CAC = 0
- No calcified plaque on the scan.
- About 1 percent chance of a heart event in 10 years.
- Most patients can hold off on a statin if risk is otherwise low.
- Recheck risk in 5 to 10 years.
Names & Terms You Will Hear
Plain-language meanings for the terms your care team may use.
| Term | Meaning |
|---|---|
| Coronary CTA | A CT scan of the heart arteries. Uses IV dye to show plaque and narrow spots. |
| Coronary CT angiography | The full name. CT = computed tomography. Angiography = imaging of arteries. |
| Cardiac CT | Any CT scan of the heart. Coronary CTA is the kind that looks at the heart arteries. |
| CCTA | A common short form of coronary CT angiography. Same test. |
| CAD-RADS | The scoring system used to read your scan. Grades 0 to 5. 0 means no plaque. 5 means a fully blocked artery. |
| CAC score | Coronary artery calcium score. A separate non-contrast scan that counts calcified plaque. Often done with the CTA. |
| Agatston score | The number system used for the CAC score. Named after Dr. Arthur Agatston. |
| Iodinated contrast | The IV dye used. It makes arteries show up on the scan. |
| Beta-blocker | A pill or IV drug given to slow your heart rate before the scan. A slow heart rate gives sharp images. |
| Nitroglycerin | A spray or pill given just before the scan. It opens the heart arteries so they show up better. |
| FFR-CT | A computer add-on. It uses your CTA pictures to estimate blood flow through a narrow artery. |
| Stress test | A different test. It checks how the heart responds to exertion. CTA shows the arteries. Stress test shows the flow. |
Shown in English for your safety — this section is not automatically translated. Confirm with your doctor or call the office.
Call 911 now if you have hives, throat swelling, or breathing trouble after the dye. Call 911 for chest pain, fainting, or a sudden severe headache. Do not drive yourself. Severe contrast reactions are rare but need fast treatment.What Is Coronary CTA?
- A coronary CTA is a CT scan of the heart arteries. It is non-invasive.
- There is no catheter. There is no arterial puncture.
- An IV in your arm gives the contrast dye.
- The scan takes about 10 seconds. The full visit is 60 to 90 minutes.
- The CT machine is a wide donut. It is open on both ends. It is not a tunnel like an MRI.
- The scan finds soft and hard plaque in your heart arteries.
- A clean scan is very reassuring. Big blockages are highly unlikely.
- The scan does not show how well your heart muscle pumps. An echo or nuclear scan does that.
What Happens on Scan Day
- You change into a gown. You lie on a padded table that slides into the wide donut.
- ECG stickers go on your chest. They time the scan to your heartbeat.
- An IV goes in your arm. The dye and any medicines go through it.
- If your pulse is over 65, you may get a beta-blocker. It slows your heart so the scan is sharp.
- Nitroglycerin spray or pill may go under your tongue. It opens the heart arteries.
- The dye goes in. You feel a warm flush. Some taste metal. Some feel a brief urge to pee. This is normal.
- You hold your breath 5 to 10 seconds. The scan runs.
- You sit up. You go home. The full visit is 60 to 90 minutes.
Why It Matters
- A clean CTA nearly rules out big blockages. That is its most powerful use.
- Two big trials, PROMISE and SCOT-HEART, showed CTA cuts heart attacks and avoids needless cath labs.
- SCOT-HEART (2018): CTA cut fatal and non-fatal heart attacks by 41 percent at 5 years.
- The scan shows soft plaque too. Soft plaque can rupture even with little narrowing.
- A CAD-RADS grade tells your doctor the next step. No guessing.
- A CAC score from the same visit guides your statin choice.
- Modern scanners use very low radiation. About the same as 6 months of background radiation.
- Most patients can go back to work the same day. No driving limits. No recovery time.
What makes CTA different. A stress test checks blood flow during exertion. A CTA shows the arteries themselves. CTA can find soft plaque that a stress test would miss. A clean CTA also rules out the need for a cath lab visit in most low-risk patients.
The Four CAC Tiers - What Each One Means
CAC 1-99
- Mild calcium on the scan.
- About 3 percent chance of an event in 10 years.
- Start a statin in most patients.
- Tight BP. Tight A1c. Active lifestyle.
CAC 100-399
- Moderate calcium burden.
- About 7 percent chance of an event in 10 years.
- High-intensity statin. Aspirin in some patients.
- Aggressive risk factor control.
CAC >= 400
- Extensive calcified plaque.
- About 12 percent or higher chance over 10 years.
- High-intensity statin. Cardiology referral.
- Aspirin in many patients. Tight BP and A1c.
Risk Factors
Knowing your personal risks helps your care team take extra precautions.
| Risk Factor | Why It Increases Risk |
|---|---|
| Chest pain at low or moderate risk | CTA is the top test for chest pain when the cause is unclear. A clean scan rules out big plaque. |
| New heart failure or new chest discomfort | CTA can quickly find or rule out plaque as the cause. |
| Family history of early heart disease | CTA helps refine your risk. A CAC score adds to the picture. |
| Borderline cholesterol or BP risk | CTA or CAC can tip the scale on whether to start a statin. |
| After CABG or stenting (selected cases) | CTA can check graft patency. Some stents are too small to see clearly. |
| Suspected coronary anomaly | CTA shows the start and path of each artery. Best test for young patients with worrying symptoms. |
| Pre-procedure planning | CTA maps the arteries before TAVR, ablation, or other heart procedures. |
Which Test for Which Question?
| Test | Best for | Strengths | Limits |
|---|---|---|---|
| Coronary CTA | Chest pain at low to moderate risk; rule out big plaque. | Sees the arteries. Sees soft plaque. Quick. Trial-proven outcomes. | Needs IV dye. Some radiation. Calcium can blur small spots. |
| CAC score (no dye) | Adults 40-75 with unclear statin decision; no symptoms. | No IV dye. Very low radiation. Best prevention tool. | Misses soft plaque. Does not show narrow spots. |
| Stress test | Symptoms (chest pain, shortness of breath); flow question. | Shows the heart at work. No IV dye in many forms. | Does not show the arteries. Can miss soft plaque. |
| Invasive cath | Severe CTA findings; planning a stent or surgery. | Best detail. Can treat in the same visit. | Invasive. Small bleed and stroke risks. Day off work. |
Treatment Options
Shown in English for your safety — this section is not automatically translated. Confirm with your doctor or call the office.
- If your CAD-RADS is 0 or 1: no big plaque. Stay on a heart-healthy plan. Recheck risk in a few years.
- If your CAD-RADS is 2: mild plaque. Start a statin in most cases. Treat blood pressure and diabetes tightly.
- If your CAD-RADS is 3: moderate narrowing. A stress test or FFR-CT often comes next.
- If your CAD-RADS is 4 or 5: severe disease. A cath lab visit or surgery review is often the next step.
- If you have a high CAC score (>= 400): start a high-intensity statin. Aspirin may be considered.
- Quit smoking. Get blood pressure under 130/80. Aim for LDL < 70 if plaque is found.
- Manage diabetes tightly. A1c targets are set with your doctor.
- Walk 30 minutes a day on most days. Move toward a Mediterranean-style diet.
- Bring a list of all questions to your follow-up visit.
CAD-RADS Grade - What It Means and What Comes Next
| Grade | Stenosis | What it means | Typical next step |
|---|---|---|---|
| 0 | 0% | No plaque. Normal arteries. | Reassurance. Lifestyle. Recheck risk in years. |
| 1 | 1-24% | Minimal non-blocking plaque. | Statin if other risk factors are present. |
| 2 | 25-49% | Mild plaque. Not flow-limiting. | Statin. Tight BP and A1c. Lifestyle. |
| 3 | 50-69% | Moderate. May or may not limit flow. | Stress test or FFR-CT next. |
| 4A | 70-99% (1-2 vessels) | Severe single- or two-vessel disease. | Cath lab. Likely stent. |
| 4B | Left main or 3-vessel severe | High-risk anatomy. | Urgent cardiology. Often surgery (CABG). |
| 5 | 100% | Total occlusion. | Cardiology now. Viability testing if needed. |
What Your Report Will Tell You
- Your CAD-RADS grade (0 to 5). It tells the worst narrow spot in any artery.
- Your CAC score (the Agatston number). If a CAC scan was done that day.
- Any soft (non-calcified) plaque. Soft plaque can rupture even when small.
- Any high-risk plaque features (low density, positive remodeling, napkin-ring sign).
- Any incidental finding (a small lung spot, a thyroid nodule, a hiatal hernia).
- A clear recommendation for the next step. Bring this guide to your follow-up.
Where CTA Fits With Other Heart Tests
- Chest pain has many causes. CTA is one piece of the workup.
- How chest pain is sorted out: see the Chest Pain guide.
- Plaque-driven artery disease: see the Coronary Artery Disease guide.
- Calcium score for prevention: see the Coronary Calcium Score guide.
- Stable chest pain on exertion: see the Stable Angina guide.
- Heart attack: see the Heart Attack guide.
- Invasive imaging if CTA is severe: see the Cardiac Catheterization guide.
Caffeine and CTA do not mix. Caffeine raises your heart rate. A fast pulse blurs the scan. No coffee, tea, chocolate, energy drinks, or soda for 48 hours before the scan. Decaf is fine if it is truly caffeine-free.
Risks, Benefits, and Alternatives
Shown in English for your safety — this section is not automatically translated. Confirm with your doctor or call the office.
Every choice has trade-offs. Use this table to start the shared decision conversation with your care team.
| Option | Risks | Benefits | Alternatives |
|---|---|---|---|
| Coronary CTA (the test itself) | IV contrast (rare allergy, kidney effect). Radiation (~3 mSv, low). Beta-blocker side effects. | Non-invasive. Rules out big plaque. Avoids a needless cath. Trial-proven outcomes. | Stress test (exercise or chemical). Invasive cath. CAC score alone. Cardiac MRI. |
| CAC score (no contrast) | Low radiation (~1 mSv). No IV dye. | Best test for prevention. Refines risk. Guides statin choice. | Pooled cohort risk score alone. CTA. Family-history-based decisions. |
| Beta-blocker before the scan | Brief slow pulse. Fatigue. Rare wheeze in asthma. | Slows the heart so the picture is sharp. Most patients need it. | Repeat the scan another day. Use newer scanners that need less rate control. |
| IV iodinated contrast | Rare allergy (mild rash to severe). Brief kidney effect. Hold metformin 48 hours. | Makes the arteries show up clearly. Needed to grade plaque. | Non-contrast CAC scan. Stress test. Cardiac MRI. Cath with a different dye. |
| Repeat or upgrade test (stress / cath) | More time. More cost. Cath has small bleed and access risks. | Confirms whether a moderate CTA narrowing limits flow. Plans treatment. | Watch and wait with medical therapy. FFR-CT add-on. Repeat CTA in 1-2 years. |
Common Misconceptions
| Myth | Reality |
|---|---|
| A normal CTA means I will never have a heart attack. | A clean CTA is reassuring for the next 5 to 10 years. Risk factors still matter. |
| A high CAC score means I will have a heart attack soon. | CAC predicts 10-year risk. It is a planning number, not a warning. |
| A zero CAC means I am risk-free. | Soft plaque can still exist. High LDL, smoking, and family history still matter. |
| CTA shows everything wrong with my heart. | CTA shows the arteries. It does not measure pump function or valves. An echo does that. |
| The contrast dye will hurt my kidneys. | Modern dye plus hydration makes serious kidney trouble rare. Tell us if your creatinine is borderline. |
| A shellfish allergy means I cannot get contrast. | Shellfish allergy does not predict contrast allergy. Modern dye is different. Tell us all your allergies anyway. |
| My stents cannot be checked with CTA. | Most stents 3 mm or larger can be checked. Smaller ones can be hard to see. |
| I have to feel calm or my heart will speed up. | We give a beta-blocker if your pulse is fast. Most patients do fine. |
Possible Complications
Knowing what can go wrong helps you spot problems early. Most complications are uncommon, especially with treatment.
| Where / What | What Can Happen |
|---|---|
| Contrast allergy | Most are mild (rash, hives). Severe reactions are rare. Tell us about prior reactions in advance. |
| Brief kidney effect | Rare in healthy kidneys. We check your eGFR first. Hydration helps. |
| Radiation exposure | About 3 mSv. The same as 6 months of background radiation. Modern scanners use less than older ones. |
| Beta-blocker side effects | Brief slow pulse, fatigue, or wheeze. Wears off in a few hours. |
| Claustrophobia | Rare. The scanner is a wide donut, not a tunnel. Mild anti-anxiety medicine is an option. |
| Non-diagnostic scan | Motion or a fast pulse can blur images. May need a repeat or a different test. |
| Incidental finding | A small lung or thyroid finding may show up. Most are not a problem. We will follow up. |
If you take metformin. If your eGFR is below 60, hold metformin for 48 hours after the dye. Restart only after we recheck your kidneys. This rule prevents a rare but serious problem called lactic acidosis.
Points to Know
Shown in English for your safety — this section is not automatically translated. Confirm with your doctor or call the office.
If you remember nothing else, remember these key points.
- A coronary CTA is a quick CT of the heart arteries with IV dye. Non-invasive. No catheter.
- Your heart rate needs to be slow. We may give a beta-blocker by mouth or IV before the scan.
- No caffeine for 48 hours before the scan. Caffeine raises your pulse.
- Tell us about kidney problems, prior dye reactions, pregnancy, or thyroid disease.
- CAD-RADS grades the scan: 0-1 is nearly normal, 3 is moderate, 4-5 is severe.
- CAC score grades calcified plaque: 0 is excellent, >= 400 is high risk.
- Radiation is low. About 6 months of background radiation. Much less than older CT methods.
- Most patients go back to normal activities the same day.
- Call our office for any rash, breathing trouble, or swelling within 24 hours after the dye.
When to Call Us — and When to Call 911
Shown in English for your safety — this section is not automatically translated. Confirm with your doctor or call the office.
If you are not sure, call. We would rather hear from you twice than miss a real problem.
- Hives, throat swelling, or breathing trouble after the dye - call 911.
- Chest pain, fast or irregular pulse, or severe shortness of breath during or after the scan - call 911.
- Fainting or sudden severe headache - call 911.
- Pain, redness, or swelling at the IV site after the scan - call our office.
- A mild rash that shows up 1 to 2 days after the dye - call our office.
- Less urine than usual after the scan - call our office.
- No results within 5 business days - call our office.
- Trouble paying for the scan or follow-up - call us; we can help.
Office: (727) 943-5200
Trusted Resources
Independent, evidence-based pages we recommend for deeper reading.
- RadiologyInfo - Coronary CTA — ACR / RSNA patient guide. Clear text, simple diagrams, what to expect.
- American Heart Association - Cardiac CT — AHA plain-language page. Covers when CTA is used and what the results mean.
- Mayo Clinic - Coronary Angiogram (and CTA) — Mayo Clinic overview. Covers CTA and the older invasive angiogram.
- Cleveland Clinic - Coronary CT Angiography — Cleveland Clinic patient page. Brief, clear, well written.
- MedlinePlus - CT Angiography — US National Library of Medicine page. Plain language.
- NHLBI - Coronary Heart Disease Tests — NIH overview. Compares CTA, stress, and cath testing.
- 2021 AHA/ACC Chest Pain Guideline — Top US guideline. Class I recommendation for CTA in low-intermediate-risk chest pain.
Sources Used to Build This Guide
- 2023 AHA/ACC Chest Pain Guideline — Coronary CTA in Acute and Stable Chest Pain [Guideline] — Class I recommendation for coronary CTA in low-intermediate risk chest pain evaluation.
- CAD-RADS 2.0 — Coronary Artery Disease Reporting and Data System [Guideline / Reporting System] — Standardized grading system for coronary CTA results (CAD-RADS 0–5); defines clinical management recommendations for each grade.
- PROMISE Trial: Anatomical vs Functional Testing in Stable Chest Pain [Landmark RCT (NEJM 2015)] — CTA-first strategy non-inferior to functional testing for outcomes and reduced unnecessary catheterization.
- SCOT-HEART Trial: CTA in Stable Chest Pain — 5-Year Outcomes [Landmark RCT (NEJM 2018)] — Coronary CTA reduced fatal MI and non-fatal MI at 5 years by 41% vs standard care — changed practice guidelines.
- ACR Manual on Contrast Media — Iodinated Contrast Safety [Clinical Reference] — Contrast allergy premedication protocols, GFR thresholds, and post-contrast hydration guidelines.
- 2022 ACC/AHA/SCAI Coronary Artery Calcium Score Guideline [Guideline] — CAC score interpretation, risk stratification thresholds (0, 1–99, 100–399, 400+), and clinical decision support.
- MESA Study: Coronary Artery Calcium and Cardiovascular Risk [Landmark Cohort Study (NEJM 2004)] — Established CAC score as independent predictor of cardiovascular events beyond traditional risk factors.
- RadiologyInfo: Coronary CTA Patient Guide [Patient education] — Plain-language ACR/RSNA patient guide explaining the coronary CTA procedure, preparation, and what to expect.
- AHA: Cardiac Imaging Tests [Patient education] — AHA patient-facing explanation of cardiac CT, when it is used, and what the results mean.
- Mayo Clinic: Coronary Angiogram (including CTA) [Patient education] — Accessible Mayo Clinic overview of coronary imaging options including CTA and traditional angiography.
- MedlinePlus: CT Angiography [Patient education] — NIH patient resource on CTA procedure, preparation, results, and safety.
- NHLBI: Coronary Heart Disease Diagnosis [Patient education] — NIH overview of all coronary diagnostic tests including CTA, stress testing, and catheterization.
