CT Coronary Angiography in Hyderabad

What Does CT Coronary Angiography Show?

Coronary Artery Plaque

Both soft (non-calcified) and hard (calcified) plaques are visualized within the arterial wall. Soft plaques are more vulnerable to rupture and cause heart attacks. CT is uniquely able to detect non-obstructive plaque not visible on functional tests like the TMT.

Degree of Stenosis

The percentage narrowing of each coronary artery segment is assessed. Stenoses are classified as non-significant (under 50%), moderate (50 to 70%), or severe (above 70%). Severe stenoses typically require further management.

Coronary Artery Anatomy

Number, origin, and course of coronary arteries. Anomalous coronary anatomy (vessels arising from abnormal origins) is identified precisely, which is important in young patients with unexplained symptoms or before surgery.

Calcium Scoring (CAC)

A non-contrast CT acquired alongside CTCA quantifies coronary artery calcium. High calcium scores indicate advanced atherosclerosis and elevated cardiac risk even in the absence of obstructive stenosis.

Coronary Artery Bypass Grafts

CTCA effectively assesses the patency (openness) of bypass grafts in post-CABG patients, a technically challenging assessment for invasive angiography.

Aortic Root and Pericardium

Structures adjacent to the coronary arteries, including the aortic root, main pulmonary artery, and pericardium, are also visualized and assessed in the same scan.

Fractional Flow Reserve CT (FFR-CT)

Advanced computational analysis of CTCA images can calculate the functional significance of a stenosis, predicting whether it restricts blood flow enough to cause ischemia, without requiring invasive pressure wire measurement.

Who is CTCA Recommended For?

Chest pain with intermediate pre-test probability

Patients with chest pain who have an intermediate likelihood of coronary artery disease based on age, gender, symptoms, and risk factors. CTCA has the highest negative predictive value of any non-invasive test, effectively ruling out significant coronary disease.

Equivocal or inconclusive stress test

When a treadmill stress test produces borderline or non-diagnostic results, CTCA provides anatomical clarification of whether significant coronary disease is present.

Atypical chest pain in younger patients

Chest pain with atypical features in patients under 50 where the clinical probability of significant disease is lower but not negligible. CTCA provides definitive anatomical assessment.

Pre-TAVI assessment

Evaluation of coronary artery anatomy before transcatheter aortic valve implantation to plan for any coronary protection needed during the procedure.

Suspected coronary anomaly

Anomalous coronary arteries in young patients with exertional symptoms or unexplained syncope require precise anatomical mapping.

Post-bypass graft assessment

Evaluating graft patency in patients with recurrent symptoms after CABG surgery without the need for repeat invasive catheterization.

High-risk screening

For patients with multiple cardiovascular risk factors who are asymptomatic, calcium scoring with or without full CTCA provides risk stratification beyond standard risk calculators.

CT Coronary Angiography vs Invasive Coronary Angiography

Invasiveness

CTCA: Non-invasive. Intravenous cannula for contrast only. Invasive angiography: Arterial catheterization through wrist or groin.

Radiation

CTCA: Low to moderate radiation dose with modern scanners and dose-reduction protocols (typically 2 to 5 mSv). Invasive angiography: Comparable or slightly higher.

Procedural Risk

CTCA: No procedural risk beyond contrast allergy. Invasive: Small risks of bleeding, artery injury, stroke (under 0.1% in elective cases).

Plaque Detection

CTCA: Detects both obstructive and non-obstructive plaque. Invasive angiography: Shows only the lumen (inside) of the artery. Cannot detect non-obstructive plaque within the wall.

Intervention

CTCA: Diagnostic only. Cannot treat a blockage during the same session. Invasive: If significant disease is found, angioplasty can be performed in the same sitting.

Recovery

CTCA: No recovery needed. Resume normal activity immediately. Invasive: 2 to 6 hours of observation post-procedure.

Best Use

CTCA: Rule out significant coronary disease in intermediate-risk patients. Invasive: High-risk patients, those with planned intervention, or when CTCA is technically limited.

The CT Coronary Angiography Procedure

Heart Rate Preparation:

CTCA image quality depends on a slow, stable heart rate. If your resting heart rate is above 65 beats per minute, a short-acting beta-blocker is given orally or intravenously before the scan to slow the heart rate and reduce motion artifact. This is safe and routine.

Nitrate Spray:

A sublingual nitrate spray is given just before the scan to dilate the coronary arteries and improve their visualization.

IV Cannula:

A small intravenous cannula is placed in the arm for contrast injection. No arterial puncture is needed.

Positioning:

You lie flat on the CT scanner table. Monitoring leads are attached to track heart rate during the scan.

Breath Hold:

The scan is performed during a single breath hold of approximately 5 to 10 seconds. You are guided to breathe in, breathe out, and hold by the CT technologist. Multiple practice breath holds are done before contrast is given.

Contrast Injection:

Iodine-based contrast is injected rapidly through the cannula. You may feel warmth spreading through the body for 15 to 30 seconds as the contrast circulates. This is normal and passes quickly.

Image Acquisition:

The CT scanner acquires images synchronized to the cardiac cycle (ECG-gated) to freeze cardiac motion. The entire scan takes 5 to 10 seconds.

Post-Scan:

You rest briefly while the IV cannula is removed. There is no recovery period and you can drive and return to normal activities immediately.

Reporting:

Our cardiologist reviews the reconstructed coronary images and issues a detailed report with visual reconstructions of each coronary artery. Results are typically available the same day or the following morning.

Total time at the facility for CTCA including preparation and recovery is approximately 60 to 90 minutes. The scan itself takes under 10 minutes.

Preparation for CT Coronary Angiography

Fasting

4 hours of fasting before the scan. Clear fluids are acceptable.

Medications

Continue all regular medications. Do not take Viagra (sildenafil) or similar PDE5 inhibitors within 24 hours as they interact with the nitrate spray used before the scan.

Kidney Function

A creatinine blood test is required before CTCA if you have known kidney disease, diabetes, or are over 65, as contrast can affect kidney function. Results reviewed before proceeding.

Contrast Allergy

Inform the team if you have had a prior allergic reaction to iodine-based contrast. Pre-medication with steroids and antihistamines is given in at-risk patients.

Metformin

Metformin (a diabetes medication) is typically held for 48 hours after contrast administration as a precaution in patients with borderline kidney function.

Clothing

Avoid clothing with metal zips or wires in the chest area. A hospital gown is provided.