Background —PTCA of a coronary stenosis without documented ischemia at noninvasive stress testing is often performed, but its benefit is unproven. Coronary pressure–derived fractional flow reserve (FFR) is an invasive index of stenosis severity that is a reliable substitute for noninvasive stress testing. A value of 0.75 identifies stenoses with hemodynamic significance. Methods and Results —In 325 patients for whom PTCA was planned and who did not have documented ischemia, FFR of the stenosis was measured. If FFR was &gt;0.75, patients were randomly assigned to deferral (deferral group; n=91) or performance (performance group; n=90) of PTCA. If FFR was &lt;0.75, PTCA was performed as planned (reference group; n=144). Clinical follow-up was obtained at 1, 3, 6, 12, and 24 months. Event-free survival was similar between the deferral and performance groups (92% versus 89% at 12 months and 89% versus 83% at 24 months) but was significantly lower in the reference group (80% at 12 months and 78% at 24 months). In addition, the percentage of patients free from angina was similar between the deferral and performance groups (49% versus 50% at 12 months and 70% versus 51% at 24 months) but was significantly higher in the reference group (67% at 12 and 80% at 24 months). Conclusions —In patients with a coronary stenosis without evidence of ischemia, coronary pressure–derived FFR identifies those who will benefit from PTCA.

Fractional Flow Reserve to Determine the Appropriateness of Angioplasty in Moderate Coronary Stenosis