Effects of Testosterone on Myocardial Repolarization
Condition: Hypogonadism; Chronic Heart Failure
MeSH terms: Heart Failure; Hypogonadism
Study type: Interventional
Phase: Phase 4

Summary: 
      The main of the study is to evaluate the effect of testosterone on ventricular repolarization
      in patients with mild heart failure, at risk for sudden cardiac death. The
      electrocardiographic markers studied are QT variability index, the short term variability
      index.
    

Detailed description: 
      Background:

      It has been widely demonstrated in experimental cardiology that estrogen may play a
      protective role on cardiovascular system, reducing myocardial damage in ischemia-reperfusion
      injury. Poor are the contributions of the effects of estrogen in the presence of testosterone
      which also showed potentially cardioprotective effects. Recently it has emerged strong
      evidence showing that the increase in the repolarization phase of myocardial duration and its
      temporal dispersion are predictive markers of cardiac death in post-ischemic dilated
      cardiomyopathy. In addition, the temporal dispersion of the final part of the repolarization
      phase (Tpeak-Tend) is specifically predictive for sudden cardiac death. In fact, the
      investigators propose the following plan of experimental study. It will be measured by the
      duration of the repolarization phase and its basal temporal dispersion and the peak of the
      heart rate obtained during stress test, in male subjects before and during testosterone
      replacement therapy.

      Patients evaluation baseline, after 1 month and after 6 months of follow up:

      Endocrinological evaluation with measurement of body weight, height, BMI calculation and
      (digital rectal examination) DRE, blood sample.

      Laboratory:

      Dosage of serum total testosterone, total and free PSA, blood count.

      Cardiological evaluation:

        1. Patient's clinical objective examination: measurement of blood pressure and basal heart
           rate.

        2. Traditional resting electrocardiogram 12-lead ECG in the supine position and 50 to 25 mm
           / sec, 10 millivolts.

        3. Electrocardiographic single lead computerised registration (DI, D II and D III) of 5
           minutes baseline and 5 minutes with controlled breathing (15 breaths / min), using the
           Spectralink 2011 program, which allows us to identify and calculate the variables object
           of this study;

        4. Stress cycle electrocardiogram by modified Bruce protocol (25 watts every 2 minutes).
           The test is interrupted reaching 90% of the maximum heart rate, calculated based on the
           age of the patient, or to muscular exhaustion. A single lead electrocardiographic
           recording is started in the 10 minutes period after stress test, using Spectralink 2011
           which allows investigators to calculate the variables studied.

        5. trans thoracic echocardiogram with assessment of ejection fraction and any kinetic
           alterations in contractility and / or valvular heart disease, degree of possible
           diastolic dysfunction (E / A), size (interventricular septum, posterior wall,
           end-systolic and end-diastolic diameter in mm) and volumes (end-diastolic and
           end-systolic volume) of the left and right ventricle sections.
    

Intervention name(s): Testosterone Undecanoate
Intervention type(s): Drug
Intervention description(s): just hypogonadic patients enrolled received hormone replacement therapy with testosterone undecanoate 1000 mg/4ml intramuscular (IM) at baseline, after 6 weeks and 12 weeks after the first evaluation
Intervention MeSH terms: Methyltestosterone; Testosterone; Testosterone undecanoate; Testosterone enanthate; Testosterone 17 beta-cypionate
Allocation: Non-Randomized
Intervention model: Parallel Assignment
Masking: None (Open Label)
Primary purpose: Other
Keywords: testosterone; chronic heart failure