Usefulness of fractional flow reserve to predict clinical outcome after balloon angioplasty

Background-After regular coronary balloon angioplasty, it would be helpful to identify those patients who have a low cardiac event rate. Coronary angi ography alone is not sensitive enough for that purpose, but it has been sug gested that the combination of optimal angiographic and optimal functional results indicates a low restenosis chance. Pressure-derived myocardial frac tional flow reserve (FFR) is an index of the functional severity of the res idual epicardial lesion and could be useful for that purpose. Methods and Results-In 60 consecutive patients with single-vessel disease, balloon angioplasty was performed by use of a pressure instead of a regular guide wire. Both quantitative coronary angiography (QCA) and measurement o f FFR were performed 15 minutes after the procedure. A successful angioplas ty result, defined as a residual diameter stenosis (DS) <50%, was achieved in 58 patients. In these patients, DS and FFR, measured 15 minutes after PT CA, were analyzed in relation to clinical outcome. In those 26 patients wit h both optimal angiographic (residual DS by QCA less than or equal to 35%) and optimal functional (FFR greater than or equal to 0.90) results, event-f ree survival rates at 6, 12, and 24 months were 92+/-5%, 92+/-5%, and 88+/- 6%, respectively, versus 72+/-8%, 69+/-8%, and 59+/-9%, respectively, in th e remaining 32 patients in whom the angiographic or functional result or bo th were suboptimal (P=0.047, P=0.028, and P=0.014, respectively). Conclusions-In patients with a residual DS less than or equal to 35% and FF R greater than or equal to 0.90, clinical outcome up to 2 years is excellen t. Therefore, there is a complementary value of coronary angiography and co ronary pressure measurement in the evaluation of PTCA result.