Fractional Flow Reserve (FFR)
Fractional flow reserve (FFR) measurement involves determining the ratio between the maximum achievable blood flow in a diseased coronary artery and the theoretical maximum flow in a normal coronary artery. An FFR of 1.0 is widely accepted as normal. An FFR lower than 0.75-0.80 is generally considered to be associated with myocardial ischemia (MI).
FFR is easily measured during routine coronary angiography by using a pressure wire to calculate the ratio between coronary pressure distal to a coronary artery stenosis and aortic pressure under conditions of maximum myocardial hyperemia.
- To determine the physiologic and hemodynamic significance of an angiographically intermediate coronary stenosis.
- To identify appropriate culprit lesion(s) in multi-vessel coronary artery disease (CAD).
- To measure the functional importance of stenosis in the presence of distal collateral flow.
- To identify the precise location of a coronary lesion when the angiographic image is unclear.