Functional electrical stimulation improves endothelial function and reduces peripheral immune responses in patients with chronic heart failure.

BACKGROUND: Previous studies have shown beneficial effects of functional electrical stimulation (FES) on muscle performance and exercise capacity of patients with chronic heart failure. This study evaluates the impact of FES on endothelial function and peripheral markers of immune activation in patients with moderate to severe heart failure. METHODS: Twenty-four patients with a left ventricular ejection fraction of less than 40% and New York Heart Association class II-III symptoms, undergoing optimized drug therapy, were randomly assigned (2 : 1) to a 6-week training programme of FES (n=16) or served as controls (n=8). Endothelial function was assessed by Doppler flow-mediated dilatation (FMD) of the brachial artery before and after the training programme. Peripheral pro-inflammatory/anti-inflammatory markers such as tumour necrosis factor (TNF)-alpha, interleukin (IL)-6, soluble intercellular adhesion molecule (sICAM)-1, soluble vascular cell adhesion molecule (sVCAM)-1 and IL-10 were also measured before and after training. RESULTS: A significant improvement on the 6-min walk test (7.5+/-3.3%), Minnesota Living Score (18.2+/-8.6%) and FMD (38.5+/-15.1%) was observed only in the FES-treated group. FES also causes a significant reduction of TNF-alpha (-11.5+/-8.9%), sICAM-1 (-13.1+/-9.8%), and sVCAM-1 (-10.6+/-6.6%), as well as a respective increase in the ratio IL-10/TNF-alpha (37.1+/-29.4%). In the FES group, the percentage improvement in the Minnesota Living Score was significantly correlated with respective changes in circulating TNF-alpha (r=0.624, P<0.01), sVCAM-1 (r=0.665, P<0.001) and the ratio IL-10/TNF-alpha (r=-0.641, P<0.01). CONCLUSION: FES is an exercise training programme that improves endothelial function in patients with chronic heart failure, and also has anti-inflammatory effects.

Comparison of myocardial contrast echocardiography with SPECT in the evaluation of coronary artery disease in asymptomatic patients with LBBB.

OBJECTIVE: The non-invasive assessment of coronary artery disease (CAD) in patients with left bundle branch block (LBBB) is troublesome. In this study, we investigated the diagnostic accuracy of myocardial contrast echocardiography (MCE) with adenosine to detect CAD in asymptomatic patients with LBBB, and we compared it with single photon emission computed tomography (SPECT) with adenosine. METHODS: Forty-seven patients with LBBB, and no previously documented CAD, initially underwent SPECT imaging and 1-3 days later MCE. Coronary arteriography was performed within 1 week from the latter procedure. RESULTS: The overall sensitivity, specificity, positive predictive value, negative predictive value, diagnostic accuracy, and kappa index of concordance of SPECT were 73%, 72%, 44%, 90%, 72%, and 0.37+/-0.13, respectively, whereas those of MCE were 91%, 92%, 77%, 97%, 92%, and 0.77+/-0.1, respectively (p<0.05 for all comparisons). Significant CAD was present in 11 patients (23%). Left anterior descending coronary artery was involved in 8 patients, left circumflex artery in 2 patients, and right coronary artery in 4 patients. Concerning the left anterior descending artery disease detection, SPECT had a sensitivity of 75%, a specificity of 79%, a positive predictive value of 43%, a negative predictive value of 94%, and a diagnostic accuracy of 79%. The respective values of MCE were 100% for all of the above variables. CONCLUSIONS: MCE with adenosine has a higher global diagnostic accuracy compared to SPECT for the detection of CAD in patients with LBBB, mainly due to the poor specificity of SPECT concerning perfusion defects detection in the left anterior descending artery territory.