HF: CoEnzyme Q10 (2007)
Diagnosis of CHF for a minimum of 6 months documented by a recent electrocardiogram and chest X-ray
Doses of standard therapy constant over hte previous 3 months
Valve disease with dignificant hemodymnamic distrubance, acute myocardial infaction iwthin the previous 3 months, angina, congenital heart disease, moderate or severe hypertension uncontrolled by therapy, cardiac revascularization with the past 3 months, cerebrovascular accident int he past 6 monts, history of seizures or severe reanl or helpatic disease.
Recruitment
Potentially elegible patients with signs and symptoms of CHF diagnosed for >6 months who were being seen by private and hospital cardiologists at 173 centers in Italy. Diagnosis was documented by electrocardiogram and chest X-ray.
Design
A before-after study in which a daily dosage of CoQ10 of either 50 mg (13.4 % of patients), 100 mg (78% of patients) or 150 mg (8.6% of patients) was given for 3 months to patients with a minimum of 6 month duration congestive heart failure. At baseline and at 3 months, patients were graded according to the NYHA functional class. Measurements performed included blood pressure, heart rate, respiratory rate and blood sodium and potassium levels. Two- to seven point scales were used for the assessment of clinical signa and symptoms. The clinical assessments were: cyanosis (0-3), edema (0-3), pulmonary rales (0-4), enlargement ofthe liver area (0-3), jugular reflux (0-2), dyspnea (0-6), palpitations (0-3), insomnia (0-3), sweating (0-1), subjective arrhythmia (0-3), vertigo (0-3) and nocturia (0-3). Preexisting adverse reactions were recorded at baseline. Non-preexistent adverse reactions were recorded during the 3 months of treatment.
Blinding used (if applicable)
None
Intervention (if applicable)
A daily dosage of CoQ10 of either 50 mg (13.4 % of patients), 100 mg (78% of patients) or 150 mg (8.6% of patients) was given for 3 months to all participants.
Statistical Analysis
Descriptive statistics (mean, range, standard deviation) were used for continuous variables(age, systolic and iastolic blood pressure).
Noncontinuous variables (e.g. patients with insommia) were expressed as percent and frequency.
Statistical analysis for pre/post-treatment effect was preformed using ht e paired t test for continuous variable, Wilcoxon signed-rantk test for score (e.g. dyspnea), and chi-square test for frequency data.
For all tests p = 0.05 was accepted as the significance level.
The number of patients reporting adverse reactions was tabulated with ADE descriptions.
Timing of Measurements
Meaurements were performed at baseline and at 3 months.
Dependent Variables
- Variable 1: NYHA functional class was used to grade patients
- Variable 2: Blood pressure, heart rate in the uspine and sitting position, respiratory rate, serum sodium and serum potassium were measured.
- Variable 3: Two- to seven point scales were used for the assessment of clinical signs and symptoms. The clinical assessments were: cyanosis (0-3), edema (0-3), pulmonary rales (0-4), enlargement ofthe liver area (0-3), jugular reflux (0-2), dyspnea (0-6), palpitations (0-3), insomnia (0-3), sweating (0-1), subjective arrhythmia (0-3), vertigo (0-3) and nocturia (0-3).
- Independent Variables
CoQ10
Control Variables
NYHA functional class, blood pressure, heart rate, respiratory rate, biochemical meaurements and clinical signs and symptoms.
Initial N: (e.g., 731 (298 males, 433 females))
2664
Attrition (final N):
2359 (1181 male and 1178 female)
150 were excluded due to protocol violations of inclusion criteria, 150 not analyzed because of poor compliance.
Age:
Mean of 68.5 years (range 41-91)
Ethnicity:
Living in Italy
Other relevant demographics:
Anthropometrics (e.g., were groups same or different on important measures)
All had been diagnosed with CHF for >6 months and had been on a constant dose of therapy for the previous 3 months. Patients who had valve disease with significant hemodymnamic disturbance, acute myocardial infarction within the previous 3 months, angina, congenital heart disease, moderate or severe hypertension uncontrolled by therapy, cardiac revascularization with the past 3 months, cerebrovascular accident int he past 6 monts, history of seizures or severe renal or hepatic disease were excluded.
Location:
Private doctor's offices and hospital clinics in Italy
Variables |
Treatmintervals Controlent Group Measures and confidence intervals |
Control group Measures and confidence intervals |
Statistical Significance of Group Difference |
Dependent Variable 1: Blood Pressure |
|||
supine systolic |
149.4 ± 18 |
143.8 ± 14.9 |
p <0.05 |
sitting diastolic |
83.7 ± 7.6 |
82.0 ± 6.8 |
p <0.05 |
supine systolic |
147.8 ± 18.7 |
143.4 ± 15.4 |
p <0.05 |
sitting diastolic |
84.2 ± 7.6 |
82.6 ± 7.1 |
p <0.05 |
Dep var 2: Heart rate |
|||
supine |
78.4 ± 9.6 |
75.1 ± 8.2 |
p <0.05 |
sitting |
80.3 ± 9.5 |
77.9 ± 8.1 |
p <0.05 |
Respiratory rate Serum sodium(mmolSymptombaseline Improved/l) Serum potassium (mmol/l) |
21.2 ± 3.9 140.9 ± 5.2
4.2 ± 0.4
|
20.6 ± 3.5 140.3 ± 5.7
4.2 ± 0.4
|
p <0.05 NS
NS |
Other Findings
Symptom | n at baseline | Improved 1 point (%) | P value |
Cyanosis | 675 | 78.67 | <0.01 |
Edema | 1764 | 78.06 | <0.01 |
Pulmonary rales | 1752 | 77.85 | <0.01 |
Enlarged liver area | 1285 | 49.26 | <0.01 |
Jugular reflux | 713 | 71.81 | <0.01 |
Dyspnea | 2163 | 52.75 | <0.01 |
Palpitations | 1903 | 75.46 | <0.01 |
Sweating | 1044 | 79.79 | <0.01 |
Subjective arrhythmia | 1143 | 63.43 | <0.01 |
Insomnia | 1597 | 62.87 | <0.01 |
Dizziness | 1282 | 73.13 | <0.01 |
Nocturia | 1541 | 53.67 | <0.01 |
184 patients changed from NYHA class III to class II, 69 increased to the lowest class, 35 increased from class II to class III, 142 did not change class and 1538 decreased their score.
Seven patients had to discontinue CoQ10 because of disabling symptomatology (maculopapular rash or nausea and epigastric pain). Other side effects reported were dizziness, photophobia, and irritability. Dosage of the drug appeared to resolve the problem
University/Hospital: | V. Buzzi Hospital (Italy), General Hospital (Reggio Emilia), University Parma |
A large study in which a large percentage showed improved in symptoms of CHF. Unfortunately the paper did not document how the 173 different centers were equally assessing those symptoms.
Quality Criteria Checklist: Primary Research
|
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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? | Yes | |
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? | Yes | |
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? | N/A | |
3.1. | Was the method of assigning subjects/patients to groups described and unbiased? (Method of randomization identified if RCT) | N/A | |
3.2. | Were distribution of disease status, prognostic factors, and other factors (e.g., demographics) similar across study groups at baseline? | N/A | |
3.3. | Were concurrent controls or comparisons used? (Concurrent preferred over historical control or comparison groups.) | N/A | |
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? | Yes | |
4.1. | Were follow-up methods described and the same for all groups? | N/A | |
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%.) | Yes | |
4.3. | Were all enrolled subjects/patients (in the original sample) accounted for? | Yes | |
4.4. | Were reasons for withdrawals similar across groups? | N/A | |
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? | N/A | |
5.1. | In intervention study, were subjects, clinicians/practitioners, and investigators blinded to treatment group, as appropriate? | N/A | |
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.) | N/A | |
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? | Yes | |
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? | Yes | |
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? | Yes | |
6.5. | Were co-interventions (e.g., ancillary treatments, other therapies) described? | N/A | |
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? | ??? | |
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? | N/A | |
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? | ??? | |
7.5. | Was the measurement of effect at an appropriate level of precision? | ??? | |
7.6. | Were other factors accounted for (measured) that could affect outcomes? | N/A | |
7.7. | Were the measurements conducted consistently across groups? | ??? | |
8. | Was the statistical analysis appropriate for the study design and type of outcome indicators? | Yes | |
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)? | N/A | |
8.5. | Were adequate adjustments made for effects of confounding factors that might have affected the outcomes (e.g., multivariate analyses)? | N/A | |
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? | No | |
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? | No | |
10.2. | Was the study free from apparent conflict of interest? | ??? | |