Coronary artery height differences and their effect on fractional flow reserve

Background: Fractional flow reserve (FFR) uses pressure-based measurements to assess the severity of a coronary stenosis. Distal pressure (Pd) is often at different vertical height that proximal aortic (Pa). The difference in between Pd and Pa due hydrostatic pressure, may impact FFR calculation. Methods: One hundred computed tomography angiographies were used measure differences ostia points tree. Mean heights calculate effect each artery, using correction factor 0.8 mmHg/cm. This was tested simulation intermediate stenosis give “corrected FFR” (cFFR) percentage values, which crossed threshold 0.8. Results: mean from ostium distal left anterior descending (LAD) +5.26 cm, circumflex (Cx) –3.35 right artery-posterior ventricular artery (RCA-PLV) –5.74 cm RCA-posterior (PDA) +1.83 cm. For LAD, resulted change +0.042, –0.027 Cx, –0.046 PLV +0.015 PDA. Using 200 random values 0.75 0.85, resulting cFFR clinical treatment 43% 27% 47% 15% PDA cases. Conclusions: There are significant its point normalization likely have modest on FFR, correcting for this results proportion crossing thresholds. Operators should be mindful phenomenon when interpreting values.