Fractional flow reserve

Fractional Flow Reserve (FFR) is a technique used in cardiology to measure the pressure differences across a coronary artery stenosis to assess the likelihood that the stenosis impedes oxygen delivery to the heart muscle. It is a valuable tool in the diagnosis and management of coronary artery disease.

Definition

Fractional Flow Reserve is defined as the ratio of the maximum achievable blood flow in a diseased coronary artery to the maximum achievable blood flow in a normal coronary artery. It is calculated during coronary catheterization using a specialized pressure wire.

Procedure

The FFR procedure involves the insertion of a pressure wire into the coronary artery during angiography. The wire measures the pressure before and after a stenosis. The patient is often administered a vasodilator such as adenosine to induce maximal blood flow, allowing for accurate measurement of the pressure gradient across the stenosis.

Clinical Significance

FFR is used to determine the functional significance of coronary artery stenoses. An FFR value of 0.80 or less is generally considered indicative of a hemodynamically significant stenosis, which may benefit from percutaneous coronary intervention (PCI) or coronary artery bypass grafting (CABG).

Advantages

FFR provides a more accurate assessment of the need for revascularization compared to angiography alone. It helps in avoiding unnecessary procedures and in optimizing patient outcomes by targeting interventions to lesions that are truly flow-limiting.

Limitations

While FFR is a powerful tool, it is not without limitations. It requires the use of adenosine, which can have side effects, and the procedure itself is invasive. Additionally, FFR measurements can be affected by technical factors such as wire drift and pressure damping.

Related pages

• Coronary artery disease
• Percutaneous coronary intervention
• Coronary artery bypass surgery
• Angiography

See also

• Intravascular ultrasound
• Optical coherence tomography