Fractional flow reserve
From Standard of Care
An index of physiological significance of coronary stenosis: defined as the ratio of maximal blood flow is a stenotic artery to a normal maximal flow.
Fractional flow reserve performed during invasive coronary angiography provides lesion specific data on ischemia which when used to direct revascularization procedures, leads to improved clinical outcomes.
Fractional flow reserve is the ratio of the mean coronary artery pressure distal to an obstructive coronary lesion relative to the mean aortic pressure during maximum coronary blood flow and represents a physiologic measure of coronary stenosis.
Measured during coronary angiography by calculating the ratio of distal coronary pressure measured with a coronary pressure guidewire to aortic pressure measured simultaneously with a catheter.
A pressure wire based index used during coronary angiography assessing potential of coronary stenosis to induce myocardial ischemia.
In a normal coronary artery is 1.0.
A value of 0.8 or less identifies ischemic associated coronary artery stenosis and has an accuracy of more than 90% (Pijls).
Provides information similar to myocardial perfusion but is more specific analyzing separately segments or coronary arteries and prevents the masking of ischemic areas.
Deferring the placement of stents in lesions assessed by FFR results in a annual rate of death or myocardial infarction of 1% in patients with single coronary artery disease, which is a lower percentage than associated with routing stenting.
In patients with stable coronary artery disease and functionally significant stenosis a fractional flow reserve guided PCI plus the best available medical therapy, as compared with the best medical therapy alone, decreased the need for urgent revascularization. (FAME 2 trial investigators).
In the above study, patients without ischemia, the outcome appeared to be favorable with the best available medical therapy alone.
