EAL

HF: CoEnzyme Q10 (2007)

Citation:

Study Design:

Class:

- Click here for explanation of classification scheme.

Quality Rating:

Research Purpose:

To determine if treatment with CoQ₁₀ is effective in treating different diseases of the cardiovascular system in their production of myocardial failure.

Inclusion Criteria:

Patients presented for cardiology consultation and care from 1985 to 1993 at two clinics in Texas.

Exclusion Criteria:

None listed.

Description of Study Protocol:

Recruitment:Patients who presented for cardiology consultation and care from 1985 to 1993 at two clinics in Texas
Design: Single group before-after.

Intervention

Daily dose of 242mg (range 75mg to 600mg) CoQ₁₀taken twice daily
The starting dose varied according to severity of illness, financial considerations, concomitant medications and author's experience.

Statistical Analysis

Not described: Only P-values were given in the figures.

Data Collection Summary:

Timing of Measurements

Baseline and an average of 17.8 months later
213 patients were measured at 12 months
107 patients were measured at between 13 and 24 months
66 patients were measured at 25 to 36 months
38 patients were measured more than 36 months after baseline.

Dependent Variables

Variable One: Functional class, according to the New York Heart Association scale
Variable Two
- The same technician performed echocardiograms using a Toshiba 140A echocardiogram
- Left ventricular size was measured by M-mode in the parasternal window as left ventricular end diastolic dimension (LVEDD) and left ventricular end systolic dimension (LVESD)
- Fractional shortening (FS) was recorded as a percentage [(LVEDD- LVESD)/LVEDD]
- Diastolic function was measured by pulsed wave doppler of the mitral valve inflow, with recording of the EF slope in m/s²
- Left ventricular wall thickness was measured by M-mode from parasternal window and recorded as the sum of the septum and posterior wall in centimeters.
Variable Three: Detailed histories of activity tolerance and medication usage were recorded
Variable Four: Vital signs, weight and a directed cardiopulmonary examination.

Independent Variables

CoQ₁₀.

Description of Actual Data Sample:

Initial N

424 patients
66 (39% female, 61% male) with idiopathic dilated cardiomyopathy (DCM)
58 (73% female, 27% male) with primary diastolic dysfunction (PDD)
109 (54% female, 46% male) with hypertensive heart disease (HTN)
131 (31% female, 69% male) with ischemic cardiomyopathy (ICM)
12 (65% female, 35% male) with valvular heart disease (VHD)
48 (83% female, 17% male) with mitral valve prolapse (MVP).

Attrition (Final N)

394 for NYHA functional class
210 for echocardiogram comparison.

Age

Average for all of the groups ranged from 56 to 70 years.

Ethnicity

Not provided.

Other Relevant Demographics

All patients who presented for cardiology consultation and care in Temple and Tyler, Texas.

Anthropometrics

Groups were the same when comparing the results of echocardiograms. However, the groups were not in the same diagnostic group when comparing functional status and change in number of drugs.

Location

Temple and Tyler, Texas.

Summary of Results:

Variables		Treatment Group Measures and Confidence Intervals	Control Group Measures and Confidence Intervals	Statistical Significance of Group Difference
Dependent Variable One		Mean, CI	Mean, CI	Statistically significant difference between groups
	NYHA class	Class I: 3 Class II: 146 Class III: 213 Class IV: 62.	Class I: 212 Class II: 173 Class III: 33 Class IV: 6.	Not given
Dependent Variable Two		DCM, PDD, ICM, VHD groups		NS
	LVEDD	HTN group MVP group.	Increase towards normal Increase towards normal.	P<0.02 P<0.06.
Dependent Variable Three		DCM group	Improvement	P<0.002
	FS	All other groups		NS

Other Findings

LVH	VHD group		NS
	DCM group	Improvement	P<0.001
	PDD	Improvement	P<0.03
	HTN group	Improvement	P<0.001
	ICM group	Improvement	P<0.001
	MVP group	Improvement	P<0.01
LVH	VHD group		NS
	DCM group	Improvement	p<0.001
	PDD	Improvement	P<0.03
	HTN group	Improvement	P<0.001
	ICM group	Improvement	P<0.001
	MVP group	Improvement	P<0.01
Diastolic Function	VHD group	Improvement	P<0.002
Diastolic Function	Remaining groups	Improvement	P<0.001
Cardiovascular drugs	80 on no drugs	120⁺ on no drugs	Not given
	~90 on 1 drug	~130, 1 drug	Not given
	~13 on 2 drugs	~110, 2 drugs	Not given
	~80 on 3 drugs	~40, 3 drugs	Not given
	~30 on 4 drugs	~5, 4 drugs	Not given
Specific drugs	Digoxin	19% decrease	Not given
	Beta-blockers	51% decrease	Not given
	Other antiarrhythmic drugs	61% decrease	Not given
	Long-acting nitrates	27% decrease	Not given
	Calcium channel blockers	24% decrease	Not given
	ACE inhibitors	32% decrease	Not given
	Other HTN drugs	37% decrease	Not given
	Affect of fat on absorption of CoQ₁₀	Increases	P<0.001

Only one patient experienced any side effects and that was documented as a single case of transient nausea.

Author Conclusion:

Patients with a wide range of cardiac diseases, a common capacity to produce symptomatic myocardial failure and responding favorably to treatment with oral CoQ₁₀ administered to maintain whole blood levels of 2.0µg per ml or greater.

Funding Source:

Industry:

DFG, sudzucker/wirtschaftliche vereinigung zucker

Commodity Group:

Reviewer Comments:

Nice description of the subgroups of etiologies for CHF
No exclusion criteria
Statistics description lacking
Finding that peanut butter and possibly other fats affects the absorption of CoQ₁₀ may have affected the results.

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?		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?		No
	3.1.	Was the method of assigning subjects/patients to groups described and unbiased? (Method of randomization identified if RCT)	Yes
	3.2.	Were distribution of disease status, prognostic factors, and other factors (e.g., demographics) similar across study groups at baseline?	No
	3.3.	Were concurrent controls or comparisons used? (Concurrent preferred over historical control or comparison groups.)	No
	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?	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%.)	Yes
	4.3.	Were all enrolled subjects/patients (in the original sample) accounted for?	Yes
	4.4.	Were reasons for withdrawals similar across groups?	Yes
	4.5.	If diagnostic test, was decision to perform reference test not dependent on results of test under study?	Yes
5.	Was blinding used to prevent introduction of bias?		No
	5.1.	In intervention study, were subjects, clinicians/practitioners, and investigators blinded to treatment group, as appropriate?	No
	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.)	No
	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?	No
	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?	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?	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?	Yes
	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?		???
	8.1.	Were statistical analyses adequately described and the results reported appropriately?	No
	8.2.	Were correct statistical tests used and assumptions of test not violated?	???
	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)?	Yes
	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?	No
	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?		N/A
	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?	No
	10.2.	Was the study free from apparent conflict of interest?	???