HF: CoEnzyme Q10 (2007)

Citation:
 
Study Design:
Class:
- Click here for explanation of classification scheme.
Quality Rating:
Research Purpose:
To investigate the changes of  mitochondrial membrane-phopholipid (MMP) of peripheral lymphocytes and the effects of the protection and repairment of the injury of MMP on the prognosis in patients with  dilated cardiomyopathy (DCM).
Inclusion Criteria:
Inpatients with the diagnosis of DCM by history, physical examination, ECG, UCG, X-ray, SPECT, Swan-Ganz catheter and laboratory tests. 
Exclusion Criteria:

Severe infection

Impaired function of the liver or kidney

Description of Study Protocol:

Recruitment

Inpatients with the diagnosis of DCM by history, physical examination, ECG, UCG, X-ray, SPECT, Swan-Ganz catheter and laboratory tests

Design

Subjects were randomly divided into receiving 20 mg of CoQ10 tid, 12.5 mg captopril tid or 2 tablets of placebo tid for 16.1 ± 7.8 months

Blinding used (if applicable)

None described

Intervention (if applicable)

20 mg of CoQ10 tid, 12.5 mg captopril tid or 2 tablets of placebo tid

Statistical Analysis

All data was computerized and then statistical analysis were performed with SAS software by ANOVA, Student's t-test and Longrank test.  The data was expressed as % or X ± SD. p < 0.05 was used as the significant boundary.

 

 

Data Collection Summary:

Timing of Measurements

Baseline (7 days after  admission) and 13 weeks after admission

 

Dependent Variables

  • Variable 1:  Thirty milliliters of fasting blood was drawn from the ante-cubital vein in the morning on the seventh day and at the 13th week after admission.  Heparin was used for anticoagulation.  Lymphocytes and erythrocytes were separated with Boyunn's Method.  Demer's tricomplex flocculation method was followed.  Transmissional electron microscopy was used to observe randomly 100 lymphocytes of each patient and to determine MMP localization.  Percentages were recorded according to the degree of MMP loss, which was divided into three different conditions: normal localization, mild loss of MMP (<50%), and severe loss of MMP (>50%). 
  • Variable 2:  Survival rate at 2 years post intervention
  •  Independent Variables

 

Control Variables

 

Description of Actual Data Sample:

Initial N:  65 (47 males, 18 females)

Attrition (final N):

61

Age:

43.3 ± 15.8

Ethnicity:

Other relevant demographics:

Anthropometrics (e.g., were groups same or different on important measures)

After admission, routine medications of digoxin, diuretics and vascular dilators were given for 1 week.  Heart function assessment was then performed.   Eleven had class IIC, 24 class IIID and 30 class IVD heart function using the NYHA classification. 

Location:

First Affiliated Hospital of Xian Medical University, Xian China

 

Summary of Results:

 

Group

Normal MMP

Mean, CI

Mild MMP Loss

Mean, CI

Severe MMP Loss

Mean, CI

Captopril Pretreat 59.2 ± 8.1 25.9 ± 4.9 14.7 ± 8.6
Captopril Post-treat 72.4 ± 6.6 *2 17.3 ± 4.6 *1 10.3 ± 4.0 *1
CoQ10 Pretreat 56.6 ± 9.3 24.8 ± 5.6 18.6 ± 9.1
CoQ10 Post-trat 73.8 ± 9.4*2 17.7 ± 6.5*1 8.5 ± 3.1*1
Control Pretreat 61.1 ± 10.3 24.2 ± 3.7 14.7 ± 8.0
Control Post-treat 63.3 ± 9.9 22.7 ± 3.5 14.0 ± 7.6

*P <0.001.  Compare pre-treatment with post-treatment 1 p <0.05, 2 p < 0.025.  Compare Captopril-group and CoQ10-group with Control-group respectively.

Group 2 year Survival Rate Statistical Significance
Captopril 64.0 % p <0.05
CoQ10 72.7% p <0.05
Placebo 35.7% p <0.05

 

Other Findings

Twenty two of the subjects were <35 years of age and had a survival rate of 36.4 % vs 77.4 % in those >35 years of age.  Eighteen patients with a systolic pressure <= 90 mmHg died within 2 years.  Eighteen patients had a heart-chest ration above 0.7; ten died and the 2-year survival rate was 45.0% vs a 69.4% survival rate in those with a heart-chest ratio below 0.7.

The paper does not mention any side effects of the drug.

Author Conclusion:
The degree of the loss of peripheral lymphocytic MMP was closely relative to the heart function of the patients with DCM.  Short-term (12 weeks) intervention of CoQ10 and captopril could protect against and repair the injury of peripheral lymphocytic MMP , and at the same time heart function was improved in the DCM patients.  Our results also showed that these two drugs could increase 2-year survival rate in the patients with DCM after long-term application (more than 6 months).
Funding Source:
Government: chinese nature scientific fund
Reviewer Comments:

Randomization process not described

It was not indicated which treatment group the patients who had remarkably lower survival rates due to age, systolic pressure and heart-chest ratio were in.

Table I which describes the changes in MMP is confusing.   Those patients who had normal localization demonstated an increase in MMP following treatment while those with mild or severe loss of MMP had a decrease in MMP.

 

Quality Criteria Checklist: Primary Research
Relevance Questions
  1. Would implementing the studied intervention or procedure (if found successful) result in improved outcomes for the patients/clients/population group? (Not Applicable for some epidemiological studies) Yes
  2. Did the authors study an outcome (dependent variable) or topic that the patients/clients/population group would care about? Yes
  3. Is the focus of the intervention or procedure (independent variable) or topic of study a common issue of concern to dieteticspractice? Yes
  4. Is the intervention or procedure feasible? (NA for some epidemiological studies) Yes
 
Validity Questions
1. Was the research question clearly stated? ???
  1.1. Was (were) the specific intervention(s) or procedure(s) [independent variable(s)] identified? Yes
  1.2. Was (were) the outcome(s) [dependent variable(s)] clearly indicated? ???
  1.3. Were the target population and setting specified? Yes
2. Was the selection of study subjects/patients free from bias? Yes
  2.1. Were inclusion/exclusion criteria specified (e.g., risk, point in disease progression, diagnostic or prognosis criteria), and with sufficient detail and without omitting criteria critical to the study? Yes
  2.2. Were criteria applied equally to all study groups? Yes
  2.3. Were health, demographics, and other characteristics of subjects described? Yes
  2.4. Were the subjects/patients a representative sample of the relevant population? Yes
3. Were study groups comparable? ???
  3.1. Was the method of assigning subjects/patients to groups described and unbiased? (Method of randomization identified if RCT) No
  3.2. Were distribution of disease status, prognostic factors, and other factors (e.g., demographics) similar across study groups at baseline? ???
  3.3. Were concurrent controls or comparisons used? (Concurrent preferred over historical control or comparison groups.) Yes
  3.4. If cohort study or cross-sectional study, were groups comparable on important confounding factors and/or were preexisting differences accounted for by using appropriate adjustments in statistical analysis? N/A
  3.5. If case control study, were potential confounding factors comparable for cases and controls? (If case series or trial with subjects serving as own control, this criterion is not applicable.) N/A
  3.6. If diagnostic test, was there an independent blind comparison with an appropriate reference standard (e.g., "gold standard")? N/A
4. Was method of handling withdrawals described? ???
  4.1. Were follow-up methods described and the same for all groups? Yes
  4.2. Was the number, characteristics of withdrawals (i.e., dropouts, lost to follow up, attrition rate) and/or response rate (cross-sectional studies) described for each group? (Follow up goal for a strong study is 80%.) No
  4.3. Were all enrolled subjects/patients (in the original sample) accounted for? Yes
  4.4. Were reasons for withdrawals similar across groups? ???
  4.5. If diagnostic test, was decision to perform reference test not dependent on results of test under study? N/A
5. Was blinding used to prevent introduction of bias? ???
  5.1. In intervention study, were subjects, clinicians/practitioners, and investigators blinded to treatment group, as appropriate? ???
  5.2. Were data collectors blinded for outcomes assessment? (If outcome is measured using an objective test, such as a lab value, this criterion is assumed to be met.) ???
  5.3. In cohort study or cross-sectional study, were measurements of outcomes and risk factors blinded? N/A
  5.4. In case control study, was case definition explicit and case ascertainment not influenced by exposure status? N/A
  5.5. In diagnostic study, were test results blinded to patient history and other test results? N/A
6. Were intervention/therapeutic regimens/exposure factor or procedure and any comparison(s) described in detail? Were interveningfactors described? No
  6.1. In RCT or other intervention trial, were protocols described for all regimens studied? Yes
  6.2. In observational study, were interventions, study settings, and clinicians/provider described? N/A
  6.3. Was the intensity and duration of the intervention or exposure factor sufficient to produce a meaningful effect? Yes
  6.4. Was the amount of exposure and, if relevant, subject/patient compliance measured? No
  6.5. Were co-interventions (e.g., ancillary treatments, other therapies) described? Yes
  6.6. Were extra or unplanned treatments described? N/A
  6.7. Was the information for 6.4, 6.5, and 6.6 assessed the same way for all groups? Yes
  6.8. In diagnostic study, were details of test administration and replication sufficient? N/A
7. Were outcomes clearly defined and the measurements valid and reliable? Yes
  7.1. Were primary and secondary endpoints described and relevant to the question? Yes
  7.2. Were nutrition measures appropriate to question and outcomes of concern? Yes
  7.3. Was the period of follow-up long enough for important outcome(s) to occur? Yes
  7.4. Were the observations and measurements based on standard, valid, and reliable data collection instruments/tests/procedures? Yes
  7.5. Was the measurement of effect at an appropriate level of precision? Yes
  7.6. Were other factors accounted for (measured) that could affect outcomes? N/A
  7.7. Were the measurements conducted consistently across groups? Yes
8. Was the statistical analysis appropriate for the study design and type of outcome indicators? No
  8.1. Were statistical analyses adequately described and the results reported appropriately? Yes
  8.2. Were correct statistical tests used and assumptions of test not violated? Yes
  8.3. Were statistics reported with levels of significance and/or confidence intervals? Yes
  8.4. Was "intent to treat" analysis of outcomes done (and as appropriate, was there an analysis of outcomes for those maximally exposed or a dose-response analysis)? No
  8.5. Were adequate adjustments made for effects of confounding factors that might have affected the outcomes (e.g., multivariate analyses)? No
  8.6. Was clinical significance as well as statistical significance reported? Yes
  8.7. If negative findings, was a power calculation reported to address type 2 error? N/A
9. Are conclusions supported by results with biases and limitations taken into consideration? No
  9.1. Is there a discussion of findings? Yes
  9.2. Are biases and study limitations identified and discussed? No
10. Is bias due to study's funding or sponsorship unlikely? ???
  10.1. Were sources of funding and investigators' affiliations described? Yes
  10.2. Was the study free from apparent conflict of interest? ???