James Rider, MD FACC Cardiology Associates of Bellin Health

James Rider, MD FACC Cardiology Associates of Bellin Health

Coronary Artery Calcium Scoring

Epidemiology• Coronary disease is the leading cause of death in the U.S

• 450,000 deaths yearly from coronary disease

• There are 1.2 million new heart attacks yearly in the U.S.

• Accounts for 36% of all deaths and exceeds death rates from all cancers and accidental deaths combined

• Most people have no symptoms prior to a heart attack

Who is at Risk?

• Most people who suffer a heart attack do not fall into a “high risk” category

• The traditional tools we have to identify who is at risk depend on statistical analysis of large pools of historical data.

Quiz

• Which of the following is the best predictor of a future heart attack: – A) High blood pressure– B) Diabetes– C) Age– D) High coronary calcium score– E) Smoking– F) High cholesterol

Quiz

• Which of the following is the best predictor of a future heart attack:– A) High blood pressure– B) Diabetes– C) Age– D) High coronary calcium score– E) Smoking– F) High cholesterol

Case Example

• 48 year old female executive

• Avid distance runner

• Total cholesterol 192

• Good cholesterol 41

• Bad cholesterol 124

• Blood pressure 122/71

• Smoked for 1 year while in college

• Father died of heart attack at age 54

Case Example

• What is her risk of a heart attack?

• Should she be treated for her cholesterol?

Case Example

Framingham Score

Goals in Primary Prevention of Cardiovascular Disease

• Better identify those at risk for cardiovascular events by directly detecting plaque build-up early

• Aggressive treatment of risk factors (cholesterol medication, aspirin, BP control, exercise, diabetes treatment, and quitting smoking)

• By intensifying treatment strategies in those at the highest levels of risk this will improve efficacy, safety, and cost-effectiveness of these treatments

Is There a Better Tool for Identifying People Who are at Risk?

• Routine exercise stress testing

• C-reactive protein

• Carotid Intimal Medial Thickness

• Coronary Calcium Scoring

Coronary Calcium

• Coronary calcification is found when the arteries harden from plaque build-up

• First identified in the 1950’s from plain x-rays• Early generation CT scanners were able to detect calcium

but scanner speeds too slow for reliable measurement of calcium in the beating heart

• Faster CT speeds improved in the 1980’s to allow measurement of coronary calcium

Coronary Artery Calcium Scoring (CACS)

• Recent generation CT scanners can image the beating heart in 6-10 seconds, latest generation in ¼ of a second

• No IV or dye needed• Entire scanning process takes 5-10 minutes• Protocol designed to minimize radiation exposure• Typical radiation is equivalent to about 2 chest x-rays

(about 8-10 times less than a standard CT)


• Normal score = 0

• Minimal disease = 1-10

• Mild disease 11-100

• Moderate disease 101-400

• Severe disease >400

Criticism for Calcium Scoring• Calcium scoring was criticized in the 1990’s for

poor correlation between the amount of calcium and the presence of blockages

• This is a fundamental misunderstanding

• Coronary calcification = coronary disease

• Up to 75% of all heart attacks occur at the site of non-critical blockages (50% blockage or less) and are due to ruptured plaque and clot formation

Positive Remodeling

Early Late

How a Heart Attack Occurs

Prognostic Significance

Shaw et al. Radiology 2003

Case Example• 48 year old executive with a Framingham score of 1%

chance of a heart attack in the next 10 years based on statistical models

• Coronary calcium score 1206• Based on calcium score her risk is estimated at 20-30%

over the next 10 years• Now identified as a high risk individual and will be

treated as a coronary risk equivalent

Case Example

CACS in Green Bay• Calcium score historically costs $350-400• Now much more affordable

– Bellin Health $50– Prevea Health $49.95– Aurora BayCare $100

• Images of the chest are read by the radiologists• Available through a self-referral process based

on criteria or through your primary care provider

Who Should Have the Test• Recommended by American Heart Association for people at

intermediate risk (Framingham score 10-20%)• Can be considered in people who are at low risk (score <10%)

but controversial• Criteria for self-referral at Bellin:

– Male over age 30 with at least one risk factor – Female over age 40 with at least one risk factor

• Controversial in patients at high risk (known diabetes or history of blockages in the arteries of the neck or legs) – these patients should be treated aggressively regardless of calcium score. Might help some of these patients become more motivated to treat risk factors aggressively

• Controversial in older patients over age 70

Who Should Not Have the Test• History of angioplasty or coronary stents

• History of coronary bypass surgery

• Very low risk individual– Young patients with no risk factors

• Patients who have already had a calcium score

What to Do With Test Results• Review results with your primary care provider

• Remember the limitations of the test– Does not detect plaque that has not yet hardened

• Review your risk factors with your provider and with the calcium score results create an individualized plan to treat your risk factors

Take Home Message• Coronary calcium scoring is a powerful tool

for helping people identify if they are at risk for a heart attack.

• Test is now widely available and affordable.• This test may detect early plaque that does

not require treatment with stents or surgery but does requires aggressive treatment of risk factors.

James Rider, MD FACC Cardiology Associates of Bellin Health

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