Ultrasound Screening of the Neck Arteries: A Simple Way to Uncover Hidden Heart Disease Before Symptoms Appear

Table of Contents

• Key Points
• Study at a Glance
• Why This Research Matters
• How the Research Was Conducted
• What the Ultrasound Findings Mean
• The Follow-Up Results: What Happened to Participants
• Key Findings: What the Heart Scans Revealed
• Comparing People With and Without Advanced Plaque
• What This Means for Patients
• Limitations of the Study
• Recommendations for Patients
• Frequently Asked Questions
• Source Information

Key Points

• In a study of 6,008 German workers, advanced carotid plaque on ultrasound often meant hidden coronary blockages, even in people without symptoms.
• Among 43 asymptomatic people who had heart imaging, 23 (about 1 in 2) had a narrowing of 50% or more in at least one coronary artery.
• The ultrasound had a negative predictive value of 99% when no advanced plaque was present, meaning a normal result made hidden disease very unlikely.
• The authors recommend statin therapy for asymptomatic people with advanced carotid plaque (type III or IV b) and ultrasound screening for everyone over 35.
• The study was small for the imaging subgroup and did not prove that treating screen-detected people improves long-term outcomes.

Study at a Glance

The researchers asked a straightforward question: Can ultrasound technology detect coronary heart disease (CHD, blockages in the arteries that feed the heart muscle) early, before a person ever feels symptoms?

The answer, based on this study of 6,008 working adults, appears to be yes.

People with advanced atherosclerosis (hardening and narrowing of the arteries due to plaque buildup) in the carotid artery — even those who felt perfectly fine — turned out to have a very high chance of significant heart artery disease when examined with advanced heart imaging.

Why This Research Matters

Atherosclerosis is an inflammatory disease of the arteries. It remains the most common cause of death in developed industrial nations, accounting for about 40% of all deaths. The disease can begin as early as age 20, yet it often stays completely silent for decades.

Many people only discover they have it when they experience a sudden clinical event, such as acute coronary syndrome (a heart attack or unstable angina, chest pain at rest), stable angina (predictable chest pain with exertion), apoplexy (stroke, or bleeding or blockage in the brain), or peripheral artery disease (PAD, reduced blood flow to the limbs).

Several earlier studies have shown that even minor coronary stenoses (narrowings of the heart arteries) that do not yet obstruct blood flow are linked to an increased risk of future heart attack. The authors cite the CONFIRM study, a large multicenter registry involving 27,000 CT coronary angiograms (detailed 3-D X-ray scans of the heart's blood vessels). That study found that statin therapy (cholesterol-lowering medication) improved survival even in people with coronary narrowings below 50%. The improvement was substantial: a hazard ratio of 0.39 with a 95% confidence interval of 0.23–0.65 and a P value of less than 0.001, meaning there is less than a 0.1% chance the result was due to random chance.

Notably, the survival benefit of statins did not appear in people with completely normal coronary arteries. The authors stress that finding and treating atherosclerosis early could delay serious outcomes as long as possible.

This study is one of several showing that statin therapy improves survival in primary prevention, meaning prevention for people who have not yet had a heart attack or stroke. Numerous other studies referenced in this paper found that people with advanced carotid atherosclerosis have a significantly increased risk for heart attack and stroke.

How the Research Was Conducted

The Screening Program

The study took place within an occupational screening program in the Koblenz area of Germany. Workers from diverse sectors took part, including chemicals, glass, pharmaceuticals, administration, steel production, social services, paper production, printing, ceramics, IT, universities, universities of applied science, and retail.

Each participant was given the opportunity to determine their personal risk of a heart attack. The researchers determined three things for every participant:

• The total plaque area (TPA, the summed surface area of all plaque deposits) in the carotid artery
• The maximum plaque thickness in the carotid artery
• The PROCAM score, a well-established German risk calculator that estimates a person's 10-year risk of a heart attack based on age, cholesterol levels, blood pressure, smoking, diabetes, and family history

In total, the baseline screening included 6,008 healthy subjects — 3,748 men and 2,260 women — between the ages of 20 and 64. None of them had a previous history of a cardiovascular event.

The Follow-Up Period

Participants were then followed for an average of 47.3 months, with a standard deviation of 23 months. (The "±" figure means some people were followed for a shorter time and some for longer.) During this period, the researchers tracked who became ill.

A total of 94 subjects became sick during follow-up. In the overall group, the following events occurred:

• 8 strokes
• 31 heart attacks (myocardial infarctions)
• 10 bypass operations (open-heart surgery creating a detour around a blocked coronary artery)
• 9 stent implantations (a small mesh tube placed to hold a narrowed artery open)
• 7 patients were found to have stenoses of 30%–100% when they underwent a coronary angiogram (an invasive X-ray test that visualizes the heart's arteries)

At the baseline ultrasound examination, 5 of these subjects had a type III finding and 45 had a type IV b finding. The type classification is explained in detail below.

Validation of the Ultrasound Method

Before relying on the ultrasound technique, the research team validated it. They performed a blinded examination of 500 hospital patients one day before a scheduled coronary angiogram. "Blinded" means the ultrasound examiner did not know the patients' cardiac status. This validation allowed the team to classify ultrasound findings into four types, numbered I through IV b.

The results were strong. When patients had a type III or type IV b finding, the ultrasound predicted one-, two-, or three-vessel disease (blockages in one, two, or three of the main heart arteries) in 83% of cases. Overall, 87% of patients who truly had a stenosing coronary heart condition (a narrowing that obstructs blood flow) were correctly identified by the carotid duplex ultrasound as having a type III or type IV b finding.

Contacting People With Advanced Plaque

After the baseline screening, 464 healthy subjects — 84 of them women — who had a type III or type IV b finding were contacted by phone or in person. They were specifically asked whether they had experienced or were currently experiencing symptoms such as exertional dyspnea (shortness of breath brought on by activity) or angina pectoris (chest pain or pressure caused by reduced blood flow to the heart).

A total of 39 subjects (32 men and 7 women, aged between 43 and 61 years) complained of exertional dyspnea, atypical angina pectoris (chest discomfort that does not follow the classic pattern), or typical angina pectoris (classic chest pain or pressure with exertion). All 39 had advanced atherosclerosis of the carotid artery on ultrasound. They were advised to undergo further cardiac assessment.

The Cardiac Imaging Sub-Study

In addition, a pilot study was set up. Thirty-three asymptomatic subjects (people with no symptoms at all) who had a type III or type IV b finding and at least one risk factor were assessed using a computed tomography coronary angiogram (CT coronary angiogram, a specialized CT scan that images the coronary arteries).

Risk factors for this part of the study were defined as:

• LDL-cholesterol (the "bad" cholesterol) of 180 mg/dL or higher
• HDL-cholesterol (the "good" cholesterol) of 40 mg/dL or lower
• A positive family history of heart disease

Ten additional asymptomatic subjects were examined independently with further cardiac examinations. Combining these groups, a total of 40 subjects underwent a CT coronary angiogram, and 3 subjects were assessed directly with a conventional coronary angiogram. The 3 direct angiograms were performed because the subjects had a pathological exercise ECG (an abnormal stress test recording the heart's electrical activity) or dysrhythmia (an irregular heart rhythm).

The CT scans were performed on an 80-row multi-slice CT scanner (Toshiba Aquillon Prime) using a native scan and bolus-triggered contrast media (dye injected into the bloodstream so the arteries show up clearly).

The responsible Ethics Committee and the Federal Office for Radiation Protection approved the study.

What the Ultrasound Findings Mean

The ultrasound examination was thorough. The technologist examined the carotid artery — the common carotid artery on both the external and internal sides — using B-mode ultrasound (a standard two-dimensional imaging mode). Both sides of the neck were scanned as far as the vessels could be made visible, from the clavicle (collarbone) up to the temporomandibular joint (jaw joint).

Scanning was performed on the long and short axes, in a caudal-to-cranial direction (from the bottom of the neck toward the head), using four different angles of approach: anterior (front), anterolateral (front-side), lateral (side), and posterolateral (back-side). The device was a portable ultrasound machine with a 10 MHz linear transducer, model Imagic Agile, manufactured by Kontron Medical.

The team only counted a thickening of the artery wall as a plaque if the intima-media thickness (IMT, the combined thickness of the two inner layers of the artery wall) was greater than 1 mm. Using the device's surface-area measurement program, the examiner traced the perimeter of each plaque in its largest B-mode image view. This produced the TPA, the sum of all plaque surface areas in a longitudinal section. The maximum plaque thickness was also recorded.

Findings were classified into four main types:

• Type I: No or only minimal atherosclerosis of the carotid artery, with a TPA of up to 24 mm².
• Type II a: Only flat plaques of 2 mm or less in IMT, with a plaque surface area below the age-related cutoff for the carotid artery.
• Type II b: Only flat plaques of 2 mm or less in IMT, but with a large plaque surface area above the age-related cutoff.
• Type III: Carotid plaques with an IMT of 3.5 mm or greater, and a plaque surface area below the age-related cutoff.
• Type IV (mixed type):
  • Type IV a: Flat carotid plaques plus plaques thicker than 2 mm IMT, with a plaque surface area below the age-related cutoff.
  • Type IV b: Flat carotid plaques plus plaques thicker than 2 mm IMT, with a large plaque surface area above the age-related cutoff.

For this study, type III and type IV b findings were considered "advanced atherosclerosis."

The TPA cutoffs varied by age:

• Under 40 years of age: 60 mm²
• 40 to 49 years of age: 80 mm²
• 50 to 59 years of age: 110 mm²
• 60 to 64 years of age: 130 mm²

The cutoff for maximum plaque thickness was greater than 2 mm, or 3.5 mm or greater regardless of the TPA.

The Follow-Up Results: What Happened to Participants

The long-term results confirmed that advanced carotid plaque is a serious warning sign.

Of the men and women examined with ultrasound between 2009 and 2011 who showed a type III or type IV b finding, 49% of the men and 33% of the women were already diseased by the time of the follow-up assessment. In total, 23.7% of all men and women with a type III or type IV b finding experienced a disease event — examples included apoplexy (stroke), myocardial infarction (heart attack), bypass surgery, stent placement, or coronary stenosis of 30% or more.

Remarkably, the baseline ultrasound had shown a type III or type IV b finding in 80% of the 65 men and women who became diseased during the follow-up period. In other words, the ultrasound flagged 8 out of 10 people who would later have a serious cardiac event.

In absolute terms, of every 100 people with advanced carotid plaque, roughly 24 experienced a serious event during the average 4-year follow-up. The ultrasound gave almost no false reassurances: a person with a normal or mild finding had a very low risk of having hidden coronary disease. The researchers calculated the negative predictive value (NPV, the chance that a negative test truly means no disease) to be 99% when no type III or type IV b finding was present.

This calculation assumed a 5.5% prevalence of coronary heart disease in healthy men aged 35 to 64 and an 80% sensitivity (the ability of the test to correctly detect disease when it is present) for diagnosing coronary stenosis.

Key Findings: What the Heart Scans Revealed

The most striking results came from the 43 subjects (combining symptomatic and asymptomatic groups) who underwent advanced cardiac imaging.

Of these 43 people, the ultrasound examination of the carotid artery showed a type IV b finding in 40 patients and a type III finding in 3 subjects. Despite many of them feeling completely healthy, the heart scans told a different story:

• 5 subjects (about 12%) had entirely smooth coronary arteries with no disease at all
• 6 subjects had coronary sclerosis (hardening of the heart arteries without significant obstruction)
• 8 subjects had a 30% stenosis (narrowing of the artery by 30%)
• 1 patient had a 30–50% stenosis
• 23 patients (about 53%) had a stenosis of 50% or greater — a blockage significant enough to impair blood flow

In one extreme case, a subject had a left main coronary artery stenosis (a narrowing of the main artery that supplies the entire left side of the heart) combined with three-vessel disease (significant blockages in all three major coronary arteries).

Treatment followed quickly for the people with significant disease. A stent was inserted into 5 of these patients. Two patients underwent emergency bypass surgery immediately after their coronary angiogram. Both of those patients had main stem stenosis (blockage of the left main coronary artery) and three-vessel disease.

The authors note that, across all 82 subjects who were assessed (39 symptomatic and 43 asymptomatic), the findings were similar. Overall:

• 10% of the 82 subjects showed smooth vessels with no disease
• 74% showed a coronary stenosis of 30–100%
• 53% showed a stenosis of 50% or greater

This means that about 3 in 4 people with advanced carotid plaque had measurable coronary artery disease, and roughly 1 in 2 had a significant blockage.

Comparing People With and Without Advanced Plaque

The study also compared baseline characteristics of people with advanced carotid plaque (type III or IV b) against those without it. Men with advanced plaque were older (54 ± 6 years vs. 48 ± 7 years). They were far more likely to smoke (43.2% vs. 22.7%), and they had higher LDL cholesterol, lower HDL cholesterol, higher triglycerides (blood fats), and higher blood pressure.

Cardiovascular risk factors were dramatically more common in the advanced plaque group. Among men with type III/IV b findings, diabetes was present in 8.4% (vs. 3.4% in men without), and treated high blood pressure in 36.4% (vs. 19.1%). A positive family history of heart disease was reported by 28.3% of men with advanced plaque (vs. 21.3% without).

The plaque measurements themselves differed sharply. Men with advanced plaque had an average TPA of 150 ± 63 mm², compared with 30 ± 34 mm² in men without. Their maximum plaque thickness averaged 3.0 ± 0.8 mm, versus 1.7 ± 0.5 mm. The PROCAM risk score was more than double: 13.32% ± 10.29% in men with advanced plaque versus 6.02% ± 6.74% in men without.

The pattern was similar in women. Women with type III/IV b findings were older (54 ± 5 vs. 49 ± 7 years), more likely to smoke (46.3% vs. 20.2%), and had higher LDL cholesterol (161 ± 39 vs. 141 ± 33 mg/dL). Their average TPA was 120 ± 62 mm² versus 17 ± 24 mm², and their maximum plaque thickness was 3.2 ± 0.6 mm versus 1.6 ± 0.5 mm.

The most telling numbers, however, were the rates of disease at follow-up. Only 0.5% of men without advanced plaque (13 of 2,688) had become sick — defined as having a stenosis of 30% or greater, a heart attack, or similar events — during the study. Among men with advanced plaque, that figure was 25.6% (98 of 382). For women, the rates were 0.1% (2 of 1,898) versus 14.6% (12 of 82).

In other words, in this study population, a man with advanced carotid plaque was roughly 50 times more likely to become sick during the follow-up period than a man without it.

What This Means for Patients

These findings show that the carotid artery can act as a "window" into the heart. If the neck arteries are heavily diseased, the coronary arteries often are too.

The authors point out that earlier studies of this connection found a significantly lower positive predictive value (PPV, the chance that a positive test means disease is truly present) for coronary heart disease. They suspect the reason is that those studies did not quantify plaque burden — they only measured the thickness of the artery wall. In this study, the PPV of a type III or type IV b finding for a coronary stenosis of 30% or greater was 0.74, with a 95% confidence interval of 0.64 to 0.83. That means about 3 out of 4 people with these ultrasound findings truly had significant coronary disease.

Interestingly, the results for the symptomatic and asymptomatic groups were almost identical. People who felt fine were just as likely to have significant coronary disease as people who complained of chest pain or shortness of breath. This study suggests symptoms are an unreliable guide to the true state of the heart arteries.

The authors also discuss the CONFIRM study, which found that statins improve survival even in patients with non-obstructive coronary heart disease (narrowings under 50%). That benefit did not appear in people with entirely normal coronary arteries. The implication is clear: if ultrasound reveals advanced atherosclerosis, early treatment matters — even if the heart narrowings are not yet severe enough to cause symptoms.

A cautionary note emerges from the data as well. Because 96% of men aged 60 to 64 years show some plaque in the carotid artery, screening alone cannot justify treatment in every older person. Treating everyone with any plaque at all would lead to overtreatment. The key is distinguishing advanced, high-risk plaque (types III and IV b with large plaque area and thickness) from mild, low-risk plaque. The age-based TPA cutoffs used in this study are designed to do exactly that.

The economic and practical advantages of this approach are considerable. Measuring plaque burden with TPA and maximal plaque thickness is:

• Low-cost
• Simple to perform
• Non-invasive (no needles, no radiation, no dye)
• Free of side effects
• Suitable for use in occupational or primary care settings

By contrast, CT coronary angiography involves radiation and contrast dye, and conventional coronary angiography is an invasive procedure with small but real risks. An ultrasound screening test can identify which asymptomatic people actually need those advanced tests and which can safely avoid them.

Limitations of the Study

The authors are transparent about the weaknesses of their research. The main limitation is that only a small number of asymptomatic subjects were examined with cardiac CT or coronary angiography — 43 in total. Larger studies would strengthen confidence in the findings.

The follow-up period of 47.3 ± 23 months (roughly 2 to 6 years) is also relatively short for a disease that develops over decades. Longer follow-up would reveal whether early treatment based on ultrasound findings truly prevents heart attacks and strokes in the long term.

The study population consisted of working adults in Germany who chose to participate in an occupational screening program. This is a self-selected group, and the results may not apply to other populations, such as retired people, people unable to work, or people in other countries with different diets and healthcare systems.

The authors also acknowledge the overtreatment concern. Since most older men show some carotid plaque, using statins in everyone with any detectable plaque would be inappropriate. Only people with advanced findings (types III and IV b) appear to warrant treatment based on this evidence.

Finally, the study does not prove that treating these asymptomatic people with statins improves their long-term outcomes. It shows a strong association between carotid plaque and coronary disease, and it cites other research showing that statins help in similar situations, but the combination of screening plus treatment was not tested in a randomized controlled trial (a study where patients are randomly assigned to receive treatment or not).

Recommendations for Patients

Based on this study and the research it builds upon, the authors make two main recommendations:

1. Asymptomatic people with advanced atherosclerosis of the carotid artery (type III or type IV b findings) should be treated with statins. Their risk of coronary heart disease is high, and statin therapy has been shown to improve survival even for narrowings below 50%.
2. TPA and plaque thickness measurement by ultrasound is a low-cost, simple screening method that is advisable for everyone over the age of 35 years. The test takes only a few minutes, causes no pain, and does not expose the patient to radiation.

If you are over 35 and have risk factors such as smoking, diabetes, high cholesterol, high blood pressure, or a family history of heart disease, a carotid ultrasound could give you and your doctor valuable information. A finding of advanced plaque (type III or IV b) means your heart arteries deserve a close look, even if you feel perfectly healthy.

Conversely, if the ultrasound shows no advanced plaque, the negative predictive value of 99% means your chances of having significant hidden coronary disease are very low.

Talk to your primary care physician about whether carotid ultrasound screening is appropriate for you. If you do have advanced plaque, ask about statin therapy and about whether further cardiac imaging is warranted.

Frequently Asked Questions

What is a carotid ultrasound and how does it find hidden heart disease?

A carotid ultrasound is a painless scan of the neck arteries using sound waves. It measures plaque area and thickness. In a study of 6,008 German workers, those with advanced carotid plaque often had serious heart artery blockages, even without symptoms. The scan acts as a window to the heart.

Who should consider this screening?

The authors recommend measuring plaque by ultrasound for everyone over 35. It is especially advisable if you have risk factors such as smoking, diabetes, high cholesterol, high blood pressure, or a family history of heart disease. Talk to your primary care physician about whether it is appropriate for you.

What does a negative or normal scan result mean?

A normal or mild finding means your chance of having significant hidden coronary disease is very low. The negative predictive value was calculated at 99% when no advanced plaque was present.

Is the ultrasound scan safe and does it have any risks?

Yes, it is safe. The scan is non-invasive, uses no needles, no radiation, and no contrast dye, and is free of side effects. It takes only a few minutes and causes no pain. By contrast, CT coronary angiography involves radiation and dye, and conventional angiography is invasive with small but real risks.

Does treating asymptomatic people with statins based on this scan improve outcomes?

The study does not prove that treating asymptomatic people with statins improves long-term outcomes. It shows a strong association between carotid plaque and coronary disease, and cites other research showing statins help in similar situations. The combination of screening plus treatment was not tested in a randomized controlled trial.

If a carotid ultrasound shows advanced plaque (type III or IV b), when should I get a second opinion before starting statins or having heart imaging?

A type III or IV b finding means roughly 3 in 4 people with it have coronary narrowing of 30% or more, and about 1 in 2 have a blockage of 50% or greater, so the ultrasound result and the decision to start statins or proceed to CT or invasive coronary angiography both deserve independent review. A second opinion can confirm the plaque classification and whether further cardiac imaging is warranted, since only 43 asymptomatic people in this research had heart scans. Diagnostic Detectives Network provides independent expert second opinions.

Source Information

Original Article Title: Early diagnosis asymptomatic

Authors: Ansgar Adams, Waldemar Bojara, Klaus Schunk

Journal: Cardiology Research, 2018; volume 9, issue 1, pages 22–27

DOI: https://doi.org/10.14740/cr667w

Affiliation: B•A•D Health Care and Safety Technology Centre GmbH, Koblenz, Germany; Community Clinic Mittelrhein, Kemperhof II, The Cardiology Clinic, Koblenz, Germany; Community Clinic Mittelrhein, Kemperhof Clinic for Diagnostics and Intervention in Radiology, Germany

The authors confirmed they have no conflicts of interest. The study was approved by the responsible Ethics Committee and the Federal Office for Radiation Protection.

This patient-friendly article is based on peer-reviewed research. It is intended for educational purposes and is not a substitute for individual medical advice from a qualified healthcare professional.