The effect of CTO recanalization on FFR of the donor artery.

This case illustrates that fractional flow reserve (FFR) in addition to the severity and length of the coronary stenosis is critically dependent on the extent of viable myocardium perfused. In the presented case, the left anterior descending artery (LAD) that had modest angiographic stenosis supplied collaterals to the entire left ventricle. After recanalization of chronic total occlusions (CTO) of the right and circumflex arteries, FFR in the LAD had normalized.