muscle. Despite significant improvements in functional capacity, there were no significant changes in body composition for total skeletal muscle mass, leg muscle mass or total body fat content. Skeletal muscle mass was strongly predictive of maximum oxygen uptake at baseline (r=0.61, p<0.001) and after exercise training (r=0.68, p<0.001). CONCLUSIONS: In moderate stable chronic heart failure, exercise training using bicycle ergometer or FES results in favourable qualitative rather than quantitative changes in skeletal muscle. Correction of maximum oxygen uptake for skeletal muscle mass rather than total body mass is a more sensitive measure of changes associated with exercise training.

Change in circulating cytokines after 2 forms of exercise training in chronic stable heart failure.

BACKGROUND: A proinflammatory state is recognized in chronic heart failure and the degree of immune activation corresponds to disease severity and prognosis. Training is known to improve symptoms in heart failure but less is known about the effects of specific forms of training on the proinflammatory state. METHODS: Forty-six patients with stable chronic heart failure underwent a home-based program of exercise training for 30 minutes a day, 5 days per week over a 6-week period. Twenty-four used a bicycle ergometer and 22 used an electrical muscle stimulator applied to quadriceps and gastrocnemius muscles. Tumour necrosis factor-alpha (TNF-alpha), TNF-alpha soluble receptors 1 and 2, interleukin 6, and C-reactive protein were measured before and after the training period. RESULTS: Significant improvements in markers of exercise performance were seen in both training groups. Soluble TNF-alpha receptor 2 levels decreased after training in the bike group only (2900 +/- 1069 pg/mL to 2625 +/- 821 pg/mL, P =.013). Trends towards a decrease in levels of TNF-alpha and soluble receptor 1 were also seen in the bike group only. No change in circulating inflammatory markers was observed after stimulator training. CONCLUSIONS: Physical training improves exercise capacity for patients with chronic heart failure but degree of attenuation of the proinflammatory response may depend on the mode of training despite similar improvements in exercise capacity.

Management of chronic heart failure due to systolic left ventricular dysfunction by cardiologist and non-cardiologist physicians.

There are now a number of guidelines outlining the diagnosis and management of patients with chronic heart failure (CHF). The extent to which these guidelines are used and the effects on patient outcomes are not well known. The aim of this study was to examine the implementation of a heart failure guideline among cardiologist and non-cardiologist physicians in a university hospital setting. Case record data were examined from 400 patients with a primary diagnosis of CHF. Management of these patients was assessed using a systolic heart failure guideline (Scottish Intercollegiate Guideline Network, number 35) as a benchmark. Hospital admission data were examined contemporaneously over a 17-month period to assess associations between adherence to drug therapies and number of admissions. Overall, there was poor adherence to the guideline, with relatively high use of angiotensin-converting enzyme (ACE) inhibitors/angiotensin II receptor blockers (ARBs) (80%), low use of beta-blockers (32%) and digoxin (36%), and very low use of spironolactone (13%). Cardiologists used more beta-blockers (37 vs. 21%, P=0.003) and digoxin in sinus rhythm (18 vs. 5%, P<0.001) than non-cardiologists. Hospital admission rate was individually associated with increasing age, NYHA status, beta-blocker, diuretic and spironolactone prescription (all P<0.001). At multivariable analysis, only age, NYHA status and increased diuretic prescription were associated with more frequent admission (P<0.001, R(2)=0.15). Despite carefully designed guidelines, the implementation of evidence-based therapies for CHF remains inadequate, even in a university hospital environment. This may reflect a lack of organisational developments to facilitate the increasingly complex management of patients with CHF.

A randomised study of home-based electrical stimulation of the legs and conventional bicycle exercise training for patients with chronic heart failure.

AIMS: Recent guidelines recommend regular exercise in the management of patients with chronic heart failure (CHF). This study was designed to compare the safety and efficacy of conventional bicycle exercise and functional electrical stimulation (FES) of the legs as forms of home-based exercise training for patients with stable CHF. METHODS AND RESULTS: Forty-six patients (38 male) with stable NYHA Class II/III heart failure underwent a 6-week training programme using either a bicycle ergometer or electrical stimulation of the quadriceps and gastrocnemius muscles. In the bike group, significant increases were seen in 6-min walk (44.6m, 95% confidence interval (CI) 29.3-60.9 m), treadmill exercise time (110 s, 95% CI 72.2-148.0 s), maximum leg strength (5.32 kg, 95% CI 3.18-7.45 kg), and quadriceps fatigue index (0.08, 95% CI 0.04-0.12) following training. In the stimulator group, similar significant increases were seen following training for 6-min walk (40.6m, 95% CI 28.2-53.0m), treadmill exercise time (67 s, 95% CI 11.8-121.8s), maximum leg strength (5.35 kg, 95% CI 1.53-9.17 kg), and quadriceps fatigue index (0.10, 95% CI 0.04-0.17). Peak VO(2)did not change in either group following training, indicating a low-intensity regime. Quality of life scores improved following training when the bicycle and stimulator groups were considered together, but not when considered separately (-0.43, 95% CI -8.13 to -0.56). CONCLUSIONS: FES produces beneficial changes in muscle performance and exercise capacity in patients with CHF. Within this study, the benefits were similar to those observed following bicycle training. FES could be offered to patients with heart failure as an alternative to bicycle training as part of a home-based rehabilitation programme.