Value of Oral Phytate (InsP6) in the Prevention of Progression of the Cardiovascular Calcifications
Main objective of the study:
To evaluate whether the progression of aortic valve calcification and/or coronary arteries
in the group treated with oral InsP6 is smaller than in the placebo group, measured by
quantification of calcium (score and mass) by multidetector CT to the inclusion in the study
and 24 months.
To observe whether the progression of aortic stenosis severity in the intervention group is
smaller than in the placebo group, evaluated by echocardiography.
To compare the clinical events between the intervention and placebo groups, measured as the
combined event of death, hospitalization for angina, coronary revascularization (surgical or
percutaneous), nonfatal myocardial infarction and stroke of any type.
To compare the adverse effects collected by spontaneous reporting between the two groups.
Main variable of analysis ( multidetector CT measurements): Calcium in aortic valve and/or
coronary arteries assessed by Agatston units (AU) on two occasions: before treatment, and 2
years of follow up.
Types of analysis of the main variable:
- Percentage of change in quantity of calcium in aortic valve between baseline and study
- Absolute difference from quantity of calcium in aortic valve between baseline and study
- Percentage change in coronary calcium quantity between baseline and study end.
- Absolute difference in coronary calcium quantity between baseline and study end.
- Percentage change of total calcium in aortic valve and coronary artery between baseline
and study end.
- Absolute difference of total calcium in aortic valve and coronary artery between
baseline and study end.
Progression of aortic stenosis severity assessed by gradient and maximum speed, average by
Percentage of clinical events. The event is considered the composite event "death,
hospitalization for angina, coronary revascularization (surgical or percutaneous), valvular
surgery, nonfatal myocardial infarction or stroke of any type"
Calcium valve by echocardiography: expressed as Rosenhek score at the aortic and coronary
calcium CT MD: expressed as Agatston score units and mass determination of calcium.
Measurement of emitted radiation .
Demographic variables: age, sex, race, weight, height, and BMI SC, snuff and alcohol habits.
Food Survey: Quality and frequency of feeding in relation to income Ins6P. Conventional
hematological and biochemical parameters: blood count. ESR. Urea, Creatinine, Na, K, Ca, P
Phytate: determination in urine by InsP6 technique developed at the Universitat Illes
Balears. The blind is maintained until final results.
Events qualifiers: death, nonfatal myocardial infarction, hospitalization for angina,
coronary revascularization, stroke (score by Events Committee of the study).
Adverse events: Determination of adverse events according to RD 223/2004 (Spanish
regulation) Patient Compliance: By counting returned capsules and quantification of phytate
Withdrawals: If there are withdrawals for any reason the patient is requested authorization
for calcium measurement by CT when possible.
Predetermination of sample size:
Assuming the evolution of aortic valve calcification between 21.7% to 32% per year found in
the placebo arm of clinical trials with similar methodology and population, and based on a
standard deviation of 1100 AU per year, assuming a Type I error of 0.05 and type II of 0.2,
to detect a difference of 20% annually between treatments, we need between 124 and 105
patients, respectively, assuming a 10% of losses, and an average Agatston units at baseline,
of 1700. We decide to adopt the larger size.
Strategy for statistical analysis: The analysis of data will carry out maintaining the blind
and conducted by intention to treat and, as a secondary analysis, per protocol.
The population for the intention to treat analysis, include those randomized patients who
have received at least one dose of assigned treatment. The per protocol population will
consist of those individuals who finish the study without protocol violation.
A description of the baseline characteristics of the groups, will be carry out, verifying,
despite using a system of random assignment, the homogeneity of the two groups for baseline
variables. A test for the normality of quantitative variables to select the statistic
descriptors, mean (CI95%) or median (RI), and test for comparisons.
The main result will be a change of aortic valve calcification, calculated as the percentage
change from baseline divided by the duration of follow up as years. An analysis stratified
for each independent variable.
An increment of at least 18% of the basal calcification, will be considered evident
progression, by contrast, a lesser progression will be considered response to treatment.
Logistic regression will be used to establish the likelihood of response.
Secondary objectives will be analyzed by comparing the ratios between treatment groups.
There will be a descriptive analysis of the side effects listed in both groups.
Ethical considerations: No special ethical problems arise in the trial because of the
phytate is considered a safe product (FDA-Title 21 subchapter GRSH E-Part 582) which are a
component of the normal diet, and because of the chances of problems with excessive intake
of this are nil. Nor is amended nor intervene during the study in routine clinical practice.
The most important aspect is to control the radiation dose that patients receive during the
multidetector CT. In any case is lower than the environmental background radiation received
during 6 months.
Considering this aspect, intermediate CT study has not been scheduled.
No information is available on the extent of calcium through multidetector-CT to let us
build the sample size with great confidence. We have used the values of progressive studies
Cowell and Houslay for making this approximation.
Allocation: Randomized, Endpoint Classification: Efficacy Study, Intervention Model: Parallel Assignment, Masking: Double Blind (Subject, Caregiver, Investigator, Outcomes Assessor), Primary Purpose: Prevention
Calcium in aortic valve and in coronary arteries assessed by multidetector CT scanner (Agatston units)
Guillem Frontera, MD
Hospital Universitario Son Dureta
Spain: Ministry of Health