Patients with dilated cardiomyopathy and less than 20% ejection fraction increase exercise capacity and have less severe arrhythmia after controlled exercise training

Cardiopulmonary exercise test predicts sustained ventricular arrhythmias in chronic heart failure

BACKGROUND

The cardiopulmonary exercise test (CPX) is an affordable tool for risk prediction in patients with chronic heart failure (CHF). We aimed to determine the role of CPX parameters in predicting the risk of incidence of sustained ventricular arrhythmias (SVA) in CHF.

METHODS

Sixty-one consecutive patients with CHF enrolled in the Daunia Heart Failure Registry underwent CPX and were followed for 327 ± 247 days. Clinical follow-up was performed every month and anticipated in case of re-hospitalisation for cardiac disease. Incidence of SVA was evaluated by direct clinical examination (ECG, ambulatory ECG).

RESULTS

Patients with episodes of SVA (N 14) showed lower values of pVO2 and PetCO2, and higher values of VE/VCO2, VE/VCO2 slope, and VE%. After correction for age, gender, diabetes, ischaemic heart disease and left ventricular ejection fraction, peak VO2 (hazard ratio (HR) 0.68, 95 % confidence interval (CI) 0.51-0.91, p < 0.05), VE% (HR 1.38, 95 % CI 1.04-1.84, p < 0.05), VE/VCO2 (HR 1.38, 95 % CI 1.04-1.82, p < 0.05), VE/VCO2 slope (HR 1.77, 95 % CI 1.31-2.39, p < 0.01), PetCO2 (HR 0.66, 95 % CI 0.50-0.88, p < 0.01) were found as predictors of SVA. At Kaplan-Meier analysis, lower event-free rates were found in subjects with peak VO2 values below median (log rank p < 0.05), values of VE/VCO2 above mean (p < 0.05), higher VE/VCO2 slope tertiles (p <0.05), and values of PetCO2 below median (p < 0.05).

CONCLUSIONS

CPX provides prognostic independent information for risk of SVA in subjects with CHF.

Predictors of cardiac rehabilitation initiation

This study determines the effects of 15 potential predictors on cardiac rehabilitation (CR) initiation: demographic information, measures of perceived severity, perceived susceptibility, perceived cardiac threat, social support, depression, comorbid conditions, left ventricular ejection fraction, strength of physician recommendation, and benefits and barriers. Results showed that greater strength of physician recommendation and less disease severity were significant predictors of higher levels of CR initiation; female gender was a marginally significant predictor of less CR initiation. The strength of the associations for these predictors varied. Strength of physician recommendation was the strongest predictor. This information can be used to increase the number of patients starting CR through programs designed to increase physician awareness of the importance of their recommendation, the continuing need to refer women to CR, and the need to design programs that meet women's needs.

Benefits of Comprehensive Inpatient Education and Discharge Planning Combined With Outpatient Support in Elderly Patients With Congestive Heart Failure

Multidisciplinary disease management programs for congestive heart failure have been shown to substantially reduce readmission rates, resulting in a reduction of costs. These interventions, however, have typically included changes in medical management, making it difficult to quantitate the key elements of a successful program involving education, discharge planning, and transitional care in the outpatient setting. The investigators utilized an experienced cardiac nurse educator to coordinate a targeted inpatient congestive heart failure education program coupled with comprehensive discharge planning and immediate outpatient reinforcement through a coordinated nurse-driven home health care program. The comprehensive intervention resulted in a marked reduction in 6-month readmission rates, from 44.2% to 11.4% (p=0.01). The average total cost saving for each subject in the interventional group was $1541, based on the decreased utilization of both skilled nursing services and home health care during outpatient follow-up. The costs to implement an inpatient education program were negligible, at $158 per subject. There was no difference in discharge medications or medical management protocols that would have influenced these results.

Effect of Physical Training on Corrected QT Dispersion in Patients With Nonischemic Heart Failure

BACKGROUND

The effect of physical training (PT) on QTc dispersion and ventricular tachycardia (VT) remains unclear in patients with nonischemic heart failure.

METHODS AND RESULTS

Eight patients with nonischemic heart failure performed PT using a bicycle ergometer and their exercise tolerance increased (4.9+/-1.8 to 7.0+/-2.5 METs, p<0.05) and QTc dispersion decreased (71+/-22 to 48+/-24 ms, p<0.05). However, PT did not change the frequency of VT.

CONCLUSION

Physical training could improve QTc dispersion in patients with nonischemic heart failure, possibly by improving the autonomic nerve system.

Effects of exercise training on left ventricular volumes and function in patients with nonischemic cardiomyopathy: application of magnetic resonance myocardial tagging

BACKGROUND

Exercise training is now an accepted component of the therapeutic regimen in patients with heart failure and underlying ischemia, but few data are available on the effects of training in patients with nonischemic dilated cardiomyopathy.

METHODS

Twenty-four patients (mean age 55 +/- 9 years, mean ejection fraction 26.6% +/- 10%) were randomized to an exercise (n = 12) or a control (n = 12) group. Patients in the exercise group underwent 5 45-minute sessions of supervised training per week. Before and after the 2-month study period, exercise testing with respiratory gas exchange and lactate analysis was performed, left ventricular volumes and ejection fraction were measured with magnetic resonance imaging, and left ventricular rotation and relaxation velocities were measured with a novel magnetic resonance imaging tagging technique.

RESULTS

Training resulted in increases in peak oxygen uptake (VO2) (21.7 +/- 4 mL/kg/min to 25.3 +/- 5 mL/kg/min, P <.05) and VO2 at the lactate threshold (12.8 +/- 4 mL/kg/min to 19.0 +/- 5 mL/kg/min, P <.01). No differences were observed within or between groups in left ventricular end-diastolic volume, end-systolic volume, or ejection fraction. Velocity of left ventricular rotation during systole was unchanged in both groups, and relaxation velocity was higher after training in the exercise group (21.2 +/- 5 degrees/s versus 29.7 +/- 12 degrees/s, P <.05).

CONCLUSION

Training resulted in increases in peak VO2 and VO2 at the lactate threshold. Left ventricular volumes and systolic function (ie, ejection fraction and rotation velocity) were unchanged with training, suggesting that training in patients with dilated cardiomyopathy does not lead to further myocardial damage. However, the increase in relaxation velocity after exercise training indicates an improvement in diastolic function. The latter finding suggests an additional potential benefit of exercise training in patients with dilated cardiomyopathy.