What is Fractional Flow Reserve (FFR)?
Fractional Flow Reserve (FFR) is a special test in cardiology that measures how well blood flows through a coronary artery when there is a blockage or narrowing.
In simple words, FFR helps doctors decide whether a patient needs a stent or bypass surgery or if the blockage can be managed with medicines.
- FFR Meaning: Fractional Flow Reserve
- Field: Interventional Cardiology
- Purpose: To measure the pressure difference across a narrowed artery
- Normal FFR Range: 0.81 to 1.0 (healthy blood flow)
Table of Contents
Concept of FFR
The concept of FFR is based on comparing the maximum blood flow in a narrowed artery with the normal expected flow.
- If blood flow is normal, then no intervention is required.
- If blood flow is low, then treatment such as angioplasty or stenting may be needed.
👉 Example:
- An FFR value of 0.80 or less usually means the blockage is significant and needs treatment.
- An FFR value above 0.80 means the blockage is not severe.
Fractional Flow Reserve Formula
The formula for calculating FFR is:
FFR = Pd / Pa
Where:
- Pd = Pressure after the blockage (distal pressure)
- Pa = Pressure before the blockage (aortic pressure)
This simple formula helps cardiologists calculate whether the artery is narrowed enough to affect blood flow.
Normal FFR Range
| FFR Value | Interpretation | Treatment Decision |
|---|---|---|
| 0.81 – 1.0 | Normal blood flow | No stent required |
| 0.75 – 0.80 | Borderline | Doctor decides case by case |
| Below 0.75 | Significant blockage | Stent or bypass surgery recommended |
👉 Example: If the FFR is 0.8, it means the artery is delivering 80% of normal blood flow.
FFR Device & Equipment
To perform FFR, doctors use a special pressure wire and a monitoring device.
- FFR Wire: A thin wire with a sensor at the tip.
- FFR Console: Displays real-time pressure measurements.
- Injection of Drugs (like Adenosine): Helps increase blood flow during the test.
FFR Procedure Step by Step
The FFR procedure is usually done during a coronary angiography. Here are the steps:
- Coronary Angiogram: First, doctors take X-ray images of the heart arteries.
- Insert FFR Wire: A thin wire with a sensor is passed into the artery.
- Measure Pressure: The device measures pressure before and after the blockage.
- Drug Injection: A medicine (Adenosine) is given to increase blood flow.
- Calculate FFR: The system calculates the FFR value.
- Decision: Based on the FFR value, the doctor decides whether a stent or bypass surgery is needed.
Types of FFR
- Invasive FFR (Wire-based FFR)
- Standard method
- Uses pressure wire during angiography
- Non-invasive FFR (CT-FFR)
- Done using CT scan of the heart
- No wire needed
- Safer and quicker but expensive
FFR vs Angiography
| Feature | Angiography | FFR |
|---|---|---|
| What it shows | Structure (blockage %) | Function (blood flow) |
| Accuracy | Sometimes misleading | More accurate |
| Decision making | May lead to unnecessary stents | Prevents unnecessary stents |
| Procedure | X-ray with dye | X-ray + pressure measurement |
Indications for FFR Test
FFR is recommended in the following cases:
- Patients with chest pain (angina).
- When angiography shows intermediate blockages (40–70%).
- Before placing a stent.
- To avoid unnecessary bypass surgery.
- For patients with multiple blockages.
FFR Test Cost in India (2025)
The cost of an FFR test depends on hospital, city, and whether it is invasive or CT-based.
| Country | Cost Range |
|---|---|
| India | ₹25,000 – ₹50,000 |
| USA | $4,000 – $6,000 |
| UK | £2,000 – £3,000 |
Advantages of FFR
- Prevents unnecessary stenting
- More accurate than angiography
- Safe and reliable
- Helps doctors choose best treatment
- Improves patient outcomes
Risks of FFR
Like any invasive test, FFR has some risks:
- Bleeding at catheter site
- Temporary chest pain due to drug injection
- Rare chance of artery damage
- Allergic reaction to dye
But overall, it is considered a very safe test when done by experts.
FFR in Finance (Different Meaning)
Don’t get confused!
- In Cardiology, FFR means Fractional Flow Reserve.
- In Finance, FFR means Federal Funds Rate.
Both are completely different.
FAQs on Fractional Flow Reserve
Q1. What is a normal FFR range?
Normal FFR range is 0.81 to 1.0.
Q2. What does an FFR of 0.8 mean?
It means 80% of normal blood flow; usually considered borderline.
Q3. How is FFR calculated?
Formula: FFR = Pd / Pa (distal pressure ÷ aortic pressure).
Q4. What is FFR used for?
To check if a heart artery blockage needs stent or bypass surgery.
Q5. What is FFR CT?
A non-invasive version of FFR using CT scan of the heart.
Q6. What is the cost of an FFR test in India?
Around ₹25,000 – ₹50,000 depending on hospital.
