Exercise and Cardiac Measures in Dialysis Patients
Condition: Sudden Cardiac Death
MeSH terms: Death, Sudden, Cardiac; Death
Study type: Interventional

Summary: 
      Background: The impact of the known non-invasive cardiac indices for identification of
      hemodialysis (HD) patients at high-risk for sudden cardiac death (SCD) has not been
      evaluated.

      Patients: Fifty-nine HD patients were randomized into 2 groups. Thirty of them (group A-aged
      54.6±8.9 years) participated in a supervised training program with stationary bicycles during
      their HD sessions (3/weekly) for 10 months, while the rest (group B-aged 53.2±6.1 years)
      remained untrained and were used as controls.

      Study hypothesis: Exercise training will affect most of the non-invasive cardiac markers of
      SCD and the total score positively.

      Method: At entry, as well as at the end of the study all subjects underwent a cardiopulmonary
      exercise testing (estimation of aerobic capacity-VO2peak), an echocardiographic study (LV
      ejection fraction -LVEF evaluation), an ambulatory 24-hour Holter monitoring for cardiac
      autonomic nervous system activity evaluation by time- and frequency- domain heart rate
      variability (HRV) calculation (measurement of SDNN, mean RR and low to high frequency
      ratio-LF/HF), a signal-averaged ECG (late potentials-LP documentation) and a submaximal
      exercise test for microvolt-T-wave alternans (TWA) detection.
    

Detailed description: 
      The identification of patients on hemodialysis (HD) at increased cardiac risk with powerful
      screening tests and the reduction of factors, which increase the probability of malignant
      arrhythmias are important for primary prevention of sudden cardiac death (SCD).

      Study Design: randomized and controlled clinical trial. Setting & Participants: Fifty-nine HD
      patients were randomized into exercise training group (group A-30 patients) and controls
      (group B-29 patients).

      Intervention: Group A participated in a 10-month supervised exercise training program during
      the HD sessions (3/weekly).

      Outcomes: The effects of exercise on the score of the non-invasive cardiac markers for SCD
      risk stratification and on the occurrence of each variable separately. Statistical analysis
      included a two-group comparison of change scores and an analysis of covariance adjusting for
      baseline.

      Measurements: At entry and the end of the study, in all participants aerobic capacity
      (VO2peak) and left ventricular ejection fraction (LVEF) were estimated, late potentials and
      T-wave alternans were detected and heart rate variability was calculated. Specifically, from
      the 24-h Holter monitoring the standard deviation of all the normal R-R intervals (SDNN), the
      mean R-R intervals (mean RR), the low (LF) and high (HF) frequency components of the
      autoregressive power spectrum of the NN intervals and their ratio (LF/HF) were recorded.
    

Intervention name(s): Exercise training
Intervention type(s): Behavioral
Intervention description(s): 10-month exercise training program during hemodialysis sessions
Other intervention name(s): Group A; group B
Allocation: Randomized
Intervention model: Parallel Assignment
Masking: Triple (Care Provider, Investigator, Outcomes Assessor)
Primary purpose: Screening
Keywords: Exercise; Dialysis; Non-invasive cardiac measures; Exercise trained patients; Controls