Fractional Flow Reserve (FFR) is a diagnostic technique used during a coronary angiogram to determine the functional significance of coronary artery narrowings (stenoses). Here’s a breakdown:
Purpose:
- FFR measures the pressure difference across a coronary artery stenosis to assess whether the narrowing is actually restricting blood flow to the heart muscle.
- This helps doctors determine if a stenosis is causing ischemia (lack of blood flow) and whether it requires intervention, such as angioplasty and stenting.
- It is used to aid the doctor in making the best decision for patient care.
How it Works:
- During a coronary angiogram, a thin pressure wire is inserted into the coronary artery and passed across the stenosis.
- The pressure is measured on both sides of the narrowing.
- A medication, usually adenosine, is administered to maximize blood flow in the coronary arteries.
- The FFR is calculated as the ratio of the pressure distal (after) to the pressure proximal (before) the stenosis.
- An FFR value of 1.0 indicates normal blood flow.
- Values below a certain threshold (typically 0.80) indicate that the stenosis is significantly restricting blood flow and likely causing ischemia.
Clinical Significance:
- FFR helps doctors make more informed decisions about whether to perform angioplasty or stenting.
- It can help avoid unnecessary interventions in patients with angiographically significant, but functionally insignificant, stenoses.
- FFR can improve patient outcomes by ensuring that only hemodynamically significant lesions are treated.
In essence:
FFR provides a physiological assessment of coronary artery stenoses, complementing the anatomical information obtained from angiograms. This allows for a more accurate evaluation of the functional impact of coronary artery disease and helps guide optimal treatment strategies.