Atherosclerosis, Hypercholesterolemia
Conditions
Keywords
Atherosclerosis, Cardiovascular Disease, Cardiac MRI, Cardiac CT, Cholesterol
Brief summary
Background: \- Atherosclerosis (thickening of the artery walls caused by cholesterol and other deposits) commonly occurs in the heart vessels and carotid (neck) arteries of adults. This is often present in individuals with high cholesterol levels in their blood. These patients are usually treated with cholesterol lowering medication ( statins ) along with modification of diet and exercise. Researchers are interested in investigating new approaches including magnetic resonance imaging (MRI) and computed tomography (CT) imaging studies to detect blood vessel blockages that would not otherwise be detected by cholesterol levels and risk factors for heart disease. Objectives: \- To measure atherosclerosis in the heart vessels and carotid arteries using imaging tests (computed tomography (CT) and magnetic resonance imaging (MRI)) before and after standard treatment with cholesterol lowering medication ( statins ) Eligibility: \- Healthy individuals at least 55 years of age who are candidates for therapy to lower their blood cholesterol levels. Design: * This study will involve one screening visit and seven study visits over a period of 2 years. * Participants will be screened with a physical examination and medical history, as well as blood samples and tests to ensure that it is safe for them to have CT and MRI scans. Participants will provide information on current medications, dietary habits, smoking status, alcohol and caffeine intake, and their level of physical activity. * Participants will be divided into two groups. One group will receive standard doses of medication to lower cholesterol according to current treatment guidelines, while the other group will have MRI scans of the carotid arteries and a CT scan of the heart to determine the best medication dose levels. * Visits 3 to 5 will be scheduled 3, 6, and 9 months after visit 2. During these visits, researchers will monitor for possible side effects and may change or adjust medications and doses. * At visit 6, participants will have an MRI scan of the carotid arteries, a physical examination, and blood tests. Medications may be changed or adjusted. * At visit 7, participants will have blood tests, and medications may be changed or adjusted. * At the final visit, participants will have MRI and CT scans of the carotid arteries and heart, respectively, as well as a final physical examination and blood tests.
Detailed description
The overall aim of this proposal is to compare the effectiveness of an image guided approach to lipid lowering to standard therapy guided by clinical risk factors and blood lipid levels. Men and women over age 55 who are candidates for statin therapy will be randomized to usual cholesterol lowering care, or to care guided by MRI images of the carotid arteries. Participants randomized to the second, imaging guided, group will be assigned to LDL cholesterol targets according to the degree of atherosclerosis seen by MRI. The study endpoints will be the total degree of plaque regression seen, the dosage of statin drugs required to achieve that reduction, and the rate of cardiovascular events. FDG-PET is hypothesized to enable visualization of anti-inflammatory effects of statins that most likely occur before anatomic regression of the plaques can be demonstrated on MRI. A pilot substudy is to be conducted to explore this relationship. A subgroup of patients participating in the main study will be asked to participate in FDG PET imaging. The purpose of this pilot study is to determine if FDG avid lesions undergo a greater degree of morphologic regression with therapy controlling for the reduction in LDL cholesterol and the dosage of statins required to achieve that target. Although contrast-enhanced coronary CT angiography (CTA) with multidetector computed tomography (MDCT) has been used extensively to characterize coronary artery plaque composition, there is little data regarding its reproducibility. A recent study demonstrated excellent reproducibility for this technique but this study was performed using the older 64 detector row CT scanners2. A pilot substudy will be conducted to study the reproducibility of coronary CT angiography using the newer generation of 320 detector row CT scanners.
Interventions
DRUGStatins, HMG CoA
Statin therapy
Sponsors
National Heart, Lung, and Blood Institute (NHLBI)
Study design
Allocation
RANDOMIZED
Intervention model
PARALLEL
Primary purpose
TREATMENT
Masking
SINGLE (Investigator)
Eligibility
Sex/Gender
ALL
Age
50 Years to 99 Years
Healthy volunteers
No
Inclusion criteria
* INCLUSION CRITERIA: A. Men and Women greater than or equal to 55 years of age B. Candidates for lipid lowering therapy under NCEP ATP III guidelines without contraindication to statin therapy C. Willing to modify therapy to enroll in the study D. Willing to travel to the NIH for follow-up visits. E. Able to understand and sign informed consent F. Lab Eligibility parameters: * eGFR \> 45 mL/min/m2 * For age \>60 test GFR within 1 week prior to contrast; For age less than or equal to 60 test within 4 weeks INCLUSION CRITERIA FOR THE PET SUBSTUDY: Participants who are not participating in the CT Reproducibility study are eligible. INCLUSION CRITERIA FOR THE REPRODUCIBILITY SUBSTUDY: Patients will be selected who had a one RR interval initial CT scan with less that 10.5 mSv estimated radiation dosage and who will not be participating in the PET Substudy.
Exclusion criteria
A. Ineligibility for MR imaging due to: * Previous pacemaker implantation * Automatic implantable cardioverter-defibrillator (AICD) * Metal implants or other ferromagnetic devices, or * Foreign material B. Claustrophobia C. Contra-indication or allergy to statin medications. D. Current statin therapy at or above the maximum dosage permitted per study protocol. E. Use of fibrates, ezetimibe, niacin, or bile acid binding agents within 6 months of screening visit. F. Pregnancy and nursing. G. Liver failure defined clinically and by laboratory data. H. Mental, neurologic or social condition preventing understanding of the rationale, procedures, risks and potential benefits associated with the trial. I. Any other conditions that precludes safety for MRI and/or CT imaging per the researcher s evaluation. EXCLUSION FOR PARTICIPATION FOR GADOLINUIM CONTRAST. PARTICIPANTS MAY STILL UNDERGO ALL OTHER STUDY EVALUATIONS. (Inclusive of the above
Design outcomes
Primary
| Measure | Time frame | Description |
|---|---|---|
| Change in Mean of Wall Volume of Internal Carotid Arteries | 24 months | Wall volume of internal carotid arteries was measured using magnetic resonance imaging. Participants will undergo 2D and 3D carotid MRI using a 3 Tesla scanner and surface carotid coils. Participants with mild or no atherosclerosis, defined as the lowest tertile of wall volume, will have statin therapy adjusted to a target range of 100-130 mg/dL. Participants in the middle tertile will receive statin therapy adjusted to achieve a target LDL 70-100 mg/dL. Participants with the most severe atherosclerosis will receive statin therapy to an LDL target between 40 and 70 mg/dL. Participants in the Standard arm will have lipid sub-fraction targets determined according to estimated 10 year cardiovascular risk, as per standard NCEP guidelines. |
Countries
United States
Participant flow
Participants by arm
| Arm | Count |
|---|---|
| Imaging Lipid targets assigned according to the severity of atherosclerotic plaque measured as wall volume in the common and internal carotid arteries by MRI | 116 |
| Standard Standardized statin therapy based on NCEP ATP IIIR guidelines, including clinical risk factors and blood lipid levels. | 114 |
| Total | 230 |
Baseline characteristics
| Characteristic | Imaging | Standard | Total |
|---|---|---|---|
| Age, Categorical <=18 years | 0 Participants | 0 Participants | 0 Participants |
| Age, Categorical >=65 years | 55 Participants | 63 Participants | 118 Participants |
| Age, Categorical Between 18 and 65 years | 61 Participants | 51 Participants | 112 Participants |
| Ethnicity (NIH/OMB) Hispanic or Latino | 1 Participants | 4 Participants | 5 Participants |
| Ethnicity (NIH/OMB) Not Hispanic or Latino | 115 Participants | 110 Participants | 225 Participants |
| Ethnicity (NIH/OMB) Unknown or Not Reported | 0 Participants | 0 Participants | 0 Participants |
| Race (NIH/OMB) American Indian or Alaska Native | 0 Participants | 2 Participants | 2 Participants |
| Race (NIH/OMB) Asian | 3 Participants | 5 Participants | 8 Participants |
| Race (NIH/OMB) Black or African American | 6 Participants | 11 Participants | 17 Participants |
| Race (NIH/OMB) More than one race | 0 Participants | 1 Participants | 1 Participants |
| Race (NIH/OMB) Native Hawaiian or Other Pacific Islander | 0 Participants | 0 Participants | 0 Participants |
| Race (NIH/OMB) Unknown or Not Reported | 2 Participants | 0 Participants | 2 Participants |
| Race (NIH/OMB) White | 105 Participants | 95 Participants | 200 Participants |
| Sex: Female, Male Female | 47 Participants | 45 Participants | 92 Participants |
| Sex: Female, Male Male | 69 Participants | 69 Participants | 138 Participants |
Adverse events
| Event type | EG000 affected / at risk | EG001 affected / at risk |
|---|---|---|
| deaths Total, all-cause mortality | 0 / 116 | 1 / 114 |
| other Total, other adverse events | 58 / 116 | 51 / 114 |
| serious Total, serious adverse events | 18 / 116 | 18 / 114 |
Outcome results
Primary
Change in Mean of Wall Volume of Internal Carotid Arteries
Wall volume of internal carotid arteries was measured using magnetic resonance imaging. Participants will undergo 2D and 3D carotid MRI using a 3 Tesla scanner and surface carotid coils. Participants with mild or no atherosclerosis, defined as the lowest tertile of wall volume, will have statin therapy adjusted to a target range of 100-130 mg/dL. Participants in the middle tertile will receive statin therapy adjusted to achieve a target LDL 70-100 mg/dL. Participants with the most severe atherosclerosis will receive statin therapy to an LDL target between 40 and 70 mg/dL. Participants in the Standard arm will have lipid sub-fraction targets determined according to estimated 10 year cardiovascular risk, as per standard NCEP guidelines.
Time frame: 24 months
Population: The analyses included only those subjects who were assigned standardized statin doses based on imaging of carotids at baseline based on NCEP ATP IIIR guidelines.
| Arm | Measure | Value (MEAN) |
|---|---|---|
| Imaging | Change in Mean of Wall Volume of Internal Carotid Arteries | -3.52 Other - mm^3 ( cubic millimeter ) |
| Standard | Change in Mean of Wall Volume of Internal Carotid Arteries | -5.91 Other - mm^3 ( cubic millimeter ) |