Fractional flow reserve for guiding coronary intervention and functional SYNTAX score

Coronary angiography gives a visual impression about the severity of the stenosis. But it need not imply the actual functional significance of the stenosis in terms of flow physiology. It is often difficult to decide which are the flow limiting lesions when there are multiple stenoses in same or different territories. It is here that the fractional flow reserve estimation helps. FFR is estimated using a guide wire with a pressure transducer. FFR wires have properties similar to the floppy guide wires so that they can passed across coronary lesions back and forth easily to assess the pressure drop across the lesions. The flow reserve is calculated after inducing maximal hyperemia in the distal territory with intracoronary adenosine or papaverine or intravenous adenosine given in a central vein. FFR is obtained by dividing the pressure distal to the stenosis by the central aortic pressure, which is usually equal to the pressure proximal to the stenosis if there is no additional stenosis in between. Normal FFR is 1.0 and an FFR below 0.75 indicates inducible ischemia while an FFR above 0.80 excludes ischemia in 90% of cases. So, it is evident that the grey zone in FFR evaluation is very limited. FFR measurement is successful in almost 99% of cases and the values are reproducible. If the FFR normalizes after stenting, the restenosis rates at six months is less than 5%. Since the FFR wire can be used for guiding balloon catheters and stents, it is easy to make post procedure me...
Source: Cardiophile MD - Category: Cardiology Authors: Tags: General Cardiology Source Type: blogs