CAC Score vs Stress Test: Which Cardiac Test Do You Need?

Your cardiologist recommends cardiac testing. You have borderline cholesterol, a family history of heart disease, and you're approaching 50. But when you research "CAC score vs stress test," you encounter conflicting information about which test is right for you.

Most patients don't realize these tests measure completely different things. A CAC score visualizes plaque buildup in your arteries. A stress test detects if that buildup is restricting blood flow during exertion. Choosing the wrong test can mean missing critical information about your cardiovascular risk or subjecting yourself to unnecessary procedures.

This guide will help you understand the difference between CAC score and stress test, when each is optimal, and how to make an evidence-based decision for your heart health.

What Is a CAC Score?

Coronary Artery Calcium (CAC) Scoring uses a rapid CT scan to quantify calcified plaque in your coronary arteries.¹ The scan takes five to 10 minutes and produces an Agatston score, a number that reflects your total calcium burden.

How to interpret your CAC score:

Agatston Score	Risk Category	Annual Event Rate	What It Means
0	Very low risk	<0.1%	Minimal plaque; reassess in 3–5 years
1–99	Mild risk	0.5–1%	Early disease; consider statin therapy
100–399	Moderate risk	1.5–3%	Moderate atherosclerosis; statin recommended
400+	High risk	>3%	Significant disease; aggressive treatment needed

Best for: Asymptomatic individuals age 40–65 with cardiovascular risk factors (family history, high cholesterol, diabetes) who want to know if they have hidden heart disease.

What CAC scoring shows: The amount of calcified plaque in your arteries, which predicts your risk of future heart attack.⁸

What CAC scoring does NOT show: Whether plaque is blocking blood flow, the presence of soft (non-calcified) plaque, or how your heart performs under stress.

Cost: $100–$150 (typically not covered by insurance for screening)

Radiation: Minimal (~1 mSv, equivalent to four months of background radiation)

What Is a Stress Test?

Stress Testing evaluates how your heart performs during physical exertion.²,³,⁴ You exercise on a treadmill or receive medication that simulates exercise while your heart is monitored with ECG, echocardiography, or nuclear imaging.

Types of stress tests:

Exercise ECG: Monitors heart rhythm and electrical activity
Stress echocardiography: Uses ultrasound to visualize heart wall motion
Nuclear stress test: Uses radioactive tracer to show blood flow to heart muscle

Best for: Patients with chest pain, shortness of breath, or known coronary disease who need to determine if blockages are restricting blood flow.

What stress testing shows: Whether your heart receives adequate blood flow during exertion, which indicates if existing blockages are severe enough to cause symptoms (functional significance).

What stress testing does NOT show: The amount of plaque in your arteries, early disease that isn't yet blocking blood flow, or your overall atherosclerosis burden.

Cost: $1,000–$3,000 (often covered by insurance with appropriate symptoms)

Radiation: 9–12 mSv for nuclear stress tests; zero for stress echocardiography

CAC Score vs Stress Test: Direct Comparison

Understanding the difference between CAC score and stress test comes down to one key distinction: anatomy vs. function.

Table: CAC Score vs Stress Test Comparison

Factor	CAC Score	Stress Test
What It Measures	Amount of plaque (anatomy)	Blood flow during exertion (function)
Primary Purpose	Risk stratification; early detection	Diagnose flow-limiting blockages
Best For	Asymptomatic screening	Evaluating chest pain or known CAD
Detects Early Disease	Yes	No
Shows Functional Impact	No	Yes
Scan Time	5–10 minutes	30–60 minutes
Sensitivity for CAD	N/A (risk marker)	68–82%
Radiation Dose	~1 mSv	0–12 mSv (depending on type)
Cost Range	$100–$150	$1,000–$3,000
Insurance Coverage	Usually not for screening	Often yes with symptoms

The Critical Difference

CAC score answers: "Do I have coronary artery disease, and how much?"

Stress test answers: "Is my coronary disease restricting blood flow and causing symptoms?"

A CAC score of 200 tells you that you have moderate atherosclerosis and elevated risk. But it doesn't tell you if that plaque is blocking blood flow. A stress test tells you whether blockages are severe enough (generally ≥70% stenosis) to restrict blood flow during exertion.

Here's what confuses patients: You can have a high CAC score (lots of plaque) and a normal stress test (plaque isn't restricting flow yet). Conversely, you can have a normal CAC score and still have soft, non-calcified plaque that could rupture and cause a heart attack.

When to Get a CAC Score vs Stress Test

Choose CAC Score If You:

Are asymptomatic (no chest pain, shortness of breath, or concerning symptoms)
Are age 40–65 with cardiovascular risk factors
Want to know if you have hidden heart disease
Are uncertain whether to start statin therapy
Have a family history of premature heart disease
Want cost-effective risk assessment

Why CAC score is optimal for screening: A score of zero confers excellent prognosis (<0.1% annual cardiac event rate).⁸ A score above 100 or above the 75th percentile for your age and sex restratifies you into a higher-risk category that warrants aggressive prevention, potentially including statin therapy.

Important note: Not all medical organizations recommend routine CAC screening. The 2019 ACC/AHA guidelines suggest CAC may be reasonable for intermediate-risk patients when treatment decisions are uncertain. Discuss with your physician whether screening is appropriate for you.

Choose Stress Test If You:

Have chest pain, pressure, or discomfort with exertion
Experience shortness of breath during activit
Have known coronary artery disease from prior testing
Had a prior stent or bypass surgery
Need to determine if blockages require intervention (stent or bypass
Want to assess exercise capacity and cardiovascular fitness

Why stress testing is optimal for symptoms: If you have chest pain or shortness of breath, you need to know whether existing blockages are restricting blood flow.⁴ A positive stress test (showing ischemia) may lead to cardiac catheterization and revascularization. A negative stress test suggests continuing medical management.

When You Might Need Both

Some patients benefit from both CAC score and stress testing:

Scenario: You get a CAC score of 300 (moderate risk) but have no symptoms. Your doctor may recommend a stress test to determine if any of that plaque is causing functional problems.

Scenario: Your stress test is normal, but you have multiple risk factors. A CAC score can reveal non-obstructive disease that the stress test missed, prompting more aggressive prevention strategies.

CCTA vs Stress Test: When You Need More Detail

Coronary CT Angiography (CCTA) is a third option that combines the best of both worlds. After IV contrast injection, CCTA produces detailed 3D images of your coronary arteries.¹

CCTA vs Stress Test

CCTA Advantages Over Stress Test:

Superior sensitivity (97–99% vs. 68–82%) for diagnosing coronary disease²,³
Visualizes plaque characteristics (calcified, non-calcified, mixed
Detects non-obstructive disease that stress tests miss
Can rule out coronary disease with high confidence (negative predictive value >95%)

When CCTA Is Preferred Over Stress Test:

New chest pain in patients with low to intermediate pretest probability of CAD
Evaluation of coronary anatomy when stress test results are unclear
Assessment of coronary anomalies or bypass graft patency

Key data: The SCOT-HEART trial demonstrated that CCTA-guided management reduced heart attacks by 41% compared to standard care (predominantly stress testing) by enabling better diagnosis and earlier preventive treatment.⁵

CCTA Limitations:

Requires IV contrast (not suitable for severe kidney disease or contrast allergy)
Requires low heart rate (often needs beta-blocker medication)
More expensive than CAC score ($500–$1,500)
Higher radiation than CAC score (1–3 mSv, though modern scanners minimize this)

CCTA vs CAC Score

When to Get CCTA Instead of CAC Score:

You have symptoms (chest pain, shortness of breath)
Your CAC score is elevated and you want detailed anatomic information
You want to see the degree of stenosis (how much arteries are narrowed)
You want to visualize soft, non-calcified plaque

When CAC Score Is Sufficient:

You're asymptomatic and want cost-effective screening
You want to decide whether to start preventive therapy
You prefer minimal radiation exposure

The Hidden Risk Most Tests Miss

Here's what most patients don't know: most heart attacks occur in patients with "mild" or "moderate" stenosis, not severe blockages.⁶

Plaques with 30–70% stenosis are often the culprits. Why? Because these lesions don't restrict blood flow enough to cause ischemia on a stress test, yet they're vulnerable to rupture and thrombosis, the mechanism behind most heart attacks.

The Data:

Non-obstructive CAD (stenosis <50%) increases cardiac event risk two to three fold⁶
One in three patients with "normal" stress tests have non-obstructive plaque visible on CCTA⁷

Which Test Detects Non-Obstructive Disease: CAC score: Indirectly identifies atherosclerosis presence

CCTA: Gold standard for detecting and characterizing non-obstructive disease
Stress test: Misses it entirely by design (measures function, not anatomy)

This is why anatomic testing (CAC score or CCTA) is increasingly emphasized for prevention-focused patients. Identifying non-obstructive disease creates an opportunity for aggressive risk factor modification: high-intensity statin therapy, aspirin, and lifestyle interventions that prevent progression to obstructive disease.

Important caveat: Detecting non-obstructive disease may cause anxiety and lead to additional testing or treatment. Not all non-obstructive plaque will progress. Discuss the benefits of early detection against potential harms with your physician.

Calcium Score Test NJ: Local Information

For New Jersey residents seeking a calcium score test in NJ, several factors determine value: scan quality, radiation exposure, subspecialized interpretation, and integration with your complete cardiovascular risk profile.

What to Expect for CAC Scoring in New Jersey

Cost: A calcium score test in NJ typically costs $100–$150 as a cash-pay procedure at most facilities.

Locations: Available at imaging centers and hospitals throughout Princeton, East Brunswick, Plainsboro, and surrounding communities.

Scan process:

No preparation needed (no fasting, no contrast injection)
Five to 10-minute scan on CT scanner
Results available within 24–48 hours

What matters most: Expert interpretation by subspecialized cardiac radiologists who integrate your score with your complete risk profile, not just a number without context.

Comprehensive Cardiac Assessment in New Jersey

Some cardiology practices in New Jersey, including Pulse Perfect, offer integrated approaches that combine CAC scoring, CCTA, stress testing, and advanced risk assessment:

CAC scoring for baseline atherosclerosis burden
CCTA with plaque analysis when CAC score is elevated or symptoms are present
Stress testing if CCTA shows intermediate stenosis (50–70%)
VO₂-max testing for cardiovascular fitness assessment
Advanced lipid panels and nutrigenomics

This comprehensive approach detects early disease, determines functional significance of blockages, and guides personalized prevention strategies.

Questions to Ask Your Doctor

About Your Risk:

What is my 10-year ASCVD risk score?
Do I have risk factors that warrant a CAC score?
Has my LDL cholesterol or blood pressure been consistently elevated?

About Test Selection:

Should I get a CAC score or stress test based on my symptoms and risk?
If I get a CAC score, under what circumstances would I need a stress test or CCTA?
Will this test detect early disease that might change my treatment?

About Quality:

What is the radiation dose? (Modern CAC scans should be ~1 mSv)
Who will interpret the images?
Will I receive actionable recommendations based on my results?

Frequently Asked Questions

Q: Can I get a CAC score instead of a stress test if I have chest pain?

A: No. If you have chest pain or other symptoms, you need functional assessment (stress test or CCTA), not just a CAC score. CAC scoring is for asymptomatic screening. Symptomatic patients need to know whether blockages are restricting blood flow.

Q: If my CAC score is zero, do I still need a stress test?

A: Generally no, if you're asymptomatic. A CAC score of zero indicates very low risk (<0.1% annual cardiac event rate) and excellent prognosis.⁸ However, if you develop symptoms, a stress test may still be appropriate regardless of CAC score.

Q: My stress test was normal. Should I get a CAC score?

A: Possibly. A normal stress test means no flow-limiting blockages, but it doesn't rule out non-obstructive disease. If you have multiple cardiovascular risk factors, a CAC score can reveal early atherosclerosis that warrants aggressive prevention.

Q: Is a calcium score test in NJ covered by insurance?

A: CAC scoring is typically not covered by insurance when performed for screening in asymptomatic individuals. Most facilities in New Jersey offer it as a cash-pay service for $100–$150. Stress tests with appropriate symptoms are often covered.

Q: Which is better for screening, CAC score or stress test?

A: CAC score. For asymptomatic screening, CAC scoring is superior because it detects early disease before it causes symptoms or restricts blood flow. Stress tests are designed to detect flow-limiting blockages in symptomatic patients, not screen for early disease.

Q: Can CCTA replace both CAC score and stress test?

A: Partially. CCTA provides anatomic detail (like CAC score) and can assess stenosis severity (better than stress test for diagnosis).²,³,⁵ However, it's more expensive, requires contrast, and doesn't directly measure functional significance like a stress test does. For many patients, CAC score remains the most cost-effective first step.

The Bottom Line: CAC Score vs Stress Test

Choose CAC Score If:

You're asymptomatic with cardiovascular risk factors
You want cost-effective early detection ($100–$150)
You're uncertain about starting preventive therapy
You want minimal radiation exposure (~1 mSv)

Choose Stress Test If:

You have chest pain, shortness of breath, or concerning symptoms
You have known coronary disease and need functional assessment
You need to determine if blockages require intervention
Your doctor needs to assess exercise capacity

Consider CCTA If:

You have new chest pain with low-moderate pretest probability
Your CAC score is elevated and you want detailed anatomic information
Your stress test results are unclear or inconclusive
You want to visualize non-obstructive disease

No single test is always best. The optimal choice depends on whether you have symptoms, your cardiovascular risk factors, and what clinical question you're trying to answer.

Modern preventive cardiology increasingly emphasizes early detection through anatomic imaging (CAC score or CCTA) rather than waiting for symptoms. For asymptomatic individuals, a calcium score test in NJ provides powerful prognostic information at minimal cost and radiation exposure.

If you're interested in comprehensive cardiac assessment in the Princeton, East Brunswick, or Plainsboro, NJ area, learn more about Pulse Perfect's approach or schedule a consultation.