Table of Contents
- Key Points
- What Is Heterozygous Familial Hypercholesterolemia (HeFH)?
- Why This Research Matters
- Understanding "Subclinical" Atherosclerosis
- The Three Imaging Tools Explained
- How This Review Was Conducted
- Key Findings: What the Research Shows
- Clinical Implications: What This Means for Patients
- Limitations of the Research
- Recommendations for Patients and Families
- Frequently Asked Questions
- Source Information
Key Points
- Carotid ultrasound can measure treatment effectiveness in children with HeFH, showing statins slow plaque buildup.
- In asymptomatic adults with HeFH, CAC score improves cardiovascular risk prediction beyond standard risk equations.
- CTCA provides detailed plaque information, but its routine role in HeFH primary prevention needs more study.
- Imaging can detect subclinical atherosclerosis decades before symptoms, supporting earlier diagnosis and treatment.
- HeFH is often underdiagnosed and undertreated; discuss imaging options with your cardiologist or lipid specialist.
What Is Heterozygous Familial Hypercholesterolemia (HeFH)?
Heterozygous familial hypercholesterolemia, often shortened to HeFH, is a genetic condition that causes severely elevated levels of LDL cholesterol—the "bad" cholesterol—from birth. The word "heterozygous" means a person inherits one copy of the faulty gene from one parent, rather than two copies. It is one of the most common inherited metabolic disorders, affecting approximately 1 in 200 to 1 in 250 people worldwide.
Because the body cannot properly clear LDL cholesterol from the bloodstream, cholesterol builds up in the artery walls over time. This buildup, called atherosclerosis, can eventually narrow or block arteries and lead to heart attacks, strokes, and other cardiovascular events.
The condition is frequently undertreated and often diagnosed late in life—sometimes only after a person has already experienced a heart event. This is particularly concerning because early treatment with cholesterol-lowering medications called statins can dramatically reduce the risk of complications.
Why This Research Matters
One of the biggest challenges in managing HeFH is that cardiovascular risk varies enormously from one patient to another. Two people with the same genetic mutation and similar cholesterol levels can have very different outcomes. One might develop heart disease in their thirties, while the other remains healthy well into old age.
This variability makes it difficult for doctors to decide how aggressively to treat each individual patient. Standard risk calculators, which are designed for the general population, often underestimate risk in people with HeFH. As a result, some patients may not receive intensive enough treatment, while others may be treated more aggressively than necessary.
This review, published in Current Atherosclerosis Reports in June 2022, was written to update clinicians on the latest evidence for using non-invasive cardiovascular imaging to address this challenge. The authors—Antonio Gallo, Reed Mszar, and Marcio Hiroshi Miname—are researchers affiliated with institutions in France, the United States, and Brazil who specialize in lipid disorders and cardiovascular prevention.
Understanding "Subclinical" Atherosclerosis
The term "subclinical atherosclerosis" refers to the early stages of plaque buildup in the arteries that has not yet caused any noticeable symptoms. A person can have significant atherosclerosis and still feel perfectly healthy. They may have normal exercise tolerance, no chest pain, and no shortness of breath—yet their arteries may already be narrowing.
Subclinical atherosclerosis is essentially a warning sign hiding in plain sight. Detecting it early provides a crucial opportunity to intervene before a first heart attack or stroke occurs. This is where imaging technology comes in.
The review focuses on three specific imaging techniques that can detect subclinical atherosclerosis without invasive procedures:
- Carotid Doppler Ultrasound (US)—a painless test using sound waves to visualize the carotid arteries in the neck
- Coronary Artery Calcium (CAC) Score—a computed tomography (CT) scan that measures calcium deposits in the coronary arteries of the heart
- Computed Tomography Coronary Angiography (CTCA)—a more detailed CT scan that uses contrast dye to visualize the coronary arteries with high precision
The Three Imaging Tools Explained
Carotid Doppler Ultrasound
Carotid ultrasound uses harmless sound waves to create images of the carotid arteries, the main blood vessels in the neck that supply blood to the brain. The test measures the thickness of the inner layers of the artery wall, known as carotid intima-media thickness (cIMT), and can detect plaque buildup. It is quick, radiation-free, and relatively inexpensive, making it suitable for repeated use.
Coronary Artery Calcium (CAC) Score
The CAC score is a specialized CT scan of the heart that detects and quantifies calcium deposits in the coronary arteries. Because calcium only accumulates in atherosclerotic plaques, a CAC score of zero indicates no detectable plaque, while higher scores indicate increasing plaque burden. The test takes about 10 to 15 minutes, involves a small amount of radiation, and requires no contrast dye.
Computed Tomography Coronary Angiography (CTCA)
CTCA is a more advanced imaging method that combines a CT scanner with an intravenous contrast dye. It provides detailed, three-dimensional images of the coronary arteries, allowing doctors to see not just the degree of narrowing but also the characteristics of individual plaques. This includes information on whether a plaque is "stable" or "vulnerable"—vulnerable plaques being more likely to rupture and cause a heart attack.
Each of these tools has distinct strengths and limitations, and the review examines how each one contributes to risk stratification (the process of determining a patient's individual level of risk).
How This Review Was Conducted
This is a narrative review article, meaning the authors systematically gathered and analyzed recent published literature on the use of these imaging modalities in HeFH patients. They focused specifically on studies published in recent years that examined the predictive value of these tools for future cardiovascular events.
The review draws on evidence from a range of study types, including long-term observational studies, prospective cohort studies, and cross-national collaborations. In particular, the authors highlight findings from large prospective cohorts of asymptomatic HeFH patients—meaning patients who had confirmed HeFH but no prior cardiovascular symptoms or events.
Key Findings: What the Research Shows
Finding 1: Carotid Ultrasound Can Track Treatment Success in Children
A major focus of the review is the long-term use of carotid ultrasound in children with HeFH. Research has shown that children with HeFH who are treated early with statins experience a significant reduction in atherosclerotic progression compared to untreated, unaffected siblings.
This is a critical finding because it demonstrates that:
- Atherosclerosis begins early in life in HeFH patients
- Statin therapy can slow or halt this process when started in childhood
- Carotid ultrasound provides a reliable way to measure this benefit over time
The authors emphasize that carotid ultrasound proved its efficacy in long-term follow-up of HeFH children, reinforcing the importance of early diagnosis and early intervention.
Finding 2: CAC Score Adds Value to Existing Risk Prediction in Adults
The review confirms that the CAC score has added value in predicting the risk of cardiovascular events in asymptomatic adults with HeFH. Combining the CAC score with existing risk equations improves risk stratification—meaning it helps doctors more accurately categorize patients as low, intermediate, or high risk.
This finding is based on data from large prospective, cross-national cohorts, which strengthened the reliability of the conclusions. Patients with a CAC score of zero generally had a very low short-term risk of events, while those with higher scores had proportionally higher risks.
Finding 3: CTCA Provides Detailed but Not Yet Fully Defined Benefits
CTCA offers the most detailed information on plaque quality and stability. Unlike CAC scoring, which only detects calcified plaque, CTCA can visualize both calcified and non-calcified plaque, and it can reveal features associated with plaque vulnerability—such as a thin fibrous cap or a large lipid core.
However, the authors note that the role of CTCA in primary prevention for HeFH patients has not been fully established. More research is needed before routine use of CTCA can be recommended in this population.
Finding 4: Imaging Helps Address Underdiagnosis and Undertreatment
A broader theme of the review is that cardiovascular imaging for subclinical disease is a promising tool to improve both diagnosis and treatment of HeFH. This is significant because HeFH is an undertreated and late-diagnosed disease. Many patients are not identified until they have already suffered a heart attack or stroke, and even those who are diagnosed often receive less aggressive treatment than guidelines recommend.
Clinical Implications: What This Means for Patients
For patients with HeFH, these findings have several practical implications.
First, early detection is achievable. The imaging tools discussed in this review can identify arterial damage years or even decades before symptoms appear. A child with HeFH can undergo carotid ultrasound to establish a baseline, then have repeat scans at intervals to monitor whether treatment is working.
Second, risk assessment becomes more personalized. Rather than relying solely on cholesterol levels and risk equations, doctors can use a CAC score to refine their understanding of an individual patient's true risk. For example, a patient with a CAC score of zero may be reassured that their short-term risk is low, while a patient with a high score may be recommended for more intensive lipid-lowering therapy or additional preventive treatments.
Third, treatment decisions can be based on evidence. Seeing visible evidence of plaque buildup can be a powerful motivator for patients to adhere to statin therapy and other lifestyle changes. It also gives doctors concrete justification for intensifying treatment when needed.
The authors stress that these imaging tools are not replacements for standard risk assessment but rather complementary additions that enhance the accuracy of risk prediction.
Limitations of the Research
While the findings are promising, the authors acknowledge several important limitations.
First, much of the evidence on CAC scoring in HeFH comes from observational cohorts rather than randomized controlled trials. While these cohorts are large and international, observational data cannot prove causation as definitively as a randomized trial can.
Second, the role of CTCA in primary prevention needs further exploration. Although CTCA provides detailed plaque information, whether this translates into improved patient outcomes—such as fewer heart attacks or strokes—has not been fully demonstrated in HeFH patients specifically.
Third, there are practical considerations. CAC scoring and CTCA involve exposure to ionizing radiation, which must be weighed against the potential benefits, particularly in younger patients or those who may need repeated scans over a lifetime. Carotid ultrasound carries no radiation but requires trained sonographers and standardized protocols to ensure consistent measurements.
Finally, access to these imaging technologies varies widely by region and healthcare system. Not all patients with HeFH will have easy access to advanced imaging, and cost may be a barrier in some settings.
Recommendations for Patients and Families
Based on the findings of this review and general expert guidance, the following recommendations can help patients and families affected by HeFH:
- If you or a family member has HeFH, discuss imaging options with your cardiologist or lipid specialist. Ask whether carotid ultrasound, CAC scoring, or CTCA might be appropriate based on your age, family history, and existing risk factors.
- Early statin therapy is strongly supported by the evidence. The review confirms that children with HeFH who start statins early show significantly less atherosclerotic progression. If you have a child with HeFH, do not delay treatment discussions.
- Know your numbers. Beyond cholesterol levels, ask about imaging markers like CAC score and carotid intima-media thickness. These can provide a more complete picture of your vascular health.
- Treat imaging as one piece of the puzzle. Imaging results should be combined with clinical evaluation, cholesterol levels, blood pressure, diabetes status, and smoking history to guide treatment decisions.
- Be persistent about proper diagnosis. The authors emphasize that HeFH remains underdiagnosed and undertreated. If you have a strong family history of early heart attacks or very high cholesterol, request genetic testing or a clinical diagnosis from a specialist.
- Adhere to prescribed medications. Statins are the cornerstone of treatment, and the imaging evidence of their benefit in HeFH is compelling. Some patients may also need additional medications such as ezetimibe or PCSK9 inhibitors to reach treatment goals.
- Maintain a heart-healthy lifestyle. Diet, exercise, and avoidance of smoking complement medical therapy and help reduce overall cardiovascular risk.
It is important to remember that every patient is different. The imaging tools discussed in this review are best used as part of a personalized assessment conducted by a healthcare professional experienced in managing familial hypercholesterolemia. If you have questions about whether imaging is right for you or your family member, bring them to your next appointment.
The overarching message of this review is one of optimism. Advances in non-invasive imaging are making it possible to detect arterial disease early, personalize treatment, and potentially prevent the first—and most devastating—cardiovascular event in people with HeFH. For a condition that has historically been diagnosed too late and treated too weakly, that is meaningful progress.
Frequently Asked Questions
What is heterozygous familial hypercholesterolemia (HeFH)?
HeFH is a genetic condition inherited from one parent that causes very high LDL cholesterol from birth. It affects about 1 in 200 to 250 people. Because the body cannot clear LDL, cholesterol builds up in artery walls, raising the risk of heart attacks and strokes. Early diagnosis and statin treatment can dramatically reduce complications.
Why is cardiovascular risk hard to predict in HeFH?
Risk varies greatly even among people with the same genetic mutation and similar cholesterol levels. Standard risk calculators often underestimate risk in HeFH. Imaging tools like carotid ultrasound, CAC score, and CTCA can detect early plaque buildup without symptoms, helping doctors tailor treatment more precisely and avoid undertreatment or overtreatment.
What is a carotid ultrasound and how is it used for HeFH?
Carotid ultrasound uses sound waves to measure artery wall thickness and detect plaque in the neck arteries. It is quick, radiation-free, and inexpensive. In children with HeFH, repeat scans can track whether early statin therapy is slowing atherosclerosis. It provides a reliable way to measure treatment success over time.
What does a coronary artery calcium (CAC) score mean for an adult with HeFH?
A CAC score is a CT scan that measures calcium deposits in heart arteries, reflecting plaque burden. In asymptomatic adults with HeFH, adding CAC to existing risk equations improves risk prediction. A zero score indicates very low short-term risk, while higher scores mean greater risk and may prompt more intensive treatment.
What is CTCA and is it recommended for routine heFH care?
CTCA is a CT scan with contrast dye that provides detailed images of coronary arteries, showing both calcified and non-calcified plaque and features of vulnerable plaques. However, in HeFH patients, its role in primary prevention is not yet fully established. More research is needed before routine use can be recommended.
Are there risks from imaging tests for HeFH?
CAC scoring and CTCA involve ionizing radiation, so benefits must be weighed, especially for younger patients who may need repeated scans. Carotid ultrasound has no radiation but requires trained sonographers and standardized protocols. Access and cost can also vary. Discuss these factors with your cardiologist to decide if imaging is appropriate.
How do these imaging tests change treatment decisions for HeFH?
Imaging can show visible evidence of plaque buildup, which can motivate patients to take statins and other medications regularly. It helps doctors intensify treatment when plaque is found or reassure patients with a zero CAC score. Imaging is complementary, not a replacement, for standard risk assessment based on cholesterol and clinical factors.
I have familial hypercholesterolemia. Should I get a second opinion before deciding whether to have a coronary artery calcium scan or other heart imaging to predict my heart attack risk?
A second opinion can help you decide whether imaging is right for you and how to act on the results. In adults with familial hypercholesterolemia, a coronary artery calcium score adds value to standard risk prediction, while carotid ultrasound can track treatment success in children. However, CT coronary angiography’s role in routine prevention is not yet fully established. Because these tests involve radiation, cost, and uncertain benefits in some cases, an independent expert review can clarify which imaging, if any, fits your specific situation. Diagnostic Detectives Network provides independent expert second opinions.
Source Information
Original article title: Abstract Updates on the Use of Subclinical Atherosclerosis to Predict Risk of Cardiovascular Events in Heterozygous Familial Hypercholesterolemia - PubMed
Authors: Antonio Gallo, Reed Mszar, Marcio Hiroshi Miname
Journal: Current Atherosclerosis Reports, 2022 Jun;24(6):407-418
DOI: 10.1007/s11883-022-01017-7
PMID: 35386094
Published online: April 7, 2022
Author affiliations: University of La Réunion, INSERM, France; Sorbonne University, France; Georgetown University School of Medicine, Washington, DC, USA; Yale New Haven Health, USA; University of Sao Paulo Medical School Hospital, Brazil; Hospital Sírio-Libanês, São Paulo, Brazil
This patient-friendly article is based on peer-reviewed research. It is intended for educational purposes and does not replace individualized medical advice from a qualified healthcare provider.
