Fractional flow reserve (FFR) is a diagnostic technique used to assess the severity of narrowings or blockages in the coronary arteries. It measures the pressure difference across a stenosis (narrowing) in a coronary artery to determine if it is significantly impeding blood flow to the heart muscle.
During an FFR procedure:
Catheterization: A catheter is inserted into a blood vessel, usually in the groin or wrist, and advanced to the coronary arteries under X-ray guidance.
Measurement: Once the catheter is in place, a pressure-sensitive wire is threaded through it and positioned just beyond the narrowing in the coronary artery. The wire measures the pressure before and after the narrowing.
Inducing Hyperemia: A medication, such as adenosine, is administered to induce hyperemia, which dilates the coronary arteries and increases blood flow. This allows for more accurate measurement of pressure differences across the stenosis.
Calculation of FFR: The FFR is calculated by dividing the pressure measured beyond the stenosis by the pressure measured before the stenosis. An FFR value of 1.0 indicates normal blood flow, while values less than 0.80 typically indicate significant narrowing and reduced blood flow.
FFR provides valuable information to help guide treatment decisions, particularly in cases where the severity of a coronary artery narrowing is uncertain. It helps identify lesions that are causing ischemia (inadequate blood supply) and may benefit from interventions such as angioplasty and stenting.
The use of FFR has been shown to improve patient outcomes and reduce the need for unnecessary interventions, such as stenting, in lesions that are not causing significant ischemia. It allows for a more targeted approach to treatment, focusing on lesions that are truly causing symptoms or posing a risk to the patient’s health.