ADVISE is a prospective, multicenter, international study to determine the correlation between Fractional Flow Reserve (FFR) and the instant™ wave-Free Ratio (iFR), a new index of stenosis severity measured without the use of pharmacologic vasodilation.
So What is iFR?
iFR, or “instant™ wave-Free Ratio”, is a new index of stenosis severity measured without the use of pharmacologic vasodilation. The iFR algorithm works by calculating the Ratio over an isolated part of the cardiac cycle when distal vascular resistance is naturally constant and minimal, similar to what occurs in FFR during hyperemia. That part of the cardiac cycle is the same section where there are no proximally-originating (from the ventricle and aorta) or distally-originating (from the microvasculature) pressure waves propagating through the coronary vessel and lesion, which is why it is called the instant™ wave-Free Ratio.